Scientific Studies related to tick-borne infections in Ireland
To view Tick Talk’s surveys including results go to: http://www.ticktalkireland.org/surveys.html
For useful links including structure, borrelia up close, testing etc etc: https://ticktalkireland.wordpress.com/lyme-links/
For a 30 page compendium of studies & news (word doc): https://ticktalkireland.files.wordpress.com/2014/01/ireland-articles1.doc
For newspaper articles related to Lyme in Ireland go to: https://ticktalkireland.wordpress.com/lyme-links/irish-related-articles/
Science Articles by date in descending order
This was published in medical independent by Dr Fry (TMB clinics) Feb 2013:
Considering the unusual diagnosis
Case report 5
A 22-year-old female (MC) was referred by her GP who considered that she was probably suffering with drug abuse withdrawal after her return to Ireland from Connecticut (USA) where she had been during the summer months. On presentation this patient was fully conscious but had persistent tonic/clonic movement of the right side of her body for the entire 40 minutes of this initial consultation. The main points from past medical history were unremarkable (including no drug abuse) except she did report that she had a circular rash on her right forearm some months previously – which was confirmed on a coincidental holiday photograph. On closer evaluation she had some park and forest type exposure during the preceding weeks before the rash appeared. Blood evaluation confirmed no specific abnormality except her Lyme serology showed ‘reactive’ change but her Western Blot examination was reported as negative. No confirmed definite diagnosis was made but the patient responded very well to intense antibiotic treatment for presumed borreliosis.
Case report 3
TH and RH went on their honeymoon to South Africa. As part of this holiday trip they visited a national park close to Port Elizabeth for a few days. During this part of their holiday they undertook a guided walking safari along some of the trails to get a better view of some of the small animals Africa has to offer. They returned home a few days later and both remained well for a few days. However, on the fourth day back in Ireland they both became significantly ill. Presentation included high fever, rigors, and myalgia and, perhaps quite understandably, the initial presentation with their GP raised the possibility of malaria – although they had not actually been to any of the at-risk regions within South Africa. Following referral, on close examination the only clear physical finding they both had was a small eschar lesion, which strongly suggested the possibility of tick bite fever. In both cases they responded very quickly to a course of doxycycline.
Nowadays the term ‘chronic fatigue syndrome’ is regularly used to cover a wide variety of clinical conditions where the underlying cause may vary from physical (endocrine, tumours, bacterial, viral, parasitic, metabolic, poisoning etc) to psychological issues. Shrinking the differential diagnosis to a more manageable level takes all the detective skills of the modern medical practitioner. Of course, mistakes will be made where conditions are not considered or perhaps disregarded due to a preconception that the disease has a psychological basis. When assessing these patients it is important to consider a number of points including when the condition first become noticeable, what the individual had done in the days, weeks and even months prior to this, what aggravates or eases the condition and also if any physical (objective) signs are evident. A detailed history of the individual’s social lifestyle before becoming sick may uncover risk factors (hill walking, animal lover, work / social experiences etc) as well as potential exposure risks (organophosphate exposure, lead or radon poisoning etc). If any other individuals are affected, then the possibility of a common source needs to be considered.
An article on redwater fever in cattle spread by ticks in Ireland July 2013
Tick-borne disease on Irish farms – 23-04-2011
By Micheal Casey
#Mícheál Casey from the Department of Agriculture’s Regional Veterinary Laboratory service, outlines the common tick-borne diseases affecting Irish livestock
Ticks are blood-sucking parasitic members of the Arachnidae – the same class of eight-legged arthropods as spiders. Diseases transmitted by ticks are a major cause of economic loss, disease and deaths in farmed animals worldwide.
Although there is only one species of tick that affects Irish livestock – the ‘castor bean tick’, Ixodes ricinus – it can act as a vector for a range of diseases. All references to ticks in this article refer to this tick.
Ticks have some fairly precise environmental requirements, especially when they leave the relative shelter of the base of the vegetation. They find a new host by ‘questing’, where they climb to the tips of the vegetation and grab onto any animal (or person) that passes.
They need mild and moist conditions for questing, which are provided in late spring and in autumn in a typical Irish year, resulting in clearly defined spring and autumn peaks in tick-borne diseases.
On some farms the ticks have become adapted to one or the other season, while on other farms both peaks are seen.
This disease is caused by a bacterium (Ehrlichia phagocytophila) and is normally mild and transient. Although this is not commonly diagnosed, it is probably the most important tick-borne disease in Ireland.
Firstly, it is very common; so common, in fact, that most herds have a high level of resistance and most infection occurs in young and bought-in animals. As the name suggests, animals run a temperature for a couple of days, lose their appetite, they may cough a little and milk yield of cows drops significantly.
The reason for the significance of tick-borne fever is the brief but severe immunosuppression that accompanies infection with the organism. Affected animals are very susceptible to other infections at the time of infection, and vaccines for other diseases that are administered at the time of tick-borne fever infection will not take effect.
Furthermore, if the tick that infects the animal is also carrying one of the other tick-borne diseases, then infection is more likely and the ensuing disease may be more severe.
Tick-borne fever is a hidden but important factor in every other tick-borne disease.
This parasite, Babesia divergens, is carried by ticks and is capable of being transmitted from one generation of tick to the next, so a reservoir of infection can be maintained on pasture even when no livestock have grazed that pasture for several years.
Once inoculated into the bloodstream, the organism replicates rapidly in red blood cells, which are ruptured as each generation of the parasite emerges. Animals run a high temperature which then falls rapidly, often below normal, as the disease progresses. Affected animals become dull, lose their appetite, become slow and may have difficulty standing or walking as the disease progresses. The oxygen-carrying haemoglobin is released from the ruptured red blood cells and passes through the kidneys and out in the urine, giving it a characteristic reddish brown colour and giving the disease its common name – ‘redwater’. The heart races as the body tries to compensate for the loss of circulating blood cells. Deaths can occur due to heart failure, kidney failure or anaemia, and blood transfusions may be required in the treatment of the most severely affected cases.
Drugs that prevent multiplication of the parasite are administered, but it is the effects of disease that are the most difficult to treat – anaemia, dehydration (and associated constipation).
One unique feature of redwater is the ‘reverse age immunity’ phenomenon. Calves are resistant to the disease until they are about six months of age. After that, the resistance an animal has to redwater in later life will depend on whether they were exposed to the disease as calves. Animals that have no resistance tend to develop a very severe form of the disease, and many farms routinely protect bought-in animals with a drug that gives protection for about four weeks. If this is given just before peak tick activity, there is a good chance that the animal will be bitten, infected and develop resistance without getting the disease, while protected by the drug.
Redwater seems to be decreasing in incidence and in severity in recent years. Partly, this is due to improved pasture management, which eliminates tick habitat. It also seems likely that the widespread use of Ivermectin-type products may have had an impact on tick productivity.
This is a disease of young lambs, which is caused by a common skin bacterium, Staphylococcus aureus. These bacteria are inoculated from the skin surface by the tick as it bites and get into the bloodstream causing septicaemia (blood poisoning). While the lamb’s blood carries the bacteria around the body, the tick will frequently be infecting the animal with tick-borne fever, which results in the bacteria ‘seeding’ the internal organs and tissues, especially the liver and the joints. A second septicaemia, often fatal, may occur at this stage. Affected lambs become slow and stiff and will die if untreated.
Q fever is caused by bacterium, Coxiella burnetti, and is very similar to tick-borne fever. Little is known about Q fever in Irish farm animals, largely because of the unavailability of diagnostic tests. It is known to occur here, and is tick-transmitted. It is likely to be behind some abortion outbreaks in sheep and cattle and may have an immunosuppressive role in a wide range of diseases
This bacterial tick-borne disease caused by Borrelia burgdorferi is strongly associated with deer, and the infection risk for humans and animals is highest in woodland and nearby pasture.
It is ‘one to watch’ as our wild and farmed deer population grows. It causes a fever and rash and can progress to cause central nervous system disease, arthritis and blood vessel damage in humans.
Again, little is known about the disease in Ireland, as it is rarely diagnosed, although blood testing shows that exposure to infection is common.
This is a serious and potentially fatal disease in humans, so it is very important to seek medical attention if any relevant symptoms are seen after a tick bite.
This virus causes encephalitis (brain inflammation) in sheep and is often fatal. It tends to occur in ticks in well-defined areas and is best controlled on affected farms by sourcing replacements from home-bred animals, or at least from within those areas.
A common feature of many tick-borne diseases is the strong, often life-long, immunity that results from infection. As a result, strong herd immunity develops, and very little disease tends to occur in stable, closed herds, even in heavily infested areas.
The exception here would be tick pyemia in lambs, where certain farms have a problem year after year unless they control the ticks.
Control of ticks requires the recognition and elimination of ideal tick habitat. Because ticks require mild, moist conditions, they are usually found at the base of dense vegetation. Ideal conditions for ticks occur where grass is growing through one or two years of dead previous growth (areas ungrazed for several years), and there is a moist decaying mat of old vegetation at the base of the sward. This is something to watch for when renting grazing land that may have been fallow for some time.
Control is achieved by minimising this phenomenon and by keeping animals fenced out of likely areas. Good pasture management and the rotation (where possible) of forage and grazing areas should minimise the amount of tick habitat.
The use of acaricides (chemicals that kill ticks) with residual effect will give protection against ticks for several weeks, and is a common practice, as a way to protect cattle or lambs during periods of peak risk.
However, preventing tick bites will also prevent the acquisition of immunity, so these animals will continue to be vulnerable once the protection offered by the acaricide wears off.
Another useful control measure is to source replacements within the herd, or at least locally, so that they will have been exposed to the range of tick-borne diseases that occur in that area.
Great care is needed when introducing animals from tick-free farms to areas where they will face a significant challenge, as these animals will have no immunity to tick-borne disease.
http://www.farmersjournal.ie/site/farming-Tick-borne-disease-on-Irish-farms-12922.html [link no longer available]
Babesias of red deer (Cervus elaphus) in Ireland.
Zintl A, Finnerty EJ, Murphy TM, de Waal T, Gray JS.
UCD School of Biology and Environmental Science, University College
Vet Res. 2011 Jan 18;42(1):7.
The initial screen using PCR protocol I revealed that 18 deer carried Babesia spp. infections (26%), with 17 originating from Glenveagh and 1 from Killarney (Table (Table2).2). The Babesia species present in these animals were identified by sequence-analysis of fragments amplified using both PCR protocols.
Six samples from Glenveagh showed 100% similarity to B. divergens. In a further five isolates one amplicon (resulting either from PCR protocol I or II) showed 100% B. divergens similarity, although the second amplicon could only be identified to genus level. In addition, identical nested PCR products (amplified using protocol I) from three Glenveagh deer samples were 98% similar to B. odocoilei
Five products from PCR protocol II (4 from Glenveagh and 1 from Killarney) were also identical to each other but did not closely match any Babesia species in the GenBank database (96% similarity with B. divergens, B. odocoilei and EU1) (Table (Table2).2).
Figure Figure22 shows the phylogenetic positions of the amplicons arising from PCR protocol I, which proved to be more discriminating than PCR protocol II. The latter protocol generated amplicons that did not differentiate bovine-origin B. divergens from any of the B. divergens-like species, but showed that the unknown Babesia sp. is clearly separate from B. divergens, B. odocoilei and B. venatorum (Figure (Figure3).3). The remaining positive PCR amplicons could only be identified to Babesia genus level due to poor sequencing data.
From discussion..The highest proportion of babesia-infected deer occurred in the Glenveagh herd and most identifiable babesia sequences were also obtained from this herd. Although serology detected antibodies in the majority of the Killarney samples (unpublished data), no identifiable amplicons could be generated by PCR. It is not obvious why these differences occurred. The deer in all the locations were exposed to heavy tick (Ixodes ricinus) challenge judging by the numerous attached ticks observed at culling.
Analysis of the complete 18S rRNA gene would, of course, have provided a greater level of confidence in the identity of the babesias detected in this study. Unfortunately, available resources did not permit this. Nevertheless, the gene fragment analysis presented here suggests that there are at least two Babesia species, if not three, in the red deer sampled in this study. The significance of these parasites as disease agents is unknown and further studies, in addition to gene analysis, including isolation of the parasites and transmission studies in in vitro or in vivo systems are necessary to establish their identities, particularly that of the putative B. divergens.
Climate change could increase Irish Lyme disease risk
Written by Kay Kinsella Friday, 23 April 2010 15:31
The risk of Lyme disease in Ireland may increase as a result of climate change, according to a study published by the Irish Medical Journal. Lyme disease is the most common tick-borne disease in Europe.
The mean temperature in Ireland has risen by 0.5 degrees Celsius in the 20th century and as ticks live outside their host for the majority of their life, they can be affected by such climate change.
According to the study, the changes to the climate in Ireland, including rising temperatures and humidity, are making it a more suitable habitat for the tick to reside. Because of global warming, warmer winters are expected in Ireland, which accelerates a tick’s development.
The tick is also extremely reliant on vegetation cover, therefore, increased temperatures and forests will further its growth.
Untreated, Lyme disease can spread to produce various other symptoms, including aseptic meningitis, meningo-encephalitis, polyarthirits and myocarditis.
The study stresses the need for promotion about Lyme disease and suggests making it a notifiable disease in Ireland and Europe to help provide an explanation between this disease and the environment.
The study was carried out by the Department of Community Health in Co Kildare.
The Clinical Spectrum of Lyme Neuroborreliosis
M Elamin, T Monaghan, G Mulllins, E Ali, G Corbett-Feeney, S O’Connell, TJ Counihan
Department of Neurology, University Hospital Galway, Newcastle Rd, Galway
Ir Med J. 2010 Feb;103(2):46-9.
Lyme disease is a multisystem infectious disease, endemic in parts of Europe, including the West of Ireland. Neurological manifestions (neuroborreliosis) are variable. Presenting neurological syndromes include meningitis, cranial neuropathies, myeloradiculitis and mononeuritis multiplex. A lack of specificity in serological diagnosis may add to diagnostic confusion. We reviewed thirty cases of acute Lyme disease in the West of Ireland and found neurological syndromes in 15 (50%), with painful radiculopathy (12 patients; 80%) and cranial neuropathy (7 patients;46%) occurring frequently. Neuroborreliosis needs to be considered in the differential diagnosis of these neurological syndromes in the appropriate clinical context.
Lyme disease is a multisystem infectious disease caused by the Borrelia spirochaete genus. The predominant species in North America is Borrelia burgdorferi sensu stricto, and in Europe the predominant species are B. afzelli and B. garinii. Deer and other mammals are the intermediate hosts1. Lyme disease is the most frequently reported arthropod–borne infection of the nervous system in Europe and the USA1. Erythema migrans (EM) is regarded as the most common clinical marker of infection and is estimated to occur in 60-80% of patients1. Neurological manifestations of Lyme disease (neuroborreliosis; NB) comprise an array of both central and peripheral neurological syndromes, mimicking a variety of common disorders2. Typical neurological presenting syndromes include include meningitis, cranial neuropathies (with a predilection for the facial nerve), myeloradiculitis and mononeuritis multiplex3,4. Difficulties in the diagnosis and management of patients with Lyme NB may be compounded by a lack of specificity and sensitivity of serological tests in active disease5.
Seroprevalence studies report the Republic of Ireland as having one of the highest rates of Lyme disease in Europe6. Lyme disease is considered endemic in the West of Ireland7,8. However, few studies have explored the clinical presentation and natural history of Lyme NB in Ireland9-11. We therefore undertook a retrospective analysis of the clinical characteristics of Lyme NB in the West of Ireland. We conducted a retrospective review of the clinical presentation of patients with serologically confirmed Lyme disease diagnosed over a five-year period at a single referral centre in the West of Ireland. We identified the proportion of patients presenting with NB, we define the neurological syndromes at presentation, and report the clinical outcomes.
(Full article available below)
West of Ireland Lyme Borreliosis Mapping Project
Session: Abstracts: Bacterial Infections
Saturday, October 23, 2010
Background: Lyme disease is the most common vector-borne infection in temperate regions of the Northern Hemisphere. However, in many Lyme endemic areas epidemiologic data are sparse.
Methods: Serum samples referred for Borrelia serology processed through our centre from 2005 to 2009 inclusive were reviewed. Samples fulfilling immunoblot criteria for positivity were included. All cases were mapped using Geographical Information System (arcGIS) software based on their residential address. Cases were mapped against landuse using Corine data (Co-ordination of Information on the Environment) Land Cover 2006 courtesy of the EPA via the European Environmental Agency. Cases were also mapped per DED (District Electoral Divisions). Using population data from CSO (Central Statistics Office) Census 2006, 5 year incidence per 100,000 population per DED was calculated and mapped.
Results: 152 cases were identified over the study period, 18 in 2005, 23 in 2006, 19 in 2007, 41 in 2008 and 51 in 2009. Clinical data were available for 55 cases. There was a considerable variation in incidence per DED. ( Map to be shown) Landuse types of peat bog and transitional woodland were associated with higher incidence rates. 5 year incidence per DED showed clustering of 5 year incidence rates above 151 per 100,000 in an area of west Galway called South Connemara.
Conclusion: Considerable disparity in incidence by region was observed. This could be partially explained by differences in landuse and local ecology of hosts. This needs to be further investigated for biological explanation, such as tick or host infection rate, borrelia genospecies and human behaviour. These maps allow for targeted public health intervention, with the provision of information on prevention of tick bites and early diagnosis of Lyme Disease in high incidence areas.
Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)
Eoghan de Barra, MB, Bch , Department of Infectious Diseases, University College Hospital Galway, Galway, Ireland
Eavan Muldoon, MB, Bch , Department of Infectious Diseases, University College Hospital Galway, Galway, Ireland
Geraldine Moloney, MB, Bch , Department of Infectious Diseases, University College Hospital Galway, Galway, Ireland
Deirdre Goggin , Department of Public Health, Health Service Executive West, Galway, Ireland
Belinda Hanahoe, BSc , Department of Microbiology, Univerisity College Hospital Galway, Galway, Ireland
Geraldine Corbett Feeney, MB, Bch , Department of Microbiology, Univerisity College Hospital Galway, Galway, Ireland
Catherine Fleming, MPH, MB, Bch , Department of Infectious Diseases, University College Hospital Galway, Galway, Ireland
Prevalence of selected infectious agents in cats in Ireland
Journal of Feline Medicine & Surgery
Volume 12, Issue 6, June 2010
1 University Veterinary Hospital School of Agriculture, Food Science & Veterinary Medicine, University College Dublin, Ireland
2 College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO., Ireland
Vector-borne bacterial and rickettsial agents and Toxoplasma gondii, are common organisms in cats. Some are potentially zoonotic or may be transmitted via blood transfusion. The current study investigated the prevalence of these agents in cats from Dublin, Ireland, for which no published data exists. Whole blood (n = 116) and sera (n = 83) samples were obtained from 121 cats. DNA was extracted from blood and assayed using polymerase chain reaction techniques for Anaplasma species, Bartonella species, Ehrlichia species, Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’, ‘Candidatus Mycoplasma turicensis’ and Rickettsia species. IgG and T gondii IgG and IgM serum antibodies were detected by enzyme-linked immunosorbent assay. DNA consistent with B henselae (3.4%), B clarridgeiae (0.8%), both Bartonella species (0.8%), C M haemominutum (12.9%), or M haemofelis (2.5%) was amplified from 24/116 blood samples (20.6%). Antibodies to T gondii and Bartonella species were detected in 28 (33.7%) and 22 (26.5%) of 83 sera, respectively.
Effects of Climate Change on Ticks and Tick-Borne Diseases in Europe
J. S. Gray,1 H. Dautel,2 A. Estrada-Peña,3 O. Kahl,4 and E. Lindgren5
Interdisciplinary Perspectives on Infectious Diseases
Volume 2009 (2009), Article ID 593232, 12 pages
3.2. Summer Activity of Ixodes ricinus
..Retrospective use was made of 1976 summer temperature and tick data in an examination of the effects of high temperatures on tick development and activity in relation to the predicted global warming . In most parts of its range, I. ricinus shows some degree of bimodal seasonal activity and in 1975, more ticks were collected in autumn than in spring/summer, which may be attributed to the presence of hosts on these particular sheep pastures in late summer and autumn but not in spring or early summer for several years. However, by 1977, the pattern of tick activity had changed dramatically and more than 90% nymphal activity occurred from March to June. It was postulated that the elevated early and mid-summer temperatures of 1976 were the primary cause of the change from autumn to spring/summer-dominated nymphal activity.This possibility was investigated by studies on tick development under quasi-natural conditions. The threshold period for deposited engorged larvae to enter a developmental diapause was identified as the first two weeks of August, after which time larvae overwintered in an engorged state and did not reappear as nymphs until the following autumn. The tick abundance data suggested that the 1975 autumn-feeding adults gave rise to larvae that fed predominantly in the prediapause period, so that they had the opportunity to overwinter as unfed nymphs and thus join the spring-active ticks in 1977…
…The process revealed by this study suggests that after hotter summers much of the host-seeking activity of I. ricinus will occur in late autumn, to a lesser extent in the winter months, and with strong activity again in early spring. Larval activity is likely to be mainly restricted to mid-summer (as long as humidity requirements are satisfied) with the majority of larvae avoiding developmental diapause and becoming active as nymphs in late autumn or early spring of the following year…
…It seems likely that with increased global warming, I. ricinus activity will occur more in the autumn and winter months in many areas and, furthermore, a greater proportion of the tick population may be active at this time than at present, with a consequent temporal change in the risk of tick-borne diseases.
Here’s a bit about winter survival:
Although I. ricinus is surprisingly cold-hardy and when winter-acclimatized can survive 24-hour exposure to temperatures ranging from -14.4 to -18.9 C , the detrimental effects of cold are accumulative and exposure for 30 days to only -10 C has been shown to be lethal for a high proportion of unfed nymphs and diapausing engorged larvae and nymphs .
Lot’s more info at: http://www.hindawi.com/journals/ipid/2009/593232/
IDSA – 996. Lyme Disease: Epidemiology and Clinical Spectrum in the West of Ireland: Saturday, October 31, 2009: 12:00 AM
Background: Lyme disease (LD) is an emerging infection in Ireland. We aim to describe the epidemiology and clinical spectrum of LD in the greater Galway area.
Methods: Patients with positive Lyme serologies between 1/1/2006 and 31/12/2007 were identified by the Department of Microbiology, Galway University Hospital. This laboratory also serves Co. Roscommon, Co. Mayo and Co. Galway, and one of two private hospitals in Galway City. A retrospective review of General Practitioner (GP) and Hospital charts was conducted.
Results: 55 patients with positive Lyme serology were identified. 17/55 (30%) were tested at a hospital or outpatient clinic and 39/55 (70%) patients presented to GPs. Clinical data was available in 51/55 (93%) patients. 4/51 (7%) patients were considered to have false positive serology. 47 patients had a clinical diagnosis of LD. The mean age was 47 years (range 9 to 80). 52% were male. 26/47 (55%) presented with erythema migrans, 9/47(19%) with neurological symptoms, 6/47 (12%) with musculoskeletal symptoms, and one case each of cardiac lyme and fatigue. 39/47 (82%) cases were acquired in Ireland, 33 in Galway, two in Clare, and one each in Mayo, Roscommon, Donegal and Sligo. 3/47 cases were acquired in the US and 3 in Europe. 68% of people recalled tick bite. The peak month of diagnosis was August with 17/47 (36%) cases identified. Of cases with complete data, all treatment conformed to 2006 IDSA Guidelines. 26/29 (90%) patients treated in general practice had complete recovery within six months confirmed. The crude incidence in 2006 in Co. Galway was 10/100,000 population compared to 53/100,000 in Connecticut, USA.
Click here to see Tick Talk’s latest stats (Galway also comes high in the list. For the West of Ireland mapping project showing clusters- 5 year incidence per DED showed clustering of 5 year incidence rates above 151 per 100,000 in an area of west Galway called South Connemara (map shown): https://ticktalkireland.wordpress.com/2011/01/24/lyme-mapping-west-of-ireland/
Conclusion: Lyme disease is not an uncommon infection in the west of Ireland with many infections diagnosed and treated by GPs. The clinical spectrum is similar to North America, however there may be an increased incidence of neurological infection. With appropriate treatment clinical outcomes are good.
Geraldine Corbett-Feeney, MB, BCh1, Catherine Fleming, FRCPI1, Belinda Hanahoe, BSc2, Geraldine Moloney, MB, BCh1, Eavan Muldoon, MB, BCh, MD and G. A. Moloney
Management of Lyme disease.
Expert Rev Anti Infect Ther. 2008 Apr;6(2):241-50.
Corapi KM, Gupta S, Liang MH.
Royal College of Surgeons in Ireland, 123 St Stephen’s Green, Dublin 2, Ireland. firstname.lastname@example.org
http://www.lifestages.com/health/lymedise.html [link no longer available]
It has been 30 years since Lyme disease was first described in a cohort of patients from Connecticut. An understanding of disease transmission, clinical manifestations and prevention strategies has been established. With the number of new cases increasing each year, it is important that clinicians are aware of the available treatment options. Most patients respond well to a course of treatment with a recommended antibiotic; however, for those patients who develop post-Lyme disease syndrome, the management is unclear. This review provides an overview of Lyme disease and the recommended treatment options available to physicians.
Minireview -Ixodes ricinus seasonal activity: Implications of global warming indicated by revisiting tick and weather data.
International Journal of Medical Microbiology, Vol. 298, No. S1. (2008)
A recent climate experiment predicted that average maximum summer temperatures in southern regions of the British Isles may approach 30 degrees C by the year 2020. An opportunity for retrospective analysis of the implications of such a change for tick phenology and disease transmission was presented by the coincidence of unusually high early summer temperatures in 1976 with the collection of tick data from sites in Ireland where host availability was controlled. Subsequent identification of diapause threshold periods and simulation of temperature-dependent tick development showed that high summer temperatures can cause mass transfer of ticks between development cohorts, resulting in increased activity and therefore increased disease transmission in late autumn and early spring. This suggests that in northern temperate regions of Europe global warming is likely to cause changes in the seasonal patterns of tick-borne diseases.
Keywords: summer temperatures, disease transmission, temperatures, summer
Authored by Gray JS. School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
Nat Clin Pract Rheumatol. 2007 Jan;3(1):20-5.
Strategies for primary and secondary prevention of Lyme disease.
Corapi KM, White MI, Phillips CB, Daltroy LH, Shadick NA, Liang MH.
Royal College of Surgeons in Ireland. email@example.com
Lyme disease (borreliosis) incidence continues to increase despite a growing knowledge of primary and secondary prevention strategies. Primary prevention aims to reduce the risk of tick exposure and thereby decrease the incidence of new Lyme disease cases. Secondary prevention targets the development of disease or reduces disease severity among people who have been bitten by infected ticks. Numerous prevention strategies are available, and although they vary in cost, acceptability and effectiveness, uptake has been universally poor. Research in areas where Lyme disease is endemic has demonstrated that despite adequate knowledge about its symptoms and transmission, many people do not perform behaviors to reduce their risk of infection. New prevention strategies should aim to increase people’s confidence in their ability to carry out preventive behaviors, raise awareness of desirable outcomes, and aid in the realization that the necessary skills and resources are available for preventive measures to be taken. In this article we evaluate the prevention and treatment strategies for Lyme disease, and discuss how these strategies can be implemented effectively. As many patients with Lyme disease develop arthritis and are referred to rheumatologists it is important that these health-care providers can educate patients about disease-prevention strategies.
Blood-meal analysis for the identification of reservoir hosts of tick-borne pathogens in Ireland.
Vector Borne Zoonotic Dis. 2005 Summer;5(2):172-80.
Pichon B, Rogers M, Egan D, Gray J.
Department of Environmental Resource Management, University College Dublin, Belfield, Dublin, Ireland.
The results of analysis of blood-meal remnants in unfed nymphs, despite relatively low detection levels (49.4%, n = 322), support the conclusion from an earlier study that small rodents are relatively unimportant as reservoir hosts of B. burgdorferi s.l. in this particular area, and suggest that songbirds (Passeriformes) are the most significant hosts in this respect. Tick (Ixodes ricinus) abundance was greater in the present study, but the overall Borrelia burgdorferi s.l.-infection prevalence of nymphal ticks was the same (12.2%), and the relative proportions of the various Borrelia burgdorferi s.l. genospecies were similar. B. garinii and B. valaisiana were the most frequent, B. burgdorferi s.s the least frequent, and B. afzelii of intermediate frequency. An unusually high proportion of nymphs (39%) with multiple infections of different B. burgdorferi genospecies was detected, and Borrelia spp. related to relapsing-fever spirochetes were detected in Ireland for the first time. The results of the present study contribute to the validation of blood-meal analysis as a means of determining the host origin of certain pathogens in unfed questing ticks, and raise some questions concerning the extent of B. burgdorferi s.l. host specificity.
PMID: 16011434 [PubMed – indexed for MEDLINE]
New discoveries in the battle against arthritis
“It could be that all rheumatoid arthritis is triggered by an infectious agent, but we haven’t found it yet,” he says. Infection by the bacterium that causes Lyme disease is known to cause joint inflammation. The problem is that if an infection actually is the trigger the agent that caused it is usually long gone by the time that joint inflammation sets in. “That is why people have had so much trouble tracking down the infectious agent,” explains Prof. O’Neill.
Babesia divergens, a Bovine Blood Parasite of Veterinary and Zoonotic Importance
Annetta Zintl1, Grace Mulcahy1, Helen E. Skerrett1, Stuart M. Taylor2 and Jeremy S. Gray2,*
+ Author Affiliations
Clin. Microbiol. Rev. October 2003 vol. 16 no. 4 622-636
1Department of Veterinary Microbiology & Parasitology and Conway Institute of Biomedical & Biomolecular Research
2Department of Environmental Resource Management, University College Dublin, Dublin, Ireland, and Veterinary Research Laboratories, Stormont, Belfast BT4 3SD, Northern Ireland
Babesia divergens is an intraerythrocytic protozoan parasite, transmitted by the tick Ixodes ricinus, and is the main agent of bovine babesiosis in Europe. It is not only a cause of significant loss to the cattle industry; it can also infect immunocompromised humans, causing medical emergencies characterized by rapid fulmination and parasitemias that may exceed 70%. The current emphasis in Europe on sustainable agriculture and extensification is likely to lead to an increase in vector tick populations with increased risk of infection. Despite the veterinary and zoonotic importance of this parasite, relatively little research has been carried out on B. divergens, and many questions regarding the parasite’s epidemiology and the host’s response remain unanswered. A better understanding of the species’ biology and host-parasite interactions may lead to improved control mechanisms and new trends in vaccine and antibabesial drug development. This review provides the first comprehensive summary of B. divergens biology, including its morphology, life cycle, and host specificity, and the current state of knowledge of both human and bovine infections.
PCR-BASED SURVEY OF TICK-BORNE DISEASES IN THE UK/IRELAND
European Society for Veterinary Internal Medicine, 2001
Department of Clinical Veterinary Science, University of Bristol, UK
http://www.bris.ac.uk/acarus/esvimabst.htm [link no longer available]
Extracts of report below:
A PCR-based survey of UK/Irish dogs and cats was undertaken to obtain a preliminary picture of the distribution and presence/prevalence of tick-borne infections. Blood samples from 180 systemically ill animals (120 dogs and 60 cats) from 41 practices distributed throughout UK and Ireland were collected during September-October, 2000. The study was stratified according to clinical signs and each sample was tested by PCR for Ehrlichia, E. phagocytophila, Borrelia and Bartonella DNA. Simple PCR targeting of genus- or species-specific regions of rRNA genes (Ehrlichia), housekeeping genes (citrate synthetase and gltA in Bartonella), virulence factors (ospA in Borrelia) or multicopy sequences (epank1 in E. phagocytophila)was used.
DNA of endemic tick-borne pathogens was detected in 6.6% of sick dogs and 5% of sick cats. Borrelia burgdorferi sensu lato was detected in 5 % and E. phagocytophila in 0.8 % of canine samples. In sick cats, 3.3% were infected with B. burgdorferi sensu lato and 1.6% were infected with E. phagocytophila. No samples were positive for Bartonella DNA
using PCR. However, in a larger separate survey of cats studied here, 11% were positive for Bartonella henselae using culture.
Retrospective study of UK samples submitted for PCR diagnosis
A rapid PCR-based diagnostic service for arthropod-borne diseases in companion animals has been developed at the University of Bristol. PCR methodology used is as described for the PCR-based survey. Between January 2000 and May 2001, 100 blood samples from ill non-travelled UK dogs and cats were PCR tested. Of 89 samples tested, 6 dogs were positive for E. phagocytophila (6.7%). Of 68 tested for Borrelia, 2 dogs (3%) were positive and of the 66 samples tested for Bartonella, 2 dogs (3%) were positive.
These preliminary data suggest significant exposure of UK/Irish companion animal populations and possibly their owners, to infected arthropod vectors. Ehrlichia phagocytophila, Borrelia and Bartonella spp are human pathogens and companion animals may act as sentinels for human infection (10). In addition, the presence of E. phagocytophila infection in dogs and cats in UK and Ireland has been confirmed. Molecular evidence of Borrelia infection in dogs is confirmed and is reported for the first time to our knowledge, in cats. The Borrelia genospecies involved in infection will be further characterised using restriction fragment length polymorphism analysis. Canine Bartonella infection is reported for the first time in Europe and the canine Bartonella DNA will be sequenced.
The biology of Ixodes ticks, with special reference to Ixodes ricinus
J. S. Gray, Department of Environmental Resource Management, University College Dublin, Ireland.
Part of the proceedings of the symposium Current Research on Tick-Borne Infections, Kalmar, Sweden, March 28–30, 2001
Ticks of the Ixodes ricinus (persulcatus) species complex are vectors for several zoonotic diseases including, babesiosis, ehrlichiosis, Lyme borreliosis and tick-borne encephalitis. An understanding of the biology of the vectors is fundamental to prevention and control of these diseases, and in addition to summarising established knowledge, this review addresses recent work on seasonal activity, host specificity, inter- and intraspecific variations in biology and factors affecting distribution and abundance.
Inc table on bovine baesiosis cases in Co Westmeath plus numbers of borrelia infected mice in Ireland..
Diaphragmatic paralysis due to Lyme disease. J.L. Faul, S. Ruoss, R.L. Doyle, P.N. Kao.
#ERS Journals Ltd 1999.
A 39-yr-old male presented at the hospital with left facial weakness. He had developed a skin rash on his left flank six weeks previously, while on a camping holiday in a wooded area in County Galway, Ireland. This rash started as a coin sized area of redness, but over a period of 4 days progressed to a large ring of erythema (10 cm in diameter). The rash gradually resolved during the next 10 days. One week prior to admission he complained of right shoulder and bilateral knee pains and mild shortness of breath. He complained of dyspnoea that was not worse on exertion and he denied orthopnoea. On the morning of admission he developed weakness of the left-side of his face. There was no headache, hyperacusis, neck stiffness or visual symptoms. There was no cough or wheeze. The patient was an otherwise healthy classical guitarist. He took no medication and did not abuse tobacco or alcohol. He was allergic to penicillin.
For more go to: http://www.erj.ersjournals.com/cgi/reprint/13/3/700.pdf
Borrelia burgdorferi sensu lato in Ixodes ricinus ticks and rodents in a recreational park in south-western Ireland (1999):-
Gray JS, Kirstein F, Robertson JN, Stein J, Kahl O.
University College Dublin, Ireland.
Ixodes ricinus ticks infected with Borrelia burgdorferi sensu lato were numerous on the edges of paths and roads in a recreational park in south-western Ireland. The abundance of ticks at different sites was related to the presence of deer, but a negative relationship was shown between tick abundance and tick infection rates. This is thought to be due to the deposition of large numbers of uninfected ticks by deer, which are apparently not good reservoir hosts of B. burgdorferi s.l. Blood meal analysis only detected deer DNA in uninfected nymphs. Reservoir competent rodents, Apodemus sylvaticus and Clethrionomys glareolus, were abundant at all sites and a high proportion of captured specimens were infested with larval ticks. However, very few rodents were infected with B. burgdorferi s.l. and none of the unfed infected nymphs analysed for the identity of their larval blood meal had fed on rodents. The spirochaetes detected in I. ricinus in the study area may be poorly adapted to rodents or are not transmitted readily because of the absence of nymphal infestation. The majority of spirochaetes in these ticks were apparently acquired from non-rodent hosts, such as birds.
Tick Study Killarney National Park, Co. Kerry
Appl Environ Microbiol. 1997 March; 63(3): 1102–1106.
Local variations in the distribution and prevalence of Borrelia burgdorferi sensu lato genomospecies in Ixodes ricinus ticks.
F Kirstein, S Rijpkema, M Molkenboer, and J S Gray University College Dublin, Belfield, Ireland.
Unfed nymphal and adult Ixodes ricinus ticks were collected from five locations within the 10,000-ha Killarney National Park, Ireland. The distribution and prevalence of the genomospecies of Borrelia burgdorferi sensu lato in the ticks were investigated by PCR amplification of the intergenic spacer region between the 5S and 23S rRNA genes and by reverse line blotting with genomospecies-specific oligonucleotide probes. The prevalence of ticks infected with B. burgdorferi sensu lato was significantly variable between the five locations, ranging from 11.5 to 28.9%. Four genomospecies were identified as B. burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, and VS116. Additionally, untypeable B. burgdorferi sensu lato genomospecies were identified in two nymphs. VS116 was the most prevalent of the genomospecies and was identified in 50% of the infected ticks. Prevalences of B. garinii and B. burgdorferi sensu stricto were similar (17 and 18%, respectively); however, significant differences were observed in the prevalence of these genomospecies in mixed infections (58.8 and 23.5%, respectively). Notably, the prevalence of B. afzelii was low, comprising 9.6 and 7.4%, respectively, of single and mixed infections. Significant variability was observed in the distribution and prevalence of B. burgdorferi sensu lato genomospecies between locations in the park, and the diversity and prevalence of B. burgdorferi sensu lato genomospecies was typically associated with woodland. The distributions of B. burgdorferi sensu lato genomospecies were similar in wooded areas and in areas bordering woodland, although the prevalence of B. burgdorferi sensu lato infection was typically reduced. Spatial distributions vegetation composition, and host cenosis of the habitats were identified as factors which may affect the distribution and prevalence of B. burgdorferi sensu lato genomospecies within the park.
For full paper go to:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC168399/pdf/631102.pdf
http://www.ucd.ie/agri/html/homepage/research_96_99/research_1998_99/ERM/ERM05.html [link no longer available]
Lyme disease in Ireland
J. S. Gray, F. Kirstein, O. Kahla and J. N. Robertson
Institute of Zoology, Free University of Berlin, Germany; Lyme Disease Reference Unit, Southampton General Hospital, UK.
Lyme disease (Lyme borreliosis – LB) is a potentially debilitating disease transmitted by ticks, but although the tick vector, Ixodes ricinus, is common and widespread in Ireland, awareness of LB is low. The series of studies described here investigated the biology and epidemiology of Irish LB in an attempt to assess the present and future risk that it may pose.
Extracts from the text – full report in link above:-
Prevalence of infection in ticks:-
The influence of habitat characteristics on risk of infection was further investigated in field studies in Connemara, Co. Kerry and Co. Wicklow, in which ticks collected from well-described habitats were analysed for infection by IFA or polymerase chain reaction (PCR). It was found that ticks collected from woodland had markedly and consistently higher infection prevalences (11-28%) than ticks collected from open farmland (0-1%), in which tick hosts were almost exclusively sheep or cattle. Additionally, it was found that the highest infection prevalences were found in the most heterogeneous woodland, presumably reflecting the wider variety of vertebrate hosts present. It is thus apparent that risk of LB cannot be determined from risk of tick-bite alone and that the nature, abundance and variety of tick-hosts in a given habitat are also important.
Identification of hosts of the Lyme disease spirochaete:-
It is evident from these studies that large animals such as sheep and cattle, while important tick-hosts in many areas, are not important for the maintenance of the Lyme disease spirochaete. Studies on the distribution of infected ticks in relation to fenced herds of red and fallow deer suggest that these animals may also be discounted as significant reservoir hosts. Various species of woodland rodent have been implicated as important reservoir hosts of B. burgdorferi in the USA and Europe and this was thought to explain the association between highly infected tick populations and woodland in Ireland. However, recent studies in woodlands in Co. Kerry (2) and Co. Galway (3) have shown that whereas tick infection rates ranged from 11-18%, infection rates of trapped rodents (wood mouse, Apodemus sylvaticus, and bank vole, Clethrionomys glareolus) were very low (2- 3%). Furthermore, analysis of blood-meal remnants in B. burgdorferi-infected ticks collected from the vegetation at one particular site in Co. Kerry showed that none of them had acquired their infection from rodents (2). Although it was not possible to ascertain the identity of the vertebrate hosts of B. burgdorferi in this particular study, genospecies analysis of the spirochaetes suggested that the majority may have originated in birds. It is now recognised that B. burgdorferi consists of a complex of closely related genospecies; B. afzelii, B. burgdorferi sensu stricto, B. garinii, B. lusitaniae and B. valaisiana (1). There is increasing evidence that two of these genospecies, B. garinii and B. valaisiana, are associated with ground feeding woodland birds such as robins and blackbirds (4), and these were the predominant genospecies at the Co. Kerry site (41% and 33% respectively). Further studies at another five locations (Fig. 1) showed that B. garinii and B. valaisiana are also the predominant genospecies detected in ticks throughout the country, suggesting that birds may have widespread importance as reservoir hosts in Ireland.
First isolation and characterisation of Borrelia garinii , agent of Lyme borreliosis, from Irish ticks
Irish Journal of Medical Science
ISSN 0021-1265 (Print) 1863-4362 (Online)
Volume 165, Number 1 / January, 1996
J. S. Gray1 , A. Schönberg2 , D. Postic3 , J. Belfaiza4 and I.
(1) ERM Department, University College, Dublin, Ireland
(2) Robert von Ostertag-Institute, Federal Health Office, Berlin,
(3) Unité de Bactériologie, Pasteur Institute, Paris, France
(4) University Chouaib Doukkali, Faculté des Sciences, El Jadida, Morocco
Nymphal Ixodes ricinus, the tick vector of Lyme borreliosis, were collected from the edges of paths in Muckross Demesne, Killarney National Park, Co. Kerry, Ireland. Examination of some of these nymphs by indirect immunofluorescence showed an infection prevalence of 12% withBorrelia burgdorferi sensu Iato, the spirochaete agent of Lyme borreliosis. Gerbils (Meriones unguiculatus) were infected by infesting them with other nymphs from the same batch. Subsequently uninfected laboratory larvae were applied to the gerbils and the contents of the resulting infected engorged ticks were then placed in media and the spirochaetes cultured. The spirochaetes were identified as B. burgdorferi sensu Iato by indirect immunofluorescence using monoclonal antibodies and they were further characterised by polymerase chain reaction and pulsed-field gel electrophoresis. Both of these latter techniques showed that spirochaetes in all samples belonged to the genomic species,Borrelia garinii.
A Lyme Disease Serosurvey of Deer in Irish National Parks
J. S. Gray, T. J. Hayden, S. Casey, F. Kirstein, S. Rijpkema and S. Curtin
Biology and Environment: Proceedings of the Royal Irish Academy
Vol. 96B, No. 1 (Jun., 1996), pp. 27-32
Published by: Royal Irish Academy
Full download available to members, abstract & preview of first page available at: http://www.jstor.org/discover/10.2307/20499953?uid=2&uid=4&sid=21102640989881
The spatial distribution of Borrelia burgdorferi-infected Ixodes ricinus in the Connemara region of County Galway, Ireland (1995):-
Gray JS, Kahl O, Janetzki C, Stein J, Guy E.
Department of Environmental Resource Management, University College Dublin, Ireland.
Studies were carried out in the Connemara area of County Galway in the west of Ireland in order to determine the abundance and distribution of the tick, Ixodes ricinus and the prevalence of its infection with Borrelia burgdorferi. The tick was very abundant locally, in particular when associated with cattle, sheep and enclosed red deer. Large numbers of ticks not only occurred on the pastures, but also on adjacent roadside verges. No infections with B. burgdorferi could be demonstrated when nymphal ticks were sampled from central areas of the pastures, suggesting that livestock and red deer are probably not significant reservoirs of the spirochaete. Small numbers of infected nymphal and adult ticks were associated with hedges, dry stone walls, the margins of woodland adjoining infested pastures and in woodland from which livestock were excluded. Woodmice (Apodemus sylvaticus) were most numerous in such habitats and the majority were infected with B. burgdorferi.
Acquisition of Borrelia burgdorferi by Ixodes ricinus ticks fed on the European hedgehog, Erinaceus europaeus L.
Exp Appl Acarol. 1994 Aug;18(8):485-91.
Gray JS, Kahl O, Janetzki-Mittman C, Stein J, Guy E.
Department of Environmental Resource Management, University College Dublin, Ireland.
A hedgehog, Erinaceus europaeus, was found to be heavily infested with larval and nymphal Ixodes ricinus in a forest park in Co. Galway, Ireland. A large proportion of the ticks that engorged and detached were infected with the spirochaete, Borrelia burgdorferi, the causative agent of human Lyme borreliosis. The identity of these spirochaetes was confirmed by immunofluorescent assay with B. burgdorferi-specific monoclonal antibody and by polymerase chain reaction test and they were transmitted from the hedgehog to laboratory-reared ticks and from the ticks obtained from the hedgehog to gerbils (Meriones unguiculatus). The high infection rate of the larvae that fed on the hedgehog in comparison with unfed larvae from the same habitat was interpreted as strong evidence that this host species is reservoir competent. Since hedgehogs can evidently feed adult ticks as well as many immature stages, they may well have an important role in the ecology of Lyme borreliosis in some habitats.
PMID: 7628256 [PubMed – indexed for MEDLINE]
Tick Surveys in the West if Ireland:
Studies on the ecology of Lyme disease in a deer forest in County Galway, Ireland (1992):-
Gray JS, Kahl O, Janetzki C, Stein J.
Department of Environmental Resource Management, Faculty of Agriculture, University College Dublin, Republic of Ireland.
The abundance of the tick Ixodes ricinus (L.) and the infection rate of ticks with Borrelia burgdorferi (Johnson et al.) were compared on either side of a deer fence in a forest park in County Galway, Ireland, in an attempt to elucidate the role of fallow deer, Dama dama, and woodmice, Apodemus sylvaticus, in determining the population density of I. ricinus and the transmission of B. burgdorferi. The results showed that tick numbers were much higher on the deer side of the fence, although the density of mice was similar on both sides. This suggests that, in the absence of other obvious factors, deer rather than mice are responsible for tick abundance in this habitat. Tick infection rates, determined by immunofluorescence, were consistently higher outside the deer fence than inside it. It is suggested, therefore, that mice rather than deer may be the important reservoir hosts of B. burgdorferi in this habitat and that deer, by feeding many larvae, probably contribute large numbers of uninfected ticks to the population. If this is the case, there will not be a direct relationship between deer abundance and tick infection rates. This has important implications for risk assessment.
Neurological manifestations of Lyme disease (Ireland)
Ir Med J. 1991 Mar;84(1):20-1.
Reilly M, Hutchinson M.
Department of Neurology, Adelaide Hospital, Dublin.
* Ir Med J. 1991 Oct;84(3):103.
Neurological disorder may be the initial manifestation of Lyme disease. Six cases of neurological Lyme disease have been seen in the years 1986-89, five of whom contracted the disease in the West of Ireland. Three presented with a radiculoneuropathy, one with myalgia/fatigue and one with bilateral sixth nerve palsies and ataxia. These cases indicate the spectrum of neurological involvement of Lyme disease in Ireland which reflects that seen in Europe. They also highlight some of the problems in diagnosis which sometimes necessitate treatment while awaiting serological studies. We feel even in the absence of a history of tick-bite or rash, Lyme disease should be considered in the differential diagnosis of many neurological disorders, especially in patients from the West of Ireland.
PMID: 2045261 [PubMed – indexed for MEDLINE]
A Lyme borreliosis human serosurvey of asymptomatic adults in Ireland.
Smith HV, Gray JS, Mckenzie G.
Zentralbl Bakteriol. 1991 Aug;275(3):382-9.
Department of Bacteriology, Stobhill Hospital, Glasgow, U.K.
Blood samples were obtained through the Blood Transfusion Service in Ireland in order to obtain information on the prevalence of asymptomatic B. burgdorferi infections and in an attempt to identify the type of habitat that presents the most risk of infection. Areas in the country were rated as low, medium or high risk based on the availability of suitable tick habitat, access to the public and the distribution of deer, the latter parameter being related to both the occurrence of rodent reservoir hosts and woodland recreational areas. Approximately 100 plasma samples from each of four areas were analysed for IgG anti-Borrelia antibodies by indirect immuno-fluorescence with a titre of 1 :80 indicating a positive reaction in asymptomatic individuals. Prevalence figures of 15, 11, 8 and 5% were obtained for high, high/medium, medium/low and low risk areas respectively. No positive samples were detected in blood from an Icelandic population which is not exposed to I. ricinus bites. The overall subclinical prevalence (9.75%) is surprisingly high in view of the apparent rarity of clinical cases in Ireland, though under-diagnosis probably occurs. These results seem to indicate that farmland is less important than woodland as Lyme borreliosis habitat. If this is so, it is probably due to the presence in woodland of Apodemus sylvaticus, a putative reservoir host, and also to the use of such areas for recreation at certain times of the year.
Babesiosis: under-reporting or case-clustering?
C. S. Clarke, E. T. Rogers, and E. L. Egan
Department of Haematology, Galway Regional Hospital, Ireland.
Describes 3 cases of Babesia among farmers in the Galway region (1989)
World health organisation 1989 –
Studies on the dynamics of active populations of the sheep tick, Ixodes ricinus L in Co Wicklow, Ireland
Gray, JS., 1984: Acarologia (Paris): 252: 167-178
Exposure of cattle immunised against redwater to tick challenge in the field: challenge by a homologous strain of B divergens.
Taylor SM, Kenny J, Purnell RE, Lewis D.
Vet Rec. 1980 Feb 23;106(8):167-70.
A field trial was conducted in Northern Ireland to determine whether calves could be protected against babesiosis by the prior inoculation of irradiated blood infected with Babesia divergens; The trial involved 30 yearling calves. Ten were inoculated with infected blood from a donor calf after the blood had been irradiated at 25 kilorads, and 10 with blood irradiated at 30 kilorads. Their reactions to the inoculation were observed daily for a month. They were then released, along with a control group of 10 susceptible calves, into an area heavily infested with B divergens-infected Ixodes ricinus ticks for two months. Between 24 and 41 days after exposure all the control animals contracted babesiosis and six of them reacted severely. None of the immunised animals suffered clinical babesiosis although 14 had detectable low-level infections. The relative severity of the reactions of the groups of calves was reflected in their haematology.
PMID:7361409 [PubMed – indexed for MEDLINE] http://www.ncbi.nlm.nih.gov/pubmed/7361409
(sadly I don’t have the full version!)
Isolation of a Soldado-like virus (Hughes group) from Ornithodorus maritimus ticks in Ireland..
Human babesiosis in ireland: Further observations and the medical significance of this infection
P. C. C. Garnham, Joseph Donnelly, Harry Hoogstraal, C. Cotton Kennedy, and Gerald A. Walton
Br Med J. 1969 December 27; 4(5686): 768–770. PMCID: PMC1630245
An extract of the text below (full report available on line)
Three splenectomized persons in Yugoslavia, California, and Ireland have been reported to be infected by three different Babesia species; two cases were fatal. In a study of the site where the fatal infection was contracted in Ireland, blood samples from 36 persons who had recently been bitten by ticks were inoculated into two splenectomized calves; no response to Babesia divergens was detected. Field-collected Ixodes ricinus ticks inoculated into another splenectomized calf resulted in fever and recovery of the agent of tick-borne fever (Cytoecetes phagocytophilia). This attempt to determine the presence of latent infection in human beings with intact spleens should be repeated on a larger scale in areas with a demonstrably high incidence of Babesia in ticks and animals. Few places in the world are free of piroplasms; their presence may present a hazard to splenectomized persons or to those whose splenic function is deficient.
Pastureland Infestation By The Sheep Tick
Ixodes Ricinus L., the common sheep tick appears to be very widespread in Ireland and much less so in Britain. In southern Ireland, at least, the tick frequents pastureland, residential areas, and gardens in towns. Such records, accumulated in the past three years, will be published in a paper on the distribution of Irish ticks presently in preparation. Document Type: Research Article/Publication date: January 15, 1965
Lyme disease factsheet by Health Service Executive, Ireland:
Irish Association of General Practitioners:
Dr Pat Crowley looks at the investigation and management of LD
LYME Disease is a tick-borne spirochetal disease that is becoming important for a number of reasons. By not thinking of this possible diagnosis, one may easily overlook it in many areas: for instance, arthritic, neurological, cardiac, dermatology, autoimmune and some others. A firm diagnosis renders it susceptible to treatment by antibiotics. Left untreated, like the famous spirochete of syphilis or the Brucellosis epidemic in Ireland in the 1960’s and 1970’s, chronic ill health may ensue.
The main reason we in Ireland have to be aware of it is the explosion in travel of the general population, particularly to areas where Lyme disease is endemic. In the USA, Lyme disease is now the most common vector borne disease, reported in 45 states and endemic in more than 15. The highest rates occur in three distinct foci: Northeast U.S.A. from Maine to Maryland, Midwest in Wisconsin and Minnesota and in the West in Northern California and Oregon. Two of these areas are the most heavily visited by Irish people in the Boston, Chicago, New York triangle.
In Europe the highest incidence is in Middle Europe, particularly Germany, Austria and Switzerland – increasingly visited by Irish tourists. Pure native incidence of Lyme disease is low, mostly got in forestry workers or frequenters, but there are a number of cases described, including diaphragmatic neurological paralysis in a 39 year-old male after a camping holiday in Galway.
Lyme disease is caused by B.burgdorferi in U.S.A; and B.afzelii and B.garinii in Europe, all pathogenic species of Borrelia, a spirochetes-like organism. The complete genome of B.burgdorferi has now been sequenced. Ticks transmit the disease using deer and mice and dogs as vectors to humans. Most recently, birds have been positively implicated. In the worst areas of the USA, eg Lyme Connecticut or the Chicago area, the local incidence of the disease is 10 or more per 100 persons. American physicians are very familiar with its presentation and treat early, usually with Doxycycline 100mg BD for 3 to 4 weeks.
Clinical manifestations consist of a localised, slowly expanding skin lesion – Erythema migrans – which occurs at the site of the tick bite. This is an unusual sign for Irish GPs but almost pathgnomic of the disease. The original tick bite may be totally painless, particularly in a larval tick. The rash, usually in the midriff/upper leg area, is present usually 7 to 10 days after initial infection and is very distinctive being described typically as “doughnut” shaped and reaching a size of approximately 5cms. It is often accompanied by a flu-like syndrome and regional lymphadenopathy. As many as 80% of cases in the USA present this way. Once you have seen Erythema migrans you will never forget it. Remember “doughnut”. If you see and feel that, in all probability it’sLyme disease.
Within weeks other signs may show-up. Fifteen per cent of cases get neurological involvement. Most common is facial palsy, but others such as myelitis, lymphocytic meningitis, cerebellar ataxia and, in children, optic neuritis which may lead to blindness . About 5% of cases will have acute cardiac involvement, mostly A/V block and, in chronic cases, cardiomyopathy. Months (2 – 6) after onset, 60% of cases develop intermittent joint pain and swelling, mostly large joints – especially the knee. In about 10% of this group the arthritis persists for several years, even after antibiotic therapy. Other symptoms and signs in the dermatological and immune category may co-exist; along with fatigue and mood disorder.
The diagnosis of Lyme disease can be very difficult. It has never been isolated from CSF. Serology in the form of ELISA testing and Western blotting techniques are poor guides, with false negatives of up to 30% and false positives of 10%. Considerable evidence suggests that in all disseminated Lyme infections, seeding of the CNS occurs early, possibly within hours after the bite! Yet spinal tap antibodies to Bb are only positive in 18-20% of cases. Laboratory tests, therefore, have certain limitations and diagnosis is initially clinical and may be supported with a high degree of probability by lab tests.
In the USA now, in endemic areas, mothers check their children every night for ticks, especially in mid-body or hairline areas. The infection is possible all year round, whereas years ago it was mainly April to July. If a tick is found it is covered in olive oil and it ejects itself as it cannot breathe. If you pull it hard and crush it you may, in fact, promote infection. Physicians are very familiar with it and usually see the skin manifestation – Erthyma migrans – in a primary care setting. They immediately start antibiotics, Doxycycline or Amoxycillin for 3-4 weeks and frequently do not do blood tests as these often confuse matters. Early treatment is very important.
Treatment of Lyme disease depends on many factors and is controversial in the sense that many practitioners who treat chronic Lyme disease believe the smaller doses of antibiotics are not really effective. These doctors would advocate Doxycycline, but only in a dosage high enough (300 – 600 mg daily). They would use probenecid with Amoxycillin. Cephalosporins are also used, but must be of third generation, e.g. Claforan or Rocephin being the main ones. The latter are used usually if there is CNS involvement and are best given IV for a minimum of six weeks. Claforan is the drug of choice, as Rocephin has 95% biliary excretion which may cause ‘sludging’ problems.
Accompanying treatment recommendations are: –
* Daily yoghurt or acidophilus preparation;
* Multivitamins and B complex;
* Healthy lifestyle with avoidance of alcohol, excess stress and caffeine.
There is a growing awareness that Lyme disease is getting more prevalent and because of this we need to have a heightened index of suspicion for it as differential diagnosis.
1. Lyme Disease, Alten Steers M.D. New England Medical Journal
2. Faul et al. European Respiratory Journal 1998
3. Shapiro et al. Yale University 2000
4. Halperin et al, Cornell University, dept of Neurology
5. Jos. Burrascano M.D. New York “Current Therapy”