NB: we have shown below a study regarding single dose prophylaxis, however please note further down the page there are some articles raising questions on the safety of the single dose, note especially the ILADS document where they cover both single dose & less than 20 days treatment both have which have led to treatment failures… http://informahealthcare.com/doi/pdf/10.1586/14787210.2014.940900
Check out also this video & useful advice on what to do if you remove a tick..http://www.ilads.org/lyme/what-to-do-if-bit-by-tick.php
Prophylaxis with Single-Dose Doxycycline for the Prevention of Lyme Disease after an Ixodes scapularis Tick Bite
Robert B. Nadelman, M.D., John Nowakowski, M.D., Durland Fish, Ph.D., Richard C. Falco, Ph.D., Katherine Freeman, Dr.P.H., Donna McKenna, R.N., Peter Welch, M.D., Robert Marcus, M.D., Maria E. Aguero-Rosenfeld, M.D., David T. Dennis, M.D., Gary P. Wormser, M.D., for the Tick Bite Study Group
Background It is unclear whether antimicrobial treatment after an Ixodes scapularis tick bite will prevent Lyme disease.
Methods In an area of New York where Lyme disease is hyperendemic, we conducted a randomized, double-blind, placebo-controlled trial of treatment with a single 200-mg dose of doxycycline in 482 subjects who had removed attached I. scapularis ticks from their bodies within the previous 72 hours. At base line, three weeks, and six weeks, subjects were interviewed and examined, and serum antibody tests were performed, along with blood cultures for Borrelia burgdorferi.
Results Erythema migrans developed at the site of the tick bite in a significantly smaller proportion of the subjects in the doxycycline group than of those in the placebo group (1 of 235 subjects [0.4 percent] vs. 8 of 247 subjects [3.2 percent], P<0.04). The efficacy of treatment was 87 percent (95 percent confidence interval, 25 to 98 percent). Objective extracutaneous signs of Lyme disease did not develop in any subject, and there were no asymptomatic seroconversions. Treatment with doxycycline was associated with more frequent adverse effects (in 30.1 percent of subjects, as compared with 11.1 percent of those assigned to placebo; P<0.001), primarily nausea (15.4 percent vs. 2.6 percent) and vomiting (5.8 percent vs. 1.3 percent). Erythema migrans developed more frequently after untreated bites from nymphal ticks than after bites from adult female ticks (8 of 142 bites [5.6 percent] vs. 0 of 97 bites [0 percent], P=0.02).
Conclusions A single 200-mg dose of doxycycline given within 72 hours after an I. scapularis tick bite can prevent the development of Lyme disease.
From the Department of Medicine, Division of Infectious Diseases (R.B.N., J.N., R.C.F., D.M., G.P.W.), and the Department of Pathology (M.E.A.-R.), New York Medical College; and the Lyme Disease Diagnostic Center, Westchester Medical Center (R.B.N., J.N., D.M., G.P.W.) — both in Valhalla, N.Y.; the Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Conn. (D.F.); the Vector Ecology Laboratory, Louis Calder Center, Fordham University, Armonk, N.Y. (R.C.F.); the Department of Epidemiology and Social Medicine, Albert Einstein College of Medicine, Bronx, N.Y. (K.F.); Northern Westchester Hospital Center, Mt. Kisco, N.Y. (P.W., R.M.); and the Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colo. (D.T.D.).
Because of its potential importance in the treatment of Lyme disease, this article was published at http://www.nejm.org on June 12, 2001.
RATIONALE FOR TREATING TICK BITES
Prophylactic antibiotic treatment upon a known tick bite is recommended for those who fit the following categories:
1. People at higher health risk bitten by an unknown type of tick or tick capable of transmitting Borrelia burgdorferi, e.g., pregnant women, babies and young children, people with serious health problems, and those who are immunodeficient.
2. Persons bitten in an area highly endemic for Lyme Borreliosis by an unidentified tick or tick capable of transmitting B. burgdorferi.
3. Persons bitten by a tick capable of transmitting B. burgdorferi, where the tick is engorged, or the attachment duration of the tick is greater than four hours, and/or the tick was improperly removed. This means when the body of the tick is squeezed upon removal, irritated with toxic chemicals in an effort to get it to back out, or disrupted in such a way that its contents were allowed to contact the bite wound.
Such practices increase the risk of disease transmission.
4. A patient, when bitten by a known tick, clearly requests oral prophylaxis and understands the risks.
This is a case-by-case decision.
The physician cannot rely on a laboratory test or clinical finding at the time of the bite to definitely rule in or rule out Lyme Disease infection, so must use clinical judgment as to whether to use antibiotic prophylaxis. Testing the tick itself for the presence of the spirochete, even with PCR technology, is helpful but not 100% reliable.
An established infection by B. burgdorferi can have serious, long-standing or permanent, and painful medical consequences, and be expensive to treat. Since the likelihood of harm arising from prophylactically applied anti-spirochetal antibiotics is low, and since treatment is inexpensive and painless, it follows that the risk-benefit ratio favors tick bite prophylaxis.
As with most things associated with Lyme it is not 100% good news!
Wien Klin Wochenschr. 2002 Jul 31;114(13-14):616-9.
Development of erythema migrans in spite of treatment with antibiotics after a tick bite.
Maraspin V, Lotric-Furlan S, Strle F.
Department of Infectious Diseases, University Medical Centre Ljubljana, Ljubljana, Slovenia. firstname.lastname@example.org
OBJECTIVES: The recent information on the appearance of erythema migrans despite prophylaxis with 200 mg of doxycycline was the stimulus for a search among our patients for those who developed the skin lesion regardless of receiving antibiotics after a tick bite.
METHODS: Data were reviewed for adult patients with erythema migrans diagnosed at our institution from 1994 to July 2001, targeting those who received antibiotics after a tick bite.
RESULTS: Seven of 5056 (0.14%) patients, diagnosed with typical erythema migrans, developed the skin lesion despite receiving antibiotics after a tick bite. Antibiotics were prescribed by general physicians: in four cases as prophylaxis of Lyme borreliosis within one day after tick detachment and in three cases because of development of acute respiratory tract infection two, five, and eight days after the bite, respectively. The dosages were as follows: azithromycin in a total dose of 3 g in three patients and 1.5 g in the fourth patient, amoxicillin-clavulanic acid 625 mg t.i.d. for ten days in the fifth patient, amoxycillin 500 mg t.i.d. for seven days followed by azithromycin 250 mg o.d. for eight days in the sixth, and amoxycillin 500 mg t.i.d. for eight days in the seventh. The patients (five females and two males, aged 18-61 years) were referred to our Department on average six (1-19) days after the appearance of skin lesions. They had typical solitary (five patients) or multiple (two patients) erythema migrans with the characteristics usually seen in European patients, except for a rather long incubation period (median value 28 days, range 10-40 days). All laboratory tests, including the examination of cerebrospinal fluid in three patients with the disseminated form of the illness, were within normal range. Borrelial antibodies were demonstrated in only one patient. A skin biopsy specimen obtained from the site of the erythema migrans was culture positive for Borrelia in 2/4 patients.
CONCLUSIONS: Our study did not enable us to assess the frequency of antimicrobial prophylaxis failure or the efficacy of individual antibiotics for the prevention of Lyme borreliosis.
However, the seven patients presented demonstrate that antibiotic prophylaxis for Lyme borreliosis after a tick bite, at least in Europe, is not entirely effective.
PMID: 12422612 [PubMed – indexed for MEDLINE]
Also ILADS claim that the study on prophylaxis of one single dose is flawed
see 2014 ILADS guidelines covering prophylaxis (page 8) at: http://informahealthcare.com/doi/pdf/10.1586/14787210.2014.940900
Meta-analysis: antibiotic prophylaxis for Lyme disease
Reference: J Antimicrob Chemother 2010; 65: 1137-44
(Link below now broken but have kept for information!)
Date published: 24/05/2010 13:58
Summary by: Jim Glare
Antibiotic prophylaxis for people at risk of Lyme disease is effective with a NNT of about 50, according to a systematic review and meta-analysis.
Lyme disease, an infection contracted via a bite from an infected Ixodes tick, is the commonest vector-borne infection in the US, and it also occurs in the UK. Untreated, it can result in serious long-term morbidity. While primary prevention involves avoiding areas at risk, and appropriate clothing etc. in such areas, there is debate over the effectiveness of antibiotic prophylaxis in people bitten by a potentially infected tick. A previous meta-analysis (in 1996) lacked sufficient power to show benefit, however there has subsequently been a large trial showing possible benefit with a wide confidence interval. The authors of the previous meta-analysis have therefore carried out a new review and meta-analysis to incorporate the data from this study and identify any other trials that may have been relevant. They carried out a comprehensive literature search for randomised controlled trials (RCT) of antibiotic prophylaxis for Lyme disease. Eligible studies were RCT and involved people who were randomised to antibiotic or placebo within 72 hours of an Ixodes tick bite. Outcome was development of clinical Lyme disease.
The initial search located 1,316 potentially relevant papers, of which 141 (plus a further 10 identified from reference lists) were examined in full. Of these four studies involving 1,082 subjects, were eligible for analysis. All were carried out in Lyme-disease endemic areas and enrolled patients with an Ixodes tick bite within the previous 72 hours; antibiotics used were penicillin (in 2), amoxicillin, tetracycline (alternative to penicillin in 1), and doxycycline. Overall, patients receiving prophylaxis were at significantly lower risk of developing Lyme disease than those receiving placebo: estimated absolute risks were 0.2% (95% CI, 0.0% to 1.0%) vs. 2.2% (95% CI, 1.2% to 3.9%]. Pooled odds ratio for developing Lyme disease in the antibiotic group compared to the placebo group was 0.084 (95% CI, 0.0020 to 0.57; P = 0.0037).
The authors conclude that their meta-analysis strongly suggests that use of antibiotic prophylaxis to prevent Lyme disease is effective: they estimate that in highly endemic areas, the NNT to prevent one infection is 49. They note that antibiotic use is not risk free, and that some patients will have adverse effects from prophylaxis, however they estimate that on US data, treating 160 tick bites will prevent one case of severe late sequelae. They caution that the dynamics of transmission of the disease differ between Europe and the US, therefore their results should not be applied directly to European Lyme disease and further RCT in a European setting are needed.
Challenge to the Recommendation on the Prophylaxis of Lyme Disease
by Elizabeth L. Maloney, M.D.
April 16, 2009
This challenge is to Recommendation #2 in the 2006 IDSA guidelines regarding the prophylaxis of Lyme disease.