Donna McKenna

PROPHYLAXIS WITH SINGLE-DOSE DOXYCYCLINE FOR THE PREVENTION OF LYME DISEASE AFTER AN IXODES SCAPULARIS TICK BITE

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. Entomologists confirmed the species of the ticks and classified them according to sex, stage, and degree of engorgement. 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) and particularly after bites from nymphal ticks that were at least partially engorged with blood (8 of 81 bites [9.9 percent], as compared with 0 of 59 bites from unfed, or flat, nymphal ticks [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.

Duration of antibiotic therapy for early Lyme disease. A randomized, double-blind, placebo-controlled trial.

Context Optimal antibiotic treatment for patients with early Lyme disease is unclear. Contribution This single-center randomized, double-blind, placebo-controlled trial found that patients with erythema migrans given any of the follwoing regimens had high response rates, defined as resolution of erythema migrans and symptoms at 30 months: 20 days of doxycycline, 83.9%; 10 days of doxycycline, 90.3%; and 10 days of doxycycline plus a single intravenous dose of ceftriaxone, 86.5%. Patients given doxycycline plus ceftriaxone more often had diarrhea than patients given doxycycline alone. Implications Oral doxycycline alone for 10 days is sufficient treatment for patients with early Lyme disease that manifests as erythema migrans. The Editors Although Lyme disease is the most common vector-borne disease in the United States (1), the appropriate duration of treatment for its most common manifestation, erythema migrans, remains unclear. A small open-label prospective study reported in 1983 found that outcome did not improve when tetracycline therapy was extended from 10 days to 20 days (2). However, most recent treatment trials have used antibiotic regimens of approximately 3 weeks (3-5), and some authorities recommend 20 to 30 days of therapy (6). This change in practice has occurred in the absence of additional prospective studies on the duration of treatment and is a source of ongoing controversy. Another uncertain issue in the management of patients with erythema migrans is whether Borrelia burgdorferi, the etiologic agent, has disseminated to the central nervous system at the time of presentation (7). If so, the outcome of therapy might be enhanced by treatment with a parenteral agent such as ceftriaxone, which readily crosses the bloodbrain barrier. To address these concerns, we conducted a placebo-controlled study comparing 10 days of doxycycline with both 10 days of doxycycline plus one dose of ceftriaxone and 20 days of doxycycline. Methods Patients at least 16 years of age who had erythema migrans and satisfied the U.S. Centers for Disease Control and Preventions surveillance definition of Lyme disease (an annular erythematous skin lesion 5 cm in diameter) (8) entered the study between 1992 and 1994. Volunteers were recruited primarily through the walk-in Lyme Disease Diagnostic Center at the Westchester Medical Center, Valhalla, New York. Exclusion criteria included pregnancy or lactation, allergy to a tetracycline or a -lactam antibiotic, receipt of antibiotic treatment for Lyme disease for more than 48 hours before enrollment, meningitis or advanced heart block, or any underlying conditions that might interfere with evaluability or follow-up. All patients gave written informed consent, and the institutional review board at New York Medical College approved the study protocol. Patients were randomly assigned to one of three treatment groups: 1) a single 2-g dose of intravenous ceftriaxone followed by 10 days of oral doxycycline capsules twice daily, then by 10 days of oral placebo capsules [cornstarch], identical in appearance to the doxycycline capsules, twice daily; 2) a placebo injection [5% dextrose] followed by 10 days of oral doxycycline, 100 mg twice daily, and then by 10 days of oral placebo twice daily; or 3) a placebo injection followed by 20 days of oral doxycycline twice daily. Since ceftriaxone is yellow, infusion bags were kept covered to maintain masking. The pharmacy dispensed study medications in accordance with a randomization schedule that was based on a computer-generated random-number code with a permuted block size of 9. Clinical staff involved in recruitment of participants or in assessing clinical outcomes were isolated from the allocation process and blinded to treatment assignment. Randomization was stratified by whether patients were symptomatic (defined as having any systemic symptoms or having multiple erythema migrans lesions) or asymptomatic (defined as having a single erythema migrans lesion and no systemic symptoms). This was done to ensure that patients who may have had dissemination of B. burgdorferi were equally represented in the three treatment groups. Evaluation Trained study personnel interviewed participants and performed physical examination at baseline and 10 days, 20 days, 3 months, 6 months, 12 months, 24 months, and 30 months after initiation of therapy. If appointments were missed, patients were interviewed by telephone; however, this occurred in fewer than 5% of patient interactions. A neurologist performed complete neurologic examination at baseline, 20 days, 3 months, 12 months, 24 months, and 30 months. At 18 months, an evaluation was conducted by telephone. Structured questionnaires using both closed- and open-ended questions were used. Symptom scores were recorded on a visual analogue scale (9). A blood sample was obtained for serologic testing (enzyme-linked immunosorbent assay) at all visits. Complete blood count was determined and serum chemistries were performed at baseline, day 10, and day 20. Electrocardiography was done at baseline and was repeated if results were abnormal. Patients were considered unevaluable if they did not adhere to study medication. Nonadherence was defined as taking fewer than 90% of prescribed capsules or not returning pill containers at the 10- or 20-day visit, receiving an intercurrent antibiotic within the first 20 days, not meeting study inclusion criteria, or not attending follow-up visits after the baseline visit. Patients who had an intercurrent episode of erythema migrans due to reinfection were considered unevaluable from that point onward. Outcome was characterized as complete response, partial response, or failure. Early treatment response was assessed at 20 days. At this time, complete response was defined as resolution of erythema migrans and associated symptoms and return to preLyme disease health status. Partial response was defined as resolution of erythema migrans but incomplete resolution or development of subjective symptoms. Failure was defined as the occurrence of any one of the following during the first 20 days: no clinical improvement by day 10; recurrence of erythema migrans; recurrence of fever attributed by the study physician to Lyme disease; development of new objective rheumatologic, cardiac, or neurologic manifestations of Lyme disease that were not present within the first 10 days; or the occurrence of meningitis, advanced heart block, or other objective manifestation of Lyme disease requiring intravenous therapy. Late response was evaluated at 3 months, 12 months, and 30 months. Complete response was defined as no recurrence of erythema migrans or associated symptoms and the continued absence of objective rheumatologic, cardiac, or neurologic manifestations of Lyme disease, with return to preLyme disease health status. Partial response was defined as no recurrence of erythema migrans and the continued absence of objective manifestations of Lyme disease, but incomplete resolution or development of subjective symptoms of uncertain cause. Failure was defined as the occurrence of objective manifestations of Lyme disease. Safety Assessment Drug safety was monitored by recording adverse events (solicited by open-ended semi-structured interview) and results of laboratory tests during treatment. Neurocognitive Evaluation At baseline, 12 months, and 30 months, a psychologist performed neurocognitive testing consisting of the Booklet Categories Test, the California Verbal Learning Test, the Wechsler Memory ScaleRevised, the Block Design Test, the Trail Making Test (Parts A and B), the Boston Naming Test, the Symbol Digit Modalities Test (written and oral), the Beck Depression Inventory, and the Symptom Checklist-90Revised. Healthy volunteers without a history of Lyme disease were recruited to serve as controls for the psychiatric interview and the neuropsychological testing. Spouses were preferred as controls since they were usually similar to the patients in age, socioeconomic level, and place of residence. Controls were 27 persons with a mean age (SD) of 42.6 15.2 years; 22% were men. Statistical Analysis Groups were compared by using one-way analysis of variance for continuous variables and the chi-square test for categorical variables (two-tailed). Data were analyzed both for participants who adhered to the study protocol and on an intention-to-treat basis. Patient blinding was evaluated at the 30-month visit by using the chi-square test and the statistic (10). For the neuropsychological tests, analysis of variance techniques were used to examine differences among treatment and control groups. For analysis of raw test scores, analysis of covariance was used, controlling for the effects of age, sex, and education. Test scores that were normalized to population standards (11-19) were analyzed by using one-way analysis of variance. For all analysis of variance models, residual plots were generated to verify adequate model fit. In the few situations in which test scores were not normally distributed or model fit was questionable, nonparametric procedures (the KruskalWallis test) or conventional transformations were applied. For categorical results, the chi-square test or the Fisher exact test was used. If the treatment variable in the global tests achieved the liberal cut-point of a P value less than 0.10, pairwise comparisons were conducted. In these instances, the Bonferroni adjustment was applied to the P value to control for multiple comparisons. Sample size was based on the estimated frequency of postLyme disease syndrome, defined as an array of subjective symptoms, such as fatigue, arthralgias, or myalgias, that may occur after infection. It was assumed that 30% of patients receiving the least effective treatment would develop postLyme disease syndrome. A more effective treatment was assumed to reduce the rate to 5%. Using an level of 0.05, two-tailed testing, and a Bonferroni multiple compari

Association of Specific Subtypes of Borrelia burgdorferi with Hematogenous Dissemination in Early Lyme Disease

To investigate whether genetic diversity of Borrelia burgdorferi sensu stricto may affect the occurrence of hematogenous dissemination, 104 untreated adults with erythema migrans from a Lyme disease diagnostic center in Westchester County, New York, were studied. Cultured skin isolates were classified into 3 groups by a polymerase chain reaction amplification and restriction fragment length polymorphism (RFLP) method. A highly significant association between infecting RFLP type in skin and the presence of spirochetemia was found (P<.001). The same association existed for the presence of multiple erythema migrans lesions (P=.045), providing clinical corroboration that hematogenous dissemination is related to the genetic subtype of B. burgdorferi sensu stricto. There were no significant associations between RFLP type and seropositivity or clinical symptoms and signs except for a history of fever and chills (P=.033). These results suggest that specific genetic subtypes of B. burgdorferi sensu stricto influence disease pathogenesis. Infection with different subtypes of B. burgdorferi sensu stricto may help to explain differences in the clinical presentation of patients with Lyme disease.

Human Granulocytic Ehrlichiosis: A Case Series from a Medical Center in New York State

Human granulocytic ehrlichiosis (HGE) was first described in 1994 by Bakken and colleagues [1] in 12 patients from the midwestern United States. This report was followed by a retrospective case study [2] of 41 patients from the same geographic area. The data from these studies and from isolated case reports from several locations in the northeastern United States have been the only descriptions of the clinical and laboratory manifestations of HGE to date [2-5]. We describe the clinical and laboratory findings of 18 patients who received a diagnosis of HGE in 1994 or 1995 at a medical center in a populous area in the suburbs of New York City. Methods Patients Patients were evaluated at the Westchester County Medical Center in 1994 and 1995; one patient (patient 18) has been discussed in another report [6]. At the first visit, samples of blood were obtained for complete blood cell count, differential count, chemistry profile, buffy-coat smear for examination of morulae, polymerase chain reaction (PCR) assay for HGE, and serologic examination to test for presence of antibodies to Ehrlichia equi and E. chaffeensis. Blood samples were also collected during the first to sixth weeks of convalescence. Laboratory Testing Buffy-coat smears were stained with Wright stain, and at least 1000 granulocytes were microscopically examined for Ehrlichia morulae. The presence of antibodies was tested for by indirect immunofluorescent antibody assay using horse granulocytes infected with E. equi at an initial serum dilution of 1:80 as described elsewhere [1]. We tested for antibodies to E. chaffeensis by using immunofluorescent antibody assay with infected DH82 cells [1, 7]. Peripheral blood was tested by PCR using EDTA-anticoagulated blood and the primer pair GE9f/GE10r as described elsewhere [8]. Samples of EDTA-anticoagulated blood from two patients (patients 14 and 15) were inoculated into an HL-60 cell line for culturing as described elsewhere [9]. Statistical Analysis The two-tailed Student t-test, Pearson correlation (SPS software, Chicago, Illinois), and two-tailed Fisher exact test (EPISTAT software, Richardson, Texas) were used for data analysis. Results Eighteen patients received a diagnosis of HGE (3 in 1994 and 15 in 1995) in the Westchester County Medical Center. Most of these patients (83%) presented between June and August, Sixteen patients resided in Westchester County, and 2 resided in Putnam County; these counties are contiguous and located slightly north of New York City. Thirteen patients (72%) reported that they had been bitten by a tick: Four ticks were positively identified as Ixodes scapularis (three nymphs and one adult tick). The other nine patients who reported a tick bite described a tick whose appearance was compatible with that of I. scapularis. Symptoms appeared an average of 5.5 days after patients received the tick bite (Table 1). Two patients, neither of whom recalled being bitten by a tick, described a rash that they characterized as erythematous, pruritic, localized, and smaller than 5 cm in diameter. The described rash was not visible when these patients first visited the medical center. Patients were evaluated an average of 4.7 days after onset of symptoms (median, 3 days [range, 1 to 15 days]). Five patients (28%) required hospitalization for an average of 5 days. One patient (patient 15) was briefly admitted to an intensive care unit. None of the 18 patients died. Table 1. Demographic Characteristics, Chronology, Clinical Presentation, and Treatment of 18 Patients with Human Granulocytic Ehrlichiosis* Laboratory test results frequently showed leukopenia or thrombocytopenia and abnormal liver enzyme levels (Table 2). Lymphopenia (defined as <1.5 103 lymphocytes/mL) was seen in 8 of 13 (62%) patients, and neutropenia (defined as <2 103 neutrophils/L) was seen in 3 of 13 (23%). Lymphopenia was seen in 8 of 9 (89%) patients who presented with an illness that lasted 4 days or less and in none of 4 patients with an illness that lasted 5 days or longer (P = 0.006). Neutropenia was seen in 3 of 4 (75%) patients who had HGE for longer than 4 days but in only 1 of 9 (11%) patients who had the disease for 4 days or less (P = 0.05). Pearson correlation analysis showed that the initial neutrophil count was inversely related to the duration of symptoms before the first visit (r = 0.58[95% CI, 0.851 to 0.019];P = 0.038) and that the lymphocyte count was directly related to the duration of symptoms before the first visit (r = 0.543 [CI, 0.033 to 0.836]; P = 0.055). Patients who had HGE for longer than 4 days usually had atypical lymphocytosis of at least 10% of the differential count. No patients had elevated serum creatinine or blood urea nitrogen levels, and only one patient had a low hemoglobin level. Leukocyte and platelet counts returned to normal during observation in all patients who received treatment; these values generally returned to normal earlier than did liver enzyme levels. Table 2. Laboratory Variables during Acute and Convalescent Phases of Human Granulocytic Ehrlichiosis* Intracytoplasmic morulae were seen in 3 of 12 patients (25%). The frequency of infected granulocytes ranged from 0.3% to 6% (Table 2), and morulae were mostly seen in neutrophils (patient 15 had morulae in eosinophils). The presence of morulae correlated with age: Three of 4 patients older than 50 years of age and 0 of 8 patients younger than 50 years of age had morulae that could be detected. Results of polymerase chain reaction assay for HGE were positive in 9 of 12 patients (75%). All but 1 patient developed antibodies to E. equi. Three patients showed antibodies to E. chaffeensis in convalescent-phase specimens that had a higher titer ( 2560) to E. equi. The HGE agent grew in the HL-60 cell line from the blood of 2 patients (patients 14 and 15) who presented with HGE in the autumn of 1995. All 18 patients received doxycycline therapy, beginning an average of 13.2 days (median, 6 days [range, 1 to 78 days]) after the onset of symptoms (Table 1). Seven patients were initially treated with other antimicrobial agents. The therapy of 2 patients was changed from amoxicillin to doxycycline within 2 days of treatment. The other 4 patients, who were initially treated with amoxicillin, had recurrent fever or persistence of symptoms after 1 to 2 weeks of therapy; for these patients, therapy was changed to doxycycline. Symptoms resolved in all patients 24 to 48 hours after the start of treatment with doxycycline, which was administered for an average of 14.2 days (range, 1 to 21 days). No symptoms have been seen after follow-up as long as 1 year. Discussion We describe 18 adult patients with HGE from the northeastern United States. Symptoms in these patients developed an average of 5.5 days after a presumed or proven bite from an Ixodes tick and frequently included fever (body temperature >38.3 C), arthralgia and myalgia, and headache. Compared with the patients from the midwestern United States studied by Bakken and colleagues [1, 2], our patients were significantly younger (mean age SD, 47 16 years compared with 57 20 years; P = 0.04) and presented with a milder illness based on clinical and laboratory evaluations. Compared with the patients in our study, more midwestern patients were hospitalized (54% of midwestern patients compared with 28% in our study) and died (5% of midwestern patients compared with 0% in our study). Differences in case referral or in the threshold for diagnostic testing may explain some of these disparities. Although HGE has a nonspecific clinical presentation, abnormal results on certain routine laboratory tests considerably narrow the differential diagnosis. A diagnosis of Lyme disease may be considered in a patient with fever after a bite from I. scapularis, but cytopenia is extremely rare in that disease [10]. In contrast, approximately 80% of our patients with HGE had leukopenia or thrombocytopenia. The explanation for these abnormal hematologic values and for abnormal liver enzyme levels is not yet known. Leukopenia can be caused by lymphopenia or neutropenia, with lymphopenia in the early stages of infection, followed by lymphocytosis with atypical lymphocytes. Among the methods for specifically diagnosing HGE, microscopic detection of morulae is the quickest; for our patients, however, this method lacked sensitivity. Morulae were seen in 3 of 12 patients (25%) in our series compared with 80% of the midwestern patients. Visualization of intragranulocytic inclusions is probably an indication of massive infection and has been described as a risk factor, along with older age, for more serious illness [2]. In our series, PCR was the most sensitive diagnostic test during the acute phase. Nine of 12 (75%) of our patients had positive PCR results compared with 43% in the midwestern series [2]. As suggested by Bakken and colleagues, the lower sensitivity may have been caused by poor preservation of specimens and conditions that were suboptimal for the PCR assay. Another diagnostic approach that offers definitive evidence of infection is isolation of the organism in culture [9]. In our study, culture was done for two patients in whom morulae were seen in peripheral blood granulocytes; Ehrlichia was isolated in both cases. However, this technique is probably not easily done in most clinical laboratories, and its sensitivity has not yet been determined. Detection of antibodies to E. equi by immunofluorescent antibody assay is useful for confirming the diagnosis of HGE, but often only in retrospect. During the acute phase of HGE, the results of immunofluorescent antibody assay were positive in only 29% of our patients and 23% of the patients in the midwestern cohort. Current serologic assays to detect antibodies to Ehrlichia, however, lack standardization. Although all but one patient (94%) in our series developed antibodies to E. equi, the sensitivity and specificity of serologic testing have not been defi

Laboratory Diagnostic Techniques for Patients with Early Lyme Disease Associated with Erythema Migrans: A Comparison of Different Techniques

Recently, a number of refinements in diagnostic modalities for detection of Borrelia burgdorferi infection have been developed. These include large-volume blood cultures, quantitative polymerase chain reaction (PCR) techniques, and 2-stage serologic testing. In the present study, we compared 6 diagnostic modalities in 47 adult patients who had a clinical diagnosis of erythema migrans. Quantitative PCR on skin biopsy-derived material was the most sensitive diagnostic method (80.9%), followed by 2-stage serologic testing of convalescent-phase samples (66.0%), conventional nested PCR (63.8%), skin culture (51.1%), blood culture (44.7%), and serologic testing of acute-phase samples (40.4%). Results of all assays were negative for 3 patients (6.4%). We conclude that the clinical diagnosis of erythema migrans is highly accurate in an area where B. burgdorferi is endemic if it is made by experienced health care personnel, but some patients with this diagnosis may not have B. burgdorferi infection. No single diagnostic modality is suitable for detection of B. burgdorferi in every patient with erythema migrans.

Long-term follow-up of patients with culture-confirmed lyme disease

PURPOSE To determine the long-term outcome of patients with culture-confirmed Lyme disease. METHODS We analyzed data collected prospectively on adult patients from a highly endemic area in New York State who were diagnosed with early Lyme disease between 1991 and 1994. Patients with culture-confirmed erythema migrans were evaluated at baseline, 7 to 10 days, 21 to 28 days, 3 months, 6 months, 1 year, and annually thereafter. All patients were treated with antibiotics at the time of diagnosis. RESULTS We evaluated 96 cases on 709 separate occasions (median, eight evaluations per case). The erythema migrans rash resolved within 3 weeks in all of the 94 evaluable cases, none of whom developed an objective extracutaneous manifestation of Lyme disease. Of the 81 cases who were followed for >/=1 year, all but 8 (10%) were asymptomatic at their last visit, a mean (+/- SD) of 5.6 +/- 2.6 years into follow-up, and only 3 (4%) were symptomatic at every follow-up visit. Intercurrent tick bites were reported by 45 cases (47%), and 14 (15%) developed a second episode of erythema migrans. Four other cases who were asymptomatic seroconverted between years 2 and 5. CONCLUSION The long-term outcome of patients with erythema migrans after antibiotic therapy was excellent, but patients from a highly endemic area in New York State remained at high risk of re-exposure to ticks and reinfection. Subjective symptoms during follow-up evaluations tended to be mild to moderate, intermittent, and associated with more symptomatic illness at the time of initial diagnosis.

Prospective Clinical Evaluation of Patients from Missouri and New York with Erythema Migrans—Like Skin Lesions

BACKGROUND The most common and most recognizable feature of Borrelia burgdorferi infection (Lyme disease) is the skin lesion erythema migrans (EM). An illness associated with an EM-like skin lesion, but which is not caused by B. burgdorferi, occurs in many southern states in the United States (southern tick-associated rash illness [STARI], also known as Masters disease). METHODS Clinical features of 21 cases of EM-like skin lesions in 21 patients from Missouri were compared in a prospective study with those of 101 cases in 97 patients with EM-like skin lesions from New York. RESULTS Among Missouri cases, the peak incidence of EM-like skin lesions occurred earlier in the year than it did among New York cases (P<.001). Case patients from Missouri were more likely to recall a tick bite than were case patients from New York (85.7% and 19.8%, respectively; P<.001), and the time period from tick bite to onset of the skin lesion was shorter among Missouri case patients (6.1+/-4.2 days and 10.4+/-6.1 days, respectively; P=.011). Missouri case patients were less likely to be symptomatic than were New York case patients (19.0% and 76.2%, respectively; P<.001), and Missouri case patients were less likely to have multiple skin lesions (4.8% and 26.7%, respectively; P=.042). EM-like lesions in Missouri cases were smaller in size than those in New York cases (8.3+/-2.2 cm and 16.4+/-11.5 cm, respectively; P<.001), more circular in shape (P=.004), and more likely to have central clearing (76.2% and 21.6%, respectively; P<.001). After antibiotic treatment, Missouri case patients recovered more rapidly than did New York case patients (P=.037). CONCLUSION Cases of EM-like skin lesion in patients from Missouri and New York have distinct clinical presentations.

Quantitative Detection of Borrelia burgdorferi in 2-Millimeter Skin Samples of Erythema Migrans Lesions: Correlation of Results with Clinical and Laboratory Findings

ABSTRACT Variability of disease manifestations has been noted in patients with Lyme disease. A contributing factor to this variation may be the number of spirochetes present in infected patients. We evaluated clinical and laboratory findings for patients with erythema migrans with regard to the number of Borrelia burgdorferi organisms detected by quantitative PCR (qPCR) in 2-mm skin biopsy specimens. B. burgdorferi was detected in 80% (40 of 50) of the specimens tested; the mean number of spirochetes in these specimens ranged over 3 orders of magnitude (10 to 11,000 spirochetes per 2-mm biopsy specimen). Larger numbers of spirochetes were significantly associated with a shorter duration of the erythema migrans skin lesion (P = 0.020), smaller skin lesions (P = 0.020), and infection with a specific genotype of B. burgdorferi (P = 0.008) but not with the number or severity of symptoms. Skin culture positivity was significantly associated with skin lesions containing larger numbers of spirochetes (P = 0.019).

Differentiation of Reinfection from Relapse in Recurrent Lyme Disease

BACKGROUND Erythema migrans is the most common manifestation of Lyme disease. Recurrences are not uncommon, and although they are usually attributed to reinfection rather than relapse of the original infection, this remains somewhat controversial. We used molecular typing of Borrelia burgdorferi isolates obtained from patients with culture-confirmed episodes of erythema migrans to distinguish between relapse and reinfection. METHODS We determined the genotype of the gene encoding outer-surface protein C (ospC) of B. burgdorferi strains detected in cultures of skin or blood specimens obtained from patients with consecutive episodes of erythema migrans. After polymerase-chain-reaction amplification, ospC genotyping was performed by means of reverse line-blot analysis or DNA sequencing of the nearly full-length gene. Most strains were further analyzed by determining the genotype according to the 16S-23S ribosomal RNA intergenic spacer type, multilocus sequence typing, or both. Patients received standard courses of antibiotics for erythema migrans. RESULTS B. burgdorferi isolates obtained from 17 patients who received a diagnosis of erythema migrans between 1991 and 2011 and who had 22 paired episodes of this lesion (initial and second episodes) were available for testing. The ospC genotype was found to be different at each initial and second episode. Apparently identical genotypes were identified on more than one occasion in only one patient, at the first and third episodes, 5 years apart, but different genotypes were identified at the second and fourth episodes. CONCLUSIONS None of the 22 paired consecutive episodes of erythema migrans were associated with the same strain of B. burgdorferi on culture. Our data show that repeat episodes of erythema migrans in appropriately treated patients were due to reinfection and not relapse. (Funded by the National Institutes of Health and the William and Sylvia Silberstein Foundation.).

Failure to isolate borrelia burgdorferi after antimicrobial therapy in culture-documented Lyme borreliosis associated with erythema migrans: Report of a prospective study

BACKGROUND Borrelia burgdorferi, the etiologic agent of Lyme borreliosis, has occasionally been isolated from tissues or body fluids of patients after antimicrobial treatment. A prospective study of patients with Lyme borreliosis associated with erythema migrans (EM) was initiated in Westchester County, New York, to determine: (1) the clinical and laboratory parameters associated with culture positivity, and (2) the microbiologic response to treatment. METHODS Skin biopsies were performed in patients with EM and cultured for B. burgdorferi in modified Barbour-Stoenner-Kelly medium at 33 degrees C. Subsequent biopsies for culture were performed adjacent to the original biopsy site for culture-positive patients after the completion of antimicrobial therapy. RESULTS Initial biopsy cultures were performed for 44 patients; 6 were unevaluable due to culture contamination with other bacteria. Cultures were positive in 21 of 29 patients prior to treatment (72%), but in none of 9 patients during treatment (p < 0.001). The only other identified factor associated with successful recovery of B. burgdorferi was shorter duration of EM. When patients who had received prior antimicrobial therapy were excluded, the mean duration of the EM lesion for those with positive cultures was 5.0 +/- 5.2 days compared with 14.6 +/- 9.9 days for those with negative cultures (p < 0.01). B. burgdorferi could not be reisolated from any of 18 evaluable subsequent biopsies of skin from 13 culture-positive patients 4 to 209 days after completion of a course of antimicrobial therapy. Five patients had negative subsequent biopsy cultures on two separate occasions 3 to 5 months apart. CONCLUSIONS After brief courses of antibiotics, B. burgdorferi appears to be rapidly eliminated from the skin at EM sites. The ability to recover B. burgdorferi from skin biopsy cultures of untreated patients with EM lesions wanes with increasing duration of EM, suggesting that this organism may also be spontaneously cleared from skin over time.