Comparison of Erythema Migrans Caused by Borrelia burgdorferi and Borrelia garinii

Abstract

Background:

A comparison of patients with erythema migrans due to Borrelia garinii versus Borrelia burgdorferi has not been reported.

Patients and Methods:

One hundred nineteen patients from New York State with erythema migrans caused by B. burgdorferi were compared with 116 patients from Slovenia with erythema migrans due to B. garinii infection.

Results:

Patients with B. garinii infection were older, more often reported a tick bite, and developed larger lesions (median largest diameter: 18 and 14 cm, respectively; p=0.01) that more often had central clearing (61.2% compared with 35.3%; p<0.0001). Patients infected with B. burgdorferi, however, more often had systemic symptoms (68.9% vs. 37.1%; p<0.0001), including fatigue (p<0.0001), arthralgia (p=0.0003), myalgia (p<0.0001), headache (p=0.0008), fever and/or chills (p<0.0001), and stiff neck (p<0.0001), and more often had abnormal physical findings (57.1% compared with 11.2%; p<0.0001), such as fever (p=0.0002) or regional lymphadenopathy (p<0.0001). There was a trend for more patients with B. burgdorferi infection to have multiple erythema migrans skin lesions (13.4% compared with 5.2%; p=0.051), and among patients with multiple erythema migrans the number of lesions was greater in B. burgdorferi-infected patients (median: 5.5 compared with 2.0; p=0.006).

Conclusions:

The results of the present study indicate that in patients with erythema migrans the clinical features vary according to whether infection is caused by B. garinii or B. burgdorferi.

Introduction

L yme borreliosis is the most common tick-transmitted illness in the northern hemisphere (Steere 2001, Stanek and Strle 2003). It is caused by Borrelia burgdorferi sensu lato (Burgdorfer et al. 1982), also called Lyme borrelia. Human disease is predominantly associated with three Borrelia species: B. burgdorferi sensu stricto (henceforth referred to as B. burgdorferi), Borrelia afzelii, and Borrelia garinii. There are indications that different species of Lyme borrelia vary in their propensity to cause particular clinical manifestations. For example, B. afzelii is mostly associated with skin manifestations such as erythema migrans and acrodermatitis chronica atrophicans, B. garinii appears to be the most neurotropic, and B. burgdorferi the most arthritogenic (van Dam et al. 1993, Balmelli and Piffaretti 1995, Busch et al. 1996, Ružić-Sabljić et al. 2002, Stanek and Strle 2003). Differences in geographical distribution of the species of Lyme borrelia may explain certain differences between the clinical picture of Lyme borreliosis in Europe and North America (Nadelman and Wormser 1998, Steere 2001, Stanek and Strle 2003).

Data indicating the association of different Lyme borrelia species with specific clinical manifestations of Lyme borreliosis are relatively abundant (Busch et al. 1996, Nadelman and Wormser 1998, Steere 2001, Ružić-Sabljić et al. 2002, Stanek and Strle 2003). However, comparisons of individual clinical manifestations in patients infected with different species of Lyme borrelia are quite scarce. In fact, information is limited to one report comparing culture-confirmed Lyme neuroborreliosis caused by B. garinii with that caused by B. afzelii (Strle et al. 2006) and four reports comparing the features of culture-confirmed patients with erythema migrans due to different species of Lyme borrelia (Strle et al. 1999, Carlsson et al. 2003, Logar et al. 2004, Jones et al. 2008). Comparison of patients with erythema migrans caused by B. afzelii in Europe with that caused by B. burgdorferi in the United States showed differences in epidemiological, clinical, and laboratory findings, suggesting that these two species differ in their pathogenic potential (Strle et al. 1999, Jones et al. 2008). Two other studies of European patients demonstrated several differences in clinical presentation between erythema migrans caused by B. afzelii versus B. garinii (Carlsson et al. 2003, Logar et al. 2004). To date, no study, however, has compared patients with erythema migrans caused by B. garinii versus B. burgdorferi.

In the present study, we compared epidemiologic, demographic, clinical, and laboratory findings in patients from New York State and patients from Slovenia who had microbiologically confirmed erythema migrans caused by B. burgdorferi and B. garinii, respectively.

Methods

Patients

Patients with a clinical diagnosis of erythema migrans were recruited in two separate prospective studies. The Centers for Disease Control and Prevention surveillance definition of erythema migrans (Anonymous 1991) was satisfied in all cases. Patients from the United States were seen at the Lyme Disease Diagnostic Center, Valhalla, New York, from June 1991 through August 1995. Slovenian patients were evaluated at the Lyme Borreliosis Outpatient Clinic, Ljubljana, Slovenia, from 1993 to 2007. All patients were older than 15 years of age and gave informed consent. Most patients in Valhalla were seen at a walk-in clinic for which no appointment or referral was needed, whereas in Slovenia the majority of patients were referred by primary care physicians. Skin biopsy was offered to all patients with a clinical diagnosis of erythema migrans who had not yet received antibiotics known to be effective against Lyme borrelia. Patients were included in the present study if Borrelia were recovered from cultures obtained from an erythema migrans skin lesion and if the strains were typed as B. burgdorferi for patients from the United States or as B. garinii for the European patients. All patients meeting the aforementioned criteria were included, with the limitation that in patients who had repeated culture-confirmed episodes of erythema migrans in separate years, only the first episode was included.

A standardized questionnaire was completed for each patient at the time of the first visit. Data collected included age and gender, history of a recognized tick bite at the site of the erythema migrans, time from the bite to the onset of the skin lesion, duration of the skin lesion before examination, diameter of the skin lesion, number of skin lesions, as well as associated local symptoms and systemic symptoms defined as complaints that newly developed or intensified since the onset of erythema migrans.

Laboratory methods

All isolates were obtained from biopsy or needle aspiration of erythema migrans skin lesions (Nadelman et al. 1996, Picken et al. 1996). In an individual patient, only one skin biopsy was performed. In the case of multiple erythema migrans lesions, the primary or largest skin lesion was biopsied. Cultures were processed, as previously reported, in modified Barbour–Stoenner–Kelly medium (Nadelman et al. 1996) for U.S. patients and in modified Kelly–Pettenkofer medium (Picken et al. 1996) for Slovenian patients. During the study period, the isolation rate of B. burgdorferi sensu lato from the skin of previously untreated erythema migrans skin lesions fulfilling CDC criteria was typically between 50% and 60% in both Slovenian and U.S. patients (Nowakowski et al. 2001, Ružić-Sabljić et al. 2002, Stupica et al. 2010). At the U.S. study site, we identified spirochetes as B. burgdorferi by using polymerase chain reaction with specific primers directed at the ribosomal RNA genes of Borrelia species (Schwartz et al. 1992). We identified the species of European isolates by using pulsed-field gel electrophoretic separation of restriction enzyme MluI digestion fragments (the pattern of large restriction fragments produced is diagnostic of the species) (Belfaiza et al. 1993).

At the time when biopsies were obtained, additional laboratory testing was performed, which included complete blood counts, liver function tests, and the erythrocyte sedimentation rate.

Baseline serum specimens were tested for antibodies to B. burgdorferi sensu lato. Convalescent-phase specimens were obtained after 1 week to 1 month for U.S. patients and after 2 months for Slovenian patients. In the United States, serum specimens were tested for antibodies to B. burgdorferi with a polyvalent enzyme-linked immunosorbent assay (Whittaker Bioproducts, Inc., Walkersville, MD) (Aguero-Rosenfeld et al. 1993, Nadelman et al. 1996). In Slovenia, the presence of serum IgM and IgG antibodies to B. garinii was separately determined by immunofluorescent assay without preabsorption (Wilske et al. 1984); a local skin isolate of B. afzelii was used as antigen. Titers of 1:256 or more were considered to indicate positivity.

Statistical analysis

Data were summarized as frequencies (%) for categorical data and as medians (ranges) for numerical data.

A comparison of epidemiological and clinical data for patients with erythema migrans caused by B. burgdorferi and B. garinii was done. Differences in the numerical data were analyzed by the Mann–Whitney test and in the categorical data by Yates's corrected χ ² test or Fisher's exact test; p-values were two tailed. A significance level of 0.05 was used (p<0.05).

We used Epi-Info 6 for the analyses (Statcalc, version 6.04a; Centers for Disease Control and Prevention, Atlanta, Georgia). Ninety-five percent confidence intervals (CIs) for the observed proportions (for categorical data) and means (for numerical data) were calculated using TAMU's Confidence Interval Calculators (www.stat.tamu.edu).

Results

B. garinii was recovered from the skin specimens of 116 Slovenian patients; 64 of these patients, seen in the period from 1993 to 2000, have been previously reported (Logar et al. 2004). B. burgdorferi was cultured from 119 U.S. patients and were included in a prior publication (Strle et al. 1999).

Demographic patient data and erythema migrans characteristics are summarized in Table 1. All Slovenian patients and 113 of 119 U.S. patients (95%) were white. Slovenian patients were more likely than U.S. patients to recall a tick bite at the erythema migrans site (63.8% compared with 25.2%; p<0.0001). Patients with erythema migrans caused by B. garinii developed larger lesions (median largest diameter: 18 vs. 14 cm; p=0.01) with more frequent central clearing (61.2% compared with 35.3%, for Slovenian and U.S. patients, respectively; p<0.0001). A higher proportion of Slovenian than U.S. patients reported local symptoms at the erythema migrans lesion site (72.4% compared with 49.0%; p=0.0007). There was a trend for more patients with B. burgdorferi infection to have multiple erythema migrans skin lesions (13.4% compared with 5.2% patients with B. garinii infection; p=0.05); among patients with multiple erythema migrans, the number of lesions was greater in those infected with B. burgdorferi compared with B. garinii-infected patients (5.5 vs. 2.0 lesions, respectively; p=0.006).

Table 1.

Characteristics of Patients with Culture-Confirmed Erythema Migrans

Characteristic	Patients in Slovenia with Borrelia garinii infection (n=116)	Patients in the United States with Borrelia burgdorferi infection (n=119)	p-Value ^a
Male, n (%; 95% CI)	55 (47.4; 38.5–56.4)	70 (58.8; 49.8–67.2)	0.10
Age, years
Median (range)	54 (20–83)	40 (16–76)	<0.0001
Mean (95% CI)	52.9 (50.4–55.4)	40.9 (38.7–43.1)
Tick bite at rash site recalled, n (%; 95% CI)^b	74 (63.8; 54.7–72.0)	30 (25.2; 18.3–33.7)	<0.0001
Time from bite to rash onset, days
Median (range)	14 (1–170)	11 (1–55)	0.19
Mean (95% CI)	20.7 (16.5–25.0)	16.2 (14.0–18.4)
Duration of rash at presentation, days
Median (range)	5 (1–61)	4 (1–39)	0.32
Mean (95% CI)	8.9 (6.9–10.9)	7.4 (5.8–9.1)
Size (largest diameter) of lesion at presentation, cm^c
Median (range)	18 (5–72)	14 (5–73)	0.01
Mean (95% CI)	20.6 (18.3–22.9)	16.1 (14.1–18.1)
Multiple lesions, n (%; 95% CI)^b	6 (5.2; 2.4–10.9)^d	16 (13.4; 8.4–20.7)^e	0.05
Location of primary lesion, n (%; 95% CI)^b,f
Leg	58 (50; 41.0–59.0)	40 (33.6; 25.7–42.5)	0.02
Arm and shoulder	24 (20.7; 14.3–29.0)	17 (14.3; 9.1–21.7)	0.26
Trunk and abdomen	34 (29.3; 21.8–38.1)	60 (50.4; 41.5–59.2)	0.002
Head and neck	0 (0; 0.0–3.2)	2 (1.6; 0.4–5.8)	0.50
Central clearing of erythema migrans lesion, n (%)^b,c	71 (61.2; 52.1–70.0)	36 (35.3; 26.7–45.0)^g	0.0002
Local symptoms at erythema migrans lesion, n (%)^b	84 (72.4; 63.6–79.7)	50 (49.0; 39.5–58.6)^g	0.0007
Pruritus	63 (54.3; 45.2–63.1)	41 (40.2; 31.2–49.9)^g	0.05
Burning and/or pain	41 (35.3; 27.2–44.3)	35 (34.3; 25.8–43.9)^g	0.98

95% CI=95% confidence interval for the observed proportion (mean).

Categorical data were analyzed by using the Yates corrected χ ² test or the Fisher exact test; numerical data were analyzed by using the Mann–Whitney test. p-Values are two tailed.

Values are the number (percentage) of patients.

In patients with multiple erythema migrans, the initial (primary) lesion was the only one taken into account.

Median, 2 lesions; range, 2–3 lesions.

Median, 5.5 lesions; range, 2–70 lesions.

Leg includes hip; trunk and abdomen include axilla and groin.

Rash characteristics described for 102 of 119 (85.5%) U.S. patients.

In addition, patients in the United States were much more likely than those in Slovenia to have systemic symptoms (68.9% compared with 37.1%; p<0.0001), including fatigue (54.6% compared with 19.8%; p<0.0001), arthralgia (40.3% compared with 18.1%; p=0.0003), myalgia (44.5% compared with 19.0%; p<0.0001), headache (38.7% compared with 18.1%; p=0.0008), fever or chills (37.8% compared with 8.6%; p<0.0001), and stiff neck (38.7% compared with 3.4%; p<0.0001) (Table 2).

Table 2.

Selected Clinical and Laboratory Findings in Patients with Culture-Confirmed Erythema Migrans

	Patients in Slovenia with Borrelia garinii infection (n=116)	Patients in the United States with Borrelia burgdorferi infection (n=119)
Variable	n (%; 95% CI)		p-Value ^a
Symptoms^b
Fatigue	23 (19.8; 13.6–28.0)	65 (54.6; 45.7–63.3)	<0.0001
Arthralgia	21 (18.1; 12.2–26.1)	48 (40.3; 31.9–49.3)	0.0003
Myalgia	22 (19.0; 12.9–27.1)	53 (44.5; 35.9–53.5)	<0.0001
Headache	21 (18.1; 12.2–26.1)	46 (38.7; 30.4–47.7)	0.0008
Fever and/or chills	10 (8.6; 4.7–15.1)	45 (37.8; 29.6–46.8)	<0.0001
Stiff neck	4 (3.4; 1.5–8.5)	46 (38.7; 30.4–47.7)	<0.0001
Any systemic symptom	43 (37.1; 28.9–46.2)	82 (68.9; 60.1–76.5)	<0.0001
Physical examination findings
Lymphadenopathy	4 (3.4; 1.3–8.5)	46 (38.7; 30.4–47.7)	<0.0001
regional	4 (3.4; 1.3–8.5)	34 (28.6; 21.3–37.3)	<0.0001
generalized	0 (0; 0–3.2)	12 (10.1; 5.9–16.8)	0.001
Fever^c	1 (0.9; 0.2–4.8)	18 (15.1; 9.8–22.6)	0.0002
Tenderness on neck flexion	3 (2.6; 0.9–7.3)	14 (11.8; 7.2–18.8)	0.01
Joint swelling	0 (0; 0–3.2)	1 (0.8; 0.1–4.5)	1.0000
Joint tenderness	1 (0.9; 0.2–4.8)	9 (7.6; 4.1–13.8)	0.02
Any abnormal finding	13 (11.2; 6.7–18.2)	68 (57.1; 48.1–65.6)	<0.0001
Laboratory findings
Erythrocyte sedimentation rate ≥2 times the upper limit of normal^d	7/92 (7.6; 3.7–14.9)^e	28/112 (25.0; 17.9–33.8)^e	0.002
Alanine aminotransferase level >40 U/L	12/92 (13.0; 7.6–21.4)^e	25/118 (21.2; 14.8–29.4)^e	0.18
Alkaline phosphatase level >117 U/L	4/92 (4.3; 1.7–10.6)^e	17/118 (14.4; 9.2–21.9)^e	0.03
Any elevated result on a liver function assay^f	20/92 (21.7; 14.5–31.2)^e	38/118 (32.2; 24.4–41.1)^e	0.13
Positive result of a serologic test at baseline	23/93 (24.7; 17.1–34.4)^e	42/119 (35.3; 27.3–44.2)^e	0.13
Seroconversion (negative to positive)	8/70 (11.4; 5.9–20.9)^e	64/76 (84.2; 74.4–90.7)^e	<0.0001
Seropositivity	31/93 (33.3; 24.6–43.4)^e	106/119 (89.1; 82.2–93.5)^e	<0.0001

95% CI=95% confidence interval for the observed proportion.

Categorical data were analyzed by using the Yates corrected χ ² test or the Fisher exact test; numerical data were analyzed by using the Mann–Whitney test. p-Values are two tailed.

No significant difference was seen between the two groups in the occurrence of anorexia, dizziness, nausea or vomiting, memory or concentration disturbances, or cough.

≥38°C.

≥40 mm/h for women; ≥20 mm/h for men.

Patients with abnormal value/patients for whom test had been performed.

Assay for alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, or γ-glutamyltranspeptidase.

Objective findings on physical examination besides erythema migrans were also much more common in U.S. patients (57.1% compared with 11.2%; p<0.0001). Regional lymphadenopathy was seen in 28.6% of U.S. patients compared with 3.4% of Slovenian patients (p<0.0001), and fever (body temperature: >38°C) was seen in 15.1% of U.S. patients compared with 0.9% of Slovenian patients (p=0.0002). U.S. patients were more likely to have tenderness on neck flexion (11.8% compared with 2.6%; p=0.01) and joint tenderness (7.6% compared with 0.9%; p=0.02).

Certain laboratory test results also differed between patient groups. U.S. patients more frequently had an elevated alkaline phosphatase level (14.4% compared with 4.3%; p=0.03), more likely had an erythrocyte sedimentation rate two or more times the upper limit of normal (25% compared with 7.6%; p=0.002), and were more likely to be seropositive (89.1% compared with 33.3%; p<0.0001) on acute- or convalescent-phase testing.

Discussion

To date, there has been limited information regarding the role that different species of Lyme borrelia play in determining a specific clinical manifestation of Lyme borreliosis (Strle et al. 1999, Jones et al. 2008), and no report has directly compared patients with erythema migrans caused by B. garinii and B. burgdorferi. In the present study, we compared the epidemiologic, demographic, clinical, and laboratory findings in patients from New York State and patients from Slovenia who had microbiologically confirmed erythema migrans caused by B. burgdorferi and B. garinii, respectively.

Our study revealed that certain clinical features of patients with erythema migrans who were infected with B. garinii differed from those infected with B. burgdorferi (Tables 1 and 2). Slovenian patients with B. garinii infection were older, more often reported a tick bite at the site of their skin lesion, and had a different pattern of skin involvement than U.S. patients with B. burgdorferi infection. Greater recall of the tick bite is consistent with the hypothesis that B. garinii is more rapidly transmitted from tick to skin than is B. burgdorferi or, alternatively, that Ixodes ricinus tick bites may be more irritating than Ixodes scapularis bites. Patients with erythema migrans caused by B. garinii developed larger lesions (median largest diameter: 18 and 14 cm, respectively; p=0.01) that more often had central clearing (61.2% compared with 35.3%; p=0.0002), despite the fact that the skin lesions were of comparable duration with those due to B. burgdorferi infection, a finding that suggests that the pathogenesis of central clearing is not simply due to longer duration of the skin infection (Asbrink et al. 1986, Strle et al. 1999). Further evidence that other factors besides duration influence central clearing was that in erythema migrans caused by B. garinii the duration of the lesions was similar, with and without central clearing (median: 6, range: 1–61 days vs. median: 4, range: 1–51 days, respectively; p=0.6).

Patients with erythema migrans due to B. burgdorferi more often had systemic symptoms and abnormal physical findings such as fever or regional lymphadenopathy than patients with B. garinii infection. Differences were observed not only for the presence of systemic symptoms in general (68.9% vs. 37.1%; p<0.0001) but also for individual symptoms including fatigue (p<0.0001), arthralgia (p=0.0003), myalgia (p<0.0001), headache (p=0.0008), fever and/or chills (p<0.0001), and stiff neck (p<0.0001) (Table 2). A possible explanation for this is that B. burgdorferi stimulates a stronger and more intense immune response, which leads to more intensive inflammation. It has been recently shown that B. burgdorferi induces normal macrophages to secrete higher levels of chemokines and cytokines than B. afzelii or B. garinii, indicating that B. burgdorferi induces a greater inflammatory response in macrophages than the other two Borrelia species (Strle et al. 2009). If this explanation is valid it does not appear to pertain to the site of the erythema migrans skin lesion per se, as local symptoms were more often found with B. garinii infection (72.4% vs. 49.0%; p=0.0007). Alternatively, it is possible that B. burgdorferi infection is more often associated with spirochetemia that persists over days to weeks, which is suggested by the nearly threefold higher rate of multiple erythema migrans skin lesions with B. burgdorferi infection.

The generalizability of the findings in this comparative study depends on whether the subjects enrolled are typical of patients with erythema migrans caused by B. burgdorferi infection in the United States and by B. garinii in Europe. Potential concerns are whether bias may have been introduced based on the source of referral for the patients, the requirement for patients to agree to a skin biopsy, and/or the requirement for a positive skin culture. The clinical characteristics of the United States patients in this study, however, are consistent with those of other case series of patients with erythema migrans in the United States (Tibble and Edlow 2007). All United States patients can be assumed to have B. burgdorferi infection irrespective of culture positivity, because it is the only pathogenic species of Borrelia in North America. For example, in a recent extensive review by Tibble and Edlow (2007), the frequency of systemic symptoms was found to be 65% (95% CI: 52%–76%) in published studies of United States patients with erythema migrans, a figure remarkably similar to the 68.9% (95% CI: 60.1%–76.5%) rate observed in our study. There are only scant data, however, on the characteristics of patients with erythema migrans due to B. garinii, because only 11 culture-confirmed cases have been characterized in detail beyond those included in this report (Carlsson et al. 2003); therefore, additional studies will be needed to determine whether the findings that we observed are representative of this patient group.

Although the ratio of positive results of a serologic test at baseline were comparable, Slovenian patients were much less likely to seroconvert than U.S. patients: 8/70 (11.4%) compared with 64/76 (84.2%); p<0.0001. However, because convalescent-phase serologic samples from Slovenian patients were obtained at 2 months (rather than at 1 week to 1 month, as in U.S. patients), some cases of seroconversion may have been missed. Also, B. burgdorferi may be more likely to spread systemically from the skin site, as evidenced by the higher rates of regional lymphadenopathy and multiple skin lesions. Perhaps, most importantly, the serologic assay used at the time of the study for the Slovenian patients was less sensitive than newer assays. For example, in 106 of 148 (71.6%) culture-positive patients from Slovenia with erythema migrans, including 6 of 10 (60%) with B. garinii isolated from their skin lesion, the presence of serum IgM antibodies to OspC and VlsE and IgG antibodies to VlsE B. burgdorferi sensu lato antigens (Diasorin) was demonstrated (Stupica et al. 2010). Thus, although the differences in seroconversion and seropositivity could be due to differences in the borrelial species causing the erythema migrans, they can also be at least partly the result of differences in the sensitivity of the serologic assays used in the present study.

In conclusion, the results of the present study further corroborate the concept that characteristics of Lyme borreliosis are influenced by the species of Lyme Borrelia causing the illness.

Footnotes

Acknowledgment

F. Strle has received funding from the Ministry of Science and Technology of the Republic of Slovenia (grant no. P3-0296).

Disclaimer

The funding source had no role in the preparation of this article.

Disclosure Statement

No competing financial interests exist.

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