[Risk of Lyme disease development after a tick bite].

BACKGROUND/AIM: Despite numerous research of Lyme disease (LD), there are still many concerns about environmental of infectious agent of LD, as well as its prophylaxis, diagnosis and treatment. The aim of this work was to determine the risk of LD in relation to the way of removing ticks and duration of tick attachment. METHODS: In the period from 2000 to 2007 a prospective study was conducted including persons with tick bite referred to the Institute of Epidemiology, Military Medical Academy, and followed for the occurrence of early Lyme disease up to six months after a tick bite. Epidemiological questionnaire was used to collect relevant information about the place and time of tick bites, the way of a removing tick, duration of tick attachment, remnants of a tick left in the skin (parts of the mouth device) and the signs of clinical manifestations of LD. Duration of tick attachment was determined on the basis of size of engorged tick and epidemiological data. Removed ticks were determined by the key of Pomerancev. Professional removing of attached tick was considered to be removing of tick with mechanical means by healthcare personnel. Fisher's exact test, Chi squares test and calculation of the relative risk (RR) were used for data analysis. RESULTS: Of 3 126 patients with tick bite, clinical manifestations of LD were demonstrated in 19 (0.61%). In the group of subjects (n = 829) in which a tick was not removed professionally there were 17 (2.05%) cases with LD, while in the group of respondents (n = 2 297) in who a tick was removed professionally there were 2 (0.09%) cases with LD after tick bite (RR, 23.55; p < 0.0001). The disease was most frequent in the group of respondents with incompletely and unprofessionally removed ticks (2.46%). In the groups of patients with unprofessionally but completely removed ticks LD occurred in 0.89%, while in the group of subjects with a tick removed by an expert, but incompletely in 0.78% cases. The disease occurred rarely in the group with a tick removed completely and professionally (0.05%). There was no case of LD in the group of patients with a tick removed within 24 hours. The longer time of exposure after 24 hours, the higher absolute risk of disease was reported. CONCLUSION: In prevention of Lyme disease it is important to urgent remove a tick, to use a correct procedure of removing and to remove the whole tick without any remnants.

Lyme borreliosis in Portugal caused by Borrelia lusitaniae? Clinical report on the first patient with a positive skin isolate.

BACKGROUND: Borrelia lusitaniae was isolated from an Ixodes ricinus tick in Portugal in 1993 for the first time. Further, this borrelia genospecies has been found in ixodid ticks collected around the coasts of southern Portugal and North Africa. Its reservoir has not been defined yet. B. lusitaniae was isolated once until now from a patient with a long standing and expanding skin disorder. PATIENT AND METHODS: A 46-year-old Portuguese woman presented with a skin lesion on the left thigh which had evolved slowly over ten years. The patient reported limb paraesthesias, cramps, chronic headaches, and cardiac rhythm disturbances. History of tick bites was negative nor had the patient ever noticed a skin lesion comparable with erythema chronicum migrans. Skin biopsies were taken for histological evaluation, culture and DNA detection. Antibodies to borrelia were searched by indirect immunofluorescence assay and Western-blot. RESULTS: A bilateral carpal tunnel syndrome and local synovitis was diagnosed. Dermato-histology was normal, serology was negative. Spirochaetal organisms were cultured from a skin biopsy and identified as B. lusitaniae. The patient improved after a 2-week course of intravenous ceftriaxone; the skin lesions did not expand further. CONCLUSIONS: This culture confirmed skin infection by B. lusitaniae in a patient from Portugal suggests an additional human pathogen out of the B. burgdorferi sensu lato complex in Europe, particularly in Portugal.

Diagnostics of tick-borne diseases in the endemic region of Russia.

A clinical-laboratory survey of 1952 patients with acute feverish diseases developing after tick bite was carried out in the Pre-Ural region of Russia, which is endemic for tick-borne encephalitis and ixodid tick-borne borreliosis, in 1999-2001. Enzyme-linked immunosorbent assay and indirect immunofluorescence assay were used for the detection of tick-borne encephalitis, ixodid tick-borne borreliosis and ehrlichiosis specific antibodies. Tick-borne encephalitis was diagnosed in 22.8% of patients, ixodid tick-borne borreliosis in 50.5%, ehrlichiosis in 4.5% and mixed infections in 2.9%. For the first time in Russia, a new transmitted disease that appeared to be human monocytic ehrlichiosis was identified and its clinical manifestations were described. The common feature of these infections is the acute course and the marked general infectious syndrome at the early period of the disease. Disorders of the nervous system predominate in tick-borne encephalitis. In ixodid tick-borne borreliosis the development of erythema migrans and organic pathology (disorders of the cardio-vascular system and liver) associated with the involvement of the nervous and locomotor system are pathognomonically significant. The specific characteristics of human monocytic ehrlichiosis include nervous impairments, hepatic lesions, the frequent development of a two-wave course and hemogram changes.

Erythema migrans.

EM is the most common manifestation of early Lyme disease, occurring in a high percentage of cases. Because this phase of infection with B. burgdorferi offers an excellent opportunity to treat this potentially systemic infection, front-line physicians must be familiar with its diagnosis. Although much attention has been paid to the classic form--the target lesion or bull's eye--there are variations that are more common. These include uniform coloration, lesions with necrotic or vesicular centers, and lesions with shapes that are not circular or oval. These findings must be interpreted in epidemiologic context. Serologic testing at this phase of the illness should not be done. It is unnecessary and potentially misleading; false-positive and false-negative tests can occur. Diagnosis is clinical. Prompt initiation of appropriate antibiotic therapy for 3 weeks cures most patients at this early stage of the disease. Clinicians should be aware that 15% of patients may be coinfected with a second tick-borne pathogen, which could alter the usual clinical manifestations and the response to treatment.

Temporal relation between Ixodes scapularis abundance and risk for Lyme disease associated with erythema migrans.

Understanding the role that nymphal and female ticks, Ixodes scapularis, have in the epidemiology of Lyme disease is essential to the development of successful prevention programs. In this study, the authors sought to evaluate the seasonal and annual relations between tick densities and patients > or = 16 years of age diagnosed with erythema migrans (EM), the rash associated with early Lyme disease. Ticks were collected weekly by drag sampling throughout most of the year from 1991 to 1996 in Westchester County, New York. The number of EM cases was based on patients diagnosed at the Westchester County Medical Center using Centers for Disease Control and Prevention (CDC) criteria. No patients with EM were diagnosed from January through April, when only adult ticks were active. Correlation analysis between monthly tick densities and EM incidence was significant for nymphs (r = 0.87, p < 0.01), but not for adult ticks (r = -0.57, p > 0.05). There was a strong, although not significant, correlation between peak annual number of patients with EM and peak nymphal tick abundance (r = 0.76, p = 0.08). These data indicate that bites from adult I. scapularis only rarely result in Lyme disease, and that annual nymphal tick abundance determines exposure. This suggests that annual fluctuations in Lyme disease case numbers are largely due to natural changes in tick abundance and, therefore, that control of nymphal I. scapularis should be a major component of Lyme disease prevention efforts.

[Lyme borreliosis]. / Lyme-Borreliose.

Lyme borreliosis in childhood is a tick-borne disease that includes a variety of clinical symptoms in different organs. Most frequently dermatological manifestations such as erythema migrans and borrelial lymphocytoma are observed. Uni- or bilateral peripheral facial palsy and meningitis with lymphocytic pleocytosis represent typical symptoms of neuroborreliosis. Lyme arthritis occurs as an acute or chronic manifestation that should only be diagnosed after careful consideration of other causes of arthritis in childhood. After clinical and/or laboratory diagnosis of Lyme borreliosis, systemic antibiotic treatment should be initiated. Oral treatment with amoxicillin can be recommended for the treatment of erythema migrans and borrelial lymphocytoma. In contrast, the intravenous administration of 3rd generation cephalosporins is indicated for all generalized manifestations including facial palsy, meningitis, arthritis or involvement of other organ systems. Lyme borreliosis in childhood is characterized by a good prognosis. At the present time, many efforts are given to the development of vaccines using subunits of the different genospecies of Borrelia burgdorferi. First clinical trials with Lyme borreliosis vaccines have been started.

Comparative studies on Borrelia afzelii isolated from a patient of Lyme disease, Ixodes persulcatus ticks, and Apodemus speciosus rodents in Japan.

The genospecies Borrelia afzelii was isolated from a patient of Lyme disease in Hokkaido, Japan, for the first time, by culturing the minced erythema lesion in BSK II medium. Two analytical methods, rRNA gene restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) using the specific primer set to amplify the 16S rRNA gene, revealed that this clinical isolate belongs to the group of B. afzelii. In our culture collection of spirochetes, part of the isolates from Ixodes persulcatus ticks, and from Apodemus speciosus rodents, were also classified as B. afzelii. These results strongly suggest that the agent pathogenic to humans is maintained in "rodent-tick" transmission cycle.

Epidemiological and aetiological evidence for transmission of Lyme disease by adult Ixodes persulcatus in an endemic area in China.

Involvement of adult Ixodes persulcatus ticks in the transmission of Lyme disease in Hailin County, Heilongjiang Province, China, is reported. In 1986 from April through August adult I. persulcatus was the dominant tick in this endemic area with an infection rate of 43% for the Lyme disease spirochaete, Borrelia burgdorferi. The incidence of Lyme disease cases presenting the symptom of erythema chronicum migrans (ECM) within this area was correlated with the seasonal abundance of adult I. persulcatus and the number of people bitten by ticks. The frequency of ECM formation in all age groups varied and was associated with the frequency of tick bites. In addition, a strain of B. burgdorferi was isolated from a pool of six female I. persulcatus collected from this area. We demonstrate that the seasonal abundance of adult I. persulcatus and its frequent attachment to humans result in the spring and summer transmission of Lyme disease in this endemic area. The role of immature I. persulcatus in Lyme disease transmission is apparently minimal.

Prevalence of Erythema migrans Borreliosis in blood donors.

European Erythema migrans Borreliosis and North American Lyme disease are closely related to syphilis. This implicates a potential risk of infection for blood recipients. Eighty-six of 3,157 blood donors tested showed IgG-antibodies against Borrelia Burgdorferi. From among 47 persons of this group who could be examined, clinical signs of diseased skin, joints or nervous system, not diagnosed before, were found or could be suspected in 13 cases. Since intrauterine transmission of Borrelia infection has been described, the inevitable question of whether this disease can also be transmitted as a result of blood transfusion becomes a major concern. As the pathogen can persist even in the presence of serum antibodies, it seems advisable to examine blood donors serologically, whenever Erythema migrans Borreliosis is suspected. Though further research is required to document a transfusion-transmitted Borrelia infection, infected persons should be treated to avoid serious or late manifestations.