Clinical and epidemiologic characteristics of lyme borreliosis and tick-borne encephalitis mixed infections in Krasnoyarsk kray

Abstract

Aim. To reveal clinical features of Lyme borreliosis and tick-borne encephalitis mixed infections in Krasnoyarsk Kray. Methods. The main group consisted of 226 patients with mixed infection of Lyme borreliosis and tick-borne encephalitis (males - 57.1%, females- 42.9%, mean age 43.7±1.0 years), who were examined and compared to the control group of 88 patients with tick-borne encephalitis alone (males - 56.8%, females - 43.2%, mean age 43.9±1.8 years). Results. About 40% of acute Lyme borreliosis cases in Krasnoyarsk Kray are a mixed infection of Lyme borreliosis and tick-borne encephalitis, that is closely related to a large population of Ixodidae infected by both agents. There is no characteristic epidemiologic background in more than a half of all cases. Typical clinical features for mixed infection of Lyme borreliosis and tick-borne encephalitis are severe onset with toxic constant hyperthermia or hyperpyrexia, and joint pain (18.6% of cases). Erythema migrans was present in 22.6% of cases, involvement of central nervous system (35.4%) was mostly often associated with meningitis and meningoencephalitis (29.2%). Bannwarth syndrome (3.1%) is a clinical type of Lyme borreliosis not associated with erythema in mixed infection. Cardiovascular system damage is transient and associated with intoxication. In 57.1% of cases the diagnosis of mixed infection was confirmed at dispensary follow-up 1.5, 3, 6 months after the clinical manifestations of the disease. Conclusion. The most common clinical form of mixed infection is the non-erithemic form of Lyme borreliosis and febrile form of tick-borne encephalitis, late Lyme borreliosis after the suffered mixed infection was registered in 30.1% of cases.