Spotless Rickettsiosis Caused by<i>Rickettsia slovaca</i>and Associated with<i>Dermacentor</i>Ticks

TLDR

Rickettsia slovaca was first shown to cause disease in 1997 following a Dermacentor tick bite that produced a scalp inoculation lesion and cervical lymphadenopathy. The study assessed how frequently R. slovaca infections occurred in French and Hungarian patients presenting with scalp lesions and lymphadenopathy after tick bites.

Abstract

The pathogenic role of Rickettsia slovaca was first demonstrated in 1997 in a patient who presented with a single inoculation lesion of the scalp and enlarged cervical lymph nodes after receiving a bite from a Dermacentor tick. Subsequently, we evaluated the occurrence of R. slovaca infections among patients living in France and Hungary who presented with these symptoms. R. slovaca infections were confirmed by polymerase chain reaction (PCR) in 17 of 67 enrolled patients. Infections were most likely to occur in patients aged <10 years and in patients who were bitten during the colder months of the year. The median duration of incubation for the disease was 7 days. Fever was present in only 2 patients, and only 1 patient developed a rash. Sequelae included persistent asthenia (3 cases) and localized alopecia (4 cases). Immunofluorescence and/or Western blot analysis detected antibodies in 50% of tested patients. Three Dermacentor ticks obtained from patients revealed R. slovaca by PCR.