Spotless Rickettsiosis Caused byRickettsia slovacaand Associated withDermacentorTicks

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.

Characterization of Spotted Fever Group Rickettsiae in Flea and Tick Specimens from Northern Peru

“…The patients seen during our study experienced a mild disease typified by fever and headache, often malaise, and less frequently, a stiff neck and joint pain (7). No eschar was reported, and unlike previously reported cases of "spotless" rickettsiosis (for instance, following R. slovaca infection [36]), all our patients exhibited fever. The symptoms resolved upon treatment with doxycycline for 1 week.…”

Update on tick-borne bacterial diseases in Europe

“…This bacterium was isolated in 1968 from D. marginatus ticks in Czechoslovakia. In 1997, R. slovaca was described as a human pathogen and the agent of tick-borne lymphadenopathy (TIBOLA), also known as Dermacentor-borne necrotic erythema and lymphadenopathy (DEBONEL), which is defined as the association of a tick bite, an inoculation eschar on the scalp, and cervical lymphadenopathies (Raoult et al, 2002b (Mediannikov et al, 2008). R. raoultii was detected in ticks collected from several European countries: France, Russia, Poland, Slovakia, Spain, Portugal, Germany, Croatia and the Netherlands (Dobler & Wolfel, 2009;Ibarra et al, 2005;Matsumoto et al, 2009;Vitorino et al, 2007;Nijhof et al, 2007;Mediannikov et al, 2008).…”

Rickettsia slovacaInfection, France

“…conorii has long been considered to be the only SFG rickettsiosis but R . slovaca may also be prevalent ( 9 ), contributing 25% of the cases in the present study. This organism is also a common cause of disease in Hungary and in La Rioja, Spain ( 3 ).…”

“…This organism is also a common cause of disease in Hungary and in La Rioja, Spain ( 3 ). These data suggest that TIBOLA mainly occurs in young children, affects women predominately, and occurs primarily during the colder months ( 9 , 10 ). As previously reported ( 9 ), we found that standard microimmunofluorescence serologic testing was insensitive and that Western blot is more useful and allows identification to the species level after cross-adsorption studies.…”

“…These data suggest that TIBOLA mainly occurs in young children, affects women predominately, and occurs primarily during the colder months ( 9 , 10 ). As previously reported ( 9 ), we found that standard microimmunofluorescence serologic testing was insensitive and that Western blot is more useful and allows identification to the species level after cross-adsorption studies. Finally, DNA amplification by PCR from skin biopsy tissue, serum samples, or in ticks allowed confirmation of the diagnosis in only 50% of the cases, which suggests that other rickettsial species may be responsible for TIBOLA.…”