Spotted fever rickettsiosis caused by Rickettsia raoultii--case report

We report the case of rickettsial eschar-associated spotted fever, most probable due to Rickettsia raoultii, an emerging pathogen, which was previously described in patients with tick-borne lymphadenopathy (TIBOLA), also called Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL). The pathogenicity of R. raoultii is not well established. The survey of ticks from Poland (Ixodes ricinus and Dermacentor reticulatus) revealed that R. raoultii occur in all regions of Poland and predominate over other rickettsiae of spotted fever group--R. slovaca and R. helvetica. A 17-year-old otherwise healthy girl was admitted to Department of Zoonotic and Tropical Diseases because of fever, eschar and rash. Multiple disseminated small lesions were present on the skin of her head, trunk and limbs, also palms and soles, and mucosa of her lips. The majority of them had necrotic center slightly elevated with redness around, single ones had vesicular appearance. The lymph nodes on the right side of her neck were enlarged. Laboratory investigations revealed: leukopenia (with 22% of bands in differential), thromocytopenia, slightly elevated C-Reactive Protein, as well as procalcytonin. The quick improvement was observed with a treatment with ceftriaxone and doxycycline. Two weeks after the onset of disease, IgG serum antibodies titer of 128 reacting with R. rickettsii antigen only was detected. IFA tests with six SFG rickettsial species demonstrated the strongest reaction with R. raoultii group antigens in a titer of 64. The case we report, resembling boutonneuse fever, with leukopenia, thrombocytopenia and septic parameters indicates possible higher virulence of R. raoultii than it was previously observed.