Research Letters

A new tick-transmitted disease due to Rickettsia slovaca

A three year-old girl was admitted to our university hospital with fever, muscle and abdominal pain, and painful cervical lymph nodes after a tick bite on scalp. Rickettsia slovaca DNA was detected in eschar tissue taken from the bite site. This is the first clinical case of a R. slovaca infection reported from Turkey.

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  El diagnóstico del TIBOLA se realiza a partir de las características clínicas y epidemiológicas.

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  El cuadro clínico, con un período de incubación de 4 a 7 días tras la picadura de la garrapata en la zona de la cabeza o parte superior del cuerpo, presenta lesión dérmica con una escara amarillenta o melicérica que posteriormente se oscurece por la necrosis, con un eritema alrededor, asociada a múltiples adenopatías bastante dolorosas, con cefalea, decaimiento y, en aproximadamente el 50% de los casos, fiebre. Otras veces puede darse edema facial y periorbitario bilateral, eritema maculopapular en tronco y alopecia residual en la zona de la picadura.

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  A nivel epidemiológico, esta garrapata se presenta fundamentalmente en los meses fríos del año. Vive en mamíferos de pelo largo (vacas, jabalíes, cabras y ovejas). Tiene predilección por los pelos largos y afecta siempre a la parte superior del cuerpo.

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  Se ha demostrado el tratamiento eficaz de esta patología con pautas de doxiciclina en niños mayores de 8 años y adultos, y con azitromicina y eritromicina en niños menores de 8 años. Pueden persistir los síntomas hasta 18 meses en ausencia de tratamiento.

Antimicrobial photodynamic therapy uses a nontoxic photosensitizer with the assistance of harmless visible light to activate the photosensitizer. Consequently, the excited state of the photosensitizer interacts with molecular oxygen to produce reactive oxygen species, which have the antimicrobial effect. In this study, we evaluated the effect of photodynamic therapy on Vero cells infected with rickettsia using methylene blue as a photosensitizer along with red light. A significant reduction (by 96%) in the number of viable Rickettsia slovaca was determined by quantitative RT-PCR 48 h after the treatment with methylene blue followed by 30 min of red light excitation. A statistically significant reduction of R. slovaca was also recorded with pretreatment (by 99%). To the best of our knowledge, this result is the first one in the literature to confirm the effectiveness of photodynamic therapy for the elimination of R. slovaca and to suggest this technique as a good supportive treatment for rickettsial infections.

The aims of this study were to assess the psocids that potentially carry Rickettsia and to characterize Rickettsia species. We collected booklice from dried fragments of Chinese medicinal herbs for retail. Species identification and Rickettsia detection were performed by using nondestructive DNA extraction method and PCR. Of the 224 booklice samples collected, the following species were identified: Liposcelis pearmani (50.89%), L. bostrychophila (25.89%) and L. entomophila (23.21%). Twenty-four samples were found to be positive for Rickettsia (10.71%, 24/224), and the number of Rickettsia-positive samples per species was as follows: L. pearmani (n = 10), L. bostrychophila (n = 8) and L. entomophila (n = 6). The phylogenetic tree revealed that the rickettsial agents found in booklice cluster along with Rickettsia felis belong to the spotted fever group (SFG). Mixed booklice contamination occurs in herbal fragments. The presence of Rickettsia-infected booklice suggests that there is a risk of louse-borne rickettsioses to humans in contact with herbs. These findings can contribute to the development of a disease control program that assists relevant practitioners and promotes public health.