Rickettsia rickettsii em Amblyomma sculptum Berlese, 1888 (Ixodida: Ixodidae) em área de transição entre o bioma Cerrado e Mata Atlântica, endêmica para febre maculosa, no sudeste do Brasil

Abstract

Spotted Fever is an acute infectious disease caused by bacteria of the genus Rickettsia and transmitted by the bite of infected ticks. Not transmitted from person to person, being accidental human hosts within the ecoepidemiological chain. The evolution of the disease can occur asymptomatically, discrete symptomatology to severe forms with a high lethality rate. The present study aims to elucidate the epidemiology of the disease in the municipality of Divinópolis, Minas Gerais, Brazil, which has an occurrence of the disease, including death. Predisposing areas (presence of humans, vertebrate hosts and positive ticks) and transmission areas (confirmed SF cases) were analyzed. Four areas were selected for collect, two for transmission and two predisposed, all belonging to the transition spot between Cerrado and Atlantic Forest. A total of 5.706 ticks were collected with a well defined seasonal pattern, with a higher incidence of larvae in autumn and winter, nymphs in spring and adults in summer. Specimens were identified through specific dichotomous keys and through molecular biology, all of them being Amblyomma sculptum. Aliquots were assigned to molecular assays for the detection of Rickettsia spp. resulting in a female positive for Rickettsia rickettsii for the genes gltA (genus Rickettsia) and ompA (Spotted Fever Group), a fact that was demonstrated for the first time in said municipality. Reinforcing the importance of further epidemiological surveillance studies and attention in these areas.