Susceptibility of Amblyomma sculptum, Vector of Rickettsia rickettsii, Ticks from a National Park and an Experimental Farm to Different Synthetic Acaricides.

Amblyomma sculptum is a relevant tick species from a One Health perspective, playing an important role as a vector of Rickettsia rickettsii, the main agent of spotted fever rickettsiosis in Brazil. In this study, we evaluated the susceptibility of two A. sculptum populations from Goiás state (midwestern Brazil) to different acaricides. The first tick population (GYN strain) originated from an experimental farm, where the ticks are annually exposed to acaricides. The second (PNE strain) was collected in a national park (Emas National Park), where the ticks had not been exposed to acaricides. Immersion tests were conducted with 21-day-old laboratory-reared larvae and nymphs originating from adult ticks collected in the areas mentioned above. The chosen acaricides were two synthetic pyrethroids (cypermethrin and deltamethrin), one organophosphate (chlorfenvinphos), one formamidine (amitraz), and two combinations of pyrethroids and organophosphates (cypermethrin, chlorpyrifos and citronellal; cypermethrin, fenthion and chlorpyrifos). Mortality data were used to determine the lethal concentration (LC) values at which 50%, 90%, and 99% of the ticks died (LC50, LC90, and LC99, respectively), and resistance ratios (RR) were calculated based on the LC values. The RR revealed differences between the acaricide-exposed (GYN) and unexposed (PNE) tick strains. The PNE strain larvae and nymphs were susceptible to all the tested acaricides. The GYN strain larvae were tolerant to cypermethrin, whereas the nymphs were tolerant to deltamethrin, chlorfenvinphos, and the combination of cypermethrin, chlorpyrifos, and citronellal (2 < RR ≤ 10). The GYN strain nymphs were resistant to amitraz (RR > 10). This is the first report of A. sculptum nymphs with resistance to amitraz and tolerance to deltamethrin, chlorfenvinphos, and the combination of cypermethrin, chlorpyrifos, and citronellal.

Rickettsial Infection in Ticks from a National Park in the Cerrado Biome, Midwestern Brazil.

This study was carried out from February 2020 to September 2021 in Parque Nacional das Emas (PNE), a national park located in the Cerrado biome, midwestern Brazil, as well as in surrounding rural properties. Serum and tick samples were collected from dogs, terrestrial small mammals, and humans. Ticks were also collected from the environment. Dogs were infested with Rhipicephalus linnaei adults, whereas small mammals were infested by immature stages of Amblyomma spp., Amblyomma triste, Amblyomma dubitatum, and Amblyomma coelebs. Ticks collected from vegetation belonged to several species of the genus Amblyomma, including A. coelebs, A. dubitatum, Amblyomma naponense, Amblyomma sculptum, and A. triste. Two Rickettsia species were molecularly detected in ticks: Rickettsia parkeri in A. triste from the vegetation and a Rickettsia sp. (designated Rickettsia sp. strain PNE) in A. sculptum and A. triste collected from lowland tapirs (Tapirus terrestris). Based on short gltA gene fragments, this rickettsial organism showed 99.7-100% to Rickettsia tillamookensis. Seroreactivity to Rickettsia antigens was detected in 21.9% of dogs, 15.4% of small mammals, and 23.5% of humans. The present study reveals the richness of ticks and demonstrates the circulation of rickettsial agents in one of the largest conservation units in the Cerrado biome in Brazil. To our knowledge, this is the first report of a rickettsial phylogenetically related to R. tillamookensis in Brazil.

Epidemiologia de exames e mortalidade presuntivos à infecção pelo papiloma vírus humano / Epidemiology of presumptive exams and mortality in human papilloma virus infection

A infecção pelo papiloma vírus humano (HPV) é responsável pelo aumento de morbidade e mortalidade associada ao desenvolvimento de neoplasias malignas, principalmente de colo do útero, reportando assim uma preocupação eminente em saúde pública. O diagnóstico presuntivo do câncer do aparelho reprodutor feminino é essencial para o direcionamento a testes confirmatórios, bem como ao tratamento e cura das pacientes. Assim, o presente estudo objetivou avaliar a frequência de exames presuntivos de alterações do aparelho reprodutor feminino, incluindo por HPV, bem como correlacionar com número de óbitos nos municípios de Goiás e na cidade de Mineiros-GO. Foi realizada uma avaliação retrospectiva em um período de seis anos (2009 a 2014) tendo como base os dados do Ministério da Saúde. Foram considerados para este estudo os dados de exames citopatológico cérvico- vaginal e microflora, teste anatomopatológico do colo do útero e a CID-10 (C51 a C58). Foi consultado um total de 245 municípios, e foi evidenciada uma diminuição do número de exames preventivos com o passar dos anos avaliados, bem como uma correlação positiva dos exames citopatológicos e anatomopatológicos, e correlações negativas entre os exa- mes preventivos e o número de óbitos, assim como o número de citopatológicos e o período de avaliação no município de Mineiros-GO. Contudo, os exames preventivos ao câncer de colo uterino, bem como ações voltadas à educação em saúde da mulher, podem colaborar na maximização ao combate da mortalidade feminina.