The riverine communities of the Amazon comprise different social groups that inhabit the rural areas on the banks of rivers and lakes. Residents usually travel by river to rural and urban areas and are then exposed to urbanized diseases such as those caused by arbovirus infection. In Brazil, emerging diseases such as dengue, Zika, chikungunya, and those caused by infection with Oropouche and Mayaro viruses necessitate epidemiological surveillance. This study was aimed at determining the frequency of positivity for immunoglobulin (Ig)G and IgM antibodies against Zika, chikungunya, and dengue viruses and performing molecular analyses to detect viral RNA for the Zika, chikungunya, dengue virus, Oropouche, and Mayaro viruses, in the same serum samples obtained from riverside populations.

Bats (Chiroptera) are among the most diverse and geographically dispersed mammals. They are of great importance to the ecosystem, as pollinators, seed dispersers and pest controllers, in addition to being hosts to several parasitic arthropods, including ticks, mites, lice, fleas and flies. Their diet includes the tissue and blood or other body fluids of bats. Bats are reservoirs of several disease-causing agents, many of them pathogenic to humans, such as bacteria, as well as protozoa, viruses and fungi. This study was conducted in Monte Negro, Rondônia, Brazil and the occurrence of parasitic arthropods in bats was evaluated, as well as a screening of bacteria that these ectoparasites can carry. Through a total of 69 nocturnal captures, 217 chiropterans were sampled, representing 23 species and six families. A total of 592 specimens of parasitic arthropods (ticks, mites and flies) were collected from these bats (9% dipterans, 59% ticks and 32% mites). Bartonella spp. were found in two species of bat flies (Trichobius joblingi and Strebla mirabilis) in peri-urban and forest areas with an infection rate of 62% and 38%, respectively. We report for the first time in Rondônia the argasid tick Ornithodoros hasei and its infection by a spotted fever group bacterium ‘Candidatus Rickettsia wissemanii’ in a peri-urban area.

The mite genus Parichoronyssus Radovsky (Mesostigmata: Macronyssidae) comprises twelve known species found parasitizing bats in the New World. This study aimed to identify morphologically and molecularly macronyssid mites collected from bats and kept as backlog in the tissue bank (-80C) at the Acarological Collection of the Butantan Institute (IBSP). After the examination, the material was listed and identified as Parichoronyssus bakeri Morales-Malacara and Guerrero. Here, we were able to provide diagnostic microscopic images for the females of this species, as well as molecular information (18S rRNA and 16S rRNA) that were deposited in Genbank for reference. New locality records were also provided for P. bakeri in Rio de Janeiro and Rondônia States, Brazil.