Comparison of Black Fly Species (Diptera: Simuliidae) on an Amerindian Reservation with a High Prevalence of Fogo Selvagem to Neighboring Disease-Free Sites in the State of Mato Grosso do Sul, Brazil

Abstract

Fogo selvagem is an autoimmune blistering skin disease that principally occurs among rural Brazilians living in geographically clumped disease foci. Exposure to hematophagous black flies possibly is related to the cause of the disease. We compared the occurrence, proportions, and richness of simuliid species immatures and the biting activity of adult females within a recently discovered, high prevalence focus of fogo selvagem, the Limão Verde Terena Reservation, to that of neighboring regions with no reported cases of fogo selvagem. Nine black fly species were collected from 12 stream sites during 5 trips to the fogo selvagem focus. The species showed longitudinal (upstream-downstream) trends in occurrence, proportions, and richness, and the abundance of simuliid immatures was greater at downstream sites. The most prevalent species at the focus, Simulium nigrimanum (Macquart), dominated the stream sites with highly abundant simuliid assemblages, and was the most common black fly in human bait collections. This species was absent or in very low numbers in neighboring valleys and villages that did not have cases of fogo selvagem.

Programmed cell death 1 gene (PDCD1) polymorphism and pemphigus foliaceus (fogo selvagem) disease susceptibility

“…Inhibitory signals produced by the PD-1/PD-L pathway are of crucial relevance to the mechanisms maintaining tolerance and to terminate immune response in peripheral tissues, thus limiting organ damage (Freeman et al, 2000;Latchman et al, 2001;). The causes of initiation and perpetuation of the auto-aggressive responses in pemphigus foliaceus patients are largely unknown, although there is consensus about the influence of both genetic and environmental factors on susceptibility to this condition (Eaton et al, 1998;Petzl-Erler and Santamaria, 1989). The pathogenic concepts include defects in the maintenance of peripheral immune tolerance towards potential autoantigens (Coyle and Gutierrez-Ramos, 2001).…”

Checklist de Simuliidae (Insecta, Diptera) do Estado do Mato Grosso do Sul, Brasil

“…Todos os pontos foram amostrados apenas uma vez, e os espécimes coletados manualmente em um trecho de 100 metros de cada corpo d'água. A segunda fonte de informação foi a consulta de trabalhos publicados (Eaton et al, 1998;Hamada & Adler, 1999;Coscarón & Coscarón-Arias, 2007;Adler & Crosskey, 2015). Dada a importância de disponibilizar informações sobre a distribuição das espécies, foram incluídas no checklist todas as localidades de ocorrência dentro do estado.…”

“…De acordo com Adler & Crosskey (2015) existem atualmente 2.177 espécies de Simuliidae válidas (incluindo 12 fósseis) das quais aproximadamente 360 são encontradas na Região Neotropical (Currie & Adler, 2008), sendo 92 (Adler & Crosskey, 2015;Hamada et al, 2015) (Eaton et al, 1998;Adler & Crosskey, 2015).…”

Profile of Trypanosoma cruzi Reactivity in a Population at High Risk for Endemic Pemphigus Foliaceus (Fogo Selvagem)

“…16 It is hypothesized that a break of immune tolerance follows exposure to some environmental factor(s) that include hematophagous insect bites, as reported elsewhere. 16,23,24 The potential role of black fly triggering the autoimmune response in FS is supported by two main studies: exposure to simuliid bites as a risk factor for FS (4.7 odds ratio), 23 and the predominance of a certain black fly species (Simulium nigrimanum) in endemic areas, when compared with non-endemic areas of the Brazilian coast. 24 Additional data on the environment triggers is suggested by Aoki and others, 16 who reported a high frequency of black fly (87%), kissing bugs (67%), and bed bugs (60%) bites in FS patients, and showed that precarious living conditions represented a significant risk factor for FS.…”