Ticks on humans in the Pantanal wetlands, Brazil

Abstract

Information on ticks biting humans in Brazil is very restricted. In fact, many times when human tick-borne diseases are diagnosed, the involved vector tick is not identified, although this may be clinically helpful. Pantanal is one of the world's largest floodplains, has an exuberant wildlife, and is place of extensive cattle ranching, ecotourism, and fishing. We herein report tick species found on humans in a 13-month survey in a region with both cattle and wildlife handling in the Brazilian Pantanal. From February 2012 to February 2013, a total of 280 ticks was collected from humans (n=22), 121 of which were attached. Amblyomma cajennense sensu lato nymphs were the main tick species and stage found attached to humans (n=93) especially during the dry months (winter). In the wet season (summer), Amblyomma parvum adults were the main ticks found attached to humans (n=19) followed by A. cajennense s.l. adults (n=9). Only one unattached nymph of A. parvum was collected in this study. These results reinforce that A. cajennense s.l. nymphs are an important parasite of humans (and vectors) in Brazil and draw also attention to A. parvum adults as frequent human parasites as well.

Feral pigs as hosts for Amblyomma sculptum (Acari: Ixodidae) populations in the Pantanal, Mato Grosso do Sul, Brazil

“…From these, three species were shown to routinely bite humans in the southeast (Nhecolândia) region of Pantanal, namely, Amblyomma sculptum (formerly A. cajennense), A. parvum and Ornithodorus rostratus (Ramos et al 2014;Ribeiro et al 2013. Coincidently these three tick species are, in the same region, those found on feral pigs .…”

“…Coincidently these three tick species are, in the same region, those found on feral pigs . From these, A. sculptum is the most prevalent species in the environment, on wild animals and biting humans (Campos Pereira et al 2000;Ramos et al 2014).…”

“…-100 * N-total tick numbers released into the feeding chambers ** Means of a parameter followed by different letters in a row differed significantly (p \ 0.05) *** Accidental tick loss in both second infestation (adult ticks) and control infestation (nymphs) precluded comparative tick yield analysis 2007; Ramos et al 2014) and thus may bridge pathogens from feral pigs to people. Actually, a Rickettsia species of unknown pathogenicity and Coxiella burnetii, agent of the Q fever, were described from A. parvum (Pacheco et al 2007(Pacheco et al , 2013 and thus pathogen transmission to humans by this tick deserves attention.…”

In vitro efficacy of Metarhizium anisopliae sensu lato against unfed Amblyomma parvum (Acari: Ixodidae)

“…In fact, parasitism of domestic animals by A. parvum may be enhanced by the mandatory conservation of natural resources within rural properties throughout Brazil and the increased intermingling of domestic and wild animals. Importantly, A. parvum ticks, particularly adults, were shown to be aggressive to humans (Ramos et al 2014) as well as potential vectors of several pathogens. In this regard, this tick species has been found to be infected with Coxiella burnetii, Ehrlichia chaffeensis and Candidatus Rickettsia andeanae (Nieri-Bastos et al 2014;Pacheco et al 2013;Tomassone et al 2008).…”

Fauna, sazonalidade e riquetsias de carrapatos em área do Cerrado goiano

“…Veronez et al, (2010) descreveram um grande predomínio de Amblyomma sculptum (do complexo Amblyomma cajennense) na região de Cerrado em Minas Gerais. Outros trabalhos, como os de Szabó et al, (2007) e Ramos, et al, (2014b) também descreveram a presença de carrapatos no bioma cerrado, inclusive com relatos de picadas em humanos (SZABÓ, et al 2007;RAMOS, et al 2014b). Sabe-se que carrapatos são vetores de vários patógenos causadores de doenças em animais e seres humanos.…”