Distribution and diversity of mosquitoes and Oropouche-like virus infection rates in an Amazonian rural settlement

Jordam William Pereira-Silva,Eric Fabrício Marialva Dos Santos,Heliana Christy Matos Belchior,Felipe Arley Costa Pessoa,Claudia María Ríos-Velásquez,Felipe Gomes Naveca,Sergio Luiz Bessa Luz,Gervilane Ribeiro De Lima,Luzia Helena Carvalho

doi:10.1371/journal.pone.0246932

Abstract

Mosquito diversity and disease transmission are influenced by landscape modifications, i.e., vectors and pathogens previously found only in forests are now found close to human environments due to anthropic changes. This study determined the diversity and distribution of mosquitoes in forest environments in order to analyze the potential vectors of Amazonian forest arboviruses. Mosquitoes were collected by 1) vertical stratification from forest canopy and ground areas using Hooper Pugedo (HP) light traps and human attraction and 2) horizontal stratification using HP light traps in peridomicile, forest edge, and forest environments near the Rio Pardo rural settlement, Amazonas, Brazil. A total of 3,750 mosquitoes were collected, representing 46 species. 3,139 individuals representing 46 species were sampled by vertical stratification. Both the Shannon-Weaver diversity index (H’) and equitability (J’) were higher in the canopy than on the ground. 611 individuals representing 13 species were sampled by horizontal stratification. H’ decreased in the following order: forest edge > forest > peridomicile, and J’ was greater at the forest edge and smaller in the peridomicile environment. Moreover, H’ was higher for the human attraction collection method than the HP traps. A total of 671 pools were analyzed by RT-qPCR; three species were positive for Oropouche-like viruses (Ochlerotatus serratus, Psorophora cingulata, and Haemagogus tropicalis) and the minimum infection rate was 0.8%. The composition of mosquito species did not differ significantly between anthropic and forest environments in Rio Pardo. Some mosquito species, due to their abundance, dispersion in the three environments, and record of natural infection, were hypothesized to participate in the arbovirus transmission cycle in this Amazonian rural settlement.

Highlights

Mosquitoes are medically and veterinary important insects because they transmit arboviruses, protozoa, helminths, and other pathogens that impact public health [1]
In the Amazon region, mosquito species are diverse and the relationship between mosquito diversity and disease transmission is influenced by landscape changes related to deforestation, road construction, establishment of settlements, diversification of production activities related to family farming, and unplanned dwellings [2]
Oc. serratus is naturally infected with OROV, an arbovirus typically found in rural areas of the Amazon [52]

Summary

Introduction

Mosquitoes are medically and veterinary important insects because they transmit arboviruses, protozoa, helminths, and other pathogens that impact public health [1]. The definition of risk areas for infected vector exposure has increased considerably [6] because mosquito distribution is affected by environmental characteristics that favor changes in climate and landscape [4]. These modifications might induce favorable conditions for disease spread (e.g. increase human-mosquito contact rates, increased environmental suitability for the mosquito vector and reservoir hosts) [7]. Knowledge of mosquito fauna as well as evidence of natural infection are important for the design of vector control strategies to avoid or control disease outbreaks

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Conclusion