Sand fly population dynamics and cutaneous leishmaniasis among soldiers in an Atlantic forest remnant in northeastern Brazil.

Filipe Dantas-Torres,Luciana Aguiar Figueredo,Maria Sandra Andrade,Kamila Gaudêncio Da Silva Sales,Maria Edileuza Felinto De Brito,Fábio Lopes De Melo,Débora Elienai De Oliveira Miranda,Fernando José Da Silva,Sinval Pinto Brandão-Filho,Philippe Solano

doi:10.1371/journal.pntd.0005406

Filipe Dantas-Torres, Luciana Aguiar Figueredo + Show 8 more

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https://doi.org/10.1371/journal.pntd.0005406

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Abstract

Outbreaks of cutaneous leishmaniasis are relatively common among soldiers involved in nocturnal activities in tropical forests. We investigated the population dynamics of sand flies in a military training camp located in a remnant of Atlantic rainforest in northeastern Brazil, where outbreaks of cutaneous leishmaniasis have sporadically been described. From July 2012 to July 2014, light traps were monthly placed in 10 collection sites, being nine sites located near the forest edge and one near a sheep and goat stable. Light traps operated from 5:00 pm to 6:00 am, during four consecutive nights. Leishmania infection in sand flies was assessed using a fast real-time PCR assay. Cases of cutaneous leishmaniasis among soldiers were also investigated. In total, 24,606 sand flies belonging to 25 species were identified. Males (n = 12,683) predominated over females (n = 11,923). Sand flies were present during all months, being more numerous in March (n = 1,691) and April 2013 (n = 3,324). Lutzomyia choti (72.9%) was the most abundant species, followed by Lutzomyia longispina (13.8%), Lutzomyia complexa (5.3%), representing together >90% of the sand flies collected. Forty cases of cutaneous leishmaniasis were recorded among soldiers from January 2012 to December 2014. Leishmania isolates were obtained from eight patients and were all characterized as Leishmania braziliensis. Soldiers and anyone overnighting in Atlantic rainforest remnants should adopt preventative measures such as the use of repellents on bare skin or clothes and insecticide-treated tents.

Highlights

Cutaneous leishmaniasis is a neglected tropical disease highly prevalent in Central and South America
We investigated the population dynamics of sand flies in a military training camp located in a remnant of Atlantic rainforest in northeastern Brazil, where outbreaks of cutaneous leishmaniasis have sporadically been described
Our results suggest that the risk of cutaneous leishmaniasis by Leishmania braziliensis in Atlantic rainforest remnants is permanent and not dictated by sand fly population peaks

Summary

Introduction

Cutaneous leishmaniasis is a neglected tropical disease highly prevalent in Central and South America. Brazil, Costa Rica and Peru are among the 10 countries accounting for 70– 75% of the global estimated cutaneous leishmaniasis incidence [1]. The disease is widespread in this country occurring mainly in rural areas and forest environments, affecting mainly individuals older than 10 years and males [1, 2]. While widespread in Brazil, cutaneous leishmaniasis is more prevalent in the Amazon forest and Atlantic forest regions [1]. The largest cities (e.g., Rio de Janeiro and São Paulo) and industries in the country are located in the Atlantic forest region, which houses 70% of the Brazilians and accounts for about 80% of its gross domestic product. The Atlantic forest biome is still home to about 2,000 species of animals and 20,000 species of plants; a biological diversity similar to that found in the Amazon region (http://www.nature.org/ourinitiatives/regions/southamerica/brazil/placesweprotect/atlanticforest.xml)

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