The dominant Anopheles vectors of human malaria in the Americas: occurrence data, distribution maps and bionomic précis

Abstract

BackgroundAn increasing knowledge of the global risk of malaria shows that the nations of the Americas have the lowest levels of Plasmodium falciparum and P. vivax endemicity worldwide, sustained, in part, by substantive integrated vector control. To help maintain and better target these efforts, knowledge of the contemporary distribution of each of the dominant vector species (DVS) of human malaria is needed, alongside a comprehensive understanding of the ecology and behaviour of each species.ResultsA database of contemporary occurrence data for 41 of the DVS of human malaria was compiled from intensive searches of the formal and informal literature. The results for the nine DVS of the Americas are described in detail here. Nearly 6000 occurrence records were gathered from 25 countries in the region and were complemented by a synthesis of published expert opinion range maps, refined further by a technical advisory group of medical entomologists. A suite of environmental and climate variables of suspected relevance to anopheline ecology were also compiled from open access sources. These three sets of data were then combined to produce predictive species range maps using the Boosted Regression Tree method. The predicted geographic extent for each of the following species (or species complex*) are provided: Anopheles (Nyssorhynchus) albimanus Wiedemann, 1820, An. (Nys.) albitarsis*, An. (Nys.) aquasalis Curry, 1932, An. (Nys.) darlingi Root, 1926, An. (Anopheles) freeborni Aitken, 1939, An. (Nys.) marajoara Galvão & Damasceno, 1942, An. (Nys.) nuneztovari*, An. (Ano.) pseudopunctipennis* and An. (Ano.) quadrimaculatus Say, 1824. A bionomics review summarising ecology and behaviour relevant to the control of each of these species was also compiled.ConclusionsThe distribution maps and bionomics review should both be considered as a starting point in an ongoing process of (i) describing the distributions of these DVS (since the opportunistic sample of occurrence data assembled can be substantially improved) and (ii) documenting their contemporary bionomics (since intervention and control pressures can act to modify behavioural traits). This is the first in a series of three articles describing the distribution of the 41 global DVS worldwide. The remaining two publications will describe those vectors found in (i) Africa, Europe and the Middle East and (ii) in Asia. All geographic distribution maps are being made available in the public domain according to the open access principles of the Malaria Atlas Project.

Investigation of a Sudden Malaria Outbreak in the Isolated Amazonian Village of Saül, French Guiana, January–April 2009

“…nuneztovari, which are putative malaria vectors in the Amazonian region. 21,22 Therefore, promotion of efficient low cost topical repellents should be encouraged in the future in the context of Saü l and, on a larger scale, in all areas where populations live next to gold mining activities.…”

Mapping a Knowledge-Based Malaria Hazard Index Related to Landscape Using Remote Sensing: Application to the Cross-Border Area between French Guiana and Brazil

“…Malaria risk mapping is traditionally obtained through various statistical techniques and datadriven modeling [5,12,13,16,[21][22][23][24][25][26]. Such models are often either very specific or very general, as they are generated from data characterizing either local scale contexts at high resolutions, preventing obtaining reproducible results and to describe or predict large scale phenomena [23], or large scale contexts at low resolutions, preventing the ability to precisely describe disease transmission mechanisms [5,12,16].…”

“…Such models are often either very specific or very general, as they are generated from data characterizing either local scale contexts at high resolutions, preventing obtaining reproducible results and to describe or predict large scale phenomena [23], or large scale contexts at low resolutions, preventing the ability to precisely describe disease transmission mechanisms [5,12,16]. Moreover, the necessary data are often incomplete and highly biased and, consequently, insufficient quantitatively and qualitatively for data-driven approaches [27,28], especially in these remote areas where epidemiological, entomological, and environmental Anopheles darlingi is considered as the principal vector of malaria in the Amazon region [5]. This species plays an evident role in malaria transmission in the Amapá State and in French Guiana, even if other species could be involved locally [6][7][8].…”

“…Identifying, characterizing, and mapping malaria risk factors are of primary importance in order to better target control strategies and anticipate possible recrudescence of malaria due to environmental and socio-demographic changes and to the development of possible drug and insecticide resistance [4]. Anopheles darlingi is considered as the principal vector of malaria in the Amazon region [5]. This species plays an evident role in malaria transmission in the Amapá State and in French Guiana, even if other species could be involved locally [6][7][8].…”

Mosquito vectors of ape malarias: Another piece of the puzzle

“…Some anopheline mosquitoes like Anopheles gambiae are highly anthropophilic, preferring to feed on humans rather than on other animals, whereas others like Anopheles albimanus are more zoophilic, preferring to feed on animals over humans (8). However, host preference is not absolute: An.…”