Malaria Vectors in the Municipality of Serra do Navio, State of Amapá, Amazon Region, Brazil

Seção de Parasitologia, Instituto Evandro Chagas, Funasa, Belém, PA, 66090-000, Brasil.
Memórias do Instituto Oswaldo Cruz (Impact Factor: 1.59). 03/2001; 96(2):179-84. DOI: 10.1590/S0074-02762001000200008
Source: PubMed


We conducted a survey to determine the vectors of malaria in six localities of Serra do Navio municipality, State of Amapá, from 1990 to 1991. Malaria infection rates of 29.3%, 6.2% and 20.4% were detected by human blood smears in Colônia Agua Branca, Porto Terezinha and Arrependido, respectively. There was no malaria infection detected in Serra do Navio. Fifteen species were identified among 3,053 anopheline mosquitoes collected by human bait and 64.4% were identified as Anopheles albitarsis s.l., 16.7% An. braziliensis, 9.5% An. nuneztovari and 5.8% An. triannulatus. An. darlingi, the main vector of malaria in the Amazon region of Brazil, was scare. Using enzyme-linked immunosorbent assay (ELISA), a total positive rate of 0.8% (23/2876) was found for six species: fifteen An. albitarsis s.l., four An. nuneztovari, and one of each: An. braziliensis, An. triannulatus, An. oswaldoi and An. rangeli. Nine of 23 positive mosquitoes were infected with Plasmodium malariae, eight with P. vivax VK210, three with P. vivax VK247 and three with P. falciparum. Since An. albitarsis s.l. was collected feeding on humans, was present in the highest density and was positive by ELISA for malaria sporozoites, it probably plays an important role in malaria transmission in this area.

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Available from: David Charles Warhurst, Jul 03, 2014
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    • "Amazonian Anopheles species such as, Anopheles deaneorum, An. marajoara, Anopheles mattogrossensis, An. nuneztovari, Anopheles oswaldoi, Anopheles rondoni and An. triannulatus have been considered " naturally infected " with Plasmodium since they were captured with parasites in their blood meal (Galvão et al. 1942, Deane et al. 1948, de Arruda et al. 1986, Klein et al. 1991b, Branquinho et al. 1993, Tadei & Dutary 2000, Póvoa et al. 2001, 2003, 2006, da Silva-Vasconcelos et al. 2002, da Silva et al. 2006a, Galardo et al. 2007, da Rocha et al. 2008, Santos et al. 2009). However, their role as malaria vectors is not well defined. "
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    ABSTRACT: In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.
    Memórias do Instituto Oswaldo Cruz 02/2015; DOI:10.1590/0074-02760140266 · 1.59 Impact Factor
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    • "A. nuneztovari sensu stricto, which is geographically distributed in Colombia and Venezuela, is predominantly anthropophagic and has proven to be an efficient human malaria vector (Gabaldón, 1981). A. goeldii, which is geographically distributed in the Amazon Basin comprising the Brazilian Amazon and Suriname, has been found to be infected with 3 Plasmodium species in 5 states of the Brazilian Amazon region (de Arruda et al., 1986; Tadei et al., 1998; Póvoa et al., 2001; Galardo et al., 2007). Although the status of A. goeldii as a malaria vector has not yet been clarified in the Brazilian Amazon region because it is predominantly zoophagic, it is likely to be a local malaria vector or a secondary vector (which can contribute to malaria transmission, but cannot sustain it without the presence of a primary vector). "
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    ABSTRACT: Anopheles nuneztovari sensu lato consists of cryptic species and genetic lineages, one of which is an important human malaria vector in the northern part of South America. Population structure and evolutionary genetics studies may help in the definition and delimitation of the species and lineages within this species complex, which is relevant information for organizations involved in malaria control efforts. In this study, 10 new microsatellite markers were isolated from 2 repeat-enriched genomic libraries of A. nuneztovari s.l. and were characterized in 37-48 mosquitoes of this species. All loci were highly polymorphic and encompassed 5-25 alleles per locus. The observed (HO) and expected (HE) heterozygosities ranged from 0.354 to 0.866 and from 0.613 to 0.932, respectively. Six of the 10 new loci showed significant deviations from the Hardy-Weinberg equilibrium, and no linkage disequilibrium was detected. The loci described in this study were more polymorphic than the 18 previously characterized loci and appear to be promising markers for use in investigating the fine-scale population genetic structure and the boundaries of the cryptic species and lineages within the A. nuneztovari complex.
    Genetics and molecular research: GMR 11/2014; 13(4):8856-61. DOI:10.4238/2014.October.27.26 · 0.78 Impact Factor
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    • "In sites around Manaus, Brazil, An. darlingi is known to be strongly anthropophilic and endophilic, and population of this species occurs through the year. Anopheles albitarsis s.l. was shown to be a very susceptible species to P. vivax, and these results agree with results obtained in other Brazilian Amazonian states of Roraima, Pará, Amapá and Rondônia [15,16,19,70]. However, Klein and collaborators considered An. "
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    ABSTRACT: Anopheles darlingi is the major malaria vector in countries located in the Amazon region. Anopheles aquasalis and Anopheles albitarsis s.l. are also proven vectors in this region. Anopheles nuneztovari s.l. and Anopheles triannulatus s.l. were found infected with Plasmodium vivax; however, their status as vectors is not yet well defined. Knowledge of susceptibility of Amazon anopheline populations to Plasmodium infection is necessary to better understand their vector capacity. Laboratory colonization of An. darlingi, the main Amazon vector, has proven to be difficult and presently An. aquasalis is the only available autonomous colony. Larvae of An. darlingi, An. albitarsis s.l., An. nuneztovari s.l. and An. triannulatus s.l. were collected in the field and reared until adult stage. Adults of An. aquasalis were obtained from a well-established colony. Mosquitoes were blood-fed using a membrane-feeding device containing infected blood from malarial patients.The infection of the distinct Anopheles species was evaluated by the impact variance of the following parameters: (a) parasitaemia density; (b) blood serum inactivation of the infective bloodmeal; (c) influence of gametocyte number on infection rates and number of oocysts. The goal of this work was to compare the susceptibility to P. vivax of four field-collected Anopheles species with colonized An. aquasalis. All Anopheles species tested were susceptible to P. vivax infection, nevertheless the proportion of infected mosquitoes and the infection intensity measured by oocyst number varied significantly among species. Inactivation of the blood serum prior to mosquito feeding increased infection rates in An. darlingi and An. triannulatus s.l., but was diminished in An. albitarsis s.l. and An. aquasalis. There was a positive correlation between gametocyte density and the infection rate in all tests (Z = -8.37; p < 0.001) but varied among the mosquito species. Anopheles albitarsis s.l., An. aquasalis and An. nuneztovari s.l. had higher infection rates than An. darlingi. All field-collected Anopheles species, as well as colonized An. aquasalis are susceptible to experimental P. vivax infections by membrane feeding assays. Anopheles darlingi, An. albitarsis s.l. and An. aquasalis are very susceptible to P. vivax infection. However, colonized An. aquasalis mosquitoes showed the higher infection intensity represented by infection rate and oocyst numbers. This study is the first to characterize experimental development of Plasmodium infections in Amazon Anopheles vectors and also to endorse that P. vivax infection of colonized An. aquasalis is a feasible laboratory model.
    Malaria Journal 12/2013; 12(1):460. DOI:10.1186/1475-2875-12-460 · 3.11 Impact Factor
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