Evaluation of alternative mosquito sampling methods for malaria vectors in Lowland South - East Zambia.

Sampling malaria vectors and measuring their biting density is of paramount importance for entomological surveys of malaria transmission. Human landing catch (HLC) has been traditionally regarded as a gold standard method for surveying human exposure to mosquito bites. However, due to the risk of human participant exposure to mosquito-borne parasites and viruses, a variety of alternative, exposure-free trapping methods were compared in lowland, south-east Zambia. Centres for Disease Control and Prevention miniature light trap (CDC-LT), Ifakara Tent Trap model C (ITT-C), resting boxes (RB) and window exit traps (WET) were all compared with HLC using a 3 × 3 Latin Squares design replicated in 4 blocks of 3 houses with long lasting insecticidal nets, half of which were also sprayed with a residual deltamethrin formulation, which was repeated for 10 rounds of 3 nights of rotation each during both the dry and wet seasons. The mean catches of HLC indoor, HLC outdoor, CDC-LT, ITT-C, WET, RB indoor and RB outdoor, were 1.687, 1.004, 3.267, 0.088, 0.004, 0.000 and 0.008 for Anopheles quadriannulatus Theobald respectively, and 7.287, 6.784, 10.958, 5.875, 0.296, 0.158 and 0.458, for An. funestus Giles, respectively. Indoor CDC-LT was more efficient in sampling An. quadriannulatus and An. funestus than HLC indoor (Relative rate [95% Confidence Interval] = 1.873 [1.653, 2.122] and 1.532 [1.441, 1.628], respectively, P < 0.001 for both). ITT-C was the only other alternative which had comparable sensitivity (RR = 0.821 [0.765, 0.881], P < 0.001), relative to HLC indoor other than CDC-LT for sampling An. funestus. While the two most sensitive exposure-free techniques primarily capture host-seeking mosquitoes, both have substantial disadvantages for routine community-based surveillance applications: the CDC-LT requires regular recharging of batteries while the bulkiness of ITT-C makes it difficult to move between sampling locations. RB placed indoors or outdoors and WET had consistently poor sensitivity so it may be useful to evaluate additional alternative methods, such as pyrethrum spray catches and back packer aspirators, for catching resting mosquitoes

Phenetic studies on randomly amplified polymorphic DNA-polymerase chain reaction-variability of four geographical populations of Lutzomyia whitmani (Diptera: Psychodidae) in Brazil Estudos fenéticos de variabilidade de polimorfismos de DNA amplificados ao acaso pela reação em cadeia da polimerase em quatro populações geográficas de Lutzomyia whitmani (Diptera: Psychodidade) no Brasil

Previous evaluation of the genetic variability of four biogeographical populations of Lutzomyia whitmani from known foci of cutaneous leishmaniasis in Brazil demonstrated two main spatial clusters: Corte de Pedra-BA, Ilhéus-BA and Serra de Baturité-CE in the first cluster, and Martinho Campos-MG in the second. Further analysis showed a high degree of homogeneity in Corte de Pedra population but not in the others, which presented a significant percentage of specimens displaced from their phenon of origin (discrepant individuals). In the present work we analyzed the frequencies of association coefficients in the matrixes of similarity per population of Lutzomyia whitmani from both sexes and the general phenograms obtained, in a more detailed study of those discrepant specimens. Populational stability was observed for Corte de Pedra population, whereas the three remaining populations showed varying degrees of heterogeneity and different displacements according to sex. Our results strongly suggested the existence of a genetic flow between the lineages North-South/North-East and Ilhéus/Serra do Baturité of Lutzomyia whitmani.<br>Uma avaliação prévia da variabilidade genética de quatro populações biogeográficas de Lutzomyia whitmani oriundas de focus conhecidos de leishmaniose cutânea no Brasil, evidenciou 2 agrupamentos espaciais principais: Corte de Pedra (BA), Ilhéus (BA) e Serra de Baturité (CE) no primeiro grupo, e Martinho Campos (MG) em um segundo. O aprofundamento da análise acusou um alto grau de homogeneidade na população de Corte de Pedra mas não nas outras, nas quais uma porcentagem significativa de espécimens deslocou-se do seu feno de origem (indivíduos discrepantes). Neste trabalho analisamos as freqüências dos coeficientes de associação nas matrizes de similaridade por população de Lutzomyia whitmani, de ambos os sexos, e o fenograma geral obtido, em um estudo mais detalhado daqueles espécimens discrepantes. Para Corte de Pedra foi observada estabilidade populacional, enquanto as outras três populações restantes mostraram graus de heterogeneidade variáveis e deslocamentos distintos, de acordo com o sexo dos indivíduos. Nossos resultados sugerem fortemente a existência de um fluxo genético entre as linhagens Norte-Sul/Norte-Leste e Ilhéus/Serra do Baturité de Lutzomyia whitmani