False positive circumsporozoite protein ELISA: a challenge for the estimation of the entomological inoculation rate of malaria and for vector incrimination.

Background: The entomological inoculation rate (EIR) is an important indicator in estimating malaria transmission and the impact of vector control. To assess the EIR, the enzyme-linked immunosorbent assay (ELISA) to detect the circumsporozoite protein (CSP) is increasingly used. However, several studies have reported false positive results in this ELISA.

Malaria transmission and vector behaviour in a forested malaria focus in central Vietnam and the implications for vector control.

Background: In Vietnam, malaria is becoming progressively restricted to specific foci where human and vector characteristics alter the known malaria epidemiology, urging for alternative or adapted control strategies. Long-lasting insecticidal hammocks (LLIH) were designed and introduced in Ninh Thuan province, south-central Vietnam, to control malaria in the specific context of forest malaria. An entomological study in this specific forested environment was conducted to assess the behavioural patterns of forest and village vectors and to assess the spatio-temporal risk factors of malaria transmission in the province.

Knockdown resistance in Anopheles vagus, An. sinensis, An. paraliae and An. peditaeniatus populations of the Mekong region.

Background: In the Mekong region (Vietnam, Cambodia and Laos), a large investigation was conducted to assess the susceptibility of Anopheles species against DDT and pyrethroids. In this study, the resistance status of the potential malaria vectors An. vagus, An.

Impact of insecticide-treated nets on wild pyrethroid resistant Anopheles epiroticus population from southern Vietnam tested in experimental huts.

Background: In this study, the efficacy of insecticide-treated nets was evaluated in terms of deterrence, blood-feeding inhibition, induced exophily and mortality on a wild resistant population of Anopheles epiroticus in southern Vietnam, in order to gain insight into the operational consequences of the insecticide resistance observed in this malaria vector in the Mekong delta.

Method: An experimental station, based on the model of West Africa and adapted to the behaviour of the target species, was built in southern Vietnam. The study design was adapted from the WHO phase 2 guidelines.

Absence of knockdown resistance suggests metabolic resistance in the main malaria vectors of the Mekong region.

Background: As insecticide resistance may jeopardize the successful malaria control programmes in the Mekong region, a large investigation was previously conducted in the Mekong countries to assess the susceptibility of the main malaria vectors against DDT and pyrethroid insecticides. It showed that the main vector, Anopheles epiroticus, was highly pyrethroid-resistant in the Mekong delta, whereas Anopheles minimus sensu lato was pyrethroid-resistant in northern Vietnam. Anopheles dirus sensu stricto showed possible resistance to type II pyrethroids in central Vietnam.

The insecticide resistance status of malaria vectors in the Mekong region.

Background: Knowledge on insecticide resistance in target species is a basic requirement to guide insecticide use in malaria control programmes. Malaria transmission in the Mekong region is mainly concentrated in forested areas along the country borders, so that decisions on insecticide use should ideally be made at regional level. Consequently, cross-country monitoring of insecticide resistance is indispensable to acquire comparable baseline data on insecticide resistance.

Distribution of Anopheles in Vietnam, with particular attention to malaria vectors of the Anopheles minimus complex.

Background: The distribution of anopheline mosquitoes in Vietnam was examined, with a particular interest for the two sibling species of the Anopheles minimus complex (Cellia: Myzomyia), An. minimus and Anopheles harrisoni, respectively former species A and C. Because the morphological identification of both sibling species is difficult and may lead to misidentifications, accurate data on their respective distribution are missing.

Polymerase chain reaction identification of three members of the Anopheles sundaicus (Diptera: Culicidae) complex, malaria vectors in Southeast Asia.

Anopheles sundaicus s.l., a major malaria vector taxon, occurs primarily along coastal areas and on islands in Southeast Asia.

Genetic diversity and molecular identification of mosquito species in the Anopheles maculatus group using the ITS2 region of rDNA.

The species diversity and genetic structure of mosquitoes belonging to the Anopheles maculatus group in Southeast Asia were investigated using the internal transcribed spacer 2 (ITS2) of ribosomal DNA (rDNA). A molecular phylogeny indicates the presence of at least one hitherto unrecognised species. Mosquitoes of chromosomal form K from eastern Thailand have a unique ITS2 sequence that is 3.

Behavioural heterogeneity of Anopheles species in ecologically different localities in Southeast Asia: a challenge for vector control.

In Southeast Asia the biodiversity of Anopheles species in the domestic environment is very high. Only few species are considered major vectors throughout the region, whereas the vector status of other species varies from area to area. Often it is difficult to identify an Anopheles species as a malaria vector in areas with low malaria incidence.

Eco-ethological heterogeneity of the members of the Anopheles minimus complex (Diptera: Culicidae) in Southeast Asia and its consequences for vector control.

The presence of cryptic species within Anopheles minimus s.l. Theobald, one of the most widespread malaria vectors in Southeast Asia, was suggested on the basis of behavioral heterogeneities observed within this taxon.

Molecular evidence of speciation between island and continental populations of Anopheles (Cellia) sundaicus (Diptera: Culicidae), a principal malaria vector taxon in Southeast Asia.

Anopheles sundaicus s.l. is a principal malaria vector taxon on islands and along the coastal areas of Southeast Asia.