Malaria vectors of Timor-Leste

Area of Science:

• Entomology
• Molecular Biology
• Parasitology

Background:

• Timor-Leste is a malarious country with a known Anopheles (mosquito) fauna since the 1960s.
• Recent advances in molecular techniques allow for precise identification within Anopheles species complexes.
• Accurate vector identification is essential for effective malaria control strategies.

Purpose of the Study:

• To precisely identify the Anopheles mosquito species present in Timor-Leste.
• To utilize molecular techniques for accurate Anopheles species identification.
• To update the understanding of malaria vectors in the region.

Main Methods:

• Anopheles mosquitoes were collected using human landing catches, larval surveys, and light traps from February to June 2001.
• Specimens were identified morphologically and genotyped using ribosomal DNA ITS2 and mitochondrial cytochrome-b sequences.
• Plasmodium parasite circumsporozoite protein detection via ELISA was performed for vector incrimination.

Main Results:

• Morphological identification revealed seven Anopheles species; molecular analysis confirmed these and identified two additional species: Anopheles flavirostris and Anopheles vagus genotype B.
• Anopheles vagus genotype B, morphologically similar to Anopheles vagus and Anopheles subpictus, showed genetic affinity to the Anopheles sundaicus complex.
• Anopheles barbirostris and Anopheles vagus genotype B were the most frequent species in human landing catches and tested positive for Plasmodium circumsporozoite protein.

Conclusions:

• The Anopheles fauna in Timor-Leste is of Oriental origin, with no Australian elements detected.
• Molecular analysis resolved taxonomic ambiguities, identifying nine Anopheles species, including two significant malaria vectors.
• Anopheles barbirostris and Anopheles vagus genotype B are confirmed as primary malaria vectors in Timor-Leste, necessitating targeted control measures.