Plasmodium Infections in Anopheles Mosquitoes in Ubon Ratchathani Province, Northeastern Thailand During a Malaria Outbreak.

An unprecedented malaria outbreak occurred in Ubon Ratchathani Province, northeastern Thailand, in 2014. The province showed the highest number of malaria cases of all Thai provinces. Five entomological surveys were conducted at 8 sentinel sites from September 2013 to September 2015 to address the role of different species in malaria transmission. Mosquito collections were conducted using human landing catches and cow bait. A total of 10,369 mosquitoes were collected and 2,240 were morphologically identified as potential malaria vectors, including ( = 78), ( = 18), ( = 4), s.l. ( = 819), ( = 612), ( = 676), ( = 42), ( = 7), and ( = 142). Real-time polymerase chain reaction was used to screen for the presence of spp. in salivary glands. The proportion of primary vectors of surveyed villages was very low (<1%), and no -infected specimens were detected among in the 2,240 mosquitoes tested. The absence of positive samples during malaria outbreaks suggests that malaria transmission most likely occurred outside the villages, particularly in the deep-forested hilly areas that provided suitable habitats for competent malaria vectors. These results emphasize the need to develop vector control related to village community activities to reduce malaria transmission along Thailand border areas.