Anopheles jamesii Supports Plasmodium vivax Sporogony under Laboratory Conditions

Anopheles jamesii, considered to be a non-malaria vector, is an abundant mosquito species found in coastal India and several countries in Asia. In Goa, western India, An. jamesii is the dominant anopheline species by numbers, and in recent epidemiological surveys, they have tested positive for Plasmodium carriage. To assess An. jamesii's capacity as a malaria vector, we carried out six controlled membrane feeding assays with the F1 generation of field-caught An. jamesii and Plasmodium vivax-infected patient blood samples. As a control, the established local vector, Anopheles stephensi, was fed in parallel to compare the oocyst and sporozoite loads. The average oocyst load of An. jamesii was 3.29, while for An. stephensi it was 10.23. Furthermore, An. jamesii's blood feeding rate (21.7% versus 85%), oocyst positivity rate (60% versus 90.6%), and sporozoite positivity (45.16% versus 83%) were significantly lower (P <0.05, unpaired t test) than those of An. stephensi, suggesting a recent adaptation to support Plasmodium sporogony.