Screening of Plasmodium parasite in vectors and humans in three villages in Aswan Governorate, Egypt

Egypt has successfully eliminated malaria during 2010–2013, however, between May to mid-June 2014, an outbreak was reported in Al-Adwa village, Aswan Governorate indicating that malaria may be potentially re-emerging in the country. The aim of this work was to reevaluate malaria in Al-Adwa and surrounding villages, 1 year after malaria cases have been reported through entomological and human screening in collaboration with the Ministry of Health and Population. Four trips were conducted during the period from March 2015 to March 2016. Mosquitoes were collected, sorted and identified. Anopheles species were processed for detection of Plasmodium by polymerase chain reaction (PCR), and engorged abdomens in blood-fed mosquitoes were analyzed for host preference using multiplex PCR. Thick and thin blood films were prepared from all apparently healthy children (n = 188) attending El-Sheikh Mostafa preparatory school. Results showed that Anopheles genus existed only in East Al-Adwa village. A total of 38 Anopheles mosquitoes were collected and identified as Anopheles multicolor 70% (A. multicolor), A. sergenti 20% and A. pharoensis 10%. The latter showed 100% human blood preference compared to A. sergenti (20%) and An. multicolor (0%). All female Anopheles were 100% negative for Plasmodium DNA, and all blood films showed no detectable parasite. The absence of Plasmodium in the area under study does not rule out the risk of future infections as the vector is still present together with the imported cases and carriers. Regular screening for the presence of Plasmodium in the area is absolutely paramount for early warning.