No abstract

Background: According to entomological studies conducted over the past 30 years, there was low malaria transmission in suburb of Dakar but little evidence of it in the downtown area. However; there was some evidence of local transmission based on reports of malaria among permanent residents. An entomological evaluation of malaria transmission was conducted from

Anopheles darlingi, one of the main malaria vectors in the Neotropics, is widely distributed in French Guiana, where malaria remains a major public-health problem. Elucidation of the relationships between the population dynamics of An. darlingi and local environmental factors would appear to be an essential factor in the epidemiology of human malaria in French Guiana and the design of effective vector-control strategies. In a recent investigation, longitudinal entomological surveys were carried out for 2-4 years in one village in each of three distinct endemic areas of French Guiana. Anopheles darlingi was always the anopheline mosquito that was most frequently caught on human bait, although its relative abundance (as a proportion of all the anophelines collected) and human biting rate (in bites/person-year) differed with the study site. Seasonality in the abundance of human-landing An. darlingi (with peaks at the end of the rainy season) was observed in only two of the three study sites. Just three An. darlingi were found positive for Plasmodium (either P. falciparum or P. vivax) circumsporozoite protein, giving entomological inoculation rates of 0·0-8·7 infectious bites/person-year. Curiously, no infected An. darlingi were collected in the village with the highest incidence of human malaria. Relationships between malaria incidence, An. darlingi densities, rainfall and water levels in the nearest rivers were found to be variable and apparently dependent on land-cover specificities that reflected the diversity and availability of habitats suitable for the development and reproduction of An. darlingi.

T he Republic of Djibouti, bordered by Eritrea, Ethiopia, and Somalia, is a semiarid country in the Horn of Africa. The population comprises <900,000 persons, 70% of whom live in Djibouti, the capital city. Before 2013, malaria was hypoendemic to the country, with low levels of transmission in periruban and rural areas during December-May. Localized outbreaks occurred regularly, possibly caused by migration from surrounding countries. Most cases were caused by infection with Plasmodium falciparum (>80%) or P. vivax. Before 2013, researchers considered the Anopheles arabiensis mosquito to be the primary vector (1).The incidence of malaria had drastically decreased in the country since 2008; by 2012, this transmission level was compatible with preelimination goals (2,3). In 2013, an autochthonous outbreak of malaria occurred in Djibouti; fi eld entomologic investigations identifi ed An. stephensi mosquitoes as a new malaria vector (4). This species, a known vector of urban malaria in India and the Arabian Peninsula, has changed the epidemiologic profi le of malaria in Djibouti (5). In 2018, malaria incidence increased to 25,319 confi rmed cases (64% caused by P. falciparum and 36% by P. vivax) and >100,000 suspected cases (Appendix Figure 1, https://wwwnc.cdc.gov/EID/ article/27/6/20-4557-App1.pdf).The French Armed Forces (FAF) have served in Djibouti for decades. Service members and their families (≈2,700 persons) live in the capital. Despite malaria prevention and treatment measures described elsewhere (6), an outbreak among French military personnel occurred in February 2019; failure of early artemisinin combined therapy was documented in 1 patient. The StudyWe collated FAF epidemiologic surveillance data on malaria cases among service members in Djibouti during 1993Djibouti during -2019; the 2019 data included cases among family members. We defi ned a malaria case as an illness resulting in a positive result on a rapid diagnostic test or thin blood smear.We conducted the fi eld investigation in the capital during February 28-March 22, 2019. We obtained a dried blood spot on fi lter paper from each patient and stored the samples in a sealed plastic pouch until processing. We extracted DNA from the samples and