Low Malaria Transmission in Rosso, an Irrigated Rice-Growing Area in Mauritania

Abstract

The construction of dams along the Senegal River resulted in an increase in irrigated land areas and changes in the epidemiology and transmission of water-related diseases. The objective of this study was to update epidemiological data on malaria in Rosso, one of the major Mauritanian cities along the Senegal River. Febrile patients (n = 318) were screened for malaria using a rapid diagnostic test (RDT) for malaria and microscopic examination of blood smears. Diagnosis was later confirmed by polymerase chain reaction (PCR). The mean age of 318 febrile patients was 25.1 (range 1–80 years). Only 7 (2.2%) and 2 (0.6%) had a positive RDT and thick smear, respectively. PCR confirmed the diagnosis in two Plasmodium vivax-infected patients. Most participants (198/318, 62.3%) had no recent travel history outside Rosso. The majority of the febrile patients (90%, 284/311) owned at least one insecticide-treated net (ITN). The frequency of the use of ITNs was not significantly associated with season (rainy vs. dry seasons; p = 0.9) or with the number of ITNs per household (rs = 0.07; n = 285; p = 0.19). Of 285 individuals with ITNs, only two (0.7%) with no travel history were PCR-positive for malaria. Despite the presence of mosquito breeding sites related to rice irrigation, malaria transmission in Rosso remained very low, possibly due to the high coverage and frequent use of bed nets. Regular entomological surveillance for possible changes in the prevalence of Anopheles mosquito species and their behavioural aspects should be implemented.

Changing epidemiology of Plasmodium vivax malaria in Nouakchott, Mauritania: a six-year (2015–2020) prospective study

“…Elsewhere in southern Sahelian zone of the country (e.g., Kobeni, Kiffa, Rosso), where An. arabiensis is also the major malaria vector, P. falciparum predominates [ 8 , 10 , 11 , 14 , 46 , 47 ].…”

“…Malaria continues to be one of the major health issues in Mauritania [7]. Malaria transmission is seasonal and intense in the southern Sahelian zone and seasonal and unstable in the northern Saharan zone [8][9][10][11]. Plasmodium falciparum and P. vivax co-exist in Mauritania, but P. falciparum predominates in the Sahelian zone and P. vivax prevails in the Saharan zone [9][10][11][12][13][14][15].…”

“…Malaria transmission is seasonal and intense in the southern Sahelian zone and seasonal and unstable in the northern Saharan zone [8][9][10][11]. Plasmodium falciparum and P. vivax co-exist in Mauritania, but P. falciparum predominates in the Sahelian zone and P. vivax prevails in the Saharan zone [9][10][11][12][13][14][15]. Nouakchott, the capital city of Mauritania, is situated in the Saharan zone, where the majority of laboratoryconfirmed malaria cases are due to P. vivax [12,16].…”