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

Mohamed Aly Ould Lemrabott,Leonardo Basco,Yacoub Ould Khalef,Khadijetou Mint Lekweiry,Frédéric Simard,Ali Ould Mohamed Salem Boukhary,Jemila Deida,Hervé Bogreau,Mohamed Salem Ould Ahmedou Salem,Oum Kelthoum Mamadou Djigo

doi:10.3390/parasitologia1040027

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.

Highlights

Licensee MDPI, Basel, Switzerland.Malaria is a life-threatening disease caused by the parasites of the genus Plasmodium.In 2019, an estimated 229 million malaria cases and 409,000 deaths due to malaria were reported globally [1]
The objective of this study was to update epidemiological data on malaria in Rosso, one of the major Mauritanian cities situated along the Senegal River where a permanent irrigation scheme has been established for decades [12]
Rosso is very low (2.2% based on rapid diagnostic test (RDT); 0.6% based on polymerase chain reaction (PCR)) and (ii) high rates of mosquito net ownership and coverage at the household level and high frequency of ‘regular’ use were observed among the study population with no variation in the seasonality of insecticide-treated net (ITN) use

Summary

Introduction

Malaria is a life-threatening disease caused by the parasites of the genus Plasmodium. In 2019, an estimated 229 million malaria cases and 409,000 deaths due to malaria were reported globally [1]. Sub-Saharan Africa accounted for 94% of malaria cases [1]. The malaria parasite is transmitted to a human host by the bite of an infected female mosquito of the genus Anopheles during a blood meal. The feeding pattern of female Anopheles mosquito depends largely on host availability and preference.

Objectives

Methods

Results

Discussion

Conclusion