Malaria-associated risk factors among adolescents living in areas with persistent transmission in Senegal: a case-control study.

BACKGROUND: In Senegal, malaria morbidity has sharply decreased over these past years. However, malaria epidemiology remains heterogeneous with persistent transmission in the southeastern part of the country and many cases among older children and adolescents. Little is known about factors associated with clinical malaria among this group. A better understanding of malaria transmission among this newly emerging vulnerable group will guide future interventions targeting this population group. This study aimed to identify factors associated with clinical malaria among adolescents in Senegal. METHODS: A case-control study was conducted from November to December 2020 in four health posts located in the Saraya district. Cases were defined as adolescents (10-19 years) with an uncomplicated malaria episode with fever (temperature > 37.5°) or a history of fever and positive malaria rapid diagnostic test (RDT). Controls were from the same age group, living in the neighbourhood of the case, presenting a negative RDT. A standardized, pre-tested questionnaire was administered to each study participant followed by a home visit to assess the participant's living conditions. Factors associated with clinical malaria were assessed using stepwise logistic regression analysis. RESULTS: In total, 492 individuals were recruited (246 cases and 246 controls). In a multivariate analysis, factors associated with clinical malaria included non-use of long-lasting insecticidal net (LLIN) (aOR = 2.65; 95% CI 1.58-4.45), non-use of other preventive measures (aOR = 2.51; 95% CI 1.53-4.11) and indoor sleeping (aOR = 3.22; 95% CI 1.66-6.23). Protective factors included 15-19 years of age (aOR = 0.38; 95% CI 0.23-0.62), absence of stagnant water around the house (aOR = 0.27; 95% CI 0.16-0.44), having a female as head of household (aOR = 0.47; 95% CI 0.25-0.90), occupation such as apprentice (OR = 0.24; 95% CI 0.11-0.52). CONCLUSIONS: The study revealed that environmental factors and non-use of malaria preventive measures are the main determinants of malaria transmission among adolescents living in areas with persistent malaria transmission in Senegal. Strategies aimed at improving disease awareness and access to healthcare interventions, such as LLINs, are needed to improve malaria control and prevention among these vulnerable groups.

Impact of combining intermittent preventive treatment with home management of malaria in children less than 10 years in a rural area of Senegal: a cluster randomized trial.

BACKGROUND: Current malaria control strategies recommend (i) early case detection using rapid diagnostic tests (RDT) and treatment with artemisinin combination therapy (ACT), (ii) pre-referral rectal artesunate, (iii) intermittent preventive treatment and (iv) impregnated bed nets. However, these individual malaria control interventions provide only partial protection in most epidemiological situations. Therefore, there is a need to investigate the potential benefits of integrating several malaria interventions to reduce malaria prevalence and morbidity. METHODS: A randomized controlled trial was carried out to assess the impact of combining seasonal intermittent preventive treatment in children (IPTc) with home-based management of malaria (HMM) by community health workers (CHWs) in Senegal. Eight CHWs in eight villages covered by the Bonconto health post, (South Eastern part of Senegal) were trained to diagnose malaria using RDT, provide prompt treatment with artemether-lumefantrine for uncomplicated malaria cases and pre-referral rectal artesunate for complicated malaria occurring in children under 10 years. Four CHWs were randomized to also administer monthly IPTc as single dose of sulphadoxine-pyrimethamine (SP) plus three doses of amodiaquine (AQ) in the malaria transmission season, October and November 2010. Primary end point was incidence of single episode of malaria attacks over 8 weeks of follow up. Secondary end points included prevalence of malaria parasitaemia, and prevalence of anaemia at the end of the transmission season. Primary analysis was by intention to treat. The study protocol was approved by the Senegalese National Ethical Committee (approval 0027/MSP/DS/CNRS, 18/03/2010). RESULTS: A total of 1,000 children were enrolled. The incidence of malaria episodes was 7.1/100 child months at risk [95% CI (3.7-13.7)] in communities with IPTc + HMM compared to 35.6/100 child months at risk [95% CI (26.7-47.4)] in communities with only HMM (aOR = 0.20; 95% CI 0.09-0.41; p = 0.04). At the end of the transmission season, malaria parasitaemia prevalence was lower in communities with IPTc + HMM (2.05% versus 4.6% p = 0.03). Adjusted for age groups, sex, Plasmodium falciparum carriage and prevalence of malnutrition, IPTc + HMM showed a significant protective effect against anaemia (aOR = 0.59; 95% CI 0.42-0.82; p = 0.02). CONCLUSION: Combining IPTc and HMM can provide significant additional benefit in preventing clinical episodes of malaria as well as anaemia among children in Senegal.

A randomized trial of artesunate mefloquine versus artemether lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria in Senegalese children.

An open randomized clinical trial study was carried out to compare efficacy and tolerability of artesunate mefloquine 25 mg/kg body weight (Artequin paediatric) versus artemether lumefantrine (Coartem) in the treatment of uncomplicated Plasmodium falciparum malaria in children. In each arm, 160 patients were assigned to receive either AS + MQ or AL with 28 days follow-up. The adequate clinical and parasitological response at Day 28 for per protocol analysis was after polymerase chain reaction correction, 100% for AS + MQ and 96.8% for AL. In the intention-to-treat analysis, the respective cure rates were 96.2% for AS + MQ and 93.7% for AL. No serious adverse events (AEs) were reported. The most frequent AE was vomiting, 30% in AS + MQ arm and 36% in AL arm. No biological significant abnormal values related to the study drug have been reported. The new pediatric artesunate mefloquine formulated in granule fixed dose combination is well adapted to children in Africa.