Malaria prevalence before and 2 years after implementation of seasonal malaria chemoprevention in Saraya, Senegal

Seasonal malaria chemoprevention (SMC) is adopted and implemented in Senegal since 2013 in the southern regions in children aged between 3 and 120 months. Scaling up of this strategy requires its evaluation to assess its impact. This study was carried out to determine the dynamics of Plasmodium falciparum carriage before and after two years of SMC implementation.

Four household surveys were conducted in villages in the health district of Saraya, which is a SMC implementation area in Senegal. These villages were selected using probability proportional to size sampling. Each of the selected villages was divided into segments containing at least 50 children. In each selected segment, a household questionnaire was administered to the parents or legal representatives of children aged 3 to 120 months. Blood smears were collected to determine Plasmodium falciparum prevalence by microscopy one month before the first round of SMC and one month after the last round of the first SMC campaign and that of two years after the start of the implementation. 

A total of 2008 children were included in our study with a mean average age of 4.81 (+/-2.73) years. 50.33% of the study population were more than 5 years old and 50.3% were male. In 2013, net ownership was 99.4 % before SMC campaign and 97.4% after. In 2015, it was 36.6% before and 45.8% after the campaign. In 2013, the prevalence of plasmodium carriage was 11.8% before and 6.1% after SMC campaign. In 2015, the prevalence was 4.9% before the administration of SMC and increased up to 15.3% after. Malaria prevalence was high among children over 5 years old and boys. 

The decrease in Plasmodium falciparum parasite prevalence, which subsequently increased after two years of SMC implementation in this study, suggests adding an extra cycle of the SMC or adjusting the administration period.