A track to brake seasonal malaria

In the African regions of seasonal transmission of malaria. However, three Cycles of MDA by dihydroartemisin-pipéraquine and Primaquine reduced the incidence of malaria by 55 % in the high season. However, this effect seems to fade after the stop.

Malaria is a major public health problem in Africa. Therefore, In regions where transmission is very seasonal. Therefore, chemoprevention of malaria has been largely implemented to prevent morbidity and mortality in children (3 to 120 months) exposed to the risk of serious malaria. In addition, It consists of administering sulfadoxine-pyimethamine associated with amodiaquine at four-week intervals. Consequently, during the maximum transmission season, in order to eliminate existing parasitity and prevent new infections (1). Moreover, Since the recommendation by WHO in 2012. Meanwhile, chemoprevention of malaria has extended to 18 African countries and has reduced the incidence of infant malaria from 60 to 88 % (2).

High coverage of chemoprevention of malaria. Similarly, an effective vector struggle and rapid management have enabled sub -Saharan African countries to make considerable progress in the fight against malaria. However, advances to the elimination objectives have stagnated in the past five years (3). Similarly, A strengthening of the coverage of basic interventions. In addition, the adoption of new strategies to accelerate it to reduce it more quickly, the transmission seems necessary. For example,

The massive administration of antimalarials: a promising approach

MDA (Mass Drug Administration) consists in administering antimalarials to all. Furthermore, people in a geographic area for a period adapted to local epidemiology

malaria (4). Consequently, Its effectiveness depends on the antimalarial treatment used. In addition,

In regions where Plasmodium falciparum (The species that kills) is dominant. Moreover, dihydroartemisin-pipéraquine is an interesting choice because of its good safety profile, its long period of prophylactic efficiency and the track brake seasonal malaria low prevalence of resistance to artemisinin in Africa. However, it is not effective against mature gametocytes responsible for the transmission of man to the mosquito. A single low dose of primaquine. a gametocytocidal agent, is safe and allows an almost complete prevention of the transmission of man to the mosquito. Its addition to dihydroartemisin-pipéraquine could offer greater advantages than dihydroartemisin-pipéraquine alone. in particular the possibility of reducing the propagation of parasites resistant to drugs.

In 2022. the WHO updated its recommendations concerning MDA (1): it is recommended to quickly reduce the burden of morbidity, but not to reduce transmission due to the lack of evidence on its short or long -term benefits. It is carried out in areas where the transmission is low (WHO criteria: a prevalence of the parasite less than 10 %. an annual incidence of malaria less than 250 cases per 1,000 inhabitants).

Senegal eligible for MDA

In south-eastern Senegal. the transmission of malaria varies from low to high (from 50 to 500 cases per 1,000 inhabitants per year). It is very seasonal, most of the cases occurring

Between July and December. In this region. the National Program for the Fight against Malaria (PNLP) implements standard interventions to combat malaria, in particular the systematic distribution of mosquito nets impregnated with insecticide, the management of cases in health establishments and the chemoprevention of malaria for children aged 3 to 120 months.

Despite the intensification of these interventions. progress towards the pre-elimination of malaria in this region, defined by PNLP as an annual incidence of less than 5 cases for 1,000 inhabitants, were slow. The program needed an accelerating intervention to achieve the national objective of eliminating malaria by 2030.

An international team of researchers (Senegal. United States, England) conducted a study in south-eastern Senegal to assess the safety, track brake seasonal malaria efficiency and tolerance of three MDA cycles with dihydroartemisin-pipéraquine associated with a single and low dose of primaquine. Their work was published in The Lancet Infectious Diseases (5).

A randomized controlled trial in the south-east of Senegal

It was a test controlled with two arms. randomized by clusters, led to villages of the Tambacounda health district, in southeast of Senegal. The villages were randomly selected using a random number generator. The eligible villages had a population between 200 and 800 inhabitants, were located in an area of ​​service of a health post. Additionally, The annual malaria incidence rate was 60 to 160 cases per 1000 inhabitants. The inhabitants. residents of the intervention villages, were eligible if they were aged 3 months or more, and if they accepted, either personally or with the agreement of their parents, to comply with the procedures of the test and gave their informed consent.

The main exclusion criteria were as follows: serious. chronic disease, known hypersensitivity to drugs used, current pregnancy confirmed by a urinary test, antimalarial treatment in the previous 3 weeks. Participants under the age of 2 or who were breastfed were excluded from taking a unique low dose of Primaquine.

The 60 selected villages were distributed by randomization (1: 1) laminate. limited to receive during the intervention year, from July to December 2021 to receive three cycles of MDA with dihydroartemisin-oral piping more from the single-dose single-dose primacine administered at 6-week intervals (MDA intervention), the antipaludic prophylaxy strategy used in Senegal In this region (chemioprevention of malaria in children from 3 to 120 months) which included three cycles of seasonal malaria chemoprevention with sulfadoxin oral-pyimethamine more from the amodiaquine administered at 4-week intervals (SMC control group).

The main result was, for each village, the impact of malaria A. falciparum Biologically confirmed track brake seasonal malaria (PCR and/or parasitology), during the post-intervention year (from July to December 2022). The secondary results included the impact of malaria during the year of intervention (from July to December 2021). the coverage and safety of MDA, and adverse events linked to the drug taking. Statistical analyzes were done using an approach to deal with.

Efficiency during the intervention year

In the “intervention branch” villages. respectively 8269, 8673 and 8690 subjects were eligible for the first, second and third cycles. The distribution coverage of the three doses of dihydroartémisinin-pipéraquine was 73.6 % in the first cycle, 78.8 % for the second and 81.3 % among third cycle participants. The single -dose unique primaquine distribution coverage was 78.6 % at the first cycle, 82.1 % in the second and 84.0 % in the third cycle.

For the control group (children aged 3 to 120 months), respectively 3187, 3,158 and 3139 track brake seasonal malaria children were eligible. The distribution coverage of the three doses of SMC was 92.2 %, 91.8 % and 91.4 % in three cycles.

The average impact of malaria at the villages during the transmission season of the year preceding the intervention (from July to December 2020) was 181 cases for 1. 000 inhabitants in the intervention group and 204 cases for 1,000 inhabitants in the control group.

The average incidence of malaria during the transmission season of the intervention year was 93 cases for 1. 000 inhabitants in the intervention group and 173 cases per 1,000 in the control group. The average impact of malaria during the transmission season of the post-intervention year was 126 cases per 1. 000 in the intervention group and 146 cases per 1,000 in the control group. In total. course of the intervention year, from July to December 2021, the adjusted effect of track brake seasonal malaria the MDA (reduction of the incidence) was 55 % (95 % 28 to 71 CI). During the post-intervention year, from July to December 2022, the adjusted MDA effect was lower, valued at 26 % (17 to 53).

In south-eastern Senegal. in an area where the transmission of malaria is low to moderate, three MDA cycles with dihydroartemisin-pipéraquine plus single dose primaquine were safe and reduced the charge of malaria during the intervention year. However. the effect was not frankly lasting and, according to the authors, the continuation of the MDA or another strategy of reduction of the transmission may be necessary.