Effect of large-scale mass drug administration for malaria on mortality and morbidity in Angumu health zone, Ituri, Democratic Republic of Congo.

Background 

Angumu health zone in Ituri, Democratic Republic of Congo, is a highly malaria-endemic area with an overburdened health system and hosting internally displaced persons (IDP). The World Health Organization recommends mass drug administration (MDA) for malaria in complex emergencies. Therefore, three MDA rounds were implemented by Ministry of Public Health and Médecins sans Frontières from September 2020 to January 2021 in four health areas selected for epidemiological (high malaria incidence) and logistic reasons. Reported mortality and morbidity were compared in locations where MDA has been performed and locations where it has not.

Methods

A non-randomized controlled population-based retrospective mortality survey was conducted in March 2021. Two-stage cluster sampling was used in villages; all IDP sites were surveyed with systematic random sampling. The main (mortality rates) and secondary (morbidity) outcomes were estimated and compared between locations where MDA had been conducted and where it had not, using mixed Poisson and binomial regression models respectively.

Results

Data was collected for 2554 households and 15470 individuals, of whom 721 died in the 18-month recall period. The under-five mortality rate (U5MR) decreased in the locations where MDA had been implemented from 2.32 [1.48-3.16] "before" the MDA to 1.10 [0.5-1.71] deaths/10,000 children under 5 years/day "after", whereas it remained stable from 2.74 [2.08-3.40] to 2.67 [1.84-3.50] deaths/10,000 children/day in the same time periods in locations where MDA had not been implemented. The U5MR and malaria-specific mortality was significantly higher in non-MDA locations after MDA was implemented (aRR = 2.17 [1.36-3.49] and 2.60 [1.56-4.33], respectively, for all-cause and malaria-specific mortality among children.

Conclusions

Despite traditional limitations associated with non-randomized controlled retrospective surveys, the documented sharp decrease of under-5 mortality and morbidity shows that MDA has the potential to become an important malaria-control tool in emergency settings. Based on these results, new MDA rounds, along with indoor residual spraying campaigns, have been planned in the health zone in 2022. A set of surveys will be conducted before, during and after these rounds to confirm the effect observed in 2021 and assess its duration.

The last retrospective mortality survey in Angumu conducted in March 2021 showed that the crude and under-five mortality rates was still above the emergency threshold before the MDA, despite of the active support of MSF in the zone since 2019. It also showed a big decrease of the U5MR and malaria-specific mortality in MDA locations during and right after the three rounds of MDA. However, the study conducted in March 2021 did not allow to assess the longer-term effect of the MDA on mortality in the population. This study will therefore allow us to estimate the effect on mortality over the year following the 3 rounds of MDA conducted in 2020. Moreover, the MDA conducted in 2020 used ASAQ for two rounds, which is the first line treatment for malaria in DRC. The National programme for malaria control (PNLP) therefore requested MSF not to use ASAQ in subsequent MDAs. For the MDA in 2022, DHAP and pyramax will be used. There is a need to assess the short and longer-term effect of the MDAs conducted with these drugs. Additionally, this time the MDA will be conducted in conjunction with IRS. IRS will also be conducted (without MDA) in 5 additional HAs. And 4 HAs will receive neither MDA nor IRS (Indoor Residual Spraying) (but will continue receiving MSF support for test and treat in the SSCs and health centers). There is therefore a need to document and assess the short and longer-term effect of combining MDA and IRS. Finally, the support of MSF in some health areas in the zone makes it difficult to use routine data reported to the MoH or to MSF to estimate the prevalence malaria in the different health areas and determine whether there are some health areas with higher prevalence. It appears important for the continuation of MSF activities in relation with malaria in the zone to have a more objective estimation of malaria prevalence in the different health areas.

Main objective

To estimate retrospectively crude mortality rate (CMR) for the total population and the under-five mortality rate (U5MR) in 14 accessible HA in Angumu HZ (Health Zone), before, during and after MDA and/or IRS have been implemented in selected HA (Health Area).

Secondary objectives

• Estimate the proportion of the target population (coverage) having received each of the different MDA rounds conducted in 2022, according to a document and to recall.
• Estimate the proportion of the target households(coverage) having received each of the different IRS in 2022, according to a document and to recall.
• Describe deaths by date, age, sex, reported cause, place of death and health seeking behaviors before death
• Estimate the proportion of people who reported feeling sick in the 2 weeks preceding the survey, in 14 accessible HA in Angumu HZ, before and after MDA and IRS have been implemented in selected HA.
• Describe the people who reported having been sick by age, sex, reported morbidity and health seeking behaviors
• Estimate malaria prevalence, based on rapid diagnostic tests (RDT), before and after the malaria control activities (MDA and IRS) conducted in 2022
• Estimate household ownership, condition and use of long-lasting insecticidal nets (LLINs)
• Monitor the number of malaria cases (suspected and confirmed) and the proportion of positive RDTs by age group, gender, severity of disease during the entire recall period before, during and after the MDA, in HAs targeted and not targeted by the MDA as reported by health facilities through the routine health information system.
• Monitor the trends of incidence of malaria (uncomplicated and severe) prior to, during and after interventions in 2022 and describe the severe malaria cases reported in Angumu health zone over 2022, notably in terms of provenance and participation to MDA and IRS campaigns.
• Monitor the main entomological indicators before, during and after the interventions, in the three zones of malaria control interventions for 2022.