The impact of mass screening and treatment interventions on malaria incidence and prevalence: a retrospective analysis of a malaria elimination programme in eastern Myanmar, and systematic review and meta-analysis.

Background: Targeted interventions are often needed to accelerate malaria elimination efforts. Mass screening and treatment (MSAT) involves testing all eligible and consenting individuals in an area for malaria and treating all positive individuals simultaneously. However, there are concerns regarding the impact of MSAT. This study evaluates the impact of MSAT on malaria incidence in Karen State, Myanmar, using routine surveillance data, and investigates the impact of MSAT in other settings through a systematic review and meta-analysis.

Methods: To investigate the impact of MSAT in Karen State, we retrospectively analysed routine malaria surveillance data collected in 10 villages where MSAT was done in 2018. Pre- and post-MSAT malaria incidences were compared, and a negative binomial mixed-effects model was used to estimate the relative change in monthly incidence for each additional year since MSAT. To investigate the impact of MSAT in other settings, we searched Scopus, Ovid MEDLINE, and Web of Science (end date 11th July 2022) for studies assessing the impact of MSAT interventions on the incidence or prevalence of malaria infections. Studies were summarized, and a random-effects meta-analysis was performed on studies grouped according to study design and the comparator used to assess the impact of MSAT.

Results: In the 10 villages in Karen State, there was an overall reduction in P. falciparum incidence following MSAT (Incidence Rate Ratio 0.37; 95% CI: 0.19, 0.73). However, this is likely due to the ongoing impact of early diagnosis and treatment services offered in these communities, as shown by an overall reduction in incidence in the surrounding area. Results from nine studies identified in the systematic review demonstrate the variable impact of MSAT, which is likely influenced by a variety of factors, including intervention coverage and uptake, baseline malaria endemicity, and methods used for MSAT delivery.

Conclusions: This retrospective analysis and systemic review highlights the complexities behind the success of targeted interventions for malaria elimination. While these interventions are important drivers for achieving elimination goals, particularly in high-burden settings, it is important that various factors be considered when determining their suitability and how to optimize implementation.