Negligible Impact of Mass Screening and Treatment on Mesoendemic Malaria Transmission at West Timor in Eastern Indonesia: A Cluster-Randomized Trial

• Published in: Clinical infectious diseases Vol. 67; no. 9; pp. 1364 - 1372
• Main Authors: Sutanto, Inge, Kosasih, Ayleen, Elyazar, Iqbal R F, Simanjuntak, Deddy R, Larasati, Tri A, Dahlan, M Sopiyudin, Wahid, Isra, Mueller, Ivo, Koepfli, Cristian, Kusriastuti, Rita, Surya, Asik, Laihad, Ferdinand J, Hawley, William A, Collins, Frank H, Baird, J Kevin, Lobo, Neil F
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 15.10.2018
• Subjects: and Commentaries; malaria control; mass screening and treatment; cluster-randomized trial; Indonesia
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1093/cid/ciy231

Abstract Background Mass screening and treatment (MST) aims to reduce malaria risk in communities by identifying and treating infected persons without regard to illness. Methods A cluster-randomized trial evaluated malaria incidence with and without MST. Clusters were randomized to 3, 2, or no MST interventions: MST3, 6 clusters (156 households/670 individuals); MST2, 5 clusters (89 households/423 individuals); and MST0, 5 clusters (174 households/777 individuals). All clusters completed the study with 14 residents withdrawing. In a cohort of 324 schoolchildren (MST3, n = 124; MST2, n = 57; MST0, n = 143) negative by microscopy at enrollment, we evaluated the incidence density of malaria during 3 months of MST and 3 months following. The MST intervention involved community-wide expert malaria microscopic screening and standard therapy with dihydroartemisinin-piperaquine and primaquine for glucose-6 phosphate dehydrogenase-normal subjects. All blood examinations included polymerase chain reaction assays, which did not guide on-site treatment. Results The risk ratios for incidence density of microscopically patent malaria in MST3 or MST2 relative to that in MST0 clusters were 1.00 (95% confidence interval [CI], .53-1.91) and 1.22 (95% CI, .42-3.55), respectively. Similar results were obtained with molecular analysis and species-specific (P. falciparum and P. vivax) infections. Microscopically subpatent, untreated infections accounted for 72% of those infected. Conclusions Two or 3 rounds of MST within 3 months did not impact the force of anopheline mosquito-borne infection in these communities. The high rate of untreated microscopically subpatent infections likely explains the observed poor impact. Clinical Trials Registration NCT01878357. This cluster-randomized trial demonstrated a negligible impact of mass microscopic screening in guiding treatment as a means to reduce malaria transmission at a mesoendemic site in Indonesia. Retrospective polymerase chain reaction analysis revealed that the majority of infections were microscopically subpatent.