Malaria prevalence in symptomatic and asymptomatic pregnant women in a high malaria-burden state in India.

Introduction: Malaria in pregnancy ('MiP') poses risks to mother, foetus and newborn. Studies from Africa and Asia have reported high prevalence of 'MiP' and recommended further research to address 'MiP'. India has a significant burden of 'MiP' but most of the studies are a decade old. Hardly any studies exist in India that report on asymptomatic malaria in pregnant women. The current Indian policies for malaria control are silent on 'MiP'. A campaign was carried out by community health workers (CHWs) in 2019 to screen pregnant women across rural Chhattisgarh.

Methods: This is a cross-sectional study. Malaria was tested in pregnant women by CHWs using bivalent rapid tests. Multi-stage sampling was used to cover 21,572 pregnant women screened across different geographical areas of rural Chhattisgarh. Cross-tabulation and multivariate regression were used to find out the relationship of 'MiP' with different symptoms and geographical areas. GIS maps were used to compare malaria in pregnant women against overall febrile population.

Results: In rural Chhattisgarh, malaria was present in 0.81% of the pregnant women at the time of testing. 'MiP' prevalence varied across geographies, reaching 4.48% in the geographical division with highest burden. Febrile pregnant women had three times greater malaria-positivity than overall febrile population and both showed a similar geographical pattern.

Discussion: Prevalence of 'MiP' was found to be less than earlier studies in the state. Though overall malaria in India has shown some decline, a policy response is needed for 'MiP' in high-burden areas. Fever, diarrhoea and jaundice remain relevant symptoms in 'MiP', but around one fourth of malaria-positive pregnant-women were afebrile, suggesting the need for strategies to address it.

Conclusion: The current study based on a large sample provides fresh evidence on 'MiP' in India. It used CHWs as skilled providers for large-scale screening for malaria. In high-burden areas, intermittent screening and treatment (IST) of all pregnant women can be a useful strategy in order to address 'MiP'. Pregnant women can be considered as a pertinent sentinel population for malaria. The global and national policies need to evolve concrete strategies for addressing malaria in pregnancy.