Predictors and characteristics of malaria treatment-seeking in Malawi: a longitudinal cohort study

Prompt diagnosis and treatment are essential for malaria control but are typically assessed only among children under five. Older children and adults also experience malaria and may act as reservoirs for transmission but barriers such as distance to facilities, supply shortages, and mistrust of the health system limit access to care across age groups. This study aimed to determine how demographic and parasitological factors influence treatment-seeking behaviour over time.

A community-based, open-enrollment longitudinal cohort study was conducted in rural Malawi from April 2019 to May 2020. Data were collected during monthly scheduled active case detection (ACD) visits and passive case detection (PCD) visits at local health centres. Malaria-related treatment-seeking behaviour was assessed using two outcomes: (1) self-reported treatment-seeking between ACD visits and (2) attendance at study-linked health centres during illness. Treatment-seeking was categorized as occurring in the formal or informal sectors. Mixed-effects logistic regression models were used to identify predictors of formal-sector treatment-seeking and health centre attendance, adjusting for clustering at the individual and household levels. Poisson regression was used to estimate rate ratios of PCD visits per person-year.

The study enrolled 962 participants who contributed 7293 total visits, including 6794 ACD and 499 PCD visits. Most reported treatment-seeking (82%, 720/880 visits) occurred in the formal health sector and longer walking time and higher household head education were associated with reduced odds of formal treatment-seeking (OR = 0.28 for > 90 min vs. < 30 min; OR = 0.41 for secondary education vs. no education). In longitudinal models, older age, male sex, and greater distance to the facility were consistently associated with lower odds of attending PCD visits. Fever was positively associated with subsequent PCD visits (OR = 1.60(1.16-2.21)), but Plasmodium falciparum infection and parasite density were not. The overall PCD visit rate was 70 per 100 person-years and was significantly lower among older children, adults, males, and households farther from health facilities.

Despite free access to malaria care, barriers to treatment persist. These findings highlight the need for more equitable, community-based approaches to malaria diagnosis and treatment across all age groups.