Baseline malaria prevalence and care-seeking behaviours in rural Madagascar prior to a trial to expand malaria community case management to all ages

Abstract

Background: Integrated community case management of malaria, pneumonia, and diarrhoea can reduce mortality in children under five years (CU5) in resource-poor countries. There is growing interest in expanding malaria community case management (mCCM) to older individuals, but limited empirical evidence exists to guide this expansion. As part of a two-year cluster-randomized trial of mCCM expansion to all ages in southeastern Madagascar, a cross-sectional survey was conducted to assess baseline malaria prevalence and healthcare-seeking behaviours.

Methods: Two enumeration areas (EAs) were randomly chosen from each catchment area of the 30 health facilities (HFs) in Farafangana district designated for the mCCM age expansion trial; 28 households were randomly selected from each EA for the survey. All household members were asked about recent illness and care-seeking, and malaria prevalence was assessed by rapid diagnostic test (RDT) among children < 15 years of age. Weighted population estimates and Rao-Scott chi-squared tests were used to examine illness, care-seeking, malaria case management, and malaria prevalence patterns.

Results: Illness in the two weeks prior to the survey was reported by 459 (6.7%) of 8050 respondents in 334 of 1458 households surveyed. Most individuals noting illness (375/459; 82.3%) reported fever. Of those reporting fever, 28.7% (112/375) sought care; this did not vary by participant age (p = 0.66). Most participants seeking care for fever visited public HFs (48/112, 46.8%), or community healthcare volunteers (CHVs) (40/112, 31.0%). Of those presenting with fever at HFs or to CHVs, 87.0% and 71.0%, respectively, reported being tested for malaria. RDT positivity among 3,316 tested children < 15 years was 25.4% (CI: 21.5-29.4%) and increased with age: 16.9% in CU5 versus 31.8% in 5-14-year-olds (p < 0.0001). Among RDT-positive individuals, 28.4% of CU5 and 18.5% of 5-14-year-olds reported fever in the two weeks prior to survey (p = 0.044).

Conclusions: The higher prevalence of malaria among older individuals coupled with high rates of malaria testing for those who sought care at CHVs suggest that expanding mCCM to older individuals may substantially increase the number of infected individuals with improved access to care, which could have additional favorable effects on malaria transmission.

Fig. 1

Last visit to healthcare provider within each surveyed household by travel time by to provider in Farafangana, October–December 2019. Density plots showing household travel time to A community health volunteers and B health facilities, stratified by last visit to each within the household

Fig. 2

Type of provider visited by those seeking care for febrile illness in Farafangana, October–December, 2019. A Raw counts of individuals seeking care for febrile illnesses occurring within the two weeks prior to survey, grouped by type of provider(CHV – community health volunteer, HF – public health facility, Other¹). Colors represent each individual’s stated primary reason for choosing a provider. B. Raw counts of individuals seeking care for febrile illnesses occurring within the two weeks prior to survey, grouped by type of provider. Colors represent each individual’s age. ¹ ‘Other’ category includes: private health facility, pharmacy, marketplace, self-medication, and neighbors

Fig. 3

Observed prevalence of malaria RDT positivity among children < 15 years by household screen, Farafangana, Madagascar, October–November 2019. Colors represent interpolated malaria prevalence using ordinary Kriging. Prevalence displayed is RDT positivity for any species of Plasmodium. Black points are geographic centroids of areas surveyed. Blue icon represents the location of Farafangana city. Insert shows location of Farafangana in Madagascar. Shapefile from Humanitarian Data Exchange (https://data.humdata.org/)

Fig. 4

Prevalence of malaria RDT positivity and history of fever among all RDT + children 2 months to 14 years, by age, Farafangana 2019. A Dark gray bars show population weighted malaria prevalence (any species) estimates as measured by RDT by age in years (x-axis, rounded down to last complete year). Vertical lines in light gray illustrate 95% CI for RDT + prevalence. Dashed, jagged red line shows weighted population estimates for the percentage of those with preceding fever among all RDT + by age in years. Smooth, solid line illustrates modeled percentage of RDT + individuals with preceding fever by age using LOESS regression. Light red shading surrounding smooth regression line illustrates 95% CI of model. B Weighted percentages of all RDT + individuals grouped by age and fever status. Length of red bars extending upward from x-axis represent percentage of RDT + individuals noting fever within two weeks of survey. Length of gray bars extending downward from x-axis represent percentage of RDT + individuals without preceding fever. Vertical lines associated with each bar represent 95% confidence intervals