Southern Africa ICEMR Cross-sectional

Objectives:

Research Area A: Barriers to Malaria Control in Southern and Central Africa

Aim 1: Identify evolving temporal and spatial patterns and drivers of parasite prevalence, incidence and vector densities and guide targeted intervention strategies in moderate to high malaria transmission settings in Southern and Central Africa.

Aim 2: Identify persistent and emerging barriers to malaria control in moderate to high malaria transmission settings in Southern and Central Africa, including insecticide resistance, antimalarial drug resistance and cross-border malaria transmission.

Aim 3: Evaluate and optimize combinations of vector control and drug-based malaria control interventions in moderate to high malaria transmission settings in Southern and Central Africa in collaboration with implementing partners.

Research Area B: Intractable Malaria Vector Populations and Residual Transmission in Southern and Central Africa

Aim 1: Define and extrapolate risk of vector exposure in the context of ongoing programmatic control at a high transmission setting along the northern Zambia/Democratic Republic of Congo border and at a low transmission setting in southern Zambia.

Aim 2: Identify entomological barriers to vector control in both low and high transmission settings in Zambia.

Aim 3: Utilize changes in parasite genetic diversity in vector mosquitoes as an indicator of successful vector control and reduction of transmission in high transmission settings in Zambia and the DRC.

Research Area C: Achieving, Sustaining and Documenting Malaria Elimination in Southern Province, Zambia

Aim 1: Optimize active and passive surveillance strategies to identify and characterize residual foci of transmission in a low transmission setting in Southern Province, Zambia.

Aim 2: Determine the risk of imported malaria and the contribution of the asymptomatic reservoir to focal transmission in a pre-elimination setting in Southern Province, Zambia.

Aim 3: Quantify the role of secondary vectors in sustaining malaria transmission in a pre-elimination setting in Southern Province, Zambia.

Aim 4: Assess the utility of serosurveillance for monitoring and documenting elimination in a pre-elimination setting in Southern Province, Zambia.

Methodology:

Geographic Location/Study Sites: Two sites in Zambia (Choma and Nchelenge Districts) and one site in Zimbabwe (Mutasa District)

Dates of Data Collection: March 2012-present

Study Design: Cross-sectional survey

Eligibility Criteria: High resolution satellite images of the study areas were used to randomly select study households for each survey. Inclusion criteria included:

Resident of selected household
Willing and able to provide consent or have a parent or guardian who is willing and able to provide consent
Persons of all ages are eligible for enrollment
Pregnant and breastfeeding women are eligible for enrollment

Data Collection: Study visits were conducted over two days. During the first visit, permission for study participation was obtained from the head of the household. The next day, study questionnaires were administered and specimens were collected after written informed consent was obtained from eligible adults and parents of eligible children. Standardized, field tested survey instruments were used to collect information from each adult study participant (or caretaker for children younger than 16 years of age) on demographic characteristics, general knowledge of malaria (transmission, prevention, and treatment), malaria treatment history and health seeking behavior, recent travel history, use of ITNs and IRS, and socio-economic indicators. Data was captured and stored on Android phones using ODK software and uploaded onto a server or downloaded onto a computer hard drive. Study staff collected finger-prick blood specimens from enrolled children and adults and 1) spotted onto rapid diagnostic test cassettes that detect P. falciparum HRP-2; 2) collected in a capillary tube for serology; and 3) spotted onto filter paper for parasite detection by PCR and parasite genotyping. Individuals who were RDT-positive were offered ACT treatment by study staff with drugs provided by the Ministry of Health in Zambia or Zimbabwe. Quinine (plus clindamycin if available) was offered to pregnant women (self-reported) estimated to be in the first trimester of pregnancy, according to guidelines of the World Health Organization (WHO) and Ministry of Health in Zambia and Zimbabwe. Individuals with signs and symptoms of severe malaria, or other illness requiring urgent evaluation, were provided transport to a local health center or hospital.

See the study protocol for detailed information on all studies conducted by the Southern and Central Africa ICEMR. The figure below is a schematic of all study designs.

Study Documentation:

Household data codebook - Used to collect information related to the participant's home
Participant data codebook - Used to collect information about participants

ClinEpiDB Data Integration: Data files were provided to ClinEpiDB as flat csv files. These datasets were merged by unique ID and redundant or administrative columns were dropped from presentation on ClinEpiDB.org. All dates were obfuscated per participant through the application of a random number algorithm that shifted dates no more than seven days to comply with the ethical conduct of human subjects research.

Acknowledgements: We thank the study and field teams at the Tropical Diseases Research Centre, Macha Research Trust, Biomedical Research and Training Institute, and National Institute of Health Research for their work across nearly a decade of data collection. We are grateful to the Zambia National Malaria Elimination Centre, Zimbabwe National Malaria Control Programme, and the Medical Research Council of Zimbabwe for their support. Finally, we are extremely grateful for the participation of the communities in Zambia and Zimbabwe and for allowing us into their homes.

Financial Support: National Institute of Allergy and Infectious Diseases of the National Institutes of Health, Bloomberg Philanthropies, and Johns Hopkins Malaria Research Institute

Ethics Statement: Ethical approval was obtained from Johns Hopkins Bloomberg School of Public Health Institutional Review Board, Tropical Diseases Research Center Ethics Review Committee, Biomedical Research and Training Institute Institutional Review Board, and Medical Research Council of Zimbabwe

Last Updated: November 13, 2023
A cross-sectional study of malaria in different transmission settings was conducted in Zambia and Zimbabwe. Households were randomly surveyed, and all participants within a household were eligible for enrollment.