Factors Associated With a Malaria Outbreak at a Refugee Camp in Chipinge District, Zimbabwe, 2021
- Vector-borne
Background: Malaria is a leading cause of morbidity and mortality among refugees, with two-thirds residing in malaria-endemic regions. The rapid disease notification system data for the Tongogara Refugee Camp (TRC) Clinic reported 29, 20 and 23 malaria patients above action threshold levels during week 12, 13 and 14 of 2021 respectively, despite 85% coverage of indoor-residual spraying. We determined factors associated with contracting malaria at TRC in Chipinge District, Zimbabwe.
Methods: We conducted a 1:1 unmatched case-control study involving 80 case-control pairs from March 22–April 18, 2021. A case was a resident of TRC who presented with sudden onset of malaria sign(s) and symptom(s), and a positive rapid diagnostic test (RDT) or malaria positive slide. We collected data using interviewer-administered questionnaires. Observations were done to assess the surrounding environment, and medical records were reviewed to assess case management. We generated medians, proportions, multivariate-adjusted odds ratios (AORs), and 95% confidence intervals (CI) using Epi Info vs. 7.
Results: Males constituted 47 (59%) patients versus 43 (54%) controls, p=0.524. Despite constituting 10% of the population, Mozambican nationals were 36 (45%) out of 80 patients. The majority, 70 (87%) patients and 65 (81%) controls resided within 3 km of a stagnant water body (p=0.276). Pyrethrum spray catches (PSCs) conducted near Mayeza Dam yielded no indoor-resting mosquitoes. Larval sampling harvested 18 Anopheles larvae. Contracting malaria was associated with engaging in outdoor night activities (AOR=4.26; 95% CI=1.43–12.68] and wearing clothes exposing the body during outdoor night activities (AOR=2.74; 95% CI 1.04–7.22). Sleeping in a refugee housing unit reduced malaria risk (AOR=0.18; 95% CI, 0.06–0.55).
Conclusions: Behavioral factors such as engaging in outdoor activities at night without clothes that cover the whole body contributed to malaria transmission among refugees. We recommended intensified health education on malaria transmission and prevention measures. As a result of the study, larviciding of water bodies around TRC was conducted.
Methods: We conducted a 1:1 unmatched case-control study involving 80 case-control pairs from March 22–April 18, 2021. A case was a resident of TRC who presented with sudden onset of malaria sign(s) and symptom(s), and a positive rapid diagnostic test (RDT) or malaria positive slide. We collected data using interviewer-administered questionnaires. Observations were done to assess the surrounding environment, and medical records were reviewed to assess case management. We generated medians, proportions, multivariate-adjusted odds ratios (AORs), and 95% confidence intervals (CI) using Epi Info vs. 7.
Results: Males constituted 47 (59%) patients versus 43 (54%) controls, p=0.524. Despite constituting 10% of the population, Mozambican nationals were 36 (45%) out of 80 patients. The majority, 70 (87%) patients and 65 (81%) controls resided within 3 km of a stagnant water body (p=0.276). Pyrethrum spray catches (PSCs) conducted near Mayeza Dam yielded no indoor-resting mosquitoes. Larval sampling harvested 18 Anopheles larvae. Contracting malaria was associated with engaging in outdoor night activities (AOR=4.26; 95% CI=1.43–12.68] and wearing clothes exposing the body during outdoor night activities (AOR=2.74; 95% CI 1.04–7.22). Sleeping in a refugee housing unit reduced malaria risk (AOR=0.18; 95% CI, 0.06–0.55).
Conclusions: Behavioral factors such as engaging in outdoor activities at night without clothes that cover the whole body contributed to malaria transmission among refugees. We recommended intensified health education on malaria transmission and prevention measures. As a result of the study, larviciding of water bodies around TRC was conducted.