Factors Influencing Malaria Transmission in Gokwe South District, Midlands Province, Zimbabwe, 2021

Abstract

Malaria continues to be an ongoing problem in African countries south of the Sahara. Although a lot has been achieved in the past 15 years, millions of people still remain at risk. Correct identification of disease vectors is the first step towards implementing an effective malaria control programme. In the past few years, there has been an increase in the incidences of cases of malaria in Gokwe South district. The study sought to investigate the cases of malaria despite the interventions that were in place in the district through a correlational study in which data was recorded on exposures to mosquito bites and compared to outcome variables of those who have had malaria in 2020. Social and economic activities for those who contracted malaria were compared to those who had not contracted in the same year. A pretested, interviewer-administered questionnaire was also used to determine the sleeping habits of the participants, the known feeding habits, and the biting patterns of the anopheles mosquitoes. The Centre for Disease Control (CDC) light traps were used to capture mosquitoes for morphological identification. Data was analyzed using Epi info 7. Descriptive statistics were calculated and multiple logistic regression analysis was used to establish independent factors for residual malaria. Mosquitoes were found feeding mostly outside the house as well as both indoors and outdoors. Only Anopheles gambiae sensu lato (s.l) (100% of all captured Anopheles mosquitoes) were captured using the CDC light traps. Mosquitoes were found to be more active at dusk and at dawn for both indoor and outdoor biting. The key drivers of residual malaria transmission in Gokwe South District were established as: resting/relaxing outdoors at night (adjusted Odds Ratio (aOR): 11.5; 95%CI: 3.3-40.2), sleeping outdoors at night (aOR: 5.4; 95%CI: 1.7-17.7) and bathing outdoors before sleep (aOR: 5.1, 95%CI: 1.1-22.7). The results showed that human behaviour exposed people to An. gambiae s.l. biting. The sleeping patterns tend to be the major driver of residual malaria among the inhabitants of Gokwe south district. Health education and behavioural change communication should target adoption of malaria control measures when outdoors. Focus must be placed on dealing with the key drivers of residual malaria as established in this study.