Beyond Bed Nets: Exploring Household Malaria Prevention Methods and Health Outcomes in Western Kenya

Abstract

Background: Malaria remains a leading cause of morbidity and mortality, especially among children, in sub-Saharan Africa. Globally, there were an estimated 229 million malaria cases in 2019. The World Health Organization (WHO) promotes integrated vector management to prevent malaria, which includes the use of long-lasting insecticide treated bed nets (LLINs), Indoor Residual Spraying (IRS), and environmental management. While LLINs and IRS have been shown to be highly effective in controlled conditions, there are still challenges with community acceptance and consistent use of these methods. People often implement multiple malaria prevention strategies and the choice of which strategies to use is influenced by myriad of individual, household, community, and global factors. The use of smoke-based malaria prevention methods, like mosquito coils, has been documented across sub-Saharan Africa. Several studies have documented the association between exposure to mosquito coils/burning biomass and respiratory illnesses, including acute lower respiratory infections (ALRIs), while other studies suggest they be protective against malaria. Methods: This study combined qualitative and quantitative methods to investigate the use of malaria prevention methods in two sites in western Kenya with disparate malaria transmission. In June 2015, focus groups on malaria prevention knowledge, attitudes, and practices were held with approximately 80 people across the two sites. Simultaneously, a cross-sectional study was conducted among 1,213 households in the same areas using cluster random sampling to 1) identify the types, frequency, and determinants of malaria prevention methods used and 2) identify the risk of acute lower respiratory infections (ALRI) and malaria in relation to smoke-based malaria prevention strategies. Results: Focus group participants perceived malaria as a serious issue, but they perceived benefits of mosquito control beyond malaria prevention (ex. having more comfortable sleep). Focus Group Discussions (FGD) and the household survey confirmed that households use multiple strategies, often concurrently, to control mosquitoes and to prevent malaria. While bed nets were the most frequently used malaria prevention method, nearly 20% of households used smoke-based prevention methods. The methods varied, however, significantly between the two sites. Households from the lowlands generally used more methods and more often than those in the highlands. In this study, prevalence of ALRI and malaria was 7.5% and 20.5%, respectively. ALRI was highest among adults aged 66 and older and children aged 2-4 years, and malaria was highest in children aged 5-11. The lowlands had significantly higher ALRI and malaria prevalence for all age groups. Exposure to high levels of smoke-based malaria prevention methods among children under 5 years was associated with 3.1 times the odds of ALRI compared to those with low exposure after controlling for other sources of smoke exposure. No significant association between smoke-based malaria prevention methods exposure and ALRI was found among individuals 5 years of age and older. Additionally, there was no association between the use of smoke-based malaria prevention methods and current malaria infection. Conclusions: The use of malaria prevention methods is driven by a myriad of individual, household, community, and sociocultural factors. Households use multiple methods of malaria prevention, often concurrently. While bed nets were reported to be widely used, people were also using potentially harmful methods to prevent malaria including burning biomass, mosquito coils, and man-made materials. Our study found an association between higher levels of smoke-based malaria prevention methods exposure and ALRI among children under 5 years. We found no association between current malaria infection and exposure to smoke-based malaria prevention methods, indicating the health risks of smoke-based methods may outweigh the benefits, especially among children. Removing smoke-based methods as a source of indoor air pollution (IAP) could help reduce overall risk for ALRI among young children, and the use of smoke-based prevention methods indoors should be explicitly discouraged due to the risk of respiratory illness.