Environmental determinants and markers of Lassa fever transmission in a low socioeconomic community in Akure, southwestern Nigeria

Abstract

Background: Lassa fever is currently one of the most acute and priority vector-borne endemic viral diseases with a prevalence of 40% in Nigeria. Domestic settings or housing conditions have been hypothesized to be important sites for primary transmission but information on the relationship between morbidity and environmental factors is inadequate. We assessed environmental factors and identified markers that could predispose a community to the transmission of Lassa fever in a low socioeconomic community in Akure, Nigeria. Methods and materials: The study employed a descriptive cross sectional design with field and laboratory components of which 276 respondents and 35 households were systematically sampled. Traps were placed in each of the households sampled for four weeks and rodents captured were identified using morphological characteristics. Viral screening was done on rodents captured using reverse transcriptase polymerase chain reaction for detection of Lassa virus. Logistics regression was use to establish associations at a statistical significance of 0.05. Results: Observations showed that most houses had cracks and holes on their walls and floors respectively and hygiene/sanitary facilities and practices were poor in most houses. Respondents with good housing condition were 1.9 times more likely to have good hygiene practice compared to those that had poor housing condition (OR = 1.941, p = 0.009). 73.4% of respondents reported that they see rats every day in their houses. Three species of rodents were trapped from the selected households with Rattus rattus (43.2%) being the dominant species in the homes of the study area followed by Rattus fuscipes (38.6%) and Rattus norvegicus (18.2%). Two species of Rattus rattus tested positive, Rattus fuscipes and Rattus norvegicus had one rodent species each respectively testing positive for the strain. Conclusion: Environmental factors such as housing conditions, hygiene practices, etc. can predispose a community to the transmission of Lassa fever. Regular environmental sanitation within and around homes with surveillance is hereby advocated.