Epidemiology of tungiasis at the animal–human interface in a vulnerable rural community

Abstract

Introduction Tungiasis remains a major public health problem in Sub-Saharan Africa. Despite its substantial morbidity, the role of domestic animals to human infection risk at the household level remains poorly understood, limiting the development of effective control strategies. This study aimed to (i) determine the prevalence and determinants of tungiasis in domestic animals, and (ii) evaluate the household-level association between animal infestation and human infection in a vulnerable rural community in Badagry, Lagos State, Nigeria. Methods A cross-sectional study was conducted among 626 participants between September 2021 and June 2022. Data were collected using a structured questionnaire capturing sociodemographic characteristics, household environmental conditions, behavioral factors, and hygiene-related practices. Clinical examinations of both human participants and domestic animals were performed using standardized diagnostic criteria. Associations were evaluated using univariable and multivariable logistic models, while multilevel logistic regression was used to evaluate household-level association between animal infection and human infection. Statistical significance was set at p < 0.05. Main findings The prevalence of tungiasis was 7.2% and 5.4% for domestic animals and human participants. Factors associated with animal infection included the presence of dogs in the household (OR=3.90; 95% CI: 2.03 - 7.88), earthen flooring (OR=2.72; 95% CI: 1.31 - 5.49), the presence of at least one infected household member (OR=2.95; 95% CI: 1.07 - 7.55), and frequent rat sightings (OR=2.49; 95% CI: 1.13 - 6.30). At the household-level, the presence of infected animal (OR=2.29; 95% CI: 0.74 - 7.12), sleeping on a mat placed on the floor (OR=1.69; 95% CI: 0.47 - 6.05), and daily rat sightings (OR=2.60; 95% CI: 0.71 - 9.53) were associated with higher odds of human infections. Households with cemented floor (OR=0.25; 95% CI: 0.08 - 0.76) served as a protective factor. Interpretation Household environmental conditions appear to play an important role in the epidemiology of tungiasis. Although households with infected animals showed higher odds of human infection, this association was not statistically significant and should be interpreted cautiously. Further longitudinal studies are required to clarify the transmission dynamics and inform integrated control strategies involving housing improvements, environmental sanitation, and personal protective practices.