Prevalence and determinants of soil transmitted helminth infections among children on Highly Active Antiretroviral Therapy (HAART) in Mulobezi and Sesheke Districts, Zambia: A cross - sectional study.

BACKGROUND

Soil-transmitted helminth (STH) infections are a major public health challenge in regions where they overlap with HIV/AIDS. Children with HIV may be especially vulnerable to STHs due to immunosuppression, yet the burden and drivers of this co-infection among those on antiretroviral therapy (ART) in Zambia are not well documented. This study aimed to determine the prevalence and identify the key determinants of STH infections among ART-treated children in Western (Mulobezi and Sesheke districts) Zambia.

METHODS

We conducted a cross-sectional study with a retrospective clinical review in the Mulobezi and Sesheke districts. From a total population of 487 eligible children, a sample of 103 ART-initiated children aged 5-15 years was enrolled. Participants were selected using stratified random sampling: the sample was first proportionally allocated to six health facilities (strata), and then individual children were randomly selected from clinic lists within each facility. Data was collected using questionnaires, medical records, and laboratory analysis of blood and stool samples (using the Kato-Katz technique). Bivariate analyses used Chi-square/Fisher's exact and Mann-Whitney U tests. Viral load was log₁₀-transformed for analysis. Variables significant at *p* < 0.1, along with key clinical factors, were entered into a multivariable logistic regression model built via backward stepwise elimination to identify independent predictors. Model fit was assessed using the Hosmer-Lemeshow test.

RESULTS

The prevalence of any STH infection was 11.7% (12/103), with Ascaris lumbricoides (6.8%) being the most common species. In the final adjusted model, independent predictors of STH infection were a lower CD4 + count (aOR=3.25 per 100 cells/mm³ decrease; 95% CI: 1.82-5.80), a higher log₁₀ viral load (aOR=2.40 per unit increase; 95% CI: 1.45-3.96), and suboptimal ART adherence, with occasional misses conferring the highest risk (aOR=15.82; 95% CI: 2.98-84.02) compared to very consistent adherence. Lack of clean water access was not retained in the final model.

CONCLUSION

A notable prevalence of STH infection persists among ART-treated children in this setting, driven primarily by immunological and treatment-adherence factors. These findings support integrating routine STH screening and targeted deworming into paediatric HIV care programs, alongside interventions to optimize ART adherence and immunological recovery.