Projected Burden of Ascaris lumbricoides Infection Globally and in Afghanistan: Trends, Disparities, and Implications for Control up to 2040

Abstract

Background: Ascaris lumbricoides remains one of the most common soil-transmitted helminths (STHs) worldwide and mostly affects low-income and conflict-affected populations. Global efforts at control have reduced the prevalence in many parts of the world, but substantial inequalities persist. We aimed to project the age-standardized prevalence rates (ASPR) of A. lumbricoides globally and in Afghanistan for the period 2023-2040, emphasizing temporal trends and sex-based disparities.

Methods: We used cubic spline regression models to analyze sex-stratified ASPR data from the Global Burden of Disease Study 2023 (1990–2023), forecasting prevalence through 2040 with 95% confidence intervals (CIs) for all estimates.

Results: The ASPR of A. lumbricoides in 2023 at a global level was 4319.6 per 100,000 populations, while Afghanistan showed a burden threefold higher, with 12,962.8 per 100,000. In 2040, the global ASPR would decline by 29.6% to 3040.6 per 100,000, whereas Afghanistan's ASPR would decrease only by 21.0% to 10,243.5 per 100,000 and remain 3.4 times above the global average. Females consistently showed higher ASPRs than males both at global and national levels, a trend expected to continue to the year 2040.

Conclusions: Afghanistan is predicted to continue to have extreme levels of ascariasis, with high and inequitable burdens of disease despite continued global progress. These findings underscore serious limitations of aggregate global indicators and the need for precision public-health strategies in high-burden settings that address structural determinants such as conflict, poverty, inadequate sanitation, and gender inequality.