The spatial-temporal distribution of soil-transmitted helminth infections in Guangdong Province, China: A geostatistical analysis of data derived from the three national parasitic surveys

PLoS Negl Trop Dis. 2022 Jul 18;16(7):e0010622. doi: 10.1371/journal.pntd.0010622. eCollection 2022 Jul.

Abstract

Background: The results of the latest national survey on important human parasitic diseases in 2015-2016 showed Guangdong Province is still a moderately endemic area, with the weighted prevalence of soil-transmitted helminths (STHs) higher than the national average. High-resolution age- and gender-specific spatial-temporal risk maps can support the prevention and control of STHs, but not yet available in Guangdong.

Methodology: Georeferenced age- and gender-specific disease data of STH infections in Guangdong Province was derived from three national surveys on important human parasitic diseases, conducted in 1988-1992, 2002-2003, and 2015-2016, respectively. Potential influencing factors (e.g., environmental and socioeconomic factors) were collected from open-access databases. Bayesian geostatistical models were developed to analyze the above data, based on which, high-resolution maps depicting the STH infection risk were produced in the three survey years in Guangdong Province.

Principal findings: There were 120, 31, 71 survey locations in the first, second, and third national survey in Guangdong, respectively. The overall population-weighted prevalence of STH infections decreased significantly over time, from 68.66% (95% Bayesian credible interval, BCI: 64.51-73.06%) in 1988-1992 to 0.97% (95% BCI: 0.69-1.49%) in 2015-2016. In 2015-2016, only low to moderate infection risk were found across Guangdong, with hookworm becoming the dominant species. Areas with relatively higher risk (>5%) were mostly distributed in the western region. Females had higher infection risk of STHs than males. The infection risk of A. lumbricoides and T. trichiura were higher in children, while middle-aged and elderly people had higher infection risk of hookworm. Precipitation, elevation, land cover, and human influence index (HII) were significantly related with STH infection risk.

Conclusions/significance: We produced the high-resolution, age- and gender-specific risk maps of STH infections in the three national survey periods across nearly 30 years in Guangdong Province, which can provide important information assisting the control and prevention strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Ancylostomatoidea
  • Animals
  • Ascaris lumbricoides
  • Bayes Theorem
  • Child
  • China / epidemiology
  • Feces / parasitology
  • Female
  • Helminthiasis* / epidemiology
  • Helminthiasis* / parasitology
  • Helminths*
  • Hookworm Infections* / epidemiology
  • Humans
  • Male
  • Middle Aged
  • Parasitic Diseases*
  • Prevalence
  • Soil / parasitology

Substances

  • Soil

Grants and funding

YSL was financial supported by the National Natural Science Foundation of China (Grant No. 82073665, https://www.nsfc.gov.cn/), and by the Natural Science Foundation of Guangdong Province (Grant No. 2022A1515010042, http://gdstc.gd.gov.cn/), and by the Sanming Project of Medicine in Shenzhen (Grant No. SZSM201803061), and by the Fundamental Research Funds for the Central Universities, Sun Yat-sen University (Grant No. 22qntd4201). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.