PLoS Neglected Tropical Diseases (Jun 2022)

National surveillance of hookworm disease in China: A population study.

  • Hui-Hui Zhu,
  • Ji-Lei Huang,
  • Ying-Dan Chen,
  • Chang-Hai Zhou,
  • Ting-Jun Zhu,
  • Men-Bao Qian,
  • Mi-Zhen Zhang,
  • Shi-Zhu Li,
  • Xiao-Nong Zhou

DOI
https://doi.org/10.1371/journal.pntd.0010405
Journal volume & issue
Vol. 16, no. 6
p. e0010405

Abstract

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BackgroundHookworm disease is endemic in China and is widespread globally. The disease burden to humans is great.MethodsThe study described the national surveillance of hookworm implemented in 31 provinces/autonomous regions/municipalities (P/A/Ms) of China in 2019. Each P/A/M determined the number and location of surveillance spots (counties). A unified sampling method was employed, and at least 1000 subjects were investigated in each surveillance spot. The modified Kato-Katz thick smear method was employed for stool examination. Fifty samples positive with hookworm eggs were cultured in each surveillance spot to discriminate species between A. duodenale and N. americanus. Twenty-five soil samples were collected from each surveillance spot and examined for hookworm larva. The 2019 surveillance results were analyzed and compared with that of 2016-2018.ResultsA total of 424766 subjects were investigated in 31 P/A/Ms of China in 2019, and the overall hookworm infection rate was 0.85% (3580/424766). The weighted infection and standard infection rates were 0.66% (4288357/648063870) and 0.67% (4343844/648063870), respectively. Sichuan province had the highest standard infection rate (4.75%) in 2019, followed by Chongqing (2.54%) and Hainan (2.44%). The standard infection rates of other P/A/Ms were all below 1%, with no hookworm detected in 15 P/A/Ms. The standard hookworm infection rate in the males and the females were 0.61% (2021216/330728900) and 0.71% (2267141/317334970), respectively, with a significant difference between different genders ([Formula: see text] = 17.23, PConclusionThe national surveillance showed that the hookworm infection rate has been decreasing annually from 2016 to 2019, and it is now below 1%. China has made significant progress in controlling hookworm. The national surveillance system is an important way to understand the endemic status and provide important information in this process and thus needs to be continually optimized.