Ascaris lumbricoides egg die-off in an experimental excreta storage system and public health implication in Vietnam

Int J Public Health. 2017 Feb;62(Suppl 1):103-111. doi: 10.1007/s00038-016-0920-y. Epub 2016 Nov 22.

Abstract

Objectives: We studied the influence of different additive materials (lime, and rice husk) and aeration conditions on Ascaris lumbricoides egg die-off in 24 vaults of an experimental excreta storage unit.

Methods: Excreta samples were collected once every two weeks over a 181-day period. Temperature, pH, and moisture content were recorded. A. lumbricoides eggs were quantitatively analyzed by the Romanenko method, which identified and counted live and dead eggs.

Results: From the first sampling (0 storage day) to the final sampling (181 storage days) the average percentage of viable A. lumbricoides eggs decreased gradually from 76.72 ± 11.23% (mean ± SD) to 8.26 ± 5.20%. The storage time and the high pH value significantly increased the die-off of helminth eggs. Over 181 storage days, all vaults option effectively reduced A. lumbricoides eggs die-off.

Conclusions: The best vault option, with aeration and 10% lime per total weight, met the WHO standard for excreta treatment on the 111th storage day.

Keywords: Ascaris lumbricoides; Helminth; Human excreta; Vietnam; Waste reuse.

MeSH terms

  • Animals
  • Ascariasis / prevention & control
  • Ascaris lumbricoides / physiology*
  • Calcium Compounds / chemistry
  • Feces / chemistry
  • Feces / parasitology*
  • Humans
  • Hydrogen-Ion Concentration
  • Oryza
  • Oxides / chemistry
  • Parasite Egg Count*
  • Temperature
  • Time Factors
  • Vietnam
  • Waste Management / methods*

Substances

  • Calcium Compounds
  • Oxides
  • lime