Related Experiment Video
Updated: Mar 12, 2026

A High-throughput Platform for the Screening of Salmonella spp./Shigella spp.
Published on: November 7, 2018
Diarrhea risks by exposure to livestock waste in Vietnam using quantitative microbial risk assessment
Thu Le-Thi1, Phuc Pham-Duc1, Christian Zurbrügg2
1Center for Public Health and Ecosystem Research, Hanoi School of Public Health, Hanoi, Vietnam.
Objectives:
The aim of this paper was to assess the diarrhea risks caused by various pathogens among those exposed to biogas wastewater through different activities.
Methods:
Application of quantitative microbial risk assessment (QMRA) of biogas wastewater was conducted in Hanam Province, Vietnam. A total of 451 representatives from households that use biogas were interviewed about their practices of handling biogas plant and reuse of biogas effluent for irrigation. In addition, 150 samples of biogas wastewater were analyzed for Escherichia coli, Cryptosporidium parvum, and Giardia lamblia. Risk characterization was calculated using Monte Carlo simulation.
Results:
The annual diarrhea risk caused by exposure to biogas effluent through irrigation activities ranged from 17.4 to 21.1% (E. coli O157:H7), 1.0 to 2.3% (G. lamblia), and 0.2 to 0.5% (C. parvum), while those caused through unblocking drains connected to biogas effluent tanks were 22.0% (E. coli), 0.7% (G. lamblia), and 0.5% (C. parvum).
Conclusions:
Further measures are needed to reduce the risk by either improving the microbial quality of biogas effluent or by ensuring the use of personal protective measures when exposed to biogas wastewater.

