Epidemiology and aetiology of diarrhoeal diseases in adults engaged in wastewater-fed agriculture and aquaculture in Hanoi, Vietnam.
OBJECTIVE
To determine the occurrence of and risk factors for diarrhoea in an adult population exposed to wastewater used for agricultural and aquacultural productions.


METHODS
An open cohort of 636 adults aged 15-70 years living in a wastewater-irrigated area in Hanoi was followed by weekly visit for 18 months. The aetiology and risk factors for diarrhoeal diseases were determined in a nested case-control study. Stool specimens and exposure information related to wastewater, hygiene, water and food consumption were collected from 163 unmatched pairs of cases and controls.


RESULTS
The incidence rate of diarrhoeal diseases was 28.1 episodes per 100 person-years at risk. Of the 326 stool specimens, 47 cases and 24 controls were identified with enteric pathogens, of which diarrhoeagenic Escherichia coli and Entamoeba histolytica were the most common. Risk factors for diarrhoeal diseases included contact with wastewater [odds ratio (OR) = 1.98, attributable fraction of the population (AF) 35%], not washing hands after defecation (OR = 3.34, AF 3%), drinking water from a well (OR = 6.21, AF 6%), consumption of raw or undercooked foods (OR = 2.45, AF 6%), and contact with persons with diarrhoea (OR = 4.22, AF 5%).


CONCLUSIONS
Wastewater contact was the principal risk factor for diarrhoea in this population. As the local economy depends on the use of wastewater for agriculture and aquaculture, it is important to find ways to mitigate the public health risks associated with this use, in addition to promotions of personal, domestic and food hygiene.
Do
Thuy Trang
TT
Division of Enteric Infections, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam. tranghai16@yahoo.com
Bui
Thi Thu Hien
TT
Mølbak
Kåre
K
Phung
Dac Cam
DC
Dalsgaard
Anders
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000382:Agricultural Workers' Diseases / Q000453:epidemiology / Q000382:microbiology; D000383:Agriculture / Q000191:economics / Q000379:methods; D000818:Animals; D017756:Aquaculture / Q000191:economics / Q000379:methods; D015331:Cohort Studies; D003967:Diarrhea / Q000209:etiology* / Q000517:prevention & control; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010270:Parasite Egg Count; D011634:Public Health; D012307:Risk Factors; D012722:Sewage / Q000382:microbiology*; D014744:Vietnam / Q000453:epidemiology
D012722:Sewage