Re-examination of Opisthorchis viverrini Infection in Northeast Thailand.
BACKGROUND
Liver fluke infection caused by the parasite Opisthorchis viverrini (O. viverrini), a human carcinogen, is endemic in north-eastern Thailand and remains a major health problem.


OBJECTIVE
The objectives of the study were to (1) resurvey the prevalence of O. viverrini infection in a field site from the Khon Kaen Cohort Study (in newly recruited subjects as well as previous cohort subjects surveyed in 1992); (2) investigate how subjects' lifestyle habits and their exposure to health promotion initiatives influence changes in prevalence of O. viverrini infection.


METHODS
The prevalence of O. viverrini infection in the cohort subjects (as well as new subjects) was investigated using faecal egg counts. Information on demographic factors, lifestyle and awareness of health promotion initiatives were obtained through questionnaires.


RESULTS
O. viverrini infection rates in the same individuals of the cohort were lower in 2006 than in 1992. Also, by studying the period effect, the current 35-44 year olds had a 12.4% (95% CI 3.9% to 20.9%) lower prevalence of O. viverrini infection than the 35-44 year olds in 1992 (24.2% versus 11.8%). Lifestyle choices showed that smoking and alcohol consumption were associated with an increased chance of acquiring O. viverrini infection with adjusted odds ratios of 10.1 (95%CI 2.4-41.6) and 5.3 (95%CI 1.2-23.0), respectively.


CONCLUSIONS
Our study has demonstrated that although the prevalence of O. viverrini infection over a 14-year period has decreased, unhealthy lifestyle was common with smoking and alcohol consumption being associated with increased chances of infection, emphasising the double burden of disease which developing countries are facing.
Department of Public Health,University of Oxford, Oxford, UK.
Kheng-Wei
KW
Yeoh
supanee@kku.ac.th
Supannee
S
Promthet
Paiboon
P
Sithithaworn
Supot
S
Kamsa-Ard
Donald Maxwell
DM
Parkin
D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology*; D000818:Animals; D015331:Cohort Studies; D005243:Feces / Q000469:parasitology; D005260:Female; D006293:Health Promotion / Q000706:statistics & numerical data*; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D009889:Opisthorchiasis / Q000453:epidemiology*; D009891:Opisthorchis; D015995:Prevalence; D065840:Protective Factors; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D013785:Thailand / Q000453:epidemiology