Risk of hepatitis A infection in sewage workers.
OBJECTIVE
To evaluate the risk of hepatitis A virus (HAV) infection among sewage workers from occupational exposure to raw sewage.


METHODS
An analytical cross sectional study of 241 company employees with possible occupational exposure to sewage in a large water and sewerage company was carried out. Previous exposure to hepatitis A virus infection was assessed, as were its associations with possible risk factors.


RESULTS
Frequent occupational exposure to raw sewage was a significant risk factor for HAV infection, independently of other known risk factors (odds ratio 3.73, 95% confidence interval 1.48 to 9.37). Of 50 employees who reported occupational exposure to raw sewage most of the time, 30 (60%) had had HAV infection.


CONCLUSIONS
Employees who are likely to be at risk of frequent exposure should have their immunity ensured. The salivary assay for IgG anti-HAV used in the study was highly specific and would be suitable for prevaccination testing of older employees, who are more likely to be immune.
Brugha
R
R
Immunisation Division, Public Health Laboratory Service, Communicable Disease Surveillance Centre, London, UK.
Heptonstall
J
J
Farrington
P
P
Andren
S
S
Perry
K
K
Parry
J
J
D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D003430:Cross-Sectional Studies; D006506:Hepatitis A / Q000209:etiology*; D006515:Hepatitis B virus / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology*; D012307:Risk Factors; D012722:Sewage
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D012722:Sewage