Seroprevalence of anti-HAV total antibodies among workers in wastewater treatment plants

• Published in: International journal of occupational medicine and environmental health Vol. 31; no. 3; pp. 307 - 315
• Main Authors: Toseva, Elka, Atanasova, Mariya, Turnovska, Tanya
• Format: Journal Article
• Language: English
• Published: Poland Nofer Institute of Occupational Medicine 01.01.2018
• Subjects: Adult; Age Factors; anti-HAV total antibodies; Antibodies; Bulgaria - epidemiology; Confidence intervals; Economic activity; Economic conditions; Epidemiology; Exposure; Female; Health aspects; Hepatitis; Hepatitis A; Hepatitis A Antibodies - blood; Humans; Immune response; Immune response (humoral); Immune system; Immunization; Immunoglobulins; Infections; Male; Methods; Middle Aged; Occupational exposure; Occupational Exposure - statistics & numerical data; Operators; Personnel; Prevalence; Risk factors; Seroepidemiologic Studies; Serology; seroprevalence; Sludge; Viruses; Waste Disposal, Fluid; Wastewater; Wastewater collection; Wastewater treatment; Wastewater treatment plants; Water treatment plants; Workers; Working conditions; Bulgaria; anti-HAV total antibodies; seroprevalence; wastewater; hepatitis A; workers; immunization
• DOI: 10.13075/ijomeh.1896.01161
• ISSN: 1232-1087; 1896-494X

Data on high frequency of hepatitis A virus (HAV) antibodies for wastewater treatment staff is contradictory. Literature lacks data on the seroprevalence of antibodies to HAV (anti-HAV) among workers in wastewater treatment plants (WWTPs) in Bulgaria. The aim of this study is to establish a specific humoral immune response to hepatitis A virus - anti-HAV total antibodies among staff in WWTPs. A complex study of health and working conditions included 110 subjects working in 3 WWTPs in Bulgaria (74% of all workers in the 3 studied WWTPs and 20% of all employees in Bulgaria registered in 2014 under the wastewater collection, discharge and treatment code of economic activity). Workers had been differentiated in 3 groups on the basis of their occupational work: operators, support staff and other workers exposed to biological agents. Venous blood from all 110 subjects was tested once for carriers of HAV antibodies. Anti-HAV total antibodies were found for 52.7% of workers in WWTPs. There is a positive association between activity performed in WWTPs (operators, maintenance personnel and others exposed) and a positive one for the presence of anti-HAV (Chi = 6.882, df = 2, p = 0.032). Odds ratio (OR) for hepatitis A increases 2.9 times in the group of operators vs. others exposed to biological agents in WWTPs (OR = 2.914, 95% confidence interval (CI): 1.149-7.393, Fisher's p = 0.039). Odds ratio for hepatitis A increases 4.3 times in the group of support staff from WWTPs vs. others exposed to biological agents in WWTP (OR = 4.295, 95% CI: 1.075-17.167, Fisher's p = 0.049). Higher frequency of anti-HAV antibodies among operators and maintenance personnel at WWTPs has been established as compared to other workers exposed to biological agents in WWTPs. There is a positive association between increasing age of the workers and the presence of anti-HAV. Int J Occup Med Environ Health 2018;31(3):307-315.