Hepatitis A seroprevalence and epidemiological shift in central Adana, Turkey from 1999 to 2009

Aim: The aim of the study was to carry out the anti-Hepatitis A virus (HAV) seroprevalence among children of different socioeconomic status and age groups in Adana city center and to determine the epidemiological shift that may have occurred in the last 10 years.Material and Method: In 1999, Yapıcıoğlu and et al. reported the anti-HAV seroprevalence in 711 children aged between 2 and 16 years children with various socioeconomic levels in Adana city center. Ten years later we repeated the same study at the same locations in a similar population with the same method. Blood samples were taken from a total of 711 children between the ages of 2-16 years. Socioeconomic statuses (SES) of the families were determined according to the World Health Organization criteria and the general socioeconomic structure of Turkey. After the data collection and scoring of the questionnaires, groups were formed based on the scores. Participants with scores of 3-9 formed SES Group 1 (low), scores of 10-14 formed SES Group 2 (medium) and scores of 15-20 formed SES Group 3 (high). The total anti-HAV was studied with Architect equipment and CMIA (Chemiluminescent Immunoassay) method.Results: From 1999 to 2009 anti-HAV seroprevalence declined from 33,9 % to 22,2 %, 29,5 % to 25,3 % (p>0,05), 52,2 % to 30,8 %, 69,7 % to 35,2 %, 66,9 % to 37,7 % and 71,4 % to 47,3 % (p<0,0001) in the age groups of 48-71, 72-95, 96-119, 120-143, 144-167 and 168-198 months respectively. Anti-HAV seroprevalence in children in SES Group 1 (47 %) were found to be higher compared to that children in SES Group 2 (29,3 %) and SES Group 3 (25,9 %) (p<0,05, p<0,0001). Anti-HAV seroprevalence among pre-school children 24 to 84 months in 1999 and 2009 were 20 % vs 32,4 % in SES Group 1, 25,6 % vs 16,8 % in SES Group 2 and 7,8 % vs 18,8 % in SES Group 3, respectively (p>0.05). In 2009 anti-HAV seroprevalence among school-age children 85 to198 months decreased from 85,7 % to 53,8 % in SES Group 1, 64,4 % to 36 % in SES Group 2 and 43,7 % to 29,3 % in SES Group 3, respectively compared to 1999 (p<0,0001, p<0,0001, p<0,05).Conclusion: In conclusion, our study showed that anti-HAV seroprevalence, regardless of SES differences, has decreased statistically significantly during the last 10 years in school-aged children. Results showed that, not withstanding SES, anti-HAV seroprevalence has shifted to further ages. Since adolescents and young adults will be at risk of symptomatic HAV infection, we believe that routine hepatitis A vaccination of children in our region should be initiated.Key Words: Hepatitis A, Seroprevalence, Socioeconomic Status, Epidemiological Shift.