Effectiveness of 10-year vaccination (2001-2010) on Hepatitis A in Tianjin, China

摘要

anti-HAV IgG, anti-hepatitis A virus immunoglobulin G; HAV, hepatitis A virus; ALT, alanine aminotransferase; OD, optical density; COV, cut off value; Vaccination is an effective strategy to prevent and control the transmission of hepatitis A. Hepatitis A immunization program has been taken into effect since 2001 in Tianjin, China. This study evaluated the effectiveness of strategies in the prevention and control of hepatitis A. Data of serological survey, annual hepatitis A incidence, immunization coverage and the positive rate of hepatitis A IgG before and after the immunization program in residents under 15 years old were used to do the analysis. The results indicated that hepatitis A vaccine induced a striking decrease of hepatitis A incidence and a significant increase in the positive rate of anti-HAV IgG among the children younger than 15 years old. Hepatitis A vaccination in children was proved to be effective in the prevention and control of hepatitis A in Tianjin, China. Hepatitis A is an acute infectious disease caused by hepatitis A virus (HAV). In developing countries, its prevalence is very high among children, with the seroprevalence rate up to 100% in adolescence. Hepatitis A represents a serious public health problem, causing substantial economic burden. It was estimated that about 1.4 million individuals are infected with HAV annually in the world. In China, the incidence of hepatitis A ranks first among all types of viral hepatitis in the 1990s. More than 300000 hepatitis A cases were reported during a shellfish-associated outbreak in Shanghai in 1988. A national seroprevalence survey in 1992 demonstrated that the anti-HAV positive rate for hepatitis A was about 80.9% in China. Vaccination has long been proved to be effective since the ancient battle toward various infectious diseases. HAV-vaccination has been adopted in many countries such as Italy, Spain, Israel, and the USA. In China, a national vaccination program against hepatitis A was launched in the late 1990s, and the incidence decreased from 56/100000 to 10/100000 or even lower in the following 2 decades.