Age as a risk factor for Hepatitis A among group of children 0-4 years old

Abstract

Hepatitis A is an infectious disease with a low level of sanitary and hygiene control is approved to be a main predisposing factors. Hepatitis A is the most prevalent type of hepatitis. In Yerevan Hepatitis A cases compose about 90% of all hepatitis cases (1117 / 1237) in 1998 year whereas children under 14 compose 67% (748 / 1117) of this number. The actual number of cases is likely much higher due to the high percent of subclinical disease manifestation among children under years of 5. However the age-specific prevalence varies among different countries considerably. In the poorest developing countries, all children become infected by age 10 years whereas in northern European countries and Japan prevalence may be 30-60 % in older adults (above age 40) but is less than 10 % in young adults and virtually nil in children (1). According to CDC definition Armenia is among countries with high-intermediate prevalence of the Hepatitis A. The shift from being one of the former USSR republic to the Independence Declaration in 1991 year rapidly worsen the social and economic situation in the country. Blockade of the republic, great number of refugees from Azerbaijan, unemployment, lack of electricity provide basis for high prevalence of the disease. Not much improvement has been done for recent years. For effective improvement of the situation it is necessary to allocate prevention resources at the target group of the population and control main risk variables responsible for the disease. However no study have been conducted in the Republic before to define the age-specific prevalence of the disease and the mean age at which hepatitis A virus infection first occurs. The proposed study is attempts to resolve this problem and has a goal to provide data for educational program and health policy implementation. The objectives of the study are: 1) determination of the mean age at which HAV virus first occurs among children aged 1-4 and 2)investigation of age-specific risk variables among group of children 1-4 years old. A number of observational (cross-sectional) studies have been done worldwide to reveal the prevalence of the disease among children at different ages (3, 5). However these studies did not specify the age at which children are at the most risk for getting the disease. Only ongoing study of disease incidence during some period of time (cohort study) will give us the answer to this question and allow to annually control for any changes in risk variables associated with the disease. In the project the author describes the proposed study, justifies design and analysis methods along with general information about Hepatitis A.