The Burden of Hepatitis A in Texas Before and After Vaccination Legislation
Johnson, Kelly M. K.
Hepatitis A is one of the most commonly reported vaccine-preventable diseases in Texas. The virus that causes hepatitis A is primarily spread via the fecal-oral route. Children play an important role in spread of the disease as infected children are often asymptomatic and because most have poorly developed personal hygiene. A licensed vaccine against hepatitis A has been available since the 1995, but it was not listed among the recommended childhood vaccines until recently. The vaccine has been required for children entering school in select Texas counties beginning in 1999. The objective of this study is to determine if routine vaccination against hepatitis A in children can reduce disease incidence. Deidentified hepatitis A surveillance records were obtained from the Texas Department of State Health Services. Incidence rates adjusted for age and race/ethnicity, along with their corresponding 95% confidence limits, were calculated for the time before versus the time after vaccination against hepatitis A became required for school-age children in applicable counties. Results indicate that rates of hepatitis A infection have decreased in Texas beginning in 1999. Hispanic Texans have the highest rates both before and after vaccination legislation; however, all racial-ethnic groups had significantly decreased incidence after vaccination became a requirement. Children ages 0 to 9 years had the highest incidence rates; however, all age groups experienced significantly decreased incidence after legislation. The results of this study suggest that vaccination requirements for school-age children were successful in reducing the burden of hepatitis A infection in Texas. Further investigation is required to determine why hepatitis A vaccination rates lag behind those for other diseases for which vaccination is required for school attendance and to investigate the efficacy and cost effectiveness in controlling infection in certain special populations ( those living in prisons or nursing homes, children, college students living in dormitories, etc).
Hepatitis A--Texas, Vaccines--Texas, Vaccines--Health aspects
Johnson, K. M. K. (2005). <i>The burden of hepatitis A in Texas before and after vaccination legislation</i> (Unpublished thesis). Texas State University-San Marcos, San Marcos, Texas.