Fry, Jr, Lynn Jacobson, Linda Misenhimer, Judy. Priego, Dr Jose Manuel de la Rosa, ... Bulkow LR, Wainwright RB, McMahon BJ,. Middaugh JP, Jenkerson SA, ...
Hepatitis A among Schoolchildren in a US-Mexico Border Community Thomas Redlinger; PhD, Kathleen O'Rourke, PhD, MPH, and James VanDerslice, PhD, MSEE
Introduction A vaccine against hepatitis A has recently become available in the United States, and the efficacy of vaccinating high-risk groups is currently under study.'-3 The present study evaluated hepatitis A seroprevalence in primary school children residing in San Elizario, Tex, a community on the border between the United States and Mexico. Hepatitis A is caused by the hepatitis A virus and is transmitted predominantly through the fecal-oral route. Outbreaks are often related to contaminated water and improperly prepared or handled food.4 Hepatitis A transmission is highly correlated with low socioeconomic status (SES) and poor sanitary conditions.5 The mean age at which hepatitis A virus infection first occurs has been shown to differ in developing and developed countries, with infections occurring in younger age groups in developing countries.6 The anti-hepatitis A virus seroprevalence rate in the United States has been reported as 33% (10% for children less than 10 years
old).7 A previous study8 conducted in San Elizario determined that anti-hepatitis A virus seroprevalence rates were 33% for 8-year-old children (n = 52) and approximately 90% for adults 30 to 34 years of age (n = 48). The major goal of the present investigation was to determine anti-hepatitis A virus prevalence in younger children and to use this information to develop a vaccination program.
Methods This study, conducted from January to June 1996, involved two components: (1) a serosurvey to determine antihepatitis A virus prevalence and (2) a cross-sectional survey to identify hepatitis A risk factors. Participants included all
children attending a primary school in San Elizario. Nearly all children in the community attend the school's kindergarten and first grade, while a lower percentage attend prekindergarten and early education programs.
Trained community health workers visited the homes of all children, explained the project, and administered a questionnaire. The questionnaire included a health history of the child as well as items on demographic and household characteristics. HAVAB enzyme immunoassay (EIA) and HAVAB-M EIA (Abbott Laboratories, Chicago, Ill) were used in analyzing serum for total and IgM anti-hepatitis A virus. A positive HAVAB-M result indicates acute infection. Serum samples were initially screened for the presence of total hepatitis A virus antibodies. A second screening for anti-hepatitis A virus IgM was conducted on HAVAB-seropositive individuals. Chisquared tests and prevalence ratios were used in the bivariate analysis (SPSS, SPSS Inc, Chicago, Ill; Epi Info, Centers for Disease Control and Prevention, Atlanta, Ga). Logistic regression analysis evaluated the multivariate effect of individual risk factors on anti-hepatitis A virus status (Stata, Stata Corp, College Station, Tex).
Results Of the total school enrollment of 682 students, 561 had blood drawn, and 523 students (76.6%) also completed the questionnaire. Ages ranged from 3 to 7 years, and most of the children were in kindergarten or first grade. The majority of students (> 90%) had Hispanic surnames. Some students (13.8%) were bom in Mexico, while others (26.6%) had lived in Mexico for more than 6 months. Half of the study children lived in households connected to the municipal water supply; only 2.7% lived in homes connected to the municipal sewer system. Most households had septic tanks (87.5%), but 25% did not have a leach field. Thomas Redlinger is with the Department of Biological Sciences, University of Texas at El Paso. Kathleen O'Rourke and James VanDerslice are with the Houston School of Public Health, University of Texas, at the satellite campus in El Paso. Requests for reprints should be sent to Thomas Redlinger, PhD, Department of Biological Sciences, University of Texas, El Paso, TX 79968. This paper was accepted April 16, 1997.
American Journal of Public Health 1715
Public Health Briefs
TABLE 1-Anti-Hepatitis A Virus Prevalence Analyzed by Selected Demographic and Household Characteristics: San Elizario, Texas, 1996 Hepatitis A Negative
(n = 466), % (n Maternal education Did not complete primary Completed primary but did not complete secondary Completed secondary or more Household crowdingb Child's grade level Early education or prekindergarten Kindergarten First grade Child's age, y 3-4 5 6 7
Lived in Mexico Poor drinking water qualityc No septic systemd
Positive = 95), %
Prevalence Ratio (95% Confidence Interval)
TABLE 2-Logistic Regression Analysis of Risk Factors for Anti-Hepatitis A Virus Seroprevalence 95% Odds Confidence Ratio Interval
P
