A program to control an outbreak of hepatitis A in Alaska by using an inactivated hepatitis A vaccine

B. J. McMahon, M. Beller, J. Williams, M. Schloss, H. Tanttila and L. Bulkow
Alaska Native Medical Center, Indian Health Service, Anchorage, USA.

OBJECTIVE: To stop an epidemic of hepatitis A in rural Alaska by mass immunization of susceptible persons with 1 dose of an inactivated hepatitis A vaccine. DESIGN: Nonrandomized, uncontrolled trial. Hepatitis A vaccine was offered to all persons in susceptible age groups in villages with documented cases of hepatitis A. Immune globulin was not offered at the time of vaccination. SETTING: Twenty-five rural communities located in interior Alaska and along the northwest coast of the Bering Sea and Arctic Ocean. PARTICIPANTS: Persons without a history of acute hepatitis A in age groups selected by applying results of a previous serosurvey conducted on serum collected before the epidemic. INTERVENTION: One dose of a formalin-inactivated hepatitis A vaccine was given to each participant. Adults 20 years of age and older received 1440 enzyme-linked immunosorbent assay units and persons younger than 20 years received 720 enzyme-linked immunosorbent assay units. Prevaccination and postvaccination levels of antibody to hepatitis A IgG were obtained from 136 participants. MAIN OUTCOME MEASURES: An active surveillance system was established to detect persons with symptomatic illnesses compatible with hepatitis A; persons who met the illness criteria were tested for antibody to hepatitis A IgM. One area (the Kotzebue region), where all communities were offered vaccine, was selected for intensive surveillance and analysis. RESULTS: During the 12-month period before the vaccine trial, 529 cases of icteric hepatitis A were reported, and 443 were confirmed to be positive for antibody to hepatitis A IgM. Hepatitis A vaccine was administered to 4930 persons, 3517 of whom were younger than 20 years. After vaccination began, 237 persons positive for antibody to hepatitis A IgM were identified during a 60-week surveillance period; 46 were vaccines and 191 were unvaccinated susceptible persons. In the Kotzebue region, in communities in which more than 80% of persons considered susceptible were vaccinated, the outbreak ceased in 4 to 8 weeks, whereas in 1 large community in which less than 50% of susceptible persons were vaccinated, the outbreak continued for more than 50 weeks. More than 90% of seronegative persons developed antibody to hepatitis A IgG 3 to 4 weeks after vaccination. CONCLUSION: This trial suggested that by providing both short-term and long-term protection, hepatitis A vaccine used without immune globulin halted an established epidemic of hepatitis A in rural Alaska.

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Diagnosis of Hepatitis A Virus Infection: a Molecular Approach
Nainan et al.
Clin. Microbiol. Rev. 2006;19:63-79.
ABSTRACT | FULL TEXT  

HEPATITIS A IN LEBANON: A CHANGING EPIDEMIOLOGICAL PATTERN
SACY et al.
Am J Trop Med Hyg 2005;73:453-456.
ABSTRACT | FULL TEXT  

Incidence of Hepatitis A in Israel Following Universal Immunization of Toddlers
Dagan et al.
JAMA 2005;294:202-210.
ABSTRACT | FULL TEXT  

Hepatitis A Incidence and Hepatitis A Vaccination Among American Indians and Alaska Natives, 1990-2001
Bialek et al.
Am. J. Public Health 2004;94:996-1001.
ABSTRACT | FULL TEXT  

Prevention of Hepatitis A with the Hepatitis A Vaccine
Craig and Schaffner
NEJM 2004;350:476-481.
FULL TEXT  

Parental Knowledge, Attitudes, and Practices Associated With Not Receiving Hepatitis A Vaccine in a Demonstration Project in Butte County, California
Bardenheier et al.
Pediatrics 2003;112:e269-269.
ABSTRACT | FULL TEXT  

Jaundice in primary school pupils
Postgrad. Med. J. 2002;78:59-60.
FULL TEXT  

Control of Hepatitis A Through Routine Vaccination of Children
Averhoff et al.
JAMA 2001;286:2968-2973.
ABSTRACT | FULL TEXT  

Protecting travellers from hepatitis A
Webster et al.
BMJ 2001;322:1194-1195.
FULL TEXT  

Hepatitis A vaccination during an outbreak among gay men in Montreal, Canada, 1995-1997
Allard et al.
J. Epidemiol. Community Health 2001;55:251-256.
ABSTRACT | FULL TEXT  

Hepatitis A: Old and New
Cuthbert
Clin. Microbiol. Rev. 2001;14:38-58.
ABSTRACT | FULL TEXT  

The Case for Routine Childhood Vaccination against Hepatitis A
Koff
NEJM 1999;340:644-645.
FULL TEXT