Incidence of
hepatitis A in the United States in the era of
vaccination.
Wasley A,
Samandari T,
Bell BP.
Division of Viral Hepatitis, Centers for Disease Control and Prevention,
Atlanta,
GA
30333, USA. awasley@cdc.gov
In the United States, hepatitis A is a frequently reported
vaccine-preventable disease. Vaccination has been recommended for persons at
increased risk since 1996. In 1999, it was recommended that children living
in 11 states with the highest incidence of hepatitis A be routinely
vaccinated, and that children living in 6 additional states, with incidence
above the national average, be considered for routine vaccination. To assess
impact of the current vaccination strategy by evaluating trends in reported
cases of hepatitis A since implementation, characteristics of cases of
hepatitis A reported in the United States since 1990 to the National
Notifiable Diseases Surveillance System were analyzed. Incidence rates of
reported cases of hepatitis A in 2003 were compared with those for the
prevaccination baseline period (1990-1997) overall and in the 17 states in
which children should be routinely vaccinated or considered for routine
vaccination (vaccinating states). Incidence rates in vaccinating states were
also compared with those in the remaining states where there is no
recommendation for statewide vaccination of children (nonvaccinating
states). Between the baseline period (1990-1997) and 2003, overall hepatitis
A rates declined 76% to 2.6 per 100,000, significantly lower than previous
nadirs in 1983 (9.2/100,000) and 1992 (9.1/ 100,000). The rate in
vaccinating states declined 88% to 2.5 per 100,000 compared with 53%
elsewhere (to 2.7/100 000). In 2003, cases from vaccinating states accounted
for 33% of the national total vs 65% during the baseline period. Declines
were greater among children aged 2 to 18 years (87%) than among persons
older than age 18 years (69%); the proportion of cases in children dropped
from 35% to 19%. Since 2001, rates in adults have been higher than among
children, with the highest rates now among men aged 25 through 39 years.
CONCLUSIONS: Following
implementation of routine hepatitis A vaccination of children, hepatitis
A rates have declined to historic lows, accompanied by substantial
changes in the epidemiologic profile. Greater decreases in the age groups
and regions where routine vaccination of children is recommended likely
reflect the results of implementation of this novel vaccination strategy.
Continued monitoring is needed to verify that implementation continues to
proceed and that low rates are sustained.
SOURCE: JAMA. 2005 Jul
13;294(2):194-201.
