of HIV/HBV Coinfection in a U.S. Military Cohort
Chun and colleagues with the Infectious Disease Clinical
Research Program looked at the epidemiologic trends
of HBV infection in HIV positive patients over the
course of 20 years.
Because HIV and HBV have overlapping transmission
routes, many people are infected with both viruses.
Rates of hepatitis B in the population as a whole
have fallen dramatically since the advent of routine
childhood HBV vaccination, but trends among people
with HIV have not been well studied.
A majority of HIV negative people infected with HBV
as adults spontaneously clear the virus without treatment,
but 5%-10% develop chronic infection lasting more
that 6 months. But studies show that HIV positive
people are more likely to develop chronic infection.
As people with HIV live longer due to effective combination
antiretroviral therapy (ART), liver disease --
often associated with chronic hepatitis B or C coinfection
-- accounts for an increasing proportion of morbidity
and mortality. Fortunately, some of the ART drugs
used to treat HIV are also active against HBV, namely
(3TC; Epivir), emtricitabine
(Emtriva), and tenofovir
(Viread, also in the Truvada
The study investigators examined prevalence and risk
factors for HBV infection overall, at the time of
HIV infection, and after HIV infection among 2769
participants in U.S. Military HIV Natural History
Study, a prospective observational cohort of active
duty service members and their dependents; participants
continued to be followed after completing military
The researchers performed annual cross-sectional analyses
of HBV prevalence (total cases) and incidence (new
cases). Participants received a median of 4 HBV screenings.
Risk factors for HBV infection at the time of HIV
diagnosis and after HIV diagnosis were evaluated.
the 2769 participants evaluated, 1078 (39%) had
HBV infection, of whom 117 (11%) had chronic hepatitis
prevalence of all HBV infection decreased significantly
over time, from a peak of 49% in 1995 to 36% in
prevalence of all HBV infection existing at the
time of HIV diagnosis also declined significantly,
from 34% in 1989 to 9% in 2008.
chronic HBV infection, the prevalence fell from
a peak of 7% in 1995 to an estimated 4% in 2008.
vaccination status, the prevalence of chronic
HBV infection during the ART era was 7% among
unvaccinated participants and 2% among vaccinated
1872 participants who were HBV negative at the
time of HIV diagnosis, 181 (9.7%) became HBV infected
during follow-up, of whom 37 (20.4%) developed
chronic hepatitis B.
incidence of new HBV infections after HIV diagnosis
decreased from 4.0 cases per 100 person-years
before the advent of combination ART to 1.1 cases
per 100 person-years during the ART era.
then stabilized, however, and remained unchanged
from 2000 through 2008, at a rate about 100 times
higher than that of HIV negative service members
and 500 times higher than that of the general
than 20% of HBV infections that occurred after
HIV infection became chronic -- considerably higher
than the expected rate among HIV negative people.
a multivariate analysis, higher risk of HBV infection
at the time of HIV diagnosis was significantly
associated with older age, male sex, and history
of gonorrhea or syphilis,
of HBV infection after HIV diagnosis was associated
with male sex, lower CD4 cell count and not using
HBV-active ART, but not with receiving more than
1 HBV vaccine dose.
declined dramatically after the advent of combination
ART, with similar changes seen among HIV/HBV coinfected
patients (29% to 4%) and those without HBV (27%
Based on these findings, the researchers wrote, "Although
the burden of HBV infection overall is slowly decreasing
among HIV-infected individuals, the persistent rate
of HBV infection after diagnosis of HIV infection
raises concern that more effective prevention strategies
may be needed to significantly reduce the prevalence
of HBV infection in this patient population."
"This comprehensive examination of the epidemiology
of HBV infection in a large cohort of HIV-infected
individuals highlights the continued and significant
burden of HBV infection in HIV-infected adults, with
nearly 40% of patients with HIV infection also having
coinfection with HBV," they elaborated in their
"Despite the gradual decrease in prevalence of
chronic HBV infection over the past 2 decades, overall,
11% of patients with HBV infection had chronic HBV
infection," the researchers continued. "Furthermore,
HBV infections after diagnosis of HIV infection continue
to occur, and although the number of such HBV infections
has decreased in the HAART era, incidence rates have
remained unchanged for the past 8 years, suggesting
that additional efforts will be needed to further
reduce the incidence rate of HBV coinfection."
"Effective prevention methods are needed and
must overcome the effects of HIV-associated immune
dysfunction on HBV transmission and vaccine effectiveness,"
they concluded. "The associations of HBV-active
HAART use and higher CD4 cell count with decreased
risk of incident HBV infection suggest additional
benefits of HAART and provide further rationale for
increased use of HBV-active HAART."
Naval Health Research Center and Naval Medical Center
San Diego, San Diego, CA; University of Minnesota,
Minneapolis, MN; Infectious Disease Clinical Research
Program, Uniformed Services University of the Health
Sciences and National Naval Medical Center, Bethesda,
MD: Walter Reed Army Medical Center, Washington, DC;
Naval Medical Center Portsmouth, Portsmouth, VA; San
Antonio Military Medical Center, Fort Sam Houston,
HM Chun, AM Fieberg, K Huppler, and others. Epidemiology
of Hepatitis B Virus Infection in a US Cohort of HIV-Infected
Individuals during the Past 20 Years. Clinical
Infectious Diseases 50: 426-436 (Abstract).
February 1, 2010.