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Bradford Waters, M.D.
Staff Hepatologist, Memphis
VA Medical Center,
Associate Professor of
Medicine,
University of Tennessee,
Memphis
Hepatitis C is a major
problem in United States
military veterans. In
several studies of Veteran’s
Affairs (VA) Medical Center
patients, we find that 8-9%
are positive for hepatitis C
antibodies. Some VA Medical
Centers had 10-20% of
patients with hepatitis C
antibodies.1,2 The highest
rate of hepatitis C is found
in the Vietnam era veterans.
Several studies have been
initiated to better
understand the high
frequency of hepatitis C in
veterans of the Vietnam
conflict. Areas of research
include the demographic
characteristics, risk
factors for infection and
the potential role of
military service in the
acquisition of hepatitis C1.
Underlying this research is
the question of what is
unique about Vietnam or
Vietnam-era veterans to help
explain a high prevalence of
hepatitis C which was not
observed in World War II or
Korean era veterans.
Vietnam
era veterans are generally
defined as those serving on
active duty between 1964 and
1975. Other sources will
restrict these dates from
1964 to 1973. An estimated
8,615,000 served during the
Vietnam era while 2,150,000
actually served in Vietnam.
An estimated 1,600,000
served in combat3. The clear
majority of Vietnam era
veterans served outside
Southeast Asia during the
war. Likewise a distinction
has to be made between
active duty military
personnel, veterans and
veterans served by the VA
Medical Centers1.
The
demographics of hepatitis C
in United States civilians
and VA patients are
important. Several
epidemiological studies have
found hepatitis C to be
higher in U.S. males,
African-Americans, lower
socioeconomic groups and in
those Americans in the 40 to
60 year old age groups1. In
addition to serving
primarily males, the VA has
historically served large
populations of
disadvantaged, uninsured and
minority veterans. The VA
has had well established
programs for the treatment
of ethanol and other
substance abuse. These
substance abuse programs
have often attracted younger
veterans with prior
intranasal cocaine and
intravenous drug use
associated with hepatitis C
infection. As a result of
the VA programs’ providing
care for the disadvantaged,
uninsured and substance
abusing veterans, the VA has
acquired significant patient
populations with high risk
for hepatitis C. Many of the
highest risk groups for
hepatitis C in the
U.S.--identified by the
Centers for Disease Control
and NHANES III study: male,
poor socioeconomic group,
and between the ages of
30-50 (in the 1988-94
study)--have the same
demographic criteria met by
many Vietnam era veterans
seeking care in the VA1.
Improved screening of VA
patients with risk factors
for hepatitis C has helped
identify increasing numbers
of patients with chronic
hepatitis C.
What
are the VA patients’ risk
factors for hepatitis C? In
a study of 409 patients in
the Palo Alto VA, 81 % of
patients had a history of
intravenous drug abuse (IVDA),
11% had no identified risk
factor, 3% had a history of
transfusion and 2% had both
transfusion history and
intravenous drug use4. A
large multi-center VA study
involving twenty six Medical
Centers and approximately
5,800 patients was initiated
by the San Francisco VA
Medical Center to study
demographic factors and
treatment response in VA
patients. In preliminary
data from the Memphis VA
Medical Center, 222 patients
were entered with a mean age
of 50.7 years. 216 patients
were male and six were
female. 119 patients were
Caucasian, 100 patients were
African-American and three
were Hispanic-Americans.
68.5% of the patients were
Vietnam-era veterans, 20.3%
were Post-Vietnam/Gulf War
era veterans. Only 2.7% of
the hepatitis C patients
served in the World War II
or immediate post-World War
II eras. Only 8.5% served in
the Korean War or immediate
post-Korean War eras. Unlike
the Palo Alto VA, 47.3% of
Memphis hepatitis C patients
reported IVDA. 36.5% of
patients reported a history
of transfusion. 14.4%
reported blood exposure in
combat and 9.5% reported
combat wounds. 19.4%
reported non-combat
occupational exposure to
blood or body fluids.
The
role of tattoos in
transmission of hepatitis C
has been controversial1. In
this group of Memphis
veterans, 30.2% of patients
had tattoos. 92.8% of
patients reported multiple
risk factors for hepatitis
C. In analysis of patients
with a single risk factor
for hepatitis C, intranasal
cocaine use, non-combat
occupational exposure,
surgery, transfusion, IVDA
and sex with a prostitute
were identified.
What
was unique about the Vietnam
era and hepatitis C? Medical
advances during the Vietnam
War included rapid
evacuation, improved
transfusion and high rates
of U.S. casualty survival in
an era prior to hepatitis C
screening of the blood
supply. Many Vietnam combat
casualties who survived with
multiple transfusions would
have died on the battlefield
in previous conflicts. The
drug culture of the 1960s
and 1970s in America and
Western Europe was another
major factor. Drug
experimentation and
injection among young people
were more widespread than
previous generations of the
Twentieth century. This
seriously effected U.S.
troops stationed in West
Germany and the continental
U.S. as well as in Southeast
Asia. In Vietnam, heroin use
increased significantly in
1970, and by 1971 an
estimated 10-15% of
servicemen had used heroin.
Interestingly, 11% of these
users had used heroin prior
to coming to Vietnam.
Another overlooked factor in
Vietnam heroin use was that
it was primarily smoked. In
a 1971 study of heroin
addiction among servicemen
in Vietnam, 90-95% of
addicts smoked heroin and
only 5-10% injected5.
Although there has been much
publicity of the substance
abuse in Vietnam, there has
been much less awareness of
the degree of IVDA among
U.S. troops stationed in
Europe and the United States
during the Vietnam era.
Likewise until the hepatitis
C and HIV epidemics, many
Americans had little
appreciation of the
widespread injection drug
use among civilians from the
late 1960s to 1980s. In our
series of VA patients with
hepatitis C serving in
Southeast Asia, 43.8% had a
history of IVDA. Among
patients with hepatitis C
who served during the
Vietnam War outside of
Southeast Asia, 58.8% had
prior IVDA. Among veterans
serving after Vietnam with
hepatitis C, 42.2% had IVDA.
Intravenous drug use and
hepatitis C are not simply
problems of veterans of the
war in Southeast Asia.
In
recent years hepatitis C has
been studied in the U.S.
military. 21,000 troops were
tested in 19972. Only 0.1 %
of recruits and active duty
troops less than 30 years
old had hepatitis C
antibodies. 1.1% of active
duty personnel age 35-39 and
3.0% of those over 40 had
hepatitis C antibodies.
Approximately 0.6% of
Reservists had hepatitis C
with the highest prevalence
of 1.2% in those over 40
years old. In this study,
hepatitis C infection did
not correlate with military
service in Vietnam2.
Although intravenous drug
use is the most common risk
factor in both non-veteran
and VA studies, what are
other risk factors for
hepatitis associated with
military service? This has
been an area of ongoing
research and controversy. In
addition to the usually
accepted risk factors for
hepatitis C, several
potential categories
include:
(a) blood/body fluid
exposure to health care
personnel
(b) blood/body exposure
to combat personnel
(c) contamination of
vaccinations/immune
globulin
(d) blood exposure
through the multidose
vaccination process
(e) blood exposure
through sharing of
razors, non-sterile
instruments or utensils
Health care employment is a
well-recognized risk factor
for viral hepatitis. The
Center for Disease Control
did not find hepatitis C
infection in civilian
paramedics, emergency
medical technicians and
firemen to be associated
with the duration of
employment or exposure. The
highest rate of hepatitis C
was observed in the 35-49
year old age group6. Data on
low hepatitis C transmission
from blood exposure in
civilian paramedics may not
translate to combat exposure
where universal precautions,
intact skin and rubber glove
use are absent. In a case
report, blood exposure
during fighting has been
identified as a mode of
transmission of hepatitis
C7.
Historically, vaccine
contamination has been
recognized by the military
as a major cause of viral
hepatitis. During World War
II, the Yellow Fever vaccine
used by the U.S. Army in
1942 had contamination with
the hepatitis B virus.
Approximately 330,000
soldiers were injected and
this resulted in 50,000
hospitalizations8. No
similar association has been
identified with hepatitis C.
Hepatitis A epidemics from
contaminated food or water
are common during war. U.S.
troops suffered serious
outbreaks of hepatitis A
during World War II.
Gamma-globulin injection has
been used for decades by the
U.S. military to prevent
hepatitis A in troops going
overseas and was used during
the Vietnam and Gulf Wars.
Gamma globulin contains
antibodies obtained from
blood donors. Although
intramuscular use of immune
globulin has not been
associated with hepatitis C
in the United States,
intravenous immune globulin
transfusion has been
implicated as a risk factor
for hepatitis C9. In East
Germany, 14 batches of
anti-D immune globulin were
contaminated with hepatitis
C. 1,018 East German women
were injected from 1978-79
resulting in 76% hepatitis C
antibody positive in a
twenty year follow up
study10. The relative role
of immune globulin in
hepatitis C transmission
remains controversial11.
Since the mid-1990s, the
U.S. military has shifted to
a longer lasting hepatitis A
vaccination and the role of
immune globulin has been
limited.
The
risk of transmission of
hepatitis C by multiple dose
injections is the subject of
ongoing research1.
Fortunately, more recent
studies of military recruits
and follow up studies of
viral hepatitis during
deployments have shown very
low rates of hepatitis C
infection2,12,13.
Hepatitis C in Vietnam era
veterans is an ongoing
national problem. Complex
challenges remain in the
epidemiology and treatment
of hepatitis C. Many Vietnam
era veterans are now on the
front lines of the hepatitis
C epidemic. Improved
understanding and treatment
of these patients will
ultimately benefit all
Americans with hepatitis C.
References
- 1. Briggs ME,
Prevalence and risk
factor for hepatitis C
virus infection in an
urban Veterans
Administration medical
center. Hepatology
34:1200-1205, 2001
- Hyams KC, Prevalence
and incidence of
hepatitis C infection in
the U.S. military : A
seroepidemiologic survey
of 21,000 troops,
American Journal of
Epidemiology 153:764-70,
2001
- Horne AD, The
Wounded Generation,
America after Vietnam,
Prentice Hall, 1981
- Cheung RC,
Epidemiology of
hepatitis C infection in
American Veterans.
American Journal of
Gastroenterology
95:740-747, 2000
- MacPherson M, Long
Time Passing:Vietnam and
the Haunted Generation,
Doubleday, 1984
- Center for Disease
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medical technicians and
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2000
- Bourleiere M, Covert
transmission of
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fisticuffs,
Gastroenterology
119:507, 2000
- Norman JE, Mortality
follow up of the 1942
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in the U.S. Army,
Hepatology 18:790, 1993
- Alter MJ, The
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Clinics of Liver Disease
1:559, 1997
- Wiese M, Low
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source outbreak in
Germany, Hepatology
32:91-96, 2000
- Murphy EL, Risk
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infection in U.S. blood
donors,
Hepatology,31:756-762,
2000
- Brodine SK, The risk
of Human T cell leukemia
and viral hepatitis
infection among U.S.
Marines stationed in
Okinawa, Japan, Journal
of Infectious Diseases
171:693, 1995
- Hawkins RE, Risk of
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military personnel
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ships. Journal of
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165:716, 1992
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