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Hepatitis C in Vietnam Era Veterans
Bradford Waters, M.D.
Staff Hepatologist, Memphis VA Medical Center,
Associate Professor of Medicine,
University of Tennessee, Memphis
http://www.hcvadvocate.org/hcsp/articles/vietvet.html
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
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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
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MacPherson M, Long Time Passing:Vietnam and the Haunted
Generation, Doubleday, 1984
- Center
for Disease Control, Hepatitis C virus infection among
firefighters, emergency medical technicians and paramedics –
selected locations, United States, MMWR 49:660-665, 2000
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Bourleiere M, Covert transmission of hepatitis C during
fisticuffs, Gastroenterology 119:507, 2000
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JE, Mortality follow up of the 1942 epidemic of hepatitis B in
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The epidemiology of acute and chronic hepatitis C. Clinics of
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- Wiese M,
Low frequency of cirrhosis in a hepatitis C (genotype 1b) single
source outbreak in Germany, Hepatology 32:91-96, 2000
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EL, Risk factors for hepatitis C infection in U.S. blood donors,
Hepatology,31:756-762, 2000
- Brodine
SK, The risk of Human T cell leukemia and viral hepatitis
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Journal of Infectious Diseases 171:693, 1995
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RE, Risk of viral hepatitis among military personnel assigned to
U.S. Navy ships. Journal of Infectious Diseases 165:716, 1992
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