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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
- 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
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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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Norman JE, Mortality follow up of the 1942 epidemic of
hepatitis B in the U.S. Army, Hepatology 18:790, 1993
- Alter
MJ, The epidemiology of acute and chronic hepatitis C.
Clinics of Liver Disease 1:559, 1997
- 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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Murphy EL, Risk factors for hepatitis C infection in U.S.
blood donors, Hepatology,31:756-762, 2000
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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
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Hawkins 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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