First responders (e.g.,
firefighters, emergency medical technicians [EMTs],
and paramedics) are at risk for occupational exposure
to bloodborne pathogens. Recently, CDC has received
inquiries from state and local health departments
and occupational health services about the prevalence
of hepatitis C virus (HCV) infection among first responders
and the need for routine HCV testing among these workers.
This report summarizes the findings of five studies
of HCV infection among first responders. Although
some of these workers may need HCV testing under certain
circumstances, this report indicates that first responders
are not at greater risk than the general population
for HCV infection; therefore, routine HCV testing
is not warranted. First responders should continue
to follow standard precautions to reduce workplace
exposure to bloodborne pathogens.
Philadelphia, Pennsylvania
During November--December 1999, Home Access Health
Corporation (Hoffman Estates, Illinois)* offered specimen
collection kits (Hepatitis C Check™) to 4400 active
and retired members of the Philadelphia firefighters
union. Respondents telephoned a toll-free number to
receive their test results and to answer questions
anonymously about nonoccupational risk factors for
HCV infection. According to Home Access®,
serum was tested for antibody to HCV (anti-HCV) with
an enzyme immunoassay (EIA 3.0; Ortho Diagnostic Systems,
Inc., Raritan, New Jersey); repeatedly reactive samples
were tested with a supplemental recombinant immunoblot
assay (RIBA™ 3.0, Chiron Corporation, Emeryville,
California). In February 2000, Home Access reported
that of 2146 respondents, 97 (4.5%) screened positive
for anti-HCV. The company indicated that this prevalence
was 2.5 times higher than the national average of
1.8% (Home Access Health Corporation, personal communication,
2000).
In June 2000, CDC re-analyzed serologic and questionnaire
data and found that of 2136 participants, 64 (3.0%)
tested anti-HCV--positive (Table 1). The highest prevalence (4.9%) was among men aged
40--49 years (Figure 1). Risk
factors associated with HCV infection were a history
of blood transfusion before 1992 (age-adjusted prevalence
ratio [PR]=2.2; 95% confidence interval [CI]=1.2--4.0)
and illicit drug use (age-adjusted PR=4.0; 95% CI=2.2--7.1).
On the basis of CDC's analysis, the 4.5% prevalence
previously reported by Home Access was obtained by
classifying as positive samples that tested EIA repeatedly
reactive but indeterminate by RIBA, and those that
tested EIA repeatedly reactive or EIA initially reactive
for which no further testing was done (Table
2).
Atlanta, Georgia
In 1991, CDC conducted a voluntary, anonymous survey
among metropolitan Atlanta uniformed fire department
personnel to assess occupational and nonoccupational
risk factors for hepatitis B virus (HBV) infection
(1). In May 2000, stored serum samples were
tested at CDC for anti-HCV using EIA 3.0; repeatedly
reactive samples were tested by RIBA 3.0. Of the 437
firefighters tested, nine (2.1%) were anti-HCV--positive
(Table 1); the highest prevalence
(4.0%) was among men aged 35--39 years. HCV infection
was not associated with duration of employment as
a firefighter, occupational exposures to blood, history
of blood transfusion, or illicit drug use; however,
HCV infection was associated with a history of a sexually
transmitted disease (PR=7.4; 95% CI=1.6--35.3).
Connecticut
In 1992, Connecticut Department of Public Health
and Addiction Services collected serum samples and
demographic data on a voluntary basis from first responders
in various regions in Connecticut for a study on the
immune response to hepatitis B vaccine (2).
In June 2000, stored serum samples from the 1992 study
were tested anonymously at CDC for anti-HCV by EIA
3.0 and RIBA 3.0. Among 382 volunteer and professional
firefighters and EMTs for whom serum samples were
available, five (1.3%) tested anti-HCV--positive (Table
1); prevalence was highest (2.6%) among men aged
40--49 years.
Miami-Dade County, Florida
During March--April 2000, Hep-C ALERT, a patient
advocacy organization, collaborating with University
of Pittsburgh researchers, confidentially obtained
serum samples and information on occupational risk
factors from Miami-Dade County municipal fire department
personnel. Serum samples were tested at a commercial
laboratory for anti-HCV with EIA 3.0; repeatedly reactive
samples were tested for HCV RNA by transcription mediated
amplification (TMA™) (Bayer Corporation, Tarrytown,
New York). Of the 1314 participants, 35 (2.7%) were
anti-HCV--positive on the basis of EIA testing alone,
and 20 (1.5%) were confirmed positive for HCV RNA
(Table 1). Prevalence of anti-HCV was highest (3.7%) among
men aged >50 years. Increased risk for HCV infection
was not associated with occupational exposures to
blood, type of job (firefighter, EMT, or paramedic),
or duration of employment as a first responder.
Pittsburgh, Pennsylvania
During January--March 2000, University of Pittsburgh
researchers collected serum samples and information
on occupational exposures from paramedics working
in Pittsburgh. Samples were tested for anti-HCV by
EIA 2.0 (Abbott Laboratories, Abbott Park, Illinois)
without supplemental or confirmatory testing. Five
(3.2%) of 154 respondents tested anti-HCV--positive
(Table 1); highest prevalence
(5.2%) was among men aged 40--49 years. Anti-HCV positivity
was not associated with occupational exposures to
blood.
Reported by: AJ Roome, PhD, HIV/AIDS Surveillance
Program, JL Hadler, MD, State Epidemiologist, Connecticut
Dept of Public Health. AL Thomas, B Migicovsky, MD,
Hep-C ALERT, Miami. MW Dailey, MD, R Roth, MD, Dept
of Emergency Medicine, Univ of Pittsburgh; M Boraz,
PhD, Graduate School of Public Health, Univ of Pittsburgh;
B Kuszajewksi, D Berkowitz, MPH, Bur of Emergency
Medical Svcs, City of Pittsburgh, Pennsylvania. Hepatitis
Br, Div of Viral and Rickettsial Diseases, National
Center for Infectious Diseases; and an EIS Officer,
CDC.
Editorial Note:
Data from the Third National Health and Nutrition
Examination Survey (NHANES III), conducted during
1988--1994, indicated that 3.9 million (1.8%) persons
living in the United States have been infected with
HCV (3). Estimates indicate that three risk
factors accounted for most infections: illicit drug
use (60%), high-risk sexual behavior (15%), and blood
transfusion (7%) (CDC, unpublished data, 1996; 3,4).
Health-care workers and first responders exposed
to blood in the workplace are at risk for infection
by bloodborne pathogens. However, their risk for acquiring
HCV infection is low because HCV is not transmitted
efficiently through occupational exposure (4--6).
After an unintentional needlestick from an HCV-positive
source, the average risk for HCV infection is 1.8%
(range: 0--7%); transmission rarely occurs from mucous
membrane exposures to blood, and no transmission has
been documented from intact or nonintact skin exposures
to blood (4). Among first responders, HCV infection
was associated primarily with nonoccupational factors,
a finding similar to HBV (1), a bloodborne
virus that is transmitted at a rate 10 times higher
than HCV (7).
The initial interpretation of the results from the
Philadelphia study was incorrect because 20.6% of
the serum samples classified as positive were of insufficient
volume to complete testing as required by the Food
and Drug Administration (FDA). Manufacturer's instructions
for performing EIA for anti-HCV require initially
reactive samples to be repeated in duplicate; only
samples that are repeatedly reactive are considered
EIA-positive. For Hepatitis C Check, FDA-approved
conditions for reporting a positive anti-HCV result
require a repeatedly reactive EIA and a positive supplemental
test. Samples with insufficient volume for supplemental
testing are to be reported as "results not available
--- insufficient blood." In populations with an HCV-infection
prevalence of 0--10%, 20%--50% of EIA repeatedly reactive
results may be false positives (4,8).
HCV prevalence reported in studies in subpopulations
should be compared with appropriate referent groups
from the general population. In NHANES III, conducted
during 1988--1994, overall prevalence of HCV infection
among persons of both sexes aged >5 years was 1.8%
but was substantially higher (4.9%) among men aged
30--49 years (3), the group that represents
most of the first responders in the five studies.
Because this group has aged almost 10 years since
NHANES III was conducted, men currently aged 40--59
years would have the highest expected prevalence of
infection (Figure 1).
Because of several limitations, the five studies
could not exclude the possibility that some first
responders had acquired HCV infection from job-related
exposures. First, the small sample size and limited
information on both occupational (percutaneous, mucosal,
or skin exposures to blood) and nonoccupational risk
factors may have affected the evaluation of potential
sources for infection. Second, the findings do not
necessarily represent all first responders in the
selected locations or the United States. Third, if
first responders are less likely to have nonoccupational
risk factors for HCV infection than the general population,
then the expected prevalence in these workers might
be lower.
Routine HCV testing is not recommended for populations
with a low prevalence of HCV infection, including
first responders, unless they have a history indicating
an increased risk for infection (e.g., transfusion
before July 1992 or injecting-drug use) (4).
Testing is recommended in first responders for postexposure
management after a percutaneous or permucosal exposure
to HCV-positive blood(4), and testing could
be considered for these types of exposures when the
HCV status of the source is unknown (9). To
reduce workplace exposure to bloodborne pathogens,
standard precautions continue to apply; first responders
should be educated about transmission of bloodborne
pathogens, trained in proper safety measures, and
provided with appropriate protective equipment (10)†.
First responders also should be vaccinated against
HBV, and informed of protocols if percutaneous or
permucosal exposures to blood occur (4,10).†
References
- Woodruff BA, Moyer LA, O'Rourke KM, Margolis HS.
Blood exposure and the risk of hepatitis B virus
infection in firefighters. J Occup Med 1993;35:1048--54.
- Roome AJ, Walsh SJ, Cartter ML, Hadler JL. Hepatitis
B vaccine responsiveness in Connecticut public safety
personnel. JAMA 1993;270:2931--4.
- Alter MJ, Kruszon-Moran D, Nainan OV, et al. The
prevalence of hepatitis C virus infection in the
United States, 1988 through 1994. N Engl J Med 1999;341:556--62.
- CDC. Recommendations for prevention and control
of hepatitis C virus (HCV) infection and HCV-related
chronic disease. MMWR 1998;47(no. RR-19).
- Spitters C, Zenilman J, Yeargain J, Pardoe K.
Prevalence of antibodies to hepatitis B and C among
fire department personnel prior to implementation
of a hepatitis B vaccination program. J Occup Environ
Med 1995;37:663.
- Werman HA, Gwinn R. Seroprevalence of hepatitis
B and hepatitis C among rural emergency medical
care personnel. Am J Emerg Med 1997;15:248--51.
- Mast EE, Alter MJ. Prevention of hepatitis B virus
infection among health care workers. In: Ellis RW,
ed. Vaccines in clinical practice. New York: Marcel
Dekker, 1993:295--307.
- Gretch DR. Diagnostic tests for hepatitis C. Hepatology
1997;26(suppl 1):43S--47S.
- Cardo DM, Bell DM. Bloodborne pathogen transmission
in health care workers---risk and prevention strategies.
Infect Dis Clin North Am 1997;11:331--46.
- CDC. Guidelines for prevention of transmission
of human immunodeficiency virus and hepatitis B
virus to health-care and public-safety workers.
MMWR 1989;38(suppl 6).
* Use of trade names and commercial sources
is for identification only and does not constitute
endorsement by CDC or the U.S. Department of Health
and Human Services.
† Bloodborne pathogens, 29 CFR sect. 1910.1030
(1999).
Table 1
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