http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4929a3.htm
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
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the risk of hepatitis B virus infection in firefighters. J Occup Med
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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
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Engl J Med 1999;341:556--62.
CDC. Recommendations for prevention and control of hepatitis C virus
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Werman HA, Gwinn R. Seroprevalence of hepatitis B and hepatitis C
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Mast EE, Alter MJ. Prevention of hepatitis B virus infection among
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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).
