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).