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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).†
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A
new addition to the HEART is our
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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
Figure 1
Table 2
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