Outbreak
of Hepatitis C Virus Infection in a Hemodialysis Unit:
Potential Transmission by the Hemodialysis Machine?
Infection
Control and Hospital Epidemiology
Volume
23 (6) * June 2002 * Original Articles (abstract)
OBJECTIVE
To identify the routes of
transmission during an outbreak of infection with hepatitis C
virus (Hepatitis C Virus) genotype 2a/2c in a hemodialysis unit.
DESIGN
A matched case–control study was
conducted to identify risk factors for Hepatitis C Virus seroconversion.
Direct observation and staff interviews were conducted to
assess infection control practices. Molecular methods were
used in a comparison of Hepatitis C Virus infecting isolates from the
case-patients and from patients infected with the 2a/2c
genotype before admission to the unit.
SETTING
A hemodialysis unit treating an
average of 90 patients.
PATIENTS
A case-patient was defined as a
patient receiving hemodialysis with a seroconversion for Hepatitis C Virus
genotype 2a/2c between January 1994 and July 1997 who had
received dialysis in the unit during the 3 months before the
onset of disease. For each case-patient, 3 control-patients
were randomly selected among all susceptible patients treated
in the unit during the presumed contamination period of the
case-patient.
RESULTS
Hepatitis C Virus seroconversion was associated
with the number of hemodialysis sessions undergone on a
machine shared with (odds ratio [OR] per additional session,
1.3; 95% confidence interval [CI95], 0.9 to 1.8) or
in the same room as (OR per additional session, 1.1; CI95,
1.0 to 1.2) a patient who was anti-Hepatitis C Virus (genotype 2a/2c)
positive. We observed several breaches in infection control
procedures. Wetting of transducer protectors in the external
pressure tubing sets with patient blood reflux was observed,
leading to a potential contamination by blood of the
pressure-sensing port of the machine, which is not accessible
to routine disinfection. The molecular analysis of Hepatitis C Virus
infecting isolates identified among the case-patients revealed
two groups of identical isolates similar to those of two
patients infected before admission to the unit.
CONCLUSIONS
The results suggest
patient-to-patient transmission of Hepatitis C Virus by breaches in
infection control practices and possible contamination of the
machine. No additional cases have occurred since the
reinforcement of infection control procedures and the use of a
second transducer protector (Infect Control Hosp
Epidemiol 2002;23:328-334).
AUTHORS
Drs. Delarocque-Astagneau, de Valk,
and Desenclos are from the Institut de Veille Sanitaire; Drs.
Baffoy and Astagneau are from the Centre inter-régional de
Coordination de la Lutte contre les Infections nosocomiales,
Institut biomédical des Cordeliers; Dr. Thiers is from the
Centre National de Référence pour l’épidémiologie moléculaire
des hépatites virales; Dr. Simon is from the Centre de lutte
contre les infections nosocomiales de l’Association pour
l’Utilisation du Rein Artificiel (AURA); Dr. de Valk is from
the European Programme for Intervention Epidemiology Training;
and Drs. Laperche and Couroucé are from the Institut National
de la Transfusion Sanguine, Paris, France.
Address reprint requests to
Elisabeth Delarocque-Astagneau, InVS, 12, rue du Val d’Osne
94415 Saint-Maurice cedex, Paris, France.
The European Programme for
Intervention Epidemiology Training is sponsored by the DGV of
the European Commission under agreement number SOC 94 201561
05F01 (94CVVF-057-0).
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