Infection Control & Hospital Epidemiology
during phlebotomy (and hence, the probability of transmission) may depend on the viral load of the original source HCV-infected patient. Based on a recent study showing the presence of hemo- globin and HCV on surfaces even without visible blood con- tamination,32 we believe that simply disinfecting with alcoholic wipes or discarding only tube holders with visible blood stains is insufficient to effectively eliminate the risk of HCV transmission via this route. One previous report implicated the reuse of tube
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holders without disinfection between patients as a possible source of HCV outbreak involving 6 patients in an orthopedic ward, when the number of phlebotomies exceeded tube-holder con- sumption.33 However, environmental surveillance was not per- formed in that study. In addition, the rubber stopper of the vacuum-specimen tube
can be contaminated during contact with the contaminated inner surface of tube holder, further contaminating the environment. Lapses in infection control measures, especially hand hygiene, can carry environmental HCV to other patients during phlebotomy and other percutaneous procedures. However, direct observation of the nursing procedures did not support this route of transmission. This study has several limitations. It is a retrospective inves-
Fig. 4. Detection of 99mTc pertechnetate (99mTcO4) in saline pre-filled EDTA tubes, suggesting reflux from the rubber sleeved-needle back to the patient side. Note. Bq, becquerel is the SI derived unit of radioactivity. One becquerel is defined as the activity of a quantity of radioactive material in which 1 nucleus decays per second.
tigation, and we have only inferred what could have occurred at the time of transmission. With only 1 case, a robust case- control study could not be performed. Although there were ≤3 base-pair differences in the sequence of hypervariable region of HCV partial envelope gene (E1–E2) among the index patient, source patient, and tube holder, which suggests clonality, it was not possible to determine the direction or exact mechanism of transmission. However, given that RNA viruses have an extremely high mutation rate, that the blood of the index and source patients, that the environmental sample were collected 4 months apart, and most importantly, the lack of disinfection of the tube holder between patients, we conclude that the tube holder was the most likely vector of HCV transmission. In summary, a single-use disposable tube holder should be
used for phlebotomy to prevent needlestick injury according to OSHA andWHOguidelines, which will also minimize patient-to- patient transmission of bloodborne viruses.
Fig. 5. Scintigraphic images obtained after release of manual pressure from the saline bag (simulating release of tourniquet) to demonstrate the reflux of radioactive material into the patient side. (A) Set-up of simulated blood collection experiment to demonstrate reflux of radioisotope from collection side of reusable tube holder to saline bag (signifying patient venous system), manual pressure was used to simulate effect of tourniquet on venous pressure. (B) Scintigram of saline bag following release of pressure showing radioactivity within the bag. (C) Fused scintigraphic image.
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