Abstract & Commentary: Rare but real: Provider to patient HCV transmission
October 1, 2002 6 minutes read
Rare but real: Provider to patient HCV transmission
Synopsis: Molecular studies documented transmission of HCV from surgeons to patients; the risk of transmission during high-risk procedures in these look-back studies was 0.2-0.48%.
Sources: Ross RS, et al. Risk of hepatitis C virus transmission from an infected gynecologist to patients. Results of a 7-year retrospective investigation. Arch Intern Med 2002; 162:805-810. Ross RS, et al. Phylogenetic analysis indicates transmission of hepatitis C from an infected orthopedic surgeon to a patient. J Med Virol 2002; 66:461-467.
Abstract: Eight weeks after undergoing a cesarean delivery in December 1999, a 22-year-old woman developed acute icteric hepatitis C virus (HCV) infection. Risk factors for HCV infection were absent. One of her surgeons had been found two years previously to have chronic HCV infection and had elevated serum transaminase levels as early as 1993 when he began working as a gynecologist in Itzehoe, Germany. The surgeon was viremic when tested several months after the surgical procedure with a concentration of 266,000 IU/mL. Both the patient and the surgeon were infected with HCV-1b and sequencing of the hypervariable region 1 of the viral genomes, to-gether with phylogenetic analysis, demonstrated apparent identity of the viruses. Of 2,907 patients upon whom the surgeon had operated, 2,285 (78.6%) responded to a questionnaire and were counseled and tested. Among the remainder, 33 had died, but none as the result of liver disease. Approximately one-fifth of the 2,338 gynecological and obstetric procedures were high risk for potential patient exposure to the surgeon’s blood. These procedures included major interventions involving laparotomy, all hysterectomies, major repairs, and cesareans. One-half of the procedures were medium risk, including cone biopsies, pelvioscopic procedures, perineal sutures, and episiotomies.
Seven patients were repeatedly HCV antibody positive, but two of these had no detectable HCV RNA by PCR in blood. Serological studies found that one of these was infected with HCV, but this method does not allow determination of the subtype. Three of the remaining five were infected with HCV 1a and 2 with HCV 1b. Molecular studies, however, demonstrated that the virus from the latter two differed from that of the index patient as well as the surgeon. Thus, the index patient was unique, and the overall rate of transmission from surgeon to patients was one in 2,286 or 0.04%.
Separately, during July 2000, an orthopedic surgeon who specialized in traumatology and arthroplasty disclosed to the director of his German hospital that he was HCV-infected. At that time, his blood HCV RNA concentration was 1.3 million IU/mL; he was infected with HCV subtype 2b. The timing of his infection acquisition was unknown, but it was determined that his serum liver enzyme concentrations were normal in 1997 and slightly abnormal in August 1999. Out of 229 patients who had undergone "exposure-prone" operations performed by the orthopedic surgeon beginning 26 weeks before August 1999 (the upper limit of the HCV incubation period), which was taken as the first evidence of HCV infection, 207 were counseled and tested. Procedures considered exposure prone were open reduction of fractures, internal fixation, joint replacement, reconstruction and repair of ligaments, removal of hardware, and spine surgery.
Two of the 207 patients were infected with HCV subtype 1b and 1 with HCV subtype 2b. The latter, a 50-year-old man, had undergone a complicated total hip arthroplasty on March 21, 2000; he was known to have had normal liver enzyme levels in November 1999. Sequencing and phylogenetic analysis of the hypervariable region 1 demonstrated close relatedness to the virus infecting this patient and that recovered from the surgeon. Thus, the findings were consistent with intraoperative transmission of HCV from surgeon to patient and, if this was indeed the only instance of this, the transmission rate was 0.48%.
Comment by Stan Deresinski, MD, FACP, Clinical Professor of Medicine, Stanford (CA) University.
The reported frequency with which HCV is transmitted to a health care worker by an accidental injury with a contaminated needle is quite variable, ranging from 0-10%.1 I believe a reasonable estimate is approximately 3%. Thus, the risk of transmission of HIV, HCV, and HBV after such an injury is approximately 0.3%, 3%, and 30%: an easy and reasonably accurate progression to commit to memory. The actual risk in an individual case, however, is dependent upon a number of variables, including the HCV viral load and the volume of the inoculum. The risk of transmission as the result of an individual percutaneous exposure in the opposite direction, from health care worker to patient, cannot be calculated from the data in the studies examined here. These look-back studies do, however, provide an initial benchmark with regard to the risk of such transmission per operative procedure.
Unfortunately, the calculated transmission rates in these studies differ by an order of magnitude. Each study has deficits, which make it difficult to assess the results with great accuracy. In the first instance, the study of transmission from the gynecologic surgeon was triggered by evidence of a transmission event, and thus, potentially suffers from a bias tending to exaggerate the risk of transmission. On the other hand, the fact that more than one-fifth of those exposed, including a number who had died, were never examined provides the potential for risk underestimation.
Finally, while the overall risk of transmission in the obstetrics/gynecology setting was one in 2,338 (0.04%), it was one in 488 (0.2%; 95% CI, 0.09-2.68%) when only high-risk procedures were taken into account, a value much closer to the 0.48% reported for high-risk orthopedic procedures in the second study. Ross, et al, review two previous retrospective analyses of transmission to patients by cardiothoracic surgeons in which the calculated transmission rates were 2.3% and 0.36% during procedures most of which were likely high risk.2,3 Thus, taken together, the reported risk of such transmission during high-risk surgical procedures is in the range of 0.2% (obstetrics & gynecology), to 2.3% (cardiothoracic surgery). It is of interest that these results also are within the range reported for risk of transmission of HCV to health care workers as the result of a single sharps exposure.
However, not all intraoperative transmission of hepatitis viruses is the result of direct transmission from surgeon (or anesthesiologist) to patient. A recently described outbreak of HCV infection in patients who had undergone gynecological surgery was reported but, rather than being the consequence of direct physician to patient transmission, it was most likely the result of contamination of a multidose vial of propofol.4
Reported instances of HCV transmission from health care worker to patient remain distinctly uncommon and, as a result, the Centers for Disease Control and Prevention (CDC) does not routinely recommend work restrictions for health care workers infected with HCV.5 The CDC, the Society for Healthcare Epidemiology of America, and the British Advisory Group on Hepatitis do recommend, however, exclusion from patient care activity be considered for health care workers who have been documented to transmit HCV. In contrast, both German and Canadian regulations require that all HCV-infected health care workers be forbidden to perform exposure-prone procedures.
References
1. Sulkowski MS, et al. Needlestick transmission of hepatitis C. JAMA 2002; 287:2,406-2,413.
2. Esteban JI, et al. Transmission of hepatitis C virus by a cardiac surgeon. N Engl J Med 1996; 334:555-560.
3. Duckworth GJ, et al. Commun Dis Public Health 1998; 2:188-192.
4. Massari M, et al. Transmission of hepatitis C virus in a gynecological surgery setting. J Clin Microbiol 2001; 39:2,860-2,863.
5. Centers for Disease Control and Prevention. MMWR Morb Mortal Wkly Rep 2001; 50(RR-11):1-67.
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