Provider-to-patient HBV transmission raises issue of chronically infected health workers

CDC updates guidelines for hospitals, med schools

By Gary Evans, Executive Editor

David Henderson, MDA recently reported case of hepatitis B virus transmission from a chronically infected surgeon to as many as eight patients underscores the need for providers to know their HBV status and seek the counsel of an expert review panel if they perform invasive or so called “exposure-prone” procedures, public health officials emphasize.

“Hospitals can try, but the obligation really is on the health care providers who are doing the work,” says David Henderson, MD, hospital epidemiologist at the National Institutes of Health Clinical Center in Bethesda, MD. “This is one of those unfortunate circumstances where he may not have thought of [his HBV status] — but he should have thought of it. It is the responsibility of the health care provider, especially those that are doing these kinds of procedures.”

A leading expert on the issue of provider-to-patient infections, Henderson wrote an accompanying editorial commentary to the case report, which does not disclose the location of incident or the identity of the surgeon.1,2 The case has several unusual features, including the fact that the surgeon had asymptomatic chronic HBV infection acquired at birth in a country with high endemic levels of HBV.

In light of the case and increasing reports of endemic HBV infections in foreign medical and dental students from Asia and other areas, the Centers for Disease Control and Prevention has issued new guidelines on the issue.3 The CDC guidelines also emphasize that medical providers have a professional and ethical obligation to know their HBV status, both to protect patients and because circulating HBV can be dramatically reduced by current therapies.

“Responsible medical professionals of any ilk should know their hepatitis B status, but you have a particular responsibility if you are a surgeon or an oral surgeon,” says Scott Holmberg, MD, chief of epidemiology and surveillance at the CDC’s viral hepatitis branch. “If they are infected and they have a high viral load, we think that should be managed and they can get treatment to get that viral load down.”

The surgeon in this case had an extremely high viral load, with an HBV DNA concentration of >17.9 million IU/mL. However, that was not known until a workup investigation began following a needlestick injury to the surgeon. The injury occurred when a needle, passed by an assisting surgeon during suturing punctured the surgeon’s index finger. The surgeon immediately reported the incident to occupational health for evaluation as the assisting surgeon completed the operation. The occupational health evaluation concluded that there was no suggestion of surgeon-to-patient exposure during the event. However, as the subsequent investigation revealed the high titer of HBV in his blood, the surgeon was ordered to halt his orthopedic practice — which mainly consisted of knee and hip replacements. The surgeon was not aware of any risk factors for HBV infection and did not recall any prior instances of needle stick injury during his career, the investigators reported.

A retrospective cohort study of all patients who underwent surgery by the surgeon was conducted. A total of 232 (70.7%) of potentially exposed patients consented to testing. Of those, two were found to have acute infection and six had “possible transmission — evidence of past exposure without risk factors,” investigators reported. Genome sequence analysis of HBV DNA from the infected surgeon and patients with acute infection revealed genetically related virus (>99.9% nucleotide identity).

No follow-up on HBV vaccine failure

A critical element in the case is that the surgeon had not previously responded to two series of HBV vaccinations, but it appears no further action was taken, the authors report. “The surgeon had immigrated to the United States and completed orthopedic residency training before being employed by Facility A,” the report states. “Having previously completed 2 hepatitis B vaccination series without achieving a protective level of hepatitis B surface antibody (anti-HBs ≥10 IU/L), the provider declined further vaccination upon hire at Facility A.”

No additional evaluation of this non-responder status (i.e., testing for the presence of HBsAg) was performed prior to the needlestick injury, the authors noted.

“The hospital in question doesn’t have a policy requiring people to know their [HBV] status,” says Costi Sifri, MD, one of the authors of the report and an epidemiologist in the division of infectious diseases at the University of Virginia Health System in Charlottesville. “I know that in the state of Virginia and other states it is something that is not a requirement, but there are some questions regarding state licensure that include whether one knows if they have a chronic viral infection.”

Failure to respond to HBV vaccine — not once but twice — should have raised a red flag, suggesting the possibility the surgeon had chronic HBV infection, Henderson says. “That information should have been passed on to the director of the occupational medicine service, who should have called the surgeon up and said, ‘You are from an area where these kinds of HBV infections are endemic and you did not respond to the vaccine twice. Is it possible that you are a chronic carrier and would you like for us to look into that for you?’”

Such an intervention may have prevented the infections, but the fact that the surgeon reported his needlestick injury suggests he was not trying to conceal his HBV status.

“This probably never crossed his mind to tell you the truth,” Henderson says. “I don’t think there is a shred of malignancy in this anywhere. I don’t think there is any [evidence that] he knew he was infected and was trying to hide it.”

Transmission of blood-borne pathogens from providers to patients has become exceedingly rare, with this incident thought to be the first documented case of provider to patient HBV transmission since 1994. “It doesn’t happen very often, but then it doesn’t always get detected when it happens because hepatitis B is often a subclinical infection in some patients,” Henderson says.

Again, the case also reflects the trend of medical providers coming into the U.S. from areas in the world like China where the prevalence of HBV infection is high. In such countries of high HBV endemicity many people acquire the virus at birth and go to become asymptomatic chronic carriers.

“We didn’t state it explicitly in the paper, but it is our suspicion that he acquired HBV either prenatally or at a very young age,” Sifri says. “He had chronic hepatitis with a high viral load and no overt symptoms.”

Interviews conducted with the surgeon’s coworkers attested to his excellent technique and use of barrier precautions during operations. “He was known by his peers and supervising surgeons to have excellent surgical technique and reported double gloving for 100% of surgical procedures, standard practice for all orthopedic procedures at Facility A,” investigators said. “No incidents of percutaneous exposure, glove perforation, or other breaches in surgical technique were identified during the investigation.”

Transmission route a mystery

Ultimately no clear method of transmission could be determined, leading investigators to theorize “that unknown or microperforation of the glove might have occurred. Glove microperforation has been shown to occur with a high frequency. Bacterial transmission through microperforations has been estimated to occur at a rate of 5%; however, the rate of viral transmission is unknown. In addition to microperforation, glove laceration during arthroscopic shoulder surgery occurs in 51% of outer gloves and 17% of inner gloves,” according to studies cited by the investigators.4-9

“That is a speculative argument as to how it could have occurred — taking a look at rates of microperforation and transmission of bacteria,” Sifri said. “Viruses are much smaller, but as far as I know there has been no work done on this in terms of what is the potential risk of viral transmission through microperforation — not only clinically but in animal models.”

In any case, glove failure would have to also involve some type of blood exposure to transmit the virus, possibly through micro lesions and abrasions to the skin caused during suturing.

“Remember, he had a very high titer so it wouldn’t take very much blood to produce an infection,” Henderson says. “I think it is very likely he somehow did the equivalent of shedding blood into the patients that he infected.”

The surgeon has apparently returned to practice after his viral titer was diminished through treatment. Improved HBV medications now make it possible to lower circulating virus to near undetectable levels, making it possible for infected providers to continue their medical practice with appropriate oversight.

“I can’t disclose any specifics about the surgeon, but my understanding is that he is still practicing surgery,” Sifri says. “It is my understanding that the institution referred to a panel of experts in hepatitis and infectious diseases and that is the process that was used to determine future work practices.”

The most recent CDC guidelines recommend using HBV DNA serum levels — rather than the old hepatitis B e-antigen status — to monitor potential infectivity of a provider. For health-care professionals requiring oversight, the serum HBV DNA considered “safe” for practice is <1,000 IU/ml. The Society for Healthcare Epidemiology of America (SHEA) has also issued guidelines allowing medical practice by an HBV-infected provider if viral load and other factors are monitored by an expert review panel.10

“I would say that if the procedures are in accordance with the SHEA and CDC guidelines that the risk of transmitting these viral pathogens is vanishingly small,” Sifri says. “The public should feel very comfortable with these processes.”

References

  1. Henderson, DK. Exceptions That Prove the Rule Clin Infect Dis 2013; 56:225-227.
  2. Enfield KB, Sharapov U, Hall KK, et al. Transmission of hepatitis B virus from an orthopedic surgeon with a high viral load. Clin Infect Dis 2012; 56:218–24.
  3. Holmberg SD, Suryaprasad A, Ward JW. Updated CDC recommendations for the management of hepatitis B virus–infected health-care providers and students. MMWR 2012;61(RR-3):1–12.
  4. Harpaz R, Von Seidlein L, Averhoff FM, et al. Transmission of hepatitis B virus to multiple patients from a surgeon without evidence of inadequate infection control. N Engl J Med 1996; 334:549–54.
  5. The Incident Investigation Teams and others. Transmission of hepatitis B to patients from four infected surgeons without hepatitis B e antigen. N Engl J Med 1997; 336:178–84.
  6. Corden S, Ballard AL, Ijaz S, et al. HBV DNA levels and transmission of hepatitis B by health care workers. J Clin Virol 2003; 27:52–8.
  7. Tanner J. Surgical gloves: perforation and protection. J Perioper Pract 2006; 16:148–52.
  8. Partecke LI, Goerdt AM, Langner I, et al. Incidence of microperforation for surgical gloves depends on duration of wear. Infect Control Hosp Epidemiol 2009; 30:409–14.
  9. Kaplan KM, Gruson KI, Gorczynksi CT, et al. Glove tears during arthroscopic shoulder surgery using solid-core suture. Arthroscopy 2007; 23:51–6.
  10. Henderson DK, Dembry L, Fishman NO, et al. SHEA guideline for management of healthcare workers who are infected with hepatitis B virus, hepatitis C virus, and/or human immunodeficiency virus. Infect Control Hosp Epidemiol 2010; 31:203–32