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Case of the Month

November 2015

Case of the Month - November 2015

A 35-year-old pregnant nurse who works on a general medical ward submits a letter to the hospital administration from her treating physician.

The letter states that ‘I have been treating this patient for four years, and she is a known carrier of hepatitis B virus. She should be withdrawn from all nursing duties that require direct contact with patients and should be redeployed appropriately’.

The nurse is 20 weeks pregnant; she is generally in good health, and has had an uneventful pregnancy to date.

She supplies a copy of a laboratory report with results of hepatitis A, B, and C virus investigations (performed two weeks prior) as well as evidence that Hepatitis B surface antigen was positive 8 months prior.

The results are as follows:
TestTest
TestResult
Hepatitis A IgGPositive
Hepatitis B sAg (HBsAg)Positive
Hepatitis B cIgM (Anti-HBc IgM)Negative
Hepatitis B eAg (HBeAg)Negative
Hepatitis B eAb (Anti-HBe)Positive
Hepatitis B virus DNA* (HBV DNA)Not detected
Hepatitis C AbNegative

*Comment on laboratory report: linear reportable range of assay used is 20 – 170 000 000 IU/mL

Question 1
How do you interpret the hepatitis B virus (HBV) serology and PCR results?

Hepatitis B infection is considered chronic if HBsAg persists for >6 months, therefore this patient has chronic hepatitis B. The combination of the immunological marker profile and undetectable HBV DNA suggests an inactive HBsAg carrier state. 

Table 1, adapted from the South African guideline for the management of chronic hepatitis B (2013)1 is a useful guide for categorising the phases of chronic HBV infection using serological markers, HBV DNA levels and alanine transaminase (ALT) levels.

Table 1. Categorisation of chronic HBV infection phases according to serological markers, HBV DNA levels and ALT levels

HBsAg = HBV surface antigen; Anti-HBs = HBV surface antibody; Anti-HBcIgM = HBV core antibody IgM; Anti-HBcIgG = HBV core antibody IgG; HBeAg = HBV ‘e’ antigen; Anti-HBe = HBV ‘e’ antibody; ALT = alanine transaminase 

Case continued

The nurse supplies copies of laboratory reports for additional laboratory tests performed two weeks prior. 

The results are as follows:

Question 2

What is the patient’s HBV infection status given the liver function test results together with the HBV serology and PCR results?

Answer

All liver test results are within normal limits. The normal ALT level is in keeping with an inactive HBsAg carrier state as initially suggested by the immunological marker profile and undetectable HBV DNA result. 

Question 3

What risk do HBV-infected healthcare workers pose to patients in their care?

Answer

Published cases of HBV transmission from healthcare worker to patient are relatively rare, and have decreased substantially over the past few decades (owing in large part to enhanced practice of standard precautions & double-gloving for invasive surgical procedures, but also in part to healthcare worker HBV screening and vaccination programmes where available)2

For the healthcare worker to pose a risk for bloodborne virus transmission to a patient, three conditions need to be met3:

              i.            The healthcare worker must have infectious virus circulating in the bloodstream (i.e. viraemia)

            ii.            The healthcare worker must have an injury (e.g. puncture wound from needle, scalpel or bone shards etc) or other condition (e.g. non-intact skin) that allows exposure to their blood/other infectious body fluids

          iii.            The healthcare worker’s infected blood/body fluid must come in direct contact with a patient’s wound, traumatised tissue, or mucous membranes during an exposure-prone procedure. 

Most published cases of healthcare worker-to-patient HBV transmission have involved surgeons and dental surgeons. Transmission of HBV from infected healthcare workers in primary care settings or other specialties that do not perform exposure-prone procedures is exceedingly rare.2 

In this case, the infected healthcare worker is a nurse working on a general medical ward, and would not ordinarily perform exposure-prone procedures in her routine work. Therefore, the risk of HBV transmission to patients in her care is low.

Case continued

After consultation with specialist microbiologists and virologists and review of local and international recommendations regarding the management of HBV-infected healthcare workers, it was recommended that the nurse be allowed to continue working on the general medical ward. An important proviso was that she receive appropriate counselling as to the risk (albeit it low) of HBV transmission to patients in her care, and therefore the importance of adhering to standard precautions and double-gloving during invasive surgical procedures etc. to minimise this risk. It was also recommended that her obstetrician confer with a paediatric infectious diseases specialist in advance to plan for appropriate management of her HBV-exposed newborn after delivery, and that her obstetrician and physician be vigilant for acute hepatitis B flares during pregnancy and after delivery if she is not receiving ART. 

Question 4

Are there specific considerations in the management of chronic HBV infection in pregnant women?

Answer

Yes. There are several special considerations for pregnant women with chronic HBV infection1,4,5:

  • Interferon-based therapy is contra-indicated in pregnancy
  • Tenofovir is the preferred antiviral (rather than lamivudine, emtricitabine or entecavir), since it has a better resistance profile and there is more safety data in pregnant HBV-infected women
  • For prevention of mother-to-child HBV transmission, the most important strategy is to deliver the first dose of hepatitis B vaccine as soon as possible after birth (ideally within 12-24 hours), followed by subsequent doses as per the South African Expanded Programme of Immunisation schedule (i.e. at 6, 10 and 14 weeks of age). In addition, it is recommended to administer hepatitis B immunoglobulin to babies born to HBSAg-positive mothers in order to provide immediate passive immunity; this should also be administered soon after birth (ideally within 12 hours) but at a different injection site to the vaccine.
  • Consider offering tenofovir to pregnant women with HBV DNA >2 000 IU/mL in the third trimester to reduce risk of HBV transmission to the baby
  • HBV-infected women who are untreated or in whom anti-HBV therapy was discontinued must be monitored closely during pregnancy (and especially after delivery), since there is a risk of acute hepatic flares.

Question 5

What would further management of this healthcare worker’s HBV infection entail?

Answer

Since this healthcare worker’s HBV infection is categorized as inactive HBsAg carrier status, the SA guidelines recommend monitoring ALT and HBV DNA every 6-12 months to confirm the inactive carrier state. Also, since she is pregnant, she needs to monitored closely during pregnancy and after delivery for an acute hepatitis B flare if she is not on ART. 

An important consideration would be counselling the healthcare worker with regards the importance of knowing her HIV status, both for future management of her chronic hepatitis B and prevention of mother-to-child transmission of HIV. HIV/HBV co-infected persons require specific management, since co-infection in persons with chronic hepatitis B is associated with higher HBV DNA levels, a higher prevalence of HBV ‘e’ antigenaemia, and an increased risk of progression to fibrosis, cirrhosis and possibly hepatocellular carcinoma.6 Choice and timing of ART, monitoring of HBV infection status and liver function and monitoring for drug-induced hepatoxicity (due to ART, TB treatment, or other drugs) are important considerations in co-infected persons. The current SA HIV treatment guidelines (December 2014)7 include known HBV infection as an indication to start ART, irrespective of CD4 count. 

Discussion 

South Africa has a high prevalence of HBV infection, with more than 75% of adults having serological evidence of previous hepatitis B exposure and carrier rates between 10-25%. Historically, HBV vaccination coverage amongst South African healthcare workers is low; in 2002 Vardas et al showed that only 30.6% were immune, in 2007 De Villiers et al showed that in 67.5% of cases the healthcare worker’s HBV status was unknown following an occupational exposure, and in 2013 Khan et al showed that 39% of doctors who reported an occupational injury had no HBV immunity, whilst in total 56% of doctors were not aware of their immune status. Lack of knowledge regarding HBV immune status is unfortunately widespread and common amongst most groups of healthcare workers. Of the substantial number of healthcare workers in South Africa who are not aware of their HBV status, a proportion will be those with undiagnosed chronic hepatitis B. 

Current recommendations for the management of HBV infection in healthcare workers 

Although there are no National Department of Health guidelines for the management of HBV infection, there is a South African guideline for the management of chronic HBV infection (2013)1, which represents a consensus set of recommendations produced by a panel of expert local hepatologists, and draws on international guidelines and recommendations in the context of the epidemiology of HBV in SA. Another useful resource is the recently published World Health Organization (WHO) guidelines for the prevention, care and treatment of persons with chronic HBV infection (March 2015).2 

Both the South African (SA) and WHO chronic HBV management guidelines address the management of healthcare workers with chronic HBV infection. Both recommend that healthcare workers who are HBsAg positive and undertake exposure-prone procedures (including surgeons, gynaecologists, nurses, phlebotomists, personal care attendants and dentists):

  • should be considered for antiviral therapy, specifically a potent antiviral agent with a high barrier to resistance (i.e. entecavir or tenofovir)
  • can resume exposure-prone procedures when HBV DNA levels are undetectable or at least <2 000 IU/ml.

‘Exposure-prone procedures’ (EPP) are not explicitly defined in either the WHO or SA guidelines, but are generally defined as procedures in which there is a risk that injury to the healthcare worker may result in exposure of the patient’s open tissues to the blood of the healthcare worker (sometimes termed ‘bleedback’). Any type of invasive surgery is an EPP; surgery performed within a confined anatomical space where the healthcare worker’s hands/fingertips may not always be completely visible are also categorised as EPP. Non-exposure-prone procedures are defined as those where the hands and fingertips of the healthcare worker are visible and outside the patient’s body throughout, even when there is handling of sharp instruments (e.g. phlebotomy, insertion of peripheral IV lines).2,3 

In this case scenario, when assessing the chronic HBV-infected healthcare worker’s eligibility to continue practicing work (which in the worst-case scenario may involve exposure-prone procedures, albeit unlikely) using the SA, WHO, and other internationally recognised guidelines (United States, Canada, United Kingdom, European consensus group, and Australia), all recommend that a worker who is HBsAg-positive and HBeAg-negative with undetectable HBV DNA not be restricted from such work. 

According to South African legislation (the Occupational Health and Safety Act of 1993)8, every employer must have a system in place to ensure that all staff are immunised against HBV infection and that exposures to HBV and other bloodborne pathogens are reported and appropriately managed. However, compliance with this legislation is variable, and healthcare worker HBV immunisation programme policy and practice is unfortunately not standardised at present.  Although healthcare workers are also required to be vaccinated against HBV prior to training, this is also not uniformly enforced or monitored. 

 References 

  1. Spearman CWN, Sonderup MW, Botha JF et al. South African guideline for the management of chronic hepatitis B: 2013. S Afr Med J 2013;103(5):335-349. Available online at http://www.ajol.info/index.php/samj/article/view/88045/77687
  2. Lewis JD, Enfield KB, Sifiri CD. Hepatitis B in healthcare workers: transmission events and guidance for management. World J Hepatol 2015;7(3):488-497. Available online at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4381171/   
  3. Centers for Disease Control and Prevention. Updated CDC recommendations for the management of hepatitis B virus-infected health-care providers and students. MMWR 2012; 61(RR 3). Available online at: http://www.cdc.gov/mmwr/pdf/rr/rr6103.pdf
  4. World Health Organization. Guidelines for the prevention, care and treatment of persons with chronic hepatitis B infection. Published March 2015, available online at: http://www.who.int/hepatitis/publications/hepatitis-b-guidelines/en/ 
  5. National Institute for Health and Care Excellence (NICE). Hepatitis B (chronic): diagnosis and management – Clinical guideline. Published 26 June 2013, available online at: https://www.nice.org.uk/guidance/cg165 
  6.  Andersson MI, Preiser W, van Rensburg C et al. The HIV/HBV co-infected patient: time for proactive management. S Afr Med J 2015;105(4):281-282. Available online at  http://www.samj.org.za/index.php/samj/article/view/8907/6632 
  7. National Department of Health. National consolidated guidelines for the prevention of mother-to-child transmission of HIV (PMTCT) and the management of HIV in children, adolescents and adults. Published December 2014, available online at http://www.sahivsoc.org/upload/documents/ART%20Guidelines%2015052015.pdf
  8. Republic of South Africa Occupational Health and Safety Act, available online at http://www.labour.gov.za/DOL/downloads/legislation/acts/occupational-health-and-safety/amendments/Amended%20Act%20-%20Occupational%20Health%20and%20Safety.pdf

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