C

Hi

SHa

b

c

a

ARA

KHRCHS

1

aryEmHHl1V(Hilattp

iT

1d

Journal of Clinical Virology 46 (2009) 101–103

Contents lists available at ScienceDirect

Journal of Clinical Virology

journa l homepage: www.e lsev ier .com/ locate / j cv

ase report

epatitis B virus reactivation in a large haemodialysis unit: Virological andnfection control issues

anjay Bhattacharyaa, Samreen Ijazb, Natasha Ratnarajaa, Steve Smithc,usam Osmana, Elizabeth Boxall a,∗

HPA West Midlands Public Health Laboratory, Heartland of England NHS Foundation Trust, Birmingham, UKCentre for Infections (HPA Colindale), London, UKRenal Unit of Heart of England NHS Foundation Trust, Birmingham, UK

r t i c l e i n f o

rticle history:eceived 25 May 2009

ccepted 26 May 2009

eywords:epatitis B viruseactivationore antibodyaemodialysis

urface antigen mutation

. Case report

A 60-year-old Asian man, originally from Pakistan but presentlyUK resident had been on long-term haemodialysis for end stage

enal disease secondary to diabetic nephropathy. He was being dial-sed three times a week at the various dialysis units at the Heart ofngland NHS Trust and was not on any immunosuppressive treat-ent. He had no history of recent travel. He was “negative” forBV, HCV and HIV by routine screening. In late September 2007BsAg was weakly positive (signal/cut-off ratio 3.337) by the Mono-

isa Ultra assay (Bio-Rad Laboratories) and strongly positive (s/co37.77) by the Vidas Ultra assay (BioMérieux). The results of theidas assay were confirmed by a specific HBsAg neutralisation test

Vidas Ultra assay). He was also found to be weakly reactive forepatitis B e antigen (HBeAg), antibody to HBeAg (anti-HBe) pos-

tive, anti-HBc positive, and anti-HBc IgM negative. His HBV viraload reached a peak of 1,667,360 IU/ml (Roche Cobas Taqman HBV

ssay). The patient had mild transaminitis (peak aspartate amino-ransferase 124 IU/ml). Retrospective testing of stored sera showedhat 4 months previously he was anti-HBc positive and HBV DNAositive but HBsAg negative (HBV viral load 848 IU/ml) (Fig. 1).

∗ Corresponding author at: HPA West Midlands Public Health Laboratory, Birm-ngham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK.el.: +44 121 424 2248; fax: +44 121 772 6229.

E-mail address: Elizabeth.Boxall@heartofengland.nhs.uk (E. Boxall).

386-6532/$ – see front matter © 2009 Elsevier B.V. All rights reserved.oi:10.1016/j.jcv.2009.05.037

Sequencing of the HBV genome revealed that it belonged togenotype D with P120Q and N131P mutations in the surface antigengene. Mutations at these positions had previously been shown toabrogate HBsAg detection.1 Additional mutations found includedQ101R, T118R, K160N and E164G. The impact of these mutationson the HBsAg conformation is not known. There was also a muta-tion at codon 1 (Met to Leu) at the pre-core region which wouldhave stopped the production of HBeAg. The loss of the initiation siteprevents translation through the pre-core region and stops HBeAgsynthesis. The viral strain was fully susceptible to anti-viral agents.

As this was a “new case” of HBV in our haemodialysis unit (HU),an outbreak meeting was convened to discuss the managementof the incident. Units and haemodialysis machines used by theindex patient since the first positive HBV DNA test were identi-fied along with patients who shared machines or dialysis sessionswith the index patient. The vaccination and HBV immunity (anti-HBs titre >10 mIU/ml) status of the contact patients were reviewedand a booster dose of HBV vaccination was administered. A thor-ough review of practice, review of incident reports, and staff HBVstatus were checked for risk assessment. It was revealed that thepatient or direct contacts had used 47 different dialysis machinesin 5 different HUs (Heartlands and Solihull hospitals and their

satellite units) since the last negative PCR test. In total 173 outof 331 patients in the 5 HUs were identified as possible contacts.Non-immune contacts were put under enhanced surveillance withweekly HBsAg testing for 3 months as per the UK Department ofHealth recommendations.2 At the time of writing this report evi-

102 S. Bhattacharya et al. / Journal of Clini

Fl

dpHifHaufirouaa

oiiodtHnt

iafirtfiio(1scT

ig. 1. Results from the hepatitis B enzyme immunoassays and the hepatitis B viraload assay during the course of viral reactivation.

ence of past infection (anti-HBc positive) was found in 13 otheratients. Forty-nine patients were found to be non-immune (anti-Bc negative and anti-HBs <10 mIU/ml), 3 patients were partially

mmune (anti-HBs between 10-100 mIU/ml) and 17 patients wereully immune (13 immune from previous infection and 4 had anti-Bs >100 mIU/ml). No case of transmission within the HU, eithermong patients or staff has been identified after 8 months of follow-p. The spouse of the index patient was found to be sero-negativeor HBsAg and was offered HBV vaccination. The review of HBVmmunisation practices in the HUs revealed significant gaps withespect to uniformity of HBV immunisation practices or follow-upf immunity status. The index patient was referred to specialist livernit. On follow-up he spontaneously lost the HBsAg and HBV DNAlong with normalisation of liver function tests without any specificnti-viral treatment.

Hepatitis B virus reactivation in HUs presents a unique setf challenges with significant infection control and public healthmplications. The present case of HBV reactivation assumes signif-cance because of: (a) rarity of the HBV reactivation in the contextf HUs; (b) the detection of HBsAg gene mutations that affected theiagnostic capability of one of our screening assays; (c) the case leado a new recommendation for HBV screening in dialysis units by thePA National Standard Methods3; (d) as a result of this case immu-isation practices within the HU were reviewed and new measureso ensure adequate immunisation coverage were introduced.

To the best of our knowledge this is the first case following thencident in Ireland in April 2005 in which 306 dialysis patients,ttending 17 different dialysis centres (14 in Ireland), were identi-ed as having been potentially exposed to HBV as a result of theeactivation incident.4 Similar to our case there was no evidencehat any patient acquired HBV infection as a result of cross-infectionrom the index patient. Evidence of past infection (anti-HBc pos-tive, HBsAg negative) was found in 13 patients in the presentncident and 11 patients (3.6%) in the Irish incident. The majorityf patients in the Irish cohort had unknown HBV vaccination status

62.7%), 13.4% were fully vaccinated, 4.6% partially vaccinated and5.7% unvaccinated, and 76.6% had a titre <10 mIU/ml.4 We foundimilar findings to these observations with large number of unvac-inated, non-immune, or patients with unknown immune status.his was due to the lack of a uniform policy of HBV vaccination and

cal Virology 46 (2009) 101–103

immunity testing in our unit. Inadequate immunisation of patientsas was observed can also lead to increased population of vulner-able at risk patients. In a survey of HBV immunisation practicesin HUs within the UK it was revealed that 49% of the units didnot offer vaccine to any patient group. This is contrary to nationalguidelines.2 The problem is compounded by inadequate responseto HBV vaccination in many haemodialysis patients and alternativestrategies such as using a higher dose of vaccine (40 �g) and regularmonitoring of anti-HBs levels is recommended.5 The renal unit inour hospital is currently auditing the HBV immunisation practiceswithin the unit with the aim of taking corrective measures. It is obvi-ous that carrying out the vaccination of patients ‘in house’ ratherthan advising general practitioners of patients to take the respon-sibility of vaccination would improve compliance with standardsand improve vaccination rates.

Mutations in HBsAg involving amino acid substitution withinthe immunodominant “a” determinant have been shown to affectthe performance of commercial HBsAg assays.6 In a recent study itwas shown that several HBsAg gene mutations either present alone(G145R) or in combination (IL110R, S117I, G119R, T123N, C124R, andP203R), in diluted (P120Q, T131K, and G145R) or undiluted formmay lead to false negative results in several HBsAg assays includ-ing Monolisa Ultra and Vidas Ultra which are used in our settingfor screening and confirmation, respectively.7 Sensitivity perfor-mances for mutant HBV detection varied between 40% for Centaur,86% for Liaison, 89% for Monolisa Ultra and Vidas Ultra to 91% forAxSYM assays.7 The lack of detection of these mutants by commer-cial assays was probably due to suboptimal epitope recognition bythe monoclonal antibodies used in the capture phase and conju-gates. In that study the score of Monolisa with natural undilutedand diluted samples was 94% and 50%, respectively.7 We noticed aweak reactivity with the Monolisa assay in our case at the begin-ning of HBV reactivation, while the Vidas assay continued to givestrong signals throughout.

This case and the subsequent feedback to the Health Protec-tion Agency in the UK led to a change in the HBV screening policy(HPA National Standard Methods, VSOP10, February 2008).3 Pre-viously only HBsAg was tested in dialysis unit patients. The newpolicy recommends testing against HBsAg and anti-HBc to checkfor current/past infection. It adds that additional investigation andmonitoring (such as testing for HBsAg more frequently) may needto be considered where anti-HBc alone is found. This recommen-dation although in the best interest of the patient and the dialysisunits across the country has resource implications if implemented,but we think it is necessary to avoid the problems we encounteredwith this case.

Reactivation of HBV in CRF patients on long-term haemodialysisis a rare clinical event with a major health care impact. Good sero-logical surveillance including identification of those at risk throughanti-HBc testing and sound infection control practices includingvaccination should be fundamental in preventing HBV nosocomialtransmission.

Conflict of interest statement

We have had no involvements that might raise the question ofbias in the work reported or in the conclusions, implications, oropinions stated.The results presented in this paper have not beenpublished previously in whole or part, except in abstract format.

There is no financial or personal relationship with other peopleor organisations that could inappropriately influence this work.

Acknowledgements

We would like to acknowledge our gratitude towards spe-cialist nurses in the renal unit, infection control nurses,

f Clini

bM

R

C, Poovorawan Y. Mutation of the “a” determinant of HBsAg with discordantHBsAg diagnostic kits. Viral Immunol 2004;17:440–4.

S. Bhattacharya et al. / Journal o

iomedical scientists in HPA West Midlands, IT manager Janetowbray.

eferences

1. Gerlich WH. Diagnostic problems caused by HBsAg mutants—a consensus reportof an expert meeting. Intervirology 2004;47:310–3.

2. Department of Health. Potential viral hazards in dialysis units. In: Good prac-tice guidelines for renal dialysis/transplantation units. Prevention and control ofblood borne virus infection. London; 2002. p. 12–18 (Chapter 3).

3. Blood-borne virus testing in dialysis patients. Issue no: 1 Issue date: 20.02.08Issued by: Standards Unit, Evaluations and Standards Laboratory. SOP 10.http://www.hpa-standardmethods.org.uk/documents/vsop/pdf/vsop10.pdf.

cal Virology 46 (2009) 101–103 103

4. Thornton L, Fitzpatrick F, De La Harpe D, Brennan A, Murphy N, Connell J, etal. Hepatitis B reactivation in an Irish dialysis unit, 2005. Euro Surveill 2007;12:E7–8.

5. Department of Health. Immunisation against infectious disease—‘The Green Book’;2006. Last updated 12 February 2009.

6. Louisirirotchanakul D, Kanoksinombat C, Theamboonlert A, Puthavatana P, Wasi

7. Ly TD, Servant-Delmas A, Bagot S, Gonzalo S, Férey MP, Ebel A, et al. Sen-sitivities of four new commercial hepatitis B virus surface antigen (HBsAg)assays in detection of HBsAg mutant forms. J Clin Microbiol 2006;44:2321–6.