patient moving to an infection control area in the next city. If the
patient should ever seroconvert to HBV negative he will be
returnedtohishomeunit. Atthepresenttimethepatientcontin-
uestohavecarrierstatus. Theimmediatefamilymembersallvol-
unteeredthemselvesforscreeningwithnopositivepick-ups. The
General Practitioner offered HBV vaccinations to those family
memberswishingit.
during acute hepatitis B infection and eleven were negative
donorsduringacutehepatitisBinfection.Noreportsoferroneous
releaseofsurfaceantigenpositivebloodwereidentified(6).
The ward staff
A list of all staff who may have had contact directly or indirectly
withthepatientwascorrelatedandsubmittedtotheoccupational
health department. This list was crosschecked with those mem-
bers of staff who were immunised. Those staff that reported as
non-respondersorwereoutsidethethreetofiveyearperiodsince
their last immunisation had blood taken for surface antigen and
antibody. Twohundred andnineteenstaff had possible contacts
withthepatient. Ofthese, 34%hadnotbeenimmunised, immu-
nised without protective response or their status was unknown.
19% of staff required a booster and the remaining 47% had pro-
tection. TheUKHealthDepartment(7)statesthatanyhealthcare
workerwhoundertakesexposureproneprocedures(EPPs)must
be vaccinated against hepatitis B and have their immunity
checked, unlesstheyareknowntobenaturallyimmunetoHBV.
Mostrenalunitsmakeitaconditionofemploymentthatstaffare
screenedforhepatitisantibodies, havethehepatitisBvaccination
and subsequently have their immune status checked. The UK
Health Department’s guidance states that health care workers
who refuse immunisations will be considered HBsAg positive
and restricted from working within renal dialysis units.
Approximately7-10%ofpeoplefailtorespondtothevaccineeven
after recall and booster dosage. Staff who are in post and are vac-
cine non-responders and HBsAg negative may remain in post
without restriction of practice provided their status is regularly
reviewed.
Personal effects on other patients
Inpreviousyearsdialysismachineryenjoyedanannualturnover
ofapproximately10%. Morerecentlyhowever, thisturnoverhas
slowed down resulting in many more dialysis machines moving
from area to area within the hospital site. This movement of
machinery greatly complicated the containment and manage-
mentoftheHBVoutbreakasall230patientshadpotentiallybeen
exposedtocontaminatedequipmentduringtheriskperiod.
ThisenhancedriskledtoweeklyscreeningforHBVofall230
dialysis patients. This control measure complemented other
restrictions including closing the unit to all admissions, can-
celling all planned dialysis holidays due to be taken by patients
and refusing any incoming holiday dialysis. These restrictions
were to last for a six-month period and during this time any
patientsawaitingakidneytransplantthroughdonationoronthe
kidney transplant waiting list also had to see out this isolation
period. Two patients on the transplant list were given the
HB40microgram vaccine, developed antibodies and were rein-
stated on the transplant list. Seven other patients were also fully
immuneandwereremovedfromtheweeklyscreeningprofile.
The source of infection
Urgent investigation was required to establish the source of the
infection.Theprioritywastoprotecttheremainingdialysisgroup
and the local health-care team. Following family interviews and
otherenquiriestheinvestigationpointedtowardsbloodtransfu-
sion as the most likely cause of the infection. The patient’s last
blood transfusion was 20th December 1997. The stored sera
from all the transfused blood donated between December 1996
and October 1997 (fourteen units for this patient) were re-tested
forHBsAg. Allprovednegative. In-depthscreeningfollowedand
one unit proved positive for Hepatitis B virus DNA via poly-
merasechainreaction. Thisparticularunithadbeendonatedon
the 6th October whilst the donor was incubating the virus. The
blood was subsequently transfused on the 16th October, the
recipient being the patient under discussion. No other recipient
receivedbloodfromthisdonor.
Blood donations in England and Wales are collected from
healthy donors who may not admit to factors associated with an
increased risk of blood borne infections. Whilst all donations
sincetheearly1970’shavebeentestedforHBVsurfaceantigenas
amarkeroftransmissibleHBV,therestillremainstheproblemof
infectious donations from the blood supply. Over 2.5 million
donations are issued annually in England and Wales and whilst
transmissiondoesoccuritisrare. CasesofacuteHBVreportedto
thesurveillancecentrefoundthat24of4185(0.6%)wereassoci-
ated with transfusion in England and Wales (6). Of the 14 trace-
abledonationsthreewerefromsurfaceantigennegativedonors
Public awareness
Inresponsetolocalmediainterest,theLeedsbasedBloodAuthority
wascontactedandadvicesoughtfromtheirpublicrelationsteam.
AgreementwasreachedbetweentheBloodTransfusionAuthority
andtheTrustconcernedtoreleaseajointstatementtothepress.
Localmediainterestwasreflectedvialocalnewspapersandlocal
televisionnews.Followingpublicationofthestatementatelephone
“hotline”wassetupforthosepatientsinvolved.
Conclusion
This paper highlights the continued risk of hepatitis B within
haemodialysisunits, despiteintensiveeffortsatrecognitionand
prevention. The events in the critical incident under discussion
demonstratethedangerofcomplacencyandtherewouldappear
tohavebeenabreakdownintheusualcontrolmeasures. Thiscan
bedemonstratedbythefactthattheinfectionremainedundetect-
edforfivemonths. Whilstnoapparenttransmissionoccurredthe
potentialforanoverwhelmingoutbreakwaspresent.
The total financial cost of the incident remains at this point
unclear, however approximately twenty thousand pounds was
spenton5000HBsAgandAnti-HBSmeasurements. Threeextra
staffweredeployedwithintheoccupationalhealthdepartmentto
facilitaterapiddatacollectionandthedialysisunitremainedshut
toadmissionsandholidaypatientsforsixmonths.Whilstnosec-
ondary transmission appears to have occurred the opportunity
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EDTNA|ERCA JOURNAL 2000 XXVI 1