Routine antenatal screening for hepatitis B using pooled sera: validation and review of 10 years experience.
OBJECTIVE
To validate the sensitivity of universal antenatal screening for hepatitis B surface antigen (HBsAg) by testing pools of 10 sera, and to review 10 years' experience using this method.


METHODS
66,945 antenatal patients were tested between 1986 and 1996 using the pooled method. All sera from 1996 (n = 6050) were retrieved and retrospectively tested individually. An in vitro determination of the effect of pooling on sensitivity was performed by checkerboard neutralisation assay.


RESULTS
26 HBsAg positive women were detected by universal screening over 10 years; 12 had non-European surnames and five had known risk factors for hepatitis B infection. High titre anti-HBs sera in the pool reduced the sensitivity of the HBsAg assay, though the effect was only significant at low levels of HBsAg carriage.


CONCLUSIONS
The prevalence of hepatitis B is extremely low in the antenatal population served by Plymouth PHL. Pooling is unlikely to reduce sensitivity enough to lead to significant preventable vertical transmission, and is a cost-effective and valid strategy in areas of low seroprevalence.
Plymouth Public Health Laboratory, Derriford Hospital, UK. richard.cunningham@phnt.swest.nhs.uk
R
R
Cunningham
J L
JL
Northwood
C D
CD
Kelly
E H
EH
Boxall
N J
NJ
Andrews
D001800:Blood Specimen Collection / Q000379:methods*; D002353:Carrier State / Q000517:prevention & control; D004739:England; D005260:Female; D006509:Hepatitis B / Q000517:prevention & control*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D008403:Mass Screening / Q000379:methods*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*; D011295:Prenatal Care / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D006514:Hepatitis B Surface Antigens