Routine antenatal screening for hepatitis B using pooled sera: validation and review of 10 years experience.

AIMS: 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.

Q fever in Plymouth, 1972-88. A review with particular reference to neurological manifestations.

Between 1972 and 1988 we have serologically confirmed 103 Coxiella burnetii infections: 46 were acute, 5 were chronic, 52 represented past infections. Details of 61 cases are presented. Of acute cases 80% had respiratory involvement; at least 63% had pneumonias. The incidence (22%) of neurological complications was of particular interest; 40% of these patients had prolonged sequelae. One acutely ill patient died of fulminating hepatitis. Patients with pre-existing pathology or immunosuppression were especially susceptible to C. burnetii. In the absence of acute sera, the complement fixation test alone provided inadequate differentiation between recent and past Q fever: phase II titres persisted at greater than or equal to 80 for more than 1 year after the acute infection in 15 cases; maximum duration of persistence was 14 years. Three patients acquired high phase I titres. Only 5% of cases had chronic Q fever, but in view of the diverse sequelae observed in this series, we suggest that long-term serological and clinical follow-up of all cases of Q fever is fully justified.

Cultivation of Treponema pallidum in subcutaneous chambers implanted in golden hamsters.

Treponema pallidum was successfully grown in subcutaneous chambers in golden hamsters. Abnormally long forms of T. pallidum were found in these chambers. The cause of this abnormality may possibly be due to their being coated with antibody which could inhibit cell division or render the organism avirulent or both. T. pallidum was successfully passaged between hamsters but with a possible diminution in virulence.