Vertically transmitted HIV infection in the British Isles.

OBJECTIVE

To describe the epidemiology of vertically acquired HIV infection in the British Isles, the level of underreporting, the vertical transmission rate, and clinical spectrum of paediatric AIDS.

DESIGN

Confidential, linked registers based on reporting from obstetricians and paediatricians; anonymous unlinked neonatal HIV serosurveys.

SETTING

British Isles.

SUBJECTS

Children born to mothers with HIV infection.

MAIN OUTCOME MEASURES

Trends in HIV infection and vertical transmission rate.

RESULTS

In Scotland and the Irish Republic, where most maternal HIV infection is related to drug misuse, the annual number of reports of children born to infected mothers has fallen since 1989. In England and Wales nearly half of maternal infections have been acquired overseas, and the number of children born to these women, and to women who became infected in Britain, is increasing. In south east England the proportion of live births to women whose infection was identified before delivery was only 17% (50/287), compared with 68% (26/38) in Scotland. The vertical transmission rate was 13.7% (23/168), and 23% of infected children developed AIDS in the first year of life. 41% (38/92) of children born to infected mothers who were ascertained after delivery were breast fed, compared with 5% (12/236) of those ascertained before delivery.

CONCLUSIONS

The incidence of vertically transmitted HIV infection is increasing in England and Wales. More extensive antenatal testing would enable infected women to be counselled against breast feeding, which could prevent a substantial proportion of vertical transmission in some areas, and would increase opportunities for early diagnosis and treatment of infected children.