Globally paediatric HIV infection represents a major setback to child health. The World Health Organisation estimates that over 20 million adults and 1.5 million children have been infected with HIV since the pandemic began 20 years ago. World wide over a thousand children a day are born with HIV. The highest incidence rates are in sub-Saharan Africa and South Asia, particularly now in urban India.1 The Day report recently published projections for the incidence and prevalence of AIDS in England and Wales for 1995–9. Although a fall is expected in new AIDS cases among homo/bisexual males, a 25% rise in the heterosexual acquisition category, and a 60% increase in the incidence of AIDS in children of HIV infected mothers are projected.2 Absolute numbers of known infected children are still small in the UK, with 380 vertically infected children reported by October 1996 (table 1). Around 80% of the children with confirmed HIV infection reside in the Thames regions (predominantly in London) with about 7% resident in Scotland. View this table: Table 1 Infection status of children born to HIV positive mothers reported to the British Paediatric Surveillance Unit or Royal College of Obstetricians and Gynaecologists by 31 October 1996 (from Newsletter 29) The most exciting advance in preventing paediatric HIV infection for countries that can afford it, has been the report from the AIDS Clinical Trials Group (ACTG) protocol 076 that zidovudine (AZT) given perinatally to a selected group of HIV infected pregnant women and their infants reduced the risk of vertical transmission by two thirds (25% to 8%).3 The mothers received AZT in the second and third trimester, followed by intrapartum intravenous AZT, and AZT was given to infants for the first six weeks of life. Vertical transmission rates vary world wide, with reports from prospective studies ranging from 15–20% in …