Surveillance of antenatal infections--HIV, hepatitis B, syphilis and rubella susceptibility in London.

London has relatively high rates of HIV, hepatitis B and syphilis, and has the potential for undiagnosed infection in pregnancy. As part of a drive to improve HIV testing in pregnancy, surveillance of a number of antenatal infections has been carried out in London's 30 maternity units since 2000. Infection screening rates rose from 89% in 2000 to 94% in 2002, and HIV screening rates increased from 66% to 86%. During 2002, 115,230 women booked for antenatal care; 998 were HBsAg positive (about ten in 1000), 452 were HIV positive (five in 1,000), 412 tested positive for syphilis (four in 1000), and 3,929 were susceptible to rubella (36 in 1000). The main burden of infection was concentrated in a few geographic areas. Worryingly the majority of women found to be HIV positive were diagnosed by antenatal screening and not before.