0%) received triple PEP, two received dual PEP and 55 received single PEP. Among the 57 infants who received single or dual PEP, five were born to women who received no antenatal antiretroviral therapy, although two of these women received intravenous zidovudine during labour. Where mothers had received antiretroviral therapy in pregnancy

(n=51), most (62.7%; 32 of 51) had also received intrapartum treatment (27 intravenous zidovudine and 5 oral antiretroviral therapy). Infection status was reported Thiazovivin for 81.6% (62 of 76) of very preterm infants who received prophylaxis, and 8% (5 of 62) were infected (three received single and two triple PEP). Infection status was reported for 89.2% (7320 of 8205) of infants with information on PEP; 14.7% (5 of 34) of infants who received no prophylaxis were infected, compared with only 1.0% (72 of 7286) (P<0.001) of those who were given Selleck Navitoclax prophylaxis. All five infected infants who received no

prophylaxis were born to untreated mothers who delivered vaginally; among all infants born vaginally to untreated mothers, those who received neonatal prophylaxis were significantly less likely to be infected than those who did not [8.5% (4 of 47) vs. 45.5% (5 of 11), respectively; P=0.002]. Because of the selective use of triple PEP for infants at higher risk of MTCT, it was not appropriate to explore the association between type of prophylaxis and infection status. Sixty-four infants born to women diagnosed in the week following delivery were also reported. Information on receipt of PEP was available for 60 of these infants. Fifteen per cent (9 of 60) had no prophylaxis, 20.0% (12 of 60) received single PEP, 11.7% (7 of 60) received dual PEP, and 53.3% (32 of 60) received triple PEP. Infection status was reported for 86.7% of these infants (52 of 60); 13.5% (7 of 52) were infected, all of whom had received prophylaxis. Between 2001 and 2008, almost all infants born to diagnosed HIV-infected women in the UK and Ireland received PEP, and

selective use of triple-drug prophylaxis increased substantially over time. This increase was most apparent among infants born to women who were untreated in pregnancy or who remained viraemic near delivery despite receiving HAART; this was in line with Urease changes to national guidelines in 2005 suggesting that triple PEP be considered for these infants [9]. From 2005 onwards, triple PEP was used for over two-thirds of infants born to untreated women and almost one-third of those whose mothers were viraemic despite receipt of HAART. Within this combined group, use of triple PEP was associated with a number of factors linked to an increased risk of MTCT, including shorter duration or lack of maternal therapy, detectable maternal viral load, low CD4 cell count, unplanned vaginal or emergency caesarean section delivery, and preterm birth.