Pat Tookey

Low rates of mother-to-child transmission of HIV following effective pregnancy interventions in the United Kingdom and Ireland, 2000-2006

Aim:In the United Kingdom (UK) and Ireland, avoidance of breastfeeding and alternative combinations of antiretroviral therapy regimen and mode of delivery are recommended according to maternal clinical status. The aim of this analysis was to explore the impact of different strategies to prevent mother-to-child transmission at a population level. Design:Comprehensive national surveillance study. Methods:Pregnancies in diagnosed HIV-infected women in the UK and Ireland are notified to the National Study of HIV in Pregnancy and Childhood; infant infection status is subsequently reported. Factors associated with transmission in this observational study were explored for singleton births between 2000 and 2006. Results:The overall mother-to-child transmission rate was 1.2% (61/5151, 95% confidence interval: 0.9–1.5%), and 0.8% (40/4864) for women who received at least 14 days of antiretroviral therapy. Transmission rates following combinations recommended in British guidelines were 0.7% (17/2286) for highly active antiretroviral therapy with planned Caesarean section, 0.7% (4/559) for highly active antiretroviral therapy with planned vaginal delivery, and 0% (0/464) for zidovudine monotherapy with planned Caesarean section (P = 0.150). Longer duration of highly active antiretroviral therapy was associated with reduced transmission after adjusting for viral load, mode of delivery and sex (adjusted odds ratio = 0.90 per week of highly active antiretroviral therapy, P = 0.007). Among 2117 infants born to women on highly active antiretroviral therapy with viral load less than 50 copies/ml, only three (0.1%) were infected, two with evidence of in-utero transmission. Conclusion:Sustained low HIV transmission rates following different combinations of interventions in this large unselected population are encouraging. Current options for treatment and delivery offered to pregnant women according to British guidelines appear to be effective.

Decline in mortality, AIDS, and hospital admissions in perinatally HIV-1 infected children in the United Kingdom and Ireland

Abstract Objective To describe changes in demographic factors, disease progression, hospital admissions, and use of antiretroviral therapy in children with HIV. Design Active surveillance through the national study of HIV in pregnancy and childhood (NSHPC) and additional data from a subset of children in the collaborative HIV paediatric study (CHIPS). Setting United Kingdom and Ireland. Participants 944 children with perinatally acquired HIV-1 under clinical care. Main outcome measures Changes over time in progression to AIDS and death, hospital admission rates, and use of antiretroviral therapy. Results 944 children with perinatally acquired HIV were reported in the United Kingdom and Ireland by October 2002; 628 (67%) were black African, 205 (22%) were aged ≥ 10 years at last follow up, 193 (20%) are known to have died. The proportion of children presenting who were born abroad increased from 20% in 1994-5 to 60% during 2000-2. Mortality was stable before 1997 at 9.3 per 100 child years at risk but fell to 2.0 in 2001-2 (trend P < 0.001). Progression to AIDS also declined (P < 0.001). From 1997 onwards the proportion of children on three or four drug antiretroviral therapy increased. Hospital admission rates declined by 80%, but with more children in follow up the absolute number of admissions fell by only 26%. Conclusion In children with HIV infection, mortality, AIDS, and hospital admission rates have declined substantially since the introduction of three or four drug antiretroviral therapy in 1997. As infected children in the United Kingdom and Ireland are living longer, there is an increasing need to address their medical, social, and psychological needs as they enter adolescence and adult life.

Short-term risk of disease progression in HIV-1-infected children receiving no antiretroviral therapy or zidovudine monotherapy: a meta-analysis.

BACKGROUND Data on the short-term risk of disease progression in HIV-1-infected children are needed to address the question of when to begin combination antiretroviral therapy. We estimated 12-month risks of progression to AIDS and death, by age and most recent measurement of CD4 T-cell percentage (CD4%) or viral load, in children receiving no antiretroviral therapy or zidovudine monotherapy only. METHODS We undertook a meta-analysis of individual longitudinal data for 3941 children from eight cohort studies and nine randomised trials in Europe and the USA. Estimates of risk were derived from parametric survival models. FINDINGS 997 AIDS-defining events were recorded over 7297 person-years of follow-up in the analysis of CD4%, and 284 events over 2282 person-years in the viral load analysis, corresponding to 568 deaths (9087 person-years) and 129 deaths (2816 person-years), respectively. In children older than 2 years, risk of death increased sharply when CD4% was less than about 10%, or 15% for risk of AIDS, with a low and fairly stable risk at greater CD4%. Children younger than 2 years had worse outlook than older children with the same CD4%. Risk of progression increased when viral load exceeded about 10(5) copies per mL, although this association was more gradual compared with CD4%. Both markers had independent predictive value for disease progression; CD4% was the stronger predictor. INTERPRETATION This information is important for paediatricians making decisions, and for researchers designing trials, about when to initiate or restart antiretroviral therapy.

Antiretroviral therapy and premature delivery in diagnosed HIV-infected women in the United Kingdom and Ireland

Objective:To explore the association between antiretroviral therapy in pregnancy and premature delivery, birthweight, stillbirth and neonatal mortality, in pregnancies in HIV-infected women delivering between 1990 and 2005. Design:Pregnancies in women with diagnosed HIV infection in the UK and Ireland are notified to the National Study of HIV in Pregnancy and Childhood (NSHPC) through a well-established surveillance scheme. Results:The prematurity rate (< 37 weeks gestation) was higher in women on highly active antiretroviral therapy (HAART) (14.1%, 476/3384) than in women on mono/dual therapy (10.1%, 107/1061), even after adjusting for ethnicity, maternal age, clinical status and injecting drug use as the source of HIV acquisition [adjusted odds ratio (AOR) = 1.51, 95% confidence interval (CI), 1.19–1.93; P = 0.001]. Delivery at < 35 weeks was even more strongly associated with HAART (AOR = 2.34; 95% CI, 1.64–3.37; P < 0.001). The effect was the same whether or not HAART included a protease inhibitor. In comparison with exposure to mono/dual therapy, exposure to HAART was associated with lower birthweight standardized for gestational age (P < 0.001), and an increased risk of stillbirth (AOR = 2.27; 95% CI, 0.96–5.41; P = 0.063). Conclusions:These findings, based on comprehensive population surveillance, demonstrate an increased risk of prematurity associated with HAART, and a possible association with other perinatal outcomes, including stillbirth and birthweight. Although the beneficial effects of antiretroviral therapy on mother-to-child transmission are indisputable, monitoring antiretroviral therapy in pregnancy remains a priority.

Morbidity, Mortality, and Response to Treatment by Children in the United Kingdom and Ireland with Perinatally Acquired HIV Infection during 1996–2006: Planning for Teenage and Adult Care

BACKGROUND Recent evidence suggests that decreases in morbidity and mortality in cohorts of adults infected with human immunodeficiency virus (HIV) are showing signs of reversal. We describe changes over time in these characteristics and in the response to treatment among children in the United Kingdom and Ireland with perinatally acquired HIV infection, many of whom are now adolescents. METHODS We analyzed prospective cohort data reported to the National Study of HIV in Pregnancy and Childhood (NSHPC) and the Collaborative HIV Paediatric Study. RESULTS By mid 2006, 1441 HIV-infected children were reported to NSHPC; 40% were > or = 10 years old at their most recent follow-up visit, and 34% were receiving care outside London. The proportion of children born abroad increased from 24% during 1994-1996 to 64% during 2003-2006. The percentage of total child time during which children received highly active antiretroviral therapy (HAART) increased from 36% during 1997-1999 to 61% during 2000-2002 and 63% during 2003-2006. Of children who were naive to antiretroviral therapy at the start of HAART, the percentage with an HIV-1 RNA load of < 400 copies/mL after 12 months increased from 52% during 1997-1999 to 79% during 2003-2006. In multivariate analysis, only calendar time predicted virological response, whereas both younger age and lower CD4 cell percentage at HAART initiation predicted increases of > 10% in the CD4 cell percentage. A total of 31% of children aged 5-14 years and 38% aged > or = 15 years at their most recent follow-up visit had been exposed to drugs from each of the 3 main HAART classes. The rate of AIDS and mortality combined decreased from 13.3 cases per 100 person-years before 1997 to 3.1 and 2.5 cases per 100 person-years, respectively, during 2000-2002 and 2003-2006; rates of hospital admission also declined during this interval. Of 18 children known to have died since 2003, 9 died within 1 month after presentation. CONCLUSIONS Morbidity and mortality rates among HIV-infected children continue to decrease over time. Because these children are increasingly dispersed outside London, specialist care is now provided in national clinical networks. Transition pathways to adolescent and adult services and long-term observation to monitor the effects of prolonged exposure to both HIV and HAART are required.

Response to combination antiretroviral therapy: variation by age.

Objective:To provide information on responses to combination antiretroviral therapy in children, adolescents and older HIV-infected persons. Design and setting:Multicohort collaboration of 33 European cohorts. Subjects:Forty-nine thousand nine hundred and twenty-one antiretroviral-naive individuals starting combination antiretroviral therapy from 1998 to 2006. Outcome measures:Time from combination antiretroviral therapy initiation to HIV RNA less than 50 copies/ml (virological response), CD4 increase of more than 100 cells/μl (immunological response) and new AIDS/death were analysed using survival methods. Ten age strata were chosen: less than 2, 2–5, 6–12, 13–17, 18–29, 30–39 (reference group), 40–49, 50–54, 55–59 and 60 years or older; those aged 6 years or more were included in multivariable analyses. Results:The four youngest age groups had 223, 184, 219 and 201 individuals and the three oldest age groups had 2693, 1656 and 1613 individuals. Precombination antiretroviral therapy CD4 cell counts were highest in young children and declined with age. By 12 months, 53.7% (95% confidence interval: 53.2–54.1%) and 59.2% (58.7–59.6%) had experienced a virological and immunological response. The probability of virological response was lower in those aged 6–12 (adjusted hazard ratio: 0.87) and 13–17 (0.78) years, but was higher in those aged 50–54 (1.24), 55–59 (1.24) and at least 60 (1.18) years. The probability of immunological response was higher in children and younger adults and reduced in those 60 years or older. Those aged 55–59 and 60 years or older had poorer clinical outcomes after adjusting for the latest CD4 cell count. Conclusion:Better virological responses but poorer immunological responses in older individuals, together with low precombination antiretroviral therapy CD4 cell counts, may place this group at increased clinical risk. The poorer virological responses in children may increase the likelihood of emergence of resistance.

Earlier initiation of ART and further decline in mother-to-child HIV transmission rates, 2000-2011

Objectives:To analyze mother-to-child HIV transmission (MTCT) rates over time in light of changes in management, demographic, and pregnancy characteristics. Design:Population-based surveillance data on diagnosed HIV-positive women and their infants are routinely collected in the UK and Ireland. Methods:A total of 12 486 singleton pregnancies delivered in 2000–2011 were analyzed. HIV infection status was available for 11 515 infants (92.2%). Results:The rate of MTCT declined from 2.1% (17/816) in 2000–2001 to 0.46% (nine of 1975, 95% confidence interval: 0.21–0.86%) in 2010–2011 (trend, P = 0.01), because of a combination of factors including earlier initiation of antenatal combination antiretroviral therapy (cART). Excluding 63 infants who were breastfed or acquired HIV postnatally, MTCT risk was significantly higher for all modes of delivery in women with viral load of 50–399 copies/ml (1.0%, 14/1349), compared with viral load of less than 50 copies/ml (0.09%, six of 6347, P <0.001). Among the former (viral load 50–399 copies/ml), the risk of MTCT was 0.26% (two of 777) following elective cesarean section and 1.1% (two of 188) following planned vaginal delivery (P = 0.17), excluding in-utero transmissions. MTCT probability declined rapidly with each additional week of treatment initially, followed by a slower decline up to about 15 weeks of cART, with substantial differences by baseline viral load. Conclusion:MTCT rates in the UK and Ireland have continued to decline since 2006, reaching an all-time low of 5 per 1000 in 2010–2011. This was primarily because of a reduction in transmissions associated with late initiation or nonreceipt of antenatal cART, and an increase in the proportion of women on cART at conception.

British HIV Association guidelines for the management of HIV infection in pregnant women 2012

The overall purpose of these guidelines is to provide guidance on best clinical practice in the treatment and management of human immunodeficiency virus (HIV)-positive pregnant women in the UK. The scope includes guidance on the use of antiretroviral therapy (ART) both to prevent HIV mother-to-child transmission (MTCT) and for the welfare of the mother herself, guidance on mode of delivery and recommendations in specific patient populations where other factors need to be taken into consideration,such as coinfection with other agents. The guidelines are aimed at clinical professionals directly involved with, and responsible for, the care of pregnant women with HIV infection.

Trends in management and outcome of pregnancies in HIV-infected women in the UK and Ireland, 1990-2006

Objective  To describe the changing demographic profile of diagnosed HIV‐infected pregnant women over time and trends in pregnancy outcome, uptake of interventions and mother‐to‐child transmission.