The HIV pandemic continues to grow with
35 million people currently infected.
92% of HIV-infected pregnant women live in sub-Saharan Africa.
15 million preterm babies born worldwide every year.
How understanding the immunological status of HIV-infected pregnant women can help to identify which women are most likely to have babies born too early or too small, and support the development of novel preventative and therapeutic interventions.
Maternal HIV infection and adverse pregnancy outcomes
Our research focuses on the elucidation of the mechanisms by which HIV infection in pregnancy causes spontaneous preterm birth (PTB) and intrauterine growth restriction (IUGR), with a view to developing targeted, preventative and interventional strategies.
PTB and low birth weight (LBW) are the leading causes of perinatal morbidity and mortality around the world, the vast majority of which occur in the developing world. The HIV pandemic continues to grow with 35 million people currently infected. 92% of HIV-infected pregnant women live in sub-Saharan Africa. Maternal HIV infection is associated with increased rates of PTB and LBW. Controversy exists over whether antiretroviral therapy, instituted for maternal health or prevention of mother-to-child-transmission of HIV, contributes to PTB and IUGR.
We are conducting systematic reviews and prospective cohort studies in South Africa to better understand the relationship between maternal HIV infection and antiretroviral therapy and adverse pregnancy outcomes. Within the context of the Interbio-21st study we are conducting a unique cohort study in Soweto, Johannesburg, South Africa, following HIV-positive and HIV-negative women throughout pregnancy. All pregnancies are accurately dated and intrauterine fetal growth is measured by serial ultrasound scans. Biological samples are collected throughout pregnancy and at delivery. The aim is to characterise the immune responses associated with HIV infection in pregnancy by which HIV may cause PTB and IUGR. This work may shed light on the broader mechanisms underlying PTB and IUGR in general. A better understanding of these mechanisms should pave the way to the development of specific preventative and therapeutic strategies applicable in the developing world.
Global molecular epidemiology of HIV
HIV-1 genetic variability within individuals and populations plays a central role in the HIV pandemic. High rates of mutation and recombination during HIV reverse transcription create a genetic diversity in the host which is subject to selection pressures by the immune response and antiretroviral treatment. As a result, the global distribution of HIV-1 subtypes and recombinants is extremely complex and dynamic. The increasing diversity has profound implications for many aspects of the pandemic, including viral pathogenicity, transmission, diagnosis, treatment, and vaccine development. HIV-1 genetic diversity surveillance is crucial in tackling the pandemic and in collaboration with the HIV Vaccine Initiative at the World Health Organisation, Geneva, we collect HIV molecular epidemiology data from around the world. We use this data to describe the distribution and trends in national, regional, and global HIV genetic diversity, which is essential for HIV vaccine development. We further link our HIV distribution data to regional and global transport and accessibility models to investigate the role of infrastructure and human migration in the spread of HIV.