Wits University researchers at the MRC Respiratory and Meningeal Pathogens Research Unit contributed to the first comprehensive study of Group B Streptococcus, a bacteria that afflicts pregnant women and causes stillbirths and young-infant severe invasive disease and death.
Africa has the highest burden, with 54% of estimated cases and 65% of stillbirths and infant deaths.
The GBS burden of disease analysis, involving more than 100 researchers from around the world and comprised of 11 research papers.
Conservatively, estimates are that Group B Streptococcus infection causes an estimated 150,000 preventable stillbirths and infant deaths every year.
Shabir Madhi, Professor of Vaccinology at Wits and Director of the Wits MRC Respiratory and Meningeal Pathogens Research Unit and DST/NRF South African Research Chair in Vaccine Preventable Diseases contributed to the study.
“This research is especially important for South Africa, where the highest incidence of invasive GBS ïn young infants globally has been reported for the past 20 years,” he says.
“Furthermore, recently we have shown that at least 1 250 South African women will have a stillbirth due to GBS each year.
The study, funded by a grant from the Bill & Melinda Gates Foundation, includes data and estimates for the year 2015 from every country of the world, and includes outcomes for pregnant women, their babies and infants.
Previous data on GBS burden focused on infant cases and high-income countries, but the impact of GBS disease worldwide, especially in Asia, was less clear.
The new research found GBS colonizes the rectum and vagina of pregnant women in all regions of the world, with an average of 18% of pregnant women worldwide carrying (‘colonised’ with) the bacteria, ranging from 11% in eastern Asia to 35% in the Caribbean, totalling 21.7 million in 195 countries .
Although several vaccines to prevent GBS are in development, none is currently available.
This despite the disease accounting for more than the combined neonatal deaths from tetanus, pertussis, and respiratory syncytial virus, for which maternal vaccines are already in use, or further advanced in development.
This study shows for the first time that a maternal GBS vaccine, which was 80% effective and reached 90% of women, could potentially prevent 231,000 infant and maternal GBS cases.
The Wits MRC Respiratory and Meningeal Pathogens Research Unit recently completed the first study of an investigational GBS vaccine in pregnant women, the results of which were published in the prestigious Lancet Infectious Diseases journal.
Also, the Unit is currently investigating the potential of other components of GBS as potential vaccine targets.
Dr Keith Klugman, Director of the Pneumonia Team at the Bill & Melinda Gates Foundation and Wits Medical School alumnus, says, “The first few days and weeks of a baby's life are the most vulnerable by far.
"By filling in one of the great voids in public health data, this work provides crucial insight and shows the pressing unmet need for the development of an effective Group B Strep vaccine. Immunizing expectant mothers is a potentially ground-breaking approach that could dramatically reduce the number of maternal and child deaths.”