Hi, my name is Divya, and I just completed my first year of medical school at Keck School of Medicine, USC.
My passion for global health and pediatrics got me interested in studying infant mortality on a global context. This summer, I had the privilege of visiting the capital city of Mongolia, Ulaanbaatar, to set up a study investigating the prevalence of Group B streptococcus in Mongolia.
Group B streptococcus (GBS) is the leading cause of neonatal sepsis globally, even though it is largely preventable. In Mongolia, the infant mortality rate remains high at 11.1 per 1000 live births, with neonatal sepsis accounting for 5% of these deaths.
Many healthy women are colonized with GBS, and about half pass it on to their infant during childbirth. Although maternal GBS colonization is usually asymptomatic, it can lead to pregnancy complications such as preterm delivery and stillbirth. Additionally, a small fraction of infants born to colonized mothers go on to develop invasive GBS disease, which can be subdivided into early onset and late onset disease. Early onset GBS disease, which presents in the first 6 days of life as sepsis, meningitis, or pneumonia, usually leads to severe neurodevelopmental outcomes or death. GBS disease is largely preventable through intrapartum antibiotic prophylaxis (IAP) or maternal vaccination.
In the United States, the introduction of universal prenatal screening and IAP has dramatically reduced the incidence of early onset GBS disease. IAP, though, is not a practical solution in Mongolia, where resources are limited. In this region, maternal vaccination may provide a more effective solution. There is currently a multivalent vaccine in clinical trials, which would protect women against pregnancy complications due to GBS, as well as protect neonates against early onset and late onset GBS disease. Since the vaccine targets specific serotypes, and GBS serotype distribution varies regionally, it is necessary to identify which serotypes are present in Mongolia. Currently there is no data about the burden of GBS disease in Mongolian neonates. The goal of this study is to determine the rate of rectovaginal GBS colonization in pregnant women in Ulaanbaatar, in order to estimate the rate of GBS disease in Mongolian infants. We will also be determining which serotypes of the bacteria are found in Mongolia, in order to guide future vaccination efforts.
For this study, pregnant women receiving prenatal care at Urguu Maternity Hospital in Ulaanbaatar will be approached for participation in the study. Sample swabs will be collected from the rectum and vagina and cultured for GBS in an onsite laboratory. GBS positive samples will further be serotyped, using serotyping kits. 300 women will be enrolled in the study. The maternal prevalence data we collect, along with census data on annual birth rate, will be used to estimate incidence of GBS disease in Mongolia, given that 1-2% of infants born to colonized mothers will develop early onset GBS disease. Understanding prevalence and serotype distribution, is critical for guiding prevention programs against GBS in pregnant women and infants in Mongolia.
My mentor, Dr. Pia Pannaraj, from the Department of Infectious Disease at CHLA, and I are collaborating closely with Dr. Bardach Jargalsaikhan, from the department of Obstetrics and Gynecology at Mongolian National University of Medical Sciences, who is an obstetrician at Urguu Maternity Hospital where this study will be carried out. The purpose of my visit this summer was to initiate the study set up and training of our Mongolian colleagues. Our colleagues in Mongolia will continue the data collection phase over a period of six months after the initial set up and training is completed.
Divya Patel is a medical student at the Keck School of Medicine of USC. Her project, “Prevalence of Group B Streptococcus in Pregnant Women in Ulaanbaatar, Mongolia,” is supported by the Anderson Family Global Health Immersion Fellowship.