New laboratory test for pregnant women to detect GBS infections

A more rapid laboratory test for pregnant women to detect Group B strep (GBS), the most common cause of life-threatening infections in newborns, is being studied by researchers at The University of Texas Health Science Center at Houston (UTHealth).

"Typically, if a patient comes into the emergency room in labor and you don't know if she carries GBS, you have to treat her with antibiotics," said Jonathan Faro, M.D., PhD., chief resident in the Department of Obstetrics, Gynecology and Reproductive Sciences at The University of Texas Medical School at Houston, part of UTHealth. "Everyone is concerned that the overuse of antibiotics is leading to greater resistance to them. A more rapid test could transform this practice, allowing us to cut down on the indiscriminate use of antibiotics, which saves money and avoids any potential adverse reactions that patients may have to them."

According to the Centers for Disease Control, GBS is the most common cause of sepsis (blood infection) and meningitis and a frequent cause of pneumonia in newborns. The CDC estimates the bacterium, which is passed from mother to child through the birth canal, is carried by 25 to 30 percent of women at any one time. Because GBS has few symptoms, many women do not know they are carriers. In 2001, 1,700 babies less than one week old contracted GBS, which can lead to disability and death.

Pregnant women are typically screened for GBS at 35 to 37 weeks gestation and antibiotics can be administered at the time of delivery to kill the bacteria. But nearly 13 percent of patients experience pre-term labor before they are screened and up to 15 percent of pregnant women who arrive for full-term delivery have not been screened. Because the current test takes 48 to 72 hours for results, obstetricians must determine whether to give these women intravenous antibiotics automatically or use risk factors, shown to be only half as effective as laboratory tests, to assess whether the patient has the bacteria.

Faro hopes that the new test by NanoLogix, which in UTHealth studies last spring delivered results in just four hours, would give obstetricians a better solution through timely, accurate knowledge. The study will enroll 300 pregnant patients during their regular GBS screening at UT Physicians clinics in collaboration with Allan Katz, M.D., the Robert K. Creasy Professor in the Department of Obstetrics, Gynecology and Reproductive Sciences, which is sponsoring the project with resident research funds. Results of the new test will be compared to other current standard tests.