Jonathan Faro_MC
Jonathan Faro, MD, PhD

A more rapid lab test for pregnant women to detect potentially deadly Group B strep (GBS) from NanoLogix Inc, Hubbard, Ohio, has been successful at identifying GBS colonization in 6 1/2 hours, according to the results of a study from The University of Texas Health Science Center at Houston (UTHealth).

The test could be helpful for the 13% of patients who experience preterm labor before they are screened for GBS, which usually occurs between 35 and 37 weeks of gestation, according to researchers, who add that the current standard test takes 48 hours.

Antibiotics can be administered at the time of delivery to kill the bacteria.

“This new test could change the management of patients who present to labor and delivery with threatened preterm labor and aren’t expected to deliver right away,” says Jonathan Faro, MD, PhD, assistant professor in the Department of Obstetrics, Gynecology and Reproductive Sciences at The University of Texas Medical School at Houston, part of UTHealth. “It would likely gain use in this patient population, which is a small number, but still very significant clinically. We could target this population and this would help cut down on overuse of resources and minimize our contribution to the increased level of bacterial resistance.”

The new test can also detect antibiotic sensitivities for women who are allergic to penicillin, saving the additional 48 hours the standard test for antibiotic sensitivity takes, Faro says.

GBS is the most common cause of sepsis and meningitis and a frequent cause of pneumonia in newborns, according to the Centers for Disease Control (CDC). The CDC estimates the bacterium, which is passed from mother to child through the birth canal, is carried by 25% to 30% 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 1 week old contracted GBS, which can lead to disability and death.

Faro is studying an even faster version of the test with the hope it could detect GBS in as little as 30 minutes. That could make a difference for the up to 15% of pregnant women who arrive for full-term delivery and have not been screened. Right now, obstetricians must determine whether to give these women intravenous antibiotics automatically or use risk factors, which have been shown to be only half as effective as lab tests, to assess whether the patient has the bacteria.

“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,” Faro said. “Everyone is concerned that the overuse of antibiotics is leading to greater resistance to them. Some have expressed concern that by giving penicillin to everyone, we are increasing the number of babies who are getting sick from E. coli sepsis.”

The study, titled “Accuracy of an Accelerated, Culture-Based Assay for  Detection of Group B Streptococcus,” was published in a recent online edition of Infectious Diseases in Obstetrics and Gynecology

[Source: University of Texas Health Science Center at Houston]