GBS Prevention: When Tests Get it Wrong
Negative Test, False Reassurance
Stephanie Worthy was tested for GBS 33 weeks into her pregnancy and the test was negative. Her son, Jaxton, was born on the evening of December 7, 2011. He was completely healthy and sailed through all the newborn tests with high marks. Six hours later he was in neonatal intensive care for observation. Four days later he was dead. “They didn’t diagnose him [with GBS] for eight hours,” Worthy explains, presumably because her GBS test was negative.
RaeAnne Latimore also tested negative for GBS, at 35 and a half weeks. Her son, Blake, was born at 5:30 in the afternoon of January 6, 2012, one month after Jaxton Worthy was born. At one o’clock the next morning Blake was making strange grunting sounds and Latimore couldn’t rouse him for feeding. She became concerned, but the nurse reassured her that the noises were normal. Latimore insisted that they look Blake over in the nursery. Half an hour later the doctor came in to tell Latimore that Blake was seriously ill. At 8:37 that morning, “our little fighter gave up his fight,” says Latimore. “They ruled out GBS because of my negative test,” she explains, but a nurse practitioner who had been on the team that tried to save him thought the symptoms looked like GBS and asked the pathologist to
check for it in the autopsy.”
She was right. GBS infection was the cause of Blake’s death. “Testing negative doesn’t mean you are negative,” warns Worthy.
“False negatives can be a problem,” explains Amanda Smith, medical technologist in the microbiology department at The Pathology Lab in Lake Charles, Louisiana. “We were researching why even with patients who were getting good prenatal care, mothers who tested negative were sometimes delivering babies that were infected,” says Smith.
In January of this year, The Pathology Lab switched from the old culture-based test to the illumigene® GBS test from Meridian Bioscience, Inc. because the molecular test is more sensitive, according to Smith. As more labs switch to the more sensitive molecular test, perhaps outcomes like Blake’s and Jaxton’s will become even more uncommon.