Increase seen in serious cases of the disease.
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Ob.Gyn.News April 15, 1998
Intrapartum Administration of Ampicilln Prophylaxis in GBS Mothers May Raise Risk of Neonatal E. coli Infection
BY ELIZABETH MECHCATIE
|Despite aggressive treatment, six babies died of fulminant early-onset E. coli infection during the entire study period; all six had ampicillin-resistant organisms, and the mothers of four had received intrapartlim ampicillin.|
There is also "a lot of confusion and abuse of the two [CDC-endorsed prophylaxis] strategies," Dr. Phelan added. Some physicians are culturing women near the end of pregnancy and are immediately treating those with positive results instead of waiting until the woman is in labor; in some cases, this process is repeated before delivery, she said.
Whatever the cause, physicians need to realize that the risk of resistant strains is not just a theoretical concern. . . . This shows it is a real phenomenon," said Dr. Phelan of the University of Alabama, Birmingham.
The investigators decided to do their study after noticing an increase in the number of low-birth-weight babies delivered at Cook County Hospital who developed early-onset E. coli disease after chemoprophylaxis for GBS disease was implemented.
Their study compared infection and fatality rates between 1982 and 1987 and between 1988 and 1993 when the use of intrapartum ampicillin increased.
During the later time period, the incidence of early-onset CBS infections dropped in babies with birth weights below 1,500 g, which was attributed to chemoprophylaxis. There was a "steady shift" of early-onset GBS infections "from small neonates with high fatality rates to larger neonates with lower fatality rates."
Over both periods, 30 neonates were diagnosed with E. coli infections; the neonates had a positive blood culture and symptoms in the first week of life. The infection rate during the first period was 0.37 per 1,000 births and 0.62 per 1,000 during the second period. This increase, which was not significant, was due to an increase in infections in babies with birth weights between 1501 g and 2500 g.During the first period, 3 of the 12 cases diagnosed were caused by ampicillin resistant E. coli, versus 12 of the 18 cases diagnosed in the second period, a significant increase. During the second period, 61 % of the mothers of infected babies had received intrapartum ampicillin versus 17% in the first period.
Despite aggressive treatment, six babies died of fulminant early-onset E. coli infection during the entire study period; all six had ampicillin-resistant organisms, and the mothers of four had received intrapartlim ampicillin.