The Food and Drug Administration is warning doctors, hospitals and clinics that contaminated ultrasound gel produced by a New Jersey company infected 16 cardiac patients and could pose serious risks to pregnant women and others who undergo ultrasound imaging and treatment.
The gel is used by radiologists, urologists, gastroenterologists, OB-GYNs, internists, nurses and ultrasound technicians for diagnostic ultrasound testing. Chiropractors and physical therapists use the gel for therapeutic ultrasound treatment of pain, inflammation and injuries.
The agency told the health professionals to stop using the gel because of contamination with two strains of bacteria. "Although Other-Sonic Generic Ultrasound Transmission Gel is not labeled as either sterile or non-sterile, it is NOT sterile," the FDA cautioned.
The 16 heart patients became infected with the bacteria, Pseudomonas aeruginosa, while undergoing transesophageal ultrasound exams with Other-Sonic Generic Ultrasound Transmission Gel during heart valve replacement surgery at a single hospital, the FDA said. The product is made by Pharmaceutical Innovations Inc., of Newark, N.J., which bills itself on its website as "world leader in medical ultrasound."
In February, an FDA analysis of product samples revealed "significant amounts of Pseudomonas aeruginosa and Klebsiella oxytoca," which the FDA said suggested that the contamination occurred "during the manufacturing process." Both types of bacteria can colonize the skin without causing any symptoms, although Pseudomonas also may cause skin eruptions, even on unbroken skin, the FDA warned. More concerning, however, is the potential of the bacteria to enter the body through ultrasound exams of the airway, lower digestive tract or a woman's genital tract, where they could cause infection.
"Intact skin is a fairly good barrier to infection," said Dr. Robert A. Winters, an infectious disease specialist in Santa Monica, Calif. He said that fetal ultrasounds and ultrasounds of organs like the gall bladder, where the gel is applied to overlying skin, are of "lower concern" than more invasive ultrasounds where a probe is inserted into the body, such as during transesophageal imaging. "On the other hand, they're using the probe, they're moving it on the skin, they could be abrading the skin and potentially introducing germs into otherwise clean sites. There is probably some small added risk if you're undergoing ultrasound with a contaminated gel product."
But he noted, in the big scheme of infectious disease risks, "We all are interacting with lots of different bacteria all day long."
If you're concerned about possible exposure to a contaminated gel, "the best thing to do is go home and take a good shower with soap and water," or make sure the people performing your ultrasound "pat the area with alcohol afterwards," said Winters, chairman of the infection control division at Saint John's Health Center in Santa Monica.
"Not every patient exposed to Pseudomonas aeruginosa and Klebsiella bacteria in Other-Sonic Generic Ultrasound Transmission Gel will develop colonization (the presence of bacteria at a site without any signs of infection) or infection, but the risk remains present," the FDA alert said. It warned that biopsies can let bacteria get into tissues, causing an abscess or severe bloodstream infection called sepsis. If Klebsiella bacteria, which are common in the digestive tract, enter the lungs or spread to other tissues, they could lead to pneumonia, wound infection or bloodstream infections, the FDA said.
At the agency's request, New Jersey health authorities embargoed all lots of the gel manufactured from June through December 2011. The U.S. Marshal Service has since seized those lots. Health professionals were urged to stop using 250 milliliter bottles and 5-liter dispensing containers with three lot numbers: 060111, 090111 and 120111. They were also asked to identify any patients who underwent ultrasound exams with gel from those lots.
"This ultrasound gel presented serious health risks to patients, particularly vulnerable ones," Dara A. Corrigan, the FDA's associate commissioner for regulatory affairs, said in a statement issued by the FDA. "Therefore, FDA, with the assistance of our state partner, is taking aggressive enforcement action to protect the public health."