Pregnant women in the United States don't receive routine testing for toxoplasmosis infection. That's a potentially serious deficiency in our prenatal care, according to the authors of a new Stanford study. Their research found much higher rates of serious brain and eye disease among U.S. infants with congenital toxoplasmosis than among similar infants in Europe, where the prenatal testing is routine.
This finding was a surprise in a study originally designed to compare laboratory methods for detecting congenital toxoplasmosis. From a press release I wrote about the research, which appears today in the Pediatric Infectious Disease Journal:
Eighty-four percent of the North American infants studied had serious complications of the parasitic infection, including calcium deposits in the brain, water on the brain and eye disease that caused visual impairment or blindness. By contrast, few European infants had these problems – for instance, about 17 percent of French infants with the infection develop complications.
"It was a shock," said Jose Montoya, MD, the study's senior author and an associate professor of Medicine in Infectious Diseases at Stanford. "We were dismayed to see so many little ones with severe eye disease, hydrocephalus and brain calcifications."
Montoya gave several reasons the U.S. should implement routine prenatal testing for the Toxoplasma gondii parasite. First, expectant women can pick up toxoplasmosis without realizing it. Educating women about risky behaviors to avoid during pregnancy (such as cleaning a cat's litter box, consuming undercooked meat or gardening without gloves) prevents some infections, but women without any known risk factors can also contract toxoplasmosis. Second, effective medications exist to prevent mother-to-child transmission of the Toxoplasma gondii parasite – and babies who receive these drugs in utero have much lower rates of complications than the infants in Montoya's study, whose mothers did not get the prophylactic meds. Also, the prenatal tests are easy to do: they could be handled by any commercial lab, could use blood already drawn in pregnancy for other tests and could be made fairly cheap at $5 to $10 a pop.
Finally, parents deserve to know about the infection:
"We are strong believers that pregnant women have the right to know whether the baby is at risk, or whether the baby has been infected, in the same way that parents have a right to know if their baby has a metabolic defect or a hearing problem," Montoya said.