Test for toxoplasmosis during pregnancy?
New study says, ‘yes’
Sunday, February 20, 2005
A team of researchers who studied children born with toxoplasmosis now recommend all pregnant women and newborns be screened for this potentially fatal infection caused by a parasite passed from mother to fetus. Early detection and treatment are key to preventing vision and hearing problems, as well as seizures and brain damage, they say.
In healthy adults, the immune system usually fights the infection and the carrier shows no symptoms. If a pregnant woman becomes infected, however, chances are as high as 50 percent that she will transmit it to her fetus, according to the National Institute of Health. Women with weak immune systems who were carriers before becoming pregnant also risk passing the infection on to their fetuses.
According to the Center for the Evaluation of Risks to Human Reproduction, two in every 1,000 babies born each year are infected with toxoplasmosis. Only 10 percent show symptoms at birth; 55 to 85 percent develop symptoms later in life, according to the March of Dimes.
Because the infection often goes unnoticed, experts say pregnant women should be tested. “This is a preventable, treatable disease,” says Dr. Rima McLeod of the University of Chicago Hospitals and a co-author of the study, which was published in February’s American Journal of Obstetrics and Gynecology.
At-risk women not tested
In the study, which was also conducted by Rush University Medical Center’s Dr. Kenneth Boyer, researchers followed 131 children. They found that more than half of the mothers at risk couldn’t be identified by routine exams. A blood test could have identified the rest, they concluded. Only 8 percent of the mothers in the study had been screened with blood tests.
People typically pick up the parasite toxoplasma gondii by ingesting parasite eggs found in cat feces. That can happen when people come in contact with kitty litter or garden soil that may be frequented by outdoor cats, or eat unwashed vegetables. The parasite can also be passed through eating undercooked, infected meat.
“We could do better with education, and my opinion is we could do better with screening,” McLeod says.
Spokesmen for several major health insurance providers say toxoplasmosis screenings are typically covered, though insurance plans vary, they note. The disease is treated with antibiotics.
The American College of Obstetrics and Gynecology currently recommends routine screening only in women with HIV and possibly for cat owners. Neither the Illinois Department of Public Health nor the Centers for Disease Control and Prevention tracks toxoplasmosis cases.
Fiona Forward, the mother of one girl in the study, says she encourages all her pregnant friends to get screened. When a test showed Forward, of Brooklyn Heights, N.Y., was infected, she started taking medication. Her daughter, now 5, was born with 40 calcifications on her brain. She took medication for a year and now has slight vision problems and just three calcifications.
“We’re very lucky we had a good result,” Forward says.
Dr. Laura Riley, chair of the obstetrics practice committee for the American College of Obstetrics and Gynecology, says screening early in pregnancy results in many false positives, which can cause unneeded anxiety and may lead women to terminate a pregnancy for no reason. Paige Fumo Fox