Rubella still can occur among new immigrants

The baby girl, the child of parents who had recently come to the United States from Liberia, was born in New Hampshire with a cataract in one eye and some hearing loss.

When she was 10 weeks old and hospitalized for respiratory problems, vomiting and a failure to thrive, doctors began to consider a possible infectious cause for what ailed her -- one that, like her parents, had immigrated from a place far away: rubella.

The baby's mother had been vaccinated against rubella early in pregnancy. But lab testing indicated that she may have unknowingly caught the infection in an African refugee camp before receiving the shot and, though she had no recollection of being sick, passed it on to her fetus.

"She would have been exposed very close around the time of conception," said John Modlin, MD, one of the authors of the paper documenting this case of congenital rubella syndrome in the Nov. 18 Morbidity and Mortality Weekly Report and one of the treating physicians on the case. "There were no red flags at all," said Dr. Modlin, also chair of the Dept. of Pediatrics at Dartmouth Medical School in Hanover, N.H.

Rubella, which can be so mild in adults that it may go unnoticed but still be devastating in vitro, is so rare in the United States that in March 2005 the Centers for Disease Control and Prevention announced that the disease had been eliminated and was no longer considered endemic. But experts say that while the numbers are incredibly low, this case indicates the need to keep CRS on a list of possibilities for infants who have congenital anomalies consistent with the syndrome and who are born to parents from areas of the world where the disease is still widespread.

"It's not necessarily something that [physicians] will think of right off the bat, but it should be on the index of suspicion," said Rachel Plotinsky, MD, lead author of the paper and a member of the CDC's Epidemic Intelligence Service in New Hampshire.

More than 100,000 CRS cases are reported worldwide annually, although only four were reported in the United States from 2001 to 2004. Experts say that detection of any case is crucial, not just to provide appropriate care for the child but also to prevent spread, because an infected infant will shed virus for about a year.

"Babies have contact with many at-risk individuals. They have contact with other babies and pregnant women," said Danielle Zerr, MD, MPH, medical director of infection control at Children's Hospital and Regional Medical Center, who handled a case in 2000. "It's something we have to remain alert for."

Primary care physicians responded that this advice is appropriate, but not necessarily easy to heed.

"It's easy to not think about the zebras," said Charles Cappetta, MD, a general pediatrician at the Dartmouth-Hitchcock Medical Center in Nashua, N.H. "But this goes to the heart of medicine and thinking outside the box. If it happens one time, it's going to happen another time."

Experts also are quick to point out that this isolated case, in many ways, is a symbol of the success of rubella elimination efforts. The mother was screened for the disease in accordance with accepted guidelines, and CRS is now so unusual that a single incident is worth noting in the MMWR.

"In this case, everything was done right. That's reassuring," said Rick Pollak, MD, MPH, a family physician at Capital Region Physicians Group in Concord, N.H. "But this reminds us what a terrible disease it is."

Physicians also didn't start suspecting CRS until the infant was 10 weeks old. This meant that, unbeknownst to medical personnel and public health officials, she was shedding the virus for weeks before infection control measures were instituted. This situation did not, however, lead to a single secondary case, and the re-emergence of rubella in this country is viewed as highly unlikely as long as vaccination levels remain high.

"She was a fountain of rubella virus," Dr. Modlin said. "But we have a highly immunized population. Rubella has become such a rare disease. This is something we need to celebrate."