The largest-ever review of outcomes for pregnant women with cat scratch disease - including just eight cases - suggests the infection is not damaging to babies, but its authors say there are too few instances to glean any definitive answers.

Six of the women gave birth to healthy babies, while one woman had a miscarriage and another opted for an abortion for reasons unrelated to the infection itself.

“I think we can find some mild amounts of reassurance by saying, ‘well, six out of these eight pregnancies ended in a normal, healthy live birth’,” said Dr. Todd Florin, a senior fellow in pediatric emergency medicine at the Children’s Hospital of Philadelphia, who was not involved in this study.

Bartonella henselae is a bacterium transmitted from cats to humans that can cause cat scratch fever. Swollen lymph nodes are a hallmark of the infection, and many people also experience fever and fatigue.

In about 10 percent of cases, more severe symptoms can develop, such as temporary vision loss or a brain infection.

Oftentimes, patients are treated with antibiotics, but it’s unclear whether they work any faster than letting the infection clear up on its own. The infection can endure for weeks or months, however.

Dr. Michael Giladi at the Infectious Disease Unit of Tel-Aviv Sourasky Medical Center in Israel, the study’s senior author, said about seven out of every 100,000 people have been infected with Bartonella.

He and his colleagues point out in their report, published in the journal Obstetrics and Gynecology, that there was a known case of a newborn who died and who was also infected with Bartonella, but otherwise there has been very little information about the effects of cat scratch disease during pregnancy.

To learn more, they collected information on every known case of cat scratch disease among pregnant women in Israel from 2000 to 2010 - totaling just eight cases amid more than 1.6 million births in the country during the same period.

Of the eight cases, six women gave birth to healthy babies, and several years of follow-up showed that the children remained in good health.

One of the women had a miscarriage during the first trimester.

Giladi said there’s no way to know if Bartonella was involved.

“Unfortunately, a biopsy was not performed. So overall we cannot make any conclusions that there is a risk for miscarriage or other problems with the babies. On the contrary, all the others were having normal children,” Giladi told Reuters Health.

Another woman opted to abort her pregnancy because she had undergone a CT scan when her swollen lymph node was suspected to be a cancer. Concern that the radiation exposure from the scan might have harmed her fetus prompted her to end the pregnancy.

“The whole issue was that nobody suspected that she had cat scratch disease and her physician thought that she might have cancer,” Giladi said.

The situation makes the case for more awareness of cat scratch disease, he said, so that such unnecessary testing can be avoided.

Florin said the study is helpful in reminding physicians that these infections are out there, but there are too few cases to determine whether cat scratch disease is a concern for pregnant women.

“That’s I think the challenge in interpreting the results of this paper,” Florin said. “So it’s hard to know if being infected while pregnant has any affect on the fetus or not.”

Giladi said women can stick to current recommendations for handling cats during pregnancy - be sure to wash your hands after petting them or touching the litter box.

His group is continuing to collect information on every case of cat scratch disease in Israel, and working to develop better treatments for the infection.

SOURCE: Obstetrics & Gynecology, March 2012