Born wheezers

日期:2019-02-26 09:20:01 作者:竹军 阅读:

By Michael Day UNBORN babies infected in the womb by a common sexually transmitted bacterium are more likely to develop asthma in later life. About 50 per cent of Western women carry the bacterium. Rita DeLollis of the Winchester and Lawrence Hospital in Medford, Massachusetts, screened the blood of 132 wheezing children, three years old or younger, for Ureaplasma urealyticum. Nearly a third carried the bacterium. But in 46 children with normal breathing, only 4 per cent were infected, DeLollis told the American Society for Microbiology’s 37th Interscience Conference on Antimicrobial Agents and Chemotherapy, held in Toronto last week. U. urealyticum infects both men and women. It can cause nonspecific urethritis, and can also be passed from pregnant women to their babies—although microbiologists are not sure whether this happens in the womb or during childbirth. DeLollis believes the bacterium may be a significant cause of childhood asthma, which is on the increase throughout the developed world. In some countries as many as one child in eight is affected. “These data suggest the detection and treatment of U. urealyticum in mothers and fathers before pregnancy should be routine,” says DeLollis. She says that U. urealyticum infection in infants, which usually shows no obvious symptoms, can be treated quite easily. Although the bacterium is largely resistant to the standard antibiotic erythromycin, it clears up rapidly if treated with the newer drug clarithromycin. If the infection is detected and treated in the first 12 months of life, a baby is no more likely to show signs of asthma than an uninfected child, DeLollis has found. Other asthma researchers have suggested that a variety of chronic infections help to trigger the disease by subtly altering normal immune responses. “Clearly infections play an important role in asthma,” says Peter Openshaw, an immunologist at Imperial College, London. “And we’re only just scratching the surface.” However, Lesley Regano of St Mary’s Hospital in London, who is investigating a possible link between U. urealyticum and miscarriage, believes it is too early to call for routine testing for U. urealyticumin pregnant women. One problem is that women often become reinfected after treatment with antibiotics,