A diet high in fiber from fruit and soy foods can reduce the incidence of chronic respiratory symptoms, especially cough with phlegm production, according to data from the Singapore Chinese Health Study. Researchers studied the details from 571 cases of incident cough with phlegm along with research information collected from 44,068 men and women who did not suffer from the respiratory problem. The investigators said that nonstarch polysaccharides, a major component of dietary fiber, and certain noncitrus fruits, including apples and grapes, were independently associated with reduced development of cough with phlegm. The scientists administered a 165-item quantitative food frequency questionnaire that was developed for and validated by the men and women in the study. With ages ranging from 45 to 75, the participants were all permanent residents or citizens of Singapore and formed part of two major Chinese dialect groups. The researchers said that their data provides evidence that promoting a diet high in fiber and flavonoids, such as that in fruit and soy, might make an important contribution to primary preventive strategies for chronic respiratory symptoms, both in smokers and nonsmokers. The research appears in the first issue for August 2004 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
CAN BRIEF EXPOSURE TO MULTIDRUG RESISTANT TUBERCULOSIS CAUSE INFECTION?
The use of a rapid new molecular technique, based on testing a blood sample, to detect antigen specific T cells related to multidrug-resistant tuberculosis (TB) infection has allowed investigators to identify probable low dose M. tuberculosis in individuals who have had limited contact with a diagnosed case. Physician investigators studied 92 persons who were exposed to a 24-year-old Moldovan female who was diagnosed with multidrug-resistant TB infection several weeks after she had given birth to a healthy baby in an Italian maternity unit. Since the highly infectious case had been present in the unit for 4 days, all mothers, relatives, and neonates (in their first week of life) who had been there at the same time faced a potentially serious health risk. The mothers slept in one of three rooms with multiple beds, shared the same table for meals, and used the same lavatories. The babies were with the mothers during the day, but slept in a nursery at night. All 92 contacts, who had no symptoms, were given a tuberculin skin test (TST), and their blood was tested with the T cell-based assay. The molecular test, but not the TST, suggested quite extensive hospital based transmission of multidrug-resistant M. tuberculosis after brief exposure. The individuals with TST and molecular test positive results underwent chest radiography and high resolution computed tomography. All contacts were deemed normal by radiologists except for the Italian-born husband of the index case who showed several areas of concern in his chest. All participants became enrolled in a long-term surveillance program. The study was published in the first issue for August 2004 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
H. influenzae BACTERIA PRESENT EVEN AFTER NEGATIVE CULTURES FROM SPUTUM OF CHRONIC OBSTRUCTIVE DISEASE PATIENTS
Haemophilus influenzae, an important bacterial cause of lower respiratory infections that results in exacerbations of chronic obstructive pulmonary disease (COPD), is present far more often in the respiratory tract of adults with COPD than is apparent on the basis of sputum cultures. Investigators studied isolates of H. influenzae collected monthly over a 7-year period from 104 patients between March 1994 and December 2000. Within this period, the investigators found 122 instances of a gap of 1 month or more of negative cultures followed by isolation of an apparently identical strain of H. influenzae. Seventeen such episodes lasting 6 months or more were studied in detail to test the hypothesis that these periods of negative cultures actually represented continuous colonization of the lungs by the same strain of H. influenzae in the COPD patients. The authors said that molecular typing by three independent methods established that the strain preceding and following the episodes of negative cultures were indeed identical. Also, strain-specific H. influenzae DNA was detected in some of the sputum samples that yielded negative cultures. The authors said that their results indicate that some patients with COPD are persistently colonized with H. influenzae and that sputum cultures underestimate the frequency of colonization of the respiratory tract by H. influenzae in COPD. The research is published in the first issue for August 2004 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
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Journal
American Journal of Respiratory and Critical Care Medicine