Ground-Meat Contamination Subject of Study
One in five samples of ground meat purchased in supermarkets was contaminated with salmonella bacteria, a new study has found, and most of the bacteria isolated were resistant to at least one antibiotic.
More than half the bacteria were resistant to at least three antibiotics, making them particularly dangerous if they cause an infection in humans. The bacteria can be killed by thorough cooking, but many people do not cook foods long enough to prevent infection. An estimated 1.4 million cases of food poisoning caused by salmonella occur in the United States every year.
Researchers at the University of Maryland and the U.S. Food and Drug Administration collected 200 samples of ground beef, chicken, turkey and pork from supermarkets around Washington, D.C. They reported in the Oct. 18 New England Journal of Medicine that 41 samples contained salmonella and that 84% of the bacteria were resistant to at least one antibiotic. The results were comparable to those previously obtained in sampling at slaughterhouses.
In another study in the same journal, researchers from the federal Centers for Disease Control and Prevention purchased 407 chickens in supermarkets in four states and found that more than half of the birds carried a form of the sometimes fatal bacterium Enterococcus faecium that was resistant to Synercid, one of the major drugs used to treat antibiotic-resistant bacteria.
Researchers in both cases attributed the resistance to widespread use of antibiotics in the livestock industry and called for a ban on such routine use.
Older, Cheaper Sinusitus Drugs Found Effective
Older, cheaper antibiotics are as effective as newer, more powerful drugs in treating acute sinusitis, an infection and inflammation of the paranasal sinuses--those above, below and on either side of the nose.
Dr. Jay F. Piccirillo and his colleagues at the Washington University School of Medicine in St. Louis analyzed data from 29,102 adults who received initial antibiotic treatment for acute sinusitis between July 1, 1996, and June 30, 1997. They determined whether the patients received first-line antibiotics, such as amoxicillin, co-trimoxazole and erythromycin--which are recommended for treatment of sinusitis--or second-line drugs, such as clarithromycin and amoxicillin-clavulanate, which should only be used in patients who do not improve with other drugs or who cannot take the first-line antibiotics.
The team reported in the Oct. 17 Journal of the American Medical Assn. that 60% of patients received first-line antibiotics and 40% received second-line drugs. Treatment was successful in 90.1% of patients who received first-line antibiotics and 90.8% of those receiving second-line drugs. But the second-line antibiotics cost almost twice as much. Researchers also fear that their widespread use contributes to the emergence of antibiotic-resistant bacteria.
About 35 million people in the United States develop sinusitis each year, generating 3 million visits to physicians.
Working Nights May Raise Breast Cancer Risk
Women who work night shifts may increase their risk of breast cancer by as much as 60%, according to two new studies. The increased risk apparently results from hormonal changes arising from exposure to bright lights in the middle of the night. Researchers said the studies should be replicated and expanded, however, before they advise women against working at night.
In one study, epidemiologist Scott Davis and his associates at the Fred Hutchinson Cancer Research Center in Seattle compared the work histories of 763 women with breast cancer and 741 women without it. They reported in the Oct. 17 Journal of the National Cancer Institute that women who regularly worked night shifts for three years or less were about 40% more likely to develop breast cancer, while those who worked the shifts for more than three years were 60% more likely.
In the second study, Dr. Francine Laden and her colleagues at the Brigham and Women’s Hospital in Boston studied 78,000 nurses who are part of a continuing health study. They reported in the same journal that women who worked rotating night shifts at least three times a month for as many as 29 years were 8% more likely to develop breast cancer than women who did not. Those who worked the shifts for more than 30 years were 36% more likely to develop the disease.
Antidepressants Cut Back on Heart Attack Risk
A family of antidepressant medications called selective serotonin reuptake inhibitors (SSRIs) can reduce heart attack risk significantly, according to a new study.
The SSRIs include fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil) and sertraline (Zoloft). Earlier studies have suggested that depression is a risk factor for heart disease, and the drugs may act by lifting that depression. Alternatively, they may be reducing blood clotting and inhibiting platelet clumping, a first step in forming clots that trigger heart attacks.
Dr. Stephen E. Kimmel and his colleagues at the University of Pennsylvania studied 653 people hospitalized for a first heart attack and 2,990 closely matched people with no history of heart attack. The study was primarily designed to test the value of nicotine patches in preventing heart attacks, but it also monitored use of antidepressants and other drugs.
The researchers reported in the Oct. 16 Circulation: Journal of the American Heart Assn. that, independently of use of the patch, patients taking SSRIs had a 65% reduction in the risk of a heart attack over the 28 months of the study. “This is the largest study to show such an association,” Kimmel said. The study was funded primarily by the companies that manufacture the nicotine patches.
Crohn’s Disease Linked to Birth Months
The incidence of Crohn’s disease is highest in people born in August and nearby months, a finding that suggests that exposure to viruses during pregnancy may play a role in causing the disease. Researchers at the Aarhus and Aalborg University Hospital in Denmark studied all 662 cases of Crohn’s disease diagnosed in the country between 1977 and 1992 in people younger than 21.
They reported in the Oct. 20 British Medical Journal that the births of Crohn’s victims peaked in August and were at their lowest in March. The incidence was about 30% higher in those born in August. Crohn’s is a chronic inflammatory disease that affects primarily the small intestine. It usually strikes people before they reach age 30, causing abdominal pain, diarrhea, fever and weight loss.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
