Blood Test Can Prevent Unneeded Antibiotic Use
Shows whether bacteria or viruses cause lung infection
THURSDAY, Feb. 19, 2004 (HealthDayNews) -- A quick test for a molecule the body produces in response to infection by bacteria -- but not viruses -- can tell which patients with respiratory infections should not get antibiotics, Swiss researchers report.
In a controlled study, the use of antibiotics was almost halved in patients who got the test compared to those who didn't, says a report in the current online issue of The Lancet by doctors at University Hospital Basel.
Withholding the antibiotics did no harm, the report says. The results of treatment were just as good in both groups, with 97 percent of all patients having a favorable outcome.
The test was for a protein called procalcitonin, whose production is provoked when bacteria invade the body. Because as much as 75 percent of all antibiotic prescriptions are written for respiratory infections, "treatment based on procalcitonin measurement could have important clinical and financial implications," the journal report says.
Overuse of antibiotics has caused a dangerous increase in strains of bacteria resistant to the drugs, says lead researcher Dr. Beat Müller, an associate professor of endocrinology at Basel. Widespread use of the test could slow that trend, he says.
A procalcitonin test is now available in Europe, and is awaiting approval by the U.S. Food and Drug Administration for use in the United States.
"Maybe our finding could expedite things," Müller says.
He estimates the cost of the test at $30 to $50, and says it more than pays for itself by reducing the cost of treatment.
"The financial benefits can be substantial," Müller says. "Independent of the cost aspect, the main target in reducing antibiotic use is the prevention of antibiotic resistance."
In the study, 124 patients who came to the hospital with respiratory tract infections were given the procalcitonin test, while another 119 were not. Only 55 of the people who got the test had procalcitonin levels high enough to warrant antibiotic therapy. By contrast, 99 people who did not get the test were given antibiotics on the basis of their doctor's clinical judgment.
The study results indicate the test should be given to all patients with respiratory tract infections "on admission, and in case of uncertainty, in a follow-up after six to 24 hours," Müller says.
"I think that is correct," agrees Dr. Kenneth Becker, chief of endocrinology at George Washington University and the Veterans Administration Medical Center in Washington, D.C. Becker has done extensive research on procalcitonin.
"I find it a very valuable diagnostic test for the identification of patients with sepsis or severe infection," Becker says. "Its values correlate closely with the severity of the infection."