Recently researchers have found that a quick and easy blood test could help doctors in deciding whether they should give antibiotics for treating common lower respiratory infections. Almost 75% of the antibiotics are prescribed for lower respiratory infections. However, most of these infections are caused by a virus, not bacteria. As antibiotics are useless against viral infections, prescribing them in such cases gives bacterias in the body a chance to develop resistance against these drugs.
According to researchers, a new test seems promising in avoiding over-prescribing of antibiotics (for lower respiratory infections) that usually create drug-resistant strains. The test basically measures the level of a chemical marker-procalcitonin, which is significantly increased in bacterial infections but not so marked in viral or other infections. With the help of this test doctors can get results within an hour.
To prove the efficacy of this test a study was conducted on 243 patients admitted to the emergency room of a hospital with suspected lower respiratory infections (including exacerbations of asthma and lung disease). During the study half of the patients in the study group were given “standard care” (i.e. physical examination, temperature check and chest X-ray) while the other half were given “the above-mentioned blood test in addition to standard care”.
Once the blood test results were declared the researchers asked the doctors to give antibiotics to the patients (in blood test group) only if procalcitonin in blood was above a certain level. It was observed from the study that the antibiotic prescription rate by the doctors was similar in both the groups before the declaration of blood test results. However, once the test results were revealed it was found that the antibiotic prescription dropped to half in the ‘blood test’ group as compared to the ‘standard care’ group.
Even though researchers are convinced that the ‘procalcitonin marker’ may help the doctors in deciding whether to give antibiotics or not, this test is in no way a replacement for clinical judgments. According to some researchers more studies will be required to know whether withholding antibiotics is really safe in high-risk patients in whom a doctor cannot withhold treatment till the test results come. The risk of missing a severe bacterial infection, which is more likely when a virus damages the airways, is too great to rely solely on the blood test.