Until now, the best tool to determine if a patient had mononucleosis was the Monospot test. This test uses a blood sample to look for antibodies created by the immune system in response to the infecting virus.
However, the Monospot is expensive and not very accurate early in the disease, as antibody levels do not peak until a person has had mononucleosis for over a week. So, a patient with an inconclusive Monospot results will need additional testing. Therefore, a new test which is more accurate in the detection of mononucleosis is welcome news.
This test, analyses white blood cells directly via a routine blood sample and seems to be able to more accurately determine if the a patient’s sore throat is the result of mononucleosis.
In a study, published in the Archives of Otolaryngology, researchers looked at the white blood cell counts in 220 patients of whom 100 had tonsillitis and 120 had mononucleosis. Those patients with mononucleosis had a higher average number of lymphocytes, a specific type of white blood cell, than those with tonsillitis.
In fact, the authors conclude, this test can accurately diagnose mononucleosis 90 percent of the time, better than the Monospot test’s 85 percent effectiveness and at a cheaper price.
"The specificity and sensitivity of this test seem to be better than the mononucleosis spot test itself," the authors write.