The measles virus is a paramyxovirus, of the genus Morbillivirus.
Gary W. Procop, MD, FCAP, a fellow of the College of American Pathologists, explains that measles is characterized by the three Cs: cough, coryza and conjunctivitis. This is followed by a maculopapular rash that usually develops 14 days after the child is exposed, spreading from head to trunk and then to the extremities. When the rash appears, the measles virus can spread.
Procop is a professor and medical director of virology in the Pathology and Laboratory Medicine Institute at the Cleveland Clinic, as well as serving as medical director for enterprise test utilization and director of the parasitology and mycology laboratories.
Procop says the pediatrician will choose one of three available tests: a serologic study, a viral culture or nucleic acid amplification-based assay. Serology requires a blood sample. The best specimen to collect in the acutely ill individual suspected of having measles, according to Procop, is the nasopharyngeal swab, used in both the culture and the nucleic acid amplification test. The nasopharyngeal swab is important because measles is likely spread through coughing, the same mechanism as the common cold.
The sample is then sent to a laboratory overseen by a pathologist.
Pathologists perform the tests and interpret the findings, “which are not always straightforward,” says Dr. Procop. A high fever and feeling of malaise could characterize both measles and influenza. An accurate finding by the pathologist will identify the disease and rule out other possibilities.
Depending on which test is chosen, the results may be available in one or two days. A quick result is essential to help prevent the spread of infectious diseases by limiting the number of people who are exposed to the person with measles, according to Procop.
Advances in medicine have brought about a huge explosion of knowledge and a need for more specialists in the laboratory like Procop, who has a subspecialty in microbiology. He also chairs the CAP’s Microbiology Resource Committee.
Beyond an individual diagnosis, pathologists contribute to public awareness. “We cooperate and collaborate with public health professionals,” says Procop. “We’re reporting exactly the information they need to track and get in front of epidemics.”
Should the public be concerned about measles?
“We understand this virus,” says Procop. “There was a lot of panic recently around the Ebola virus and we learned a lot from that. There’s definitely no reason to panic about the measles virus. It doesn’t look to be any more virulent than previous measles outbreaks.”
The public health goal, according to Procop, is to decrease and interrupt transmission, eradicate the epidemic and eliminate measles from the United States. But that won’t be easy.
“We have cases that are imported from other countries and pockets of individuals here who are not vaccinated,” says Procop. “What’s happening right now—the current measles outbreaks -- will happen again.”
Source: College of American Pathologists (CAP)