“No cough, no measles” was one of the many mantras and memory aids I learned in medical school. Most were designed to reduce tomes like Gray’s Anatomy and Harrison’s Principles of Internal Medicine to a few rules. Much of the time, it was easy to miss the point, especially when the subject seemed to be an obscure disease.
Five years into a six-year medical degree at a typical Western university, none of us had ever seen measles. Nor were we bothered. Apart from HIV, microbes like measles seemed prehistoric. Public health was out, plastic surgery was in. Still, I remembered this particular rule, offered by a much-revered professor. But I wondered why he was so focused on a cough instead of “Koplik spots,” the little white dots in the mouth that are specific to measles.
Then I spent ten weeks in a pediatric infectious-disease ward in Cape Town. I thought I would see “African diseases” like hemorrhagic fever and HIV, which I did. But I also saw measles, rubella (German measles), scarlet fever, syphilis, rheumatic fever, typhoid, tuberculosis and many other causes of rash and fever.
Suddenly I could see the point of my professor’s rule. The very first signs of measles are a fever and cough, followed by a runny nose and red eyes. The appearance of a rash three or four days later is usually what prompts parents to bring their child to the emergency room. The problem is that at any given time, half the pre-school children in the ER have a fever, rash or both. The differential diagnosis is hard enough in immunized children, ranging from mild roseola to devastating meningococcal sepsis; the long list includes enterovirus 68, Lyme disease and drug rashes. In an unimmunized child, the ailment might also be rubella—harmless for the child, but catastrophic for unimmunized pregnant patients—or chickenpox.
Or it might be measles, in which case you need to know. Fast. Because measles is the most contagious disease on earth. Among unimmunized people exposed to the measles virus, some 90 percent will contract the disease. Anyone with measles is contagious for several days before the rash even appears; the cough effectively spreads tiny droplets of the virus, which can remain in the air for several hours, long after an infected person has left the room. In an unvaccinated community, each person who gets measles spreads it on average to twelve others. Complications like pneumonia and meningitis can be permanent, deadly, or both, especially for immune-compromised patients such as those with cancer. And in the ER, one of these kids might be in the next bed.
Older Americans remember measles as a common childhood disease that just had to be suffered through, but in fact it is still frequently deadly in low- and middle-income countries. And because the virus weakens the body’s natural immune system, children who survive measles get more infections and have a higher risk of dying from them for several months afterwards.