BANGOR, Maine (WABI) - It is impossible to read or listen to any news broadcasts without hearing about the latest updates on the Corona virus outbreak which started in the Chinese city of Wuhan this past month. As of this past weekend, more 11,000 cases have been confirmed in China with 259 reported deaths. Travelers have now brought the illness to 25 countries, with eight cases reported in the United States (as of February 1), and many individuals under quarantine. As frightening as this seems, let's take a step back and review what is known about this virus.
Corona viruses are a family of pathogens that usually cause the 'common cold' in humans. Many of these viruses, however, also affect other mammals, with bats being an important reservoir in the wild. Viruses on rare occasions can mutate and 'jump' from one species to another. Occasionally the mutation will allow the new host to pass the virus on to other members of its own species, triggering a wave of infections in a population of organisms that previously may have had no immune experience with that particular germ. We actually have already seen this happen twice in the past few years with other Corona viruses.
In 2002 a new form labeled the 'SARS' (severe acute respiratory syndrome) virus caused an outbreak originating in southern China that caused more than 8,000 cases, with 774 deaths reported in 17 countries and a mortality rate around 10%. And in 2012, a different Corona virus mutation was responsible for the 'MERS' (Middle East respiratory syndrome) outbreak that sickened about 700 people but had a higher mortality rate (over 34%) with 282 deaths reported. An interesting fact of this outbreak is that it appeared to have come to humans by way of camels in Saudi Arabia. Both outbreaks were brought under control by local public health experts working with the WHO (World Health Organization).
While researchers are scrambling to learn more about this latest viral threat, it does appear to be more easily transmitted from person to person than the previous infections, but the fatality rate appears to be lower. The incubation period varies from 2 to 12 days, which may allow those with no or minimal symptoms to spread the virus unknowingly during their asymptomatic phase. Transmission occurs, like many respiratory viruses, by contact with the germ from the respiratory secretions of an infected person. How long the virus can persist on surfaces such as handrails or other objects is not exactly known but thought to be measured in hours, similar to many other viruses including Influenza. That of course leads to the same recommendations to prevent spread of both viruses: everyone should utilize the hygiene practices of frequent hand-washing, avoidance of touching the face/nose/eyes with bare hands when in public, and if you have to sneeze or cough to prevent spray into the air by using the crook of the elbow or a disposable hankie. Experts are divided on the usefulness of wearing the less expensive 'surgical' mask unless the wearer themselves has signs of an infection. In healthcare settings, a much more effective N-95 mask which requires a specialized fit is necessary to prevent transmission.
For comparison purposes, most public health experts are emphasizing that Americans have much more present risk from our annual winter 'Flu' infections. Here in Maine we have already had more than 3,000 cases with 200 hospitalizations and 10 fatalities. The fatality rate for Influenza is generally estimated to be under 1%, predominately affecting the very young, elderly and those with other chronic illnesses. Unlike the Corona virus we do have antiviral medications that can be used in severe cases, and of course there is the ready availability of annual immunization with the flu shot. Although this is admittedly not as effective as the measles, smallpox or polio vaccines which provide near complete prevention of infection, it does decrease the severity of influenza for those who may not have complete blockade of the infection – and it is not too late to get the flu shot this year!
Last, I would not be doing my duty as a physician if I did not urge anyone who is concerned about preventing the spread of serious disease, especially to children in school settings, to vote this fall against the referendum to repeal the Maine law that requires all students to be up to date with their immunizations, unless they have a written exception from their physician. It will be Question #1 on the ballot, and a no vote will be necessary to prevent repeal of the law. It is very important to keep our children safe from serious preventable disease. It would be a shame, with all the concern surrounding the Corona epidemic, if Maine were to take a giant step backward in safeguarding the health of all its citizens.
Munster, et al Jan 24, 2020 NEJM – DOI: 10.1056/NEJMp2000929