Testing for COVID-19 infection has been widely publicized in the media, particularly concerning the national and local shortages of testing supplies. However, this situation appears to be gradually improving as more health care institutions and local pharmacies are offering testing. For people who are able to obtain testing, detection of COVID-19 virus RNA by reverse transcription polymerase chain reaction (which identifies the genetic fingerprint of the virus) confirms COVID-19 infection.
This test is generally done by a cotton swab that is inserted high into the nasal cavity in order to obtain mucous that can be tested for the virus. Unfortunately, the accuracy of this test is not consistent and a single negative test does not completely exclude the diagnosis of COVID-19 infection. There is a second category of testing to check for whether a person may have been exposed to the COVID-19 virus several weeks to months earlier. This is called an antibody test and is done through a blood test. Similar tests are in use for other viruses such as measles and hepatitis A and B. This test is not widely available yet for COVID-19, but it is anticipated that it will be soon.
Social distancing is also a hot topic. Despite the recent favorable trend in COVID-19 hospitalizations and deaths, it is still strongly recommended people behave cautiously in situations where they are around other people and could be exposed to people who have COVID-19. The primary recommendation continues to be wearing a mask that covers the mouth and nose when around other people, especially indoors. Hand hygiene is also strongly recommended, and finally people should stay inside their houses if they are ill. The basis for these social distancing recommendations stems from observations that were made in Europe and Asia in February and March, as super-spreading events were taking place.
The average person with a coronavirus infection has the ability to infect about two or three other people under ordinary circumstances, but in the midst of a superspreading event, an infected person can pass the virus to many more people. In addition, the COVID-19 virus has a long incubation period, in which a person can have no symptoms of illness but can still infect others. Most of the superspreading events have similar features. A person who is infected with COVID-19 could attend an indoor gathering where many people are in attendance, such as a birthday party, religious service, choir practice or indoor sporting event.
Research shows the risk of spreading COVID-19 virus is much higher in an indoor setting, with poor ventilation, and with many people who are physically close to each other for a long period of time. This is because the virus spreads mostly through droplets that become airborne when an infected person coughs, sneezes or speaks. A research study from Japan showed the odds of an infected person passing the COVID-19 virus in an indoor environment was 19 times greater compared to an open air environment.
Once the superspreading events became recognized as a cause of rapid spread of the virus, countries and states began to limit the gatherings of large numbers of people. In Germany, a study showed that banning mass gatherings was the biggest factor in bringing the pandemic under control in that country.
Keeping these facts in mind, we should all be extremely careful to follow the social distancing guidelines that continue to be recommended.
Dr. Mark Roth writes about internal medicine for the CJN. He is an internal medicine physician with University Hospitals.