Are Most Cases of COVID-19 Asymptomatic?


Over the last few months, most of the news you’ve read has been about COVID-19. Though the first cases appeared in November or December of 2019, the novel coronavirus didn’t become a huge topic of conversation until February or March of 2020. Now, declared as a viral pandemic, COVID-19 has 5.93 million diagnosed cases worldwide. But according to U.S. News and World Report, that might not be the correct number. In fact, many people might be asymptomatic, meaning the impact of the virus is even greater than we assume.

The Progression of COVID-19

Many of the 213 countries and territories impacted by COVID-19 reacted by closing non-essential businesses, closing their borders, and encouraging people to stay home. In the United States, many states began shutting down in March. Two months later, shutdowns are beginning to ease up and states are beginning the path to reopening.

Despite a lack of symptoms, asymptomatic individuals can still transmit the virus. This presents a potential issue, as those without symptoms may feel more comfortable going out and interacting with others.

Understanding Two New Studies

Two studies this week show the scope of the problem:

  • An article in Thorax explored the impact of COVID-19 on cruise passengers. On this particular cruise, which departed Argentina in mid-March, the 217 passengers and crew were all screened for any potential COVID-19 symptoms (fever, cough, shortness of breath) prior to boarding the ship. However, 128 passengers eventually tested positive for COVID-19 while on the ship. Of these, only 24 passengers showed symptoms. 8 required medical treatment. 4 patients were ventilated, and 1 patient died. However, 104 passengers, or 81% of those with COVID-19, tested positive but displayed no symptoms.
  • The second study, published in JAMA Network Open, analyzed patient data from Wuhan, China, where the virus initiated. The government asked that any people potentially exposed to COVID-19, particularly through positive family members, be screened and isolated. Through this, researchers found that of the 78 patients they examined, 42% were asymptomatic for COVID-19 despite a positive test.

Asymptomatic Cases of COVID-19

As the country shut down to stop the spread of COVID-19, the economy suffered. Now, states are hoping to stimulate the economy by reopening. Currently, the CDC estimates that only 35% of COVID-19 cases are asymptomatic. But with 1.75 million confirmed American cases, and 102,000 fatalities, is reopening the country the right move? Since the CDC’s estimates are lower than the studies’ findings, should we worry more about asymptomatic spreading?

Unfortunately, there’s no clear answer. However, one thing is certain: people need to practice health and safety guidelines, particularly if they haven’t been tested for COVID-19. According to the 2nd study, asymptomatic individuals shed the virus for a shorter period of time. But because these people aren’t aware if they have the virus, everyone should continue:

  • Wearing a mask while in public,
  • Staying away from large groups,
  • Frequently washing their hands with soap and water, and
  • Disinfecting any surfaces in the home that might have been contaminated.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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