Separating myth from fact around coronavirus


COVID-19 Shareable Science
Photo Credit: Alissa Eckert, MS; Dan Higgins, MAM

COVID-19 Q&A Session (UPDATED 4/24)

As headlines trumpet the continued spread of COVID-19, the wall-to-wall coverage has generated a secondary outbreak of breathless hype, misinformation and anxiety. Acknowledging that we’re in the midst of a rapidly evolving situation, let’s pause, take a deep breath and do our best to separate fact from myth.

Dr. Lamb has also created Beyond the Blog a set of videos exploring COVID-19 in greater detail. Using everyday jargon-free language, these short videos highlight viral infection, COVID-19 symptoms, testing and treatment, along with current updates and viewer questions.

GENERAL

COVID-19 (coronavirus disease 2019) is a respiratory infection first identified in Wuhan, China in December 2019. It is caused by a novel type of coronavirus named SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Viruses and the disease they cause often have different names.

Coronaviruses are a large family of viruses so named because proteins studded across their surface stick up like the points on a crown. These spikes assist the virus in binding to cells in order to gain entry. They are zoonotic, which means they can sometimes be transmitted between animals and people. As we’ve noted previously, the initial genetic analysis of SARS-CoV-2 suggests it may have passed through one or more species of animal before being transmitted to humans.

Coronaviruses usually lead to mild upper respiratory infections, like the common cold. However, three times in the last eighteen years coronavirus outbreaks have caused serious disease across the world: SARS (severe acute respiratory syndrome) in 2002, MERS (Middle East respiratory syndrome) in 2012 and now COVID-19. NBC news recently published a comparison of the three diseases in terms of numbers, geographic spread and breakdown of cases by age.

The seasonal flu is caused by any of a number of types and strains of the influenza virus, an altogether different family of viruses. The World Health Organization lists the similarities and differences between COVID-19 and influenza. Unlike COVID-19, influenza has been studied by scientists for decades and we know a great deal about symptoms, risk of infection and ways to treat seasonal flu.

In January, researchers published the first sequence of the viral genome responsible for COVID-19. Within a week, the sequence information was used to develop a test to detect the presence of the virus. Additional genomic studies showed the virus was similar, but distinct from the viruses responsible for SARS and MERS. Sequences from several of the earliest Chinese patients were nearly identical, suggesting the virus had only recently entered the human population. As the virus has spread, certain strains have acquired genetic changes. By sequencing the virus of different patients, these genetic changes can be compiled into a viral “family tree” and used to track disease transmission. Other researchers have used the genetic sequence to identify ideal targets for vaccine development.  

DISEASE SPREAD

The Centers for Disease Control and Prevention notes that the virus primarily spreads from person to person, through little drops of liquid called respiratory droplets. These are produced when an infected person coughs or sneezes. People must generally be within six feet of someone who is contagious to encounter these droplets and become infected.

According to The World Health Organization, preliminary studies suggest the virus may persist on hard and soft surfaces for a few hours or up to several days, depending on type of surface, temperature, humidity etc. This means the virus may possibly be spread when someone touches a surface or object with the virus on it and then touches their own mouth, nose or eyes.

The Centers for Disease Control and Prevention reports the period of infectiousness for COVID-19 isn’t fully known. Some studies suggest people who have contracted the coronavirus are “shedding” infectious viruses – and can therefore infect others – even before they develop symptoms. Scientists have also found that some individuals continue to shed the virus after they have recovered, however it’s not known whether they are shedding intact, infectious virus or inactive fragments of the viral genome.

Most confirmed cases of COVID-19 have occurred in adults. Infections have been reported in children of all ages, but the data suggests that older adults (ages 60 and above) are at higher risk for serious COVID-19 illness. The risk may be twice as high in these populations, possibly because our immune systems change as we age, making it harder to defend against disease and infection. Individuals with a certain set of pre-existing health conditions (chronic lung disease, heart disease with complications, severe obesity, diabetes, hypertension, renal failure, liver disease, or individuals who are immunocompromised) are also at high risk for severe illness from COVID-19. Data released by the CDC from the first month of the U.S. epidemic show that of the people who were sick enough to be hospitalized, nearly 90% had at least one chronic condition. It is harder for the body to recover from illness when these underlying disorders are present.
Additional data suggest African Americans are disproportionately affected by COVID-19 and are more likely to be hospitalized or die from the disease. Racial and ethnic demographic data are not always publicly reported and there are gaps in this information from state to state. Regardless, the available data suggest the increased frequency of infection and poorer outcomes are being driven by historical inequities in job opportunities, housing density, health risks, and access to healthcare.

The American Veterinary Medical Association has established a COVID-19 page for veterinarians. They note there have been two confirmed cases of SARS-CoV-2 infection in pet cats in the United States. Outside the US, two pet dogs and a pet cat have tested positive. There is no information that suggests pets can spread the infection to people. However, they recommend that individuals affected with COVID-19 limit contact with pets until more information is known.

All viruses mutate, acquiring changes in their genome over time. This is a natural part of the life cycle of a virus. As of late March 2020, the SARS-CoV-2 genome has undergone very few mutations during its global spread. While these changes can be used to track patterns of infection, they do not appear to have made the virus more severe or easier to spread.

It is possible that the number of cases will slow as the Northern Hemisphere enters spring and summer. However, not all coronaviruses follow a seasonality pattern. Additionally, while China, North America and Europe experience warmer weather, the Southern Hemisphere is headed into fall and winter. Transmission rates may actually increase in those regions over the next several months.

The best way to prevent COVID-19 is to avoid being infected. The CDC has a list of guidelines to help minimize the spread of respiratory illness, which includes common-sense advice like steer clear of close contact with individuals who are sick, avoid touching your eyes, nose and mouth, and wash your hands often with soap and water for at least 20 seconds.

Each of these ideas has been touted on social media platforms as a way to prevent disease. None of them are effective – and some are actually dangerous. The World Health Organization has an article that exposes the myths behind many rumors about the cause, prevention and treatment of COVID-19.

Initially, face masks were not recommended for people who are well. On April 3, 2020 the Centers for Disease Control and Prevention amended their recommendation, suggesting individuals wear cloth face coverings in those public settings where social distancing is a challenge – grocery stores, pharmacies etc. The wearing of surgical masks and N95 respirators is not recommended, in order to reserve their use for healthcare professionals. Cloth face coverings should also be worn by individuals who are ill when they have to be around other people. If the sick person cannot wear a cloth face covering, one should be worn by individuals who are caring for that person.

SYMPTOMS/TESTING

Accurate testing is critical to identifying and tracking the spread of COVID-19. There are currently two categories of testing: molecular and serological.
Molecular testing searches for the presence of SRAS-CoV-2 genetic material, indicating active infection. A healthcare provider collects a specimen from the nose, throat or lungs of an individual suspected of being infected. The sample is sent to a testing lab, where technicians extract the genetic information and search for sequences specific to the SARS-CoV-2 virus. Different technologies and approaches may be used, and while some test provide results in as little as 15 minutes, most take several hours or more.
Serological testing seeks evidence that the body has generated an immune response to the SARS-CoV-2 virus. This indicates the individual has previously been infected and is either currently recovering or recovered some time ago. These tests generally search for the presence of antibodies associated with the virus and may also be able to quantify the amount of antibodies or even whether those antibodies can prevent the virus from entering cells. It is believed that the presence of antibodies to the virus indicates protection from being re-infected. Based on research with other forms of coronavirus, this protection is thought to last between several months and one or two years.

In the United States, the testing process has been slow to roll out. While COVID-19 testing was initially only allowed at the Centers for Disease Control and Prevention headquarters in Atlanta, local and state public health laboratories have now received permission to offer testing using the CDC kits. A problem with the chemical components of early test kits required them to be remade, but kit availability has drastically increased during the second half of March, 2020. Many private testing labs have also created their own COVID-19 screens, working under an FDA policy that allows rapid development and deployment of these tests.

If you believe you have been exposed to COVID-19 and develop a fever and symptoms of respiratory illness, such as cough or difficulty breathing, call your healthcare provider immediately. The Centers for Disease Control and Prevention has published a set of guidelines for individuals who are sick with COVID-19 or suspect they are infected.

The current COVID-19 status can be found at both the Situation Dashboard from the World Health Organization and the COVID-19 GIS Dashboard developed by Johns Hopkins Center for Systems Science and Engineering. Both include number and geographic locations of cases, as well as data on deaths and those who have recovered.

SYMPTOMS/OUTCOME/TREATMENT

The CDC lists nine common symptoms of COVID-19: fever, cough, shortness of breath, chills, repeated shaking with chills, muscle pain, headache, sore throat or a sudden loss of taste or smell. Symptoms may appear as quickly as two days or as long as 14 days from exposure. As with other respiratory conditions, the severity of COVID-19 varies among patients. An analysis of nearly 45,000 confirmed patients in China found that 81% had mild symptoms, with 14% were classified as severe (involving serious pneumonia and shortness of breath). The remaining 5% of patients were critically ill, having developed respiratory failure, septic shock and/or multi-organ failure.

Although recovery times vary, the vast majority of people who get sick with COVID-19 will recover. People with mild cases recover within a few days, while those with more serious cases may take weeks or even months, depending on the severity of their symptoms.

We don’t have a clear understanding of the risk of death from COVID-19. Initial information from China suggested death occurred in approximately 3% of infected individuals. That figure is likely too high, as many people with mild cases of the disease were not counted in the overall numbers. A separate analysis of nearly 1,100 patients with lab-confirmed COVID-19 determined a 1.4% death rate. It will likely be some time before the actual rate is known. For comparison, the death rate of seasonal influenza is approximately 0.1%

There is currently no effective treatment for the virus that causes COVID-19. Antibiotics are not successful against viruses; neither are flu-based antiviral medications such as Tamiflu and Relenza. Treatment is instead supportive, addressing the symptoms associated with the illness. This means providing fluids, fever-reducing medication, and, in severe cases, treating symptoms associated with pneumonia or respiratory distress.

Possible vaccines and drug treatments are rapidly being developed. Genetic Engineering and Biotechnology News recently published a list of 35 potential treatment options under exploration. While many will enter the clinical trial process as early as this spring, it will likely take 18 months before any vaccine would be ready for widespread use. The Milken Institute tracks the development of treatments and vaccines for COVID-19, using publicly-available data that is regularly updated.

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