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What you should know about COVID-19

This article will be updated regularly based on the most recent medical knowledge.

Since the start of 2020, a new respiratory infection outbreak called COVID-19 has spread through Asia to the rest of the world. It’s caused by a new type of coronavirus called SARS-CoV-2.

At the start, the majority of COVID-19 cases were reported in China. But more new cases are now being detected each day outside Chinese borders than within. Over 150 countries have reported COVID-19 infections, with many experiencing clusters of community transmission. The outbreak has been declared a pandemic by the World Health Organization (WHO) and news reports are full of stories about COVID-19. But do you need to be alarmed? Is there a reason to worry? What do you need to know about this outbreak and the new virus?

Our medical professionals are answering some of your most frequently asked questions.


How likely am I to catch COVID-19?

Your risk level depends on where you live, where you have recently traveled, your age, and your overall health. The risk of infection is higher in areas where more people have received COVID-19 diagnosis.

In the beginning, most cases were reported in China, but the situation is evolving rapidly. While China has very few new cases due to effective measures, many other countries on all continents show rising case numbers, with a hotspot in Europe and the US right now. But if you aren’t in an area where COVID-19 is spreading locally, your chances of getting it are currently still low. If you are in an area with local transmission, you should take the risk seriously and follow the recommended prevention measures. In either case, the situation is changing rapidly, and it’s good to keep up to date on the current situation from your local health authority.

While people of all ages are susceptible to COVID-19 infection, four out of five have a mild to moderate illness and recover. Those over 60 years old and with pre-existing medical conditions, such as cardiovascular disease, diabetes, or high blood pressure, are more vulnerable to becoming seriously ill. Children seem to be less affected.

What are the typical COVID-19 symptoms?

Typical symptoms are fever, dry cough, and fatigue. But COVID-19 patients also showed less typical symptoms like headache, generalized muscle aches and pains, sore throat, diarrhea, reduced or lost sense of smell, runny nose, and red or sore eyes.

Could I have a COVID-19 infection?

For anyone with the typical symptoms, it’s still not likely that COVID-19 is the cause – especially as the influenza season is currently underway in the northern hemisphere. The probability of a COVID-19 infection only increases if you have the typical symptoms and have had contact with the virus.

What should I do if I think I’m infected?

As the measures differ between countries, it’s important to contact your local public health authority to get advice on what to do. Before going to a doctor’s office or the emergency room, call ahead and tell them about your recent travels, contacts, and symptoms, and then follow their advice. In the meantime, avoid contact with others and don’t travel. Cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing, and wash your hands often with soap and water for at least 20 seconds. Use an alcohol-based hand sanitizer if soap and water are not available.

If you have these or similar symptoms, you can now use Ada for a free symptom assessment. Please keep in mind that these symptoms could also indicate the common cold and further testing will be necessary to diagnose COVID-19.

Does COVID-19 cause death?

It is possible to die from COVID-19 complications. A small percentage (currently around 3.4 percent) of people who are infected develop such a severe case of the infection that they die – which means the vast majority of infected people recover. Mortality is higher in those over 60 and with pre-existing medical conditions.

Is influenza a coronavirus?

No, influenza viruses are different from coronaviruses – even though they cause similar symptoms and also mainly spread through respiratory droplets.

An illustrative representation of the SARS-CoV-2 coronavirus.


How is COVID-19 transmitted?

COVID-19 transmission is similar to other respiratory viruses. It is mainly spread through small droplets that form when an infected person sneezes or coughs. Usually these droplets only reach people (or objects/surfaces) who are near the infected person. The general rule is that droplets can spread one to two meters but not further than that. The virus does not seem to be airborne or passed through the fecal-oral route.

Can only sick people spread the virus?

As the virus is transmitted by respiratory droplets, it’s much more likely to spread through symptoms like sneezing and coughing. However, some people have become infected after contact with confirmed cases who had no or very mild symptoms at the time. That said, asymptomatic transmission does not seem to be a significant driver of the COVID-19 epidemic.

How long does the virus survive on surfaces?

Early findings indicate that COVID-19 can remain on surfaces from a few hours up to several days, depending on the type of surface, temperature, and humidity. You can use a standard disinfectant to clean surfaces to prevent infection. COVID-19 doesn’t spread through letters or packages coming from an affected region.

What is the incubation period for COVID-19?

The incubation period is the time between the infection and the first onset of symptoms. The average incubation period for COVID-19 is around five to six days but can range from one to 14 days.

Can humans get COVID-19 from dogs or cats?

The origin of the virus is still unclear, but the research points towards bats as the source. Until now, there are no reports of COVID-19 in household pets.

How long is a person with COVID-19 infectious for?

There is little information available about the duration of infectiousness. The virus can be detected for up to several weeks in samples from infected people. But that doesn’t mean the virus is active and infectious. One small study showed that the active virus was detectable in throat swabs for up to four days after symptom onset, and up to eight days in sputum samples. The active virus wasn’t detected in blood, stool, or urine. The results of this study suggested that people remain infectious for up to eight days, with reduced infectiousness after four days. These results need to be confirmed in a larger study.

Can I get COVID-19 several times?

Again, we still know little about COVID-19, especially regarding the longer lasting questions. But we have seen with other coronaviruses that previously infected people developed an immunity. There is also a very small study with monkeys who have had COVID-19. These monkeys were not able to catch the infection again, so immunity can be assumed. These are very early results in only four monkeys, so further tests are needed, but the preliminary results might give some indication of possible immunity in humans.


How can I prevent a COVID-19 infection?

Avoiding exposure to the virus is the best way to prevent infection. Standard measures to prevent the spread of respiratory viruses apply:

  • Wash your hands frequently with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer.
  • Avoid touching your eyes, nose, and mouth with unwashed hands.
  • Avoid close contact (remain at least two meters distance) with anyone who has a fever and cough.
  • Stay home when you have symptoms, even mild ones.
  • Cover your cough or sneeze with a tissue and then throw the tissue in the trash.
  • Clean and disinfect frequently touched objects and surfaces.

Should I wear a mask?

Surgical masks are more effective at preventing infected individuals from spreading diseases than protecting those who aren’t sick. You don’t need a mask if you don’t have respiratory symptoms. It is neither necessary nor useful.

You can wear a mask if you have respiratory symptoms – like coughing or difficulty breathing – to limit the spread of respiratory droplets.

Medical professionals use special filter masks that are fitted to their faces and can reduce the risk of transmission. The public shouldn’t use these masks, as they are in short supply and are required by medical professionals for the safe provision of care.


Is there a vaccine or drug for COVID-19?

There is currently no available vaccine. Vaccine production is a complicated and time-consuming process that normally takes years. In certain circumstances, like with new influenza viruses, there are established methods that can accelerate this process. That said, COVID-19 first detected at the beginning of January 2020: Many studies are ongoing, but even in the ideal scenario, it will take a few months before a vaccine is available and can be tested and used widely.

There are also several studies ongoing to test pre-existing drugs that were developed to fight other diseases such as malaria, ebola, or HIV. Tests should show if they are effective in treating COVID-19 patients. The initial results should be available soon.

COVID-19 or the common cold – how can I tell the difference?

Symptoms of the common cold and COVID-19 are very similar. That’s why understanding the significance of exposure to the virus is so important to differentiate between the two. Along with showing the typical symptoms of fever, dry cough, and fatigue, people with COVID-19 have typically also been in an area where the virus is already spreading locally, or in contact with a person who has COVID-19.

The similarity between a cold and COVID-19 in many cases means that, for some, the infection can seem no worse than a common cold.

How is COVID-19 diagnosed?

Infection is confirmed by testing respiratory samples in specialized laboratories. First antibody blood tests to identify infection and immunity are under development.


When will the outbreak be over?

It’s hard to say when the outbreak will be over. At the moment, there’s very little indication that it will stop soon. As with the mild influenza pandemic of 2009/2010, COVID-19 will probably continue spreading worldwide. Even though it’s possible that it could slow down by spring – much like seasonal influenza each year – early analysis of the virus indicates that increasing temperatures will not reduce transmission significantly.

Why are governments taking such strong measures to ‘flatten the curve’?

Affected countries are implementing strict social distancing measures to prevent the virus from spreading. Schools, offices, and shops are closing alongside event cancellations in many countries. These social distancing efforts are referred to as ‘flattening the curve’.

Social distancing has been effective at reducing the outbreak burden in several cases. These measures aim at postponing and reducing the peak of the pandemic, resulting in fewer simultaneous cases, and ideally, fewer cases overall. These strong measures are implemented during pandemics to reduce the burden of the outbreak on health systems and help free up intensive care units for the most serious cases.

Why are the measures changing over time?

A government’s public health response depends very much on the local context and the stage of the outbreak. In the beginning, the focus is on containment, detecting cases early, and preventing new infections. This buys time to prepare as well as possible – learning about the characteristics of the disease, identifying higher-risk groups, building the capacity of the local health system, and investigating treatment options. When more cases cannot be traced back to a single confirmed case, the strategy shifts to focus on controlling the epidemic and protecting the people who have an increased risk of serious illness.


Dr. Andreas Gilsdorf

Andreas is Ada's Director of Epidemiology and Public Health.