Coronavirus goes viral: A global threat to humans and animals
by Danny Frauenstein
Coronavirus (CoV) is causing widespread health, economic, and social problems. The current global threat to humans, officially named ‘COVID-19’ or ‘SARS-CoV-2’, had caused 113,672 confirmed infections and 4,012 deaths  in 110 countries as of March 10, 2020, according to WHO.
What is CoV and why is it so dangerous?
CoV consists of a group of enveloped RNA viruses. Typically, CoV causes infections of the respiratory or gastrointestinal tract in mammals or birds. The spectrum of diseases ranges from a mild cold-like illness to more severe conditions such as SARS (severe acute respiratory syndrome) or MERS (Middle East respiratory syndrome). CoV is noteworthy for its zoonotic potential .
CoV in animals
- Pigs can suffer from TGEV (transmissible gastroenteritis virus) infection. The mortality rate in piglets younger than 1 or 2 weeks is as high as 90% .
- The deadliest form of CoV infection in cats is called FIP (feline infectious peritonitis). Most cases of FCoV (feline coronavirus) infection either cause no symptoms or mild gut or respiratory tract infections. A change in virulence comes with a mutation of the virus that allows it to infect macrophages. Multiple organs become involved, triggering a disastrous immune response. Approximately 5% to 10% of FCoV-infected cats develop FIP and die from their illness .
- IB (infectious bronchitis) is a CoV disease in chicken that affects the upper respiratory tract. It primarily targets ciliated cells, thus paving the way for secondary lung infections. Once the disease has spread to the gastrointestinal tract, it can kill up to 30% of broilers in their first 5 to 6 weeks of life .
Symptoms in humans
Common features of COVID-19 infections mimic seasonal flu (influenza). Symptoms, which include fever, cough, chest tightness, and aching limbs and joints (myalgia) , usually settle after 2 to 5 days. People with other health problems (e.g., chronic obstructive pulmonary disease, diabetes, and other immunocompromising conditions) may be more severely affected. Influenza is still more common than COVID-19 but has a lower mortality (0.1% vs 1%, respectively).
As far as is known, COVID-19 is transmitted via airborne infection . It can be spread by inhalation or contact with a contaminated surface.
Preventative measures include regular hand washing with soap (for at least 20 seconds) or using hand disinfectant. Wearing quality face masks may limit your infection risk and the risk of infecting others. Avoid touching your nose, eyes, and mouth. If you cough or sneeze, use a tissue, bin it immediately, and then wash or disinfect your hands. Avoid crowds, close proximity with others, and physical contact.
The best prevention is to stay calm and to take good care of your health. If you feel ill, stay at home and keep away from others.
As for many viral diseases, there are no specific treatments available for COVID-19. The general advice from various sources is to:
- Stay home, keep away from others, and drink plenty of fluids.
- Seek early telephone or online medical advice.
- To avoid spreading the virus, do not visit your doctor, a chemist, or a hospital.
Your doctor may recommend paracetamol, aspirin, or other non-steroidal anti-inflammatory drugs (NSAIDs) for fever or myalgia. Seek further advice if your symptoms fail to resolve or worsen. Remember, your symptoms may be due to a health problem other than COVID-19.
Researchers are doing their best to develop vaccines and antiviral drugs or make use of currently available medicines. ModernaTX, for example, is testing its mRNA-1273 vaccine in phase 1 clinical studies , while other researchers are investigating whether the antiviral effects of chloroquine are of value in COVID-19 infections . As there are CoV vaccines for animals, chances are there might be CoV vaccines for humans in the future as well.
Although CoV is not new, it poses a health risk for many species. Globalisation will likely result in further epidemics by CoV and other pathogens. By learning how CoV affects humans and other species, we may be better able manage such problems in the future.
Selbitz H.-J., Truyen U., Valentin-Weigand P. (2015), Tiermedizinische Mikrobiologie, Infektions- und Seuchenlehre (10., aktualisierte Auflage). Stuttgart: Enke Verlag. S. 550–570