OVERVIEW

Epidemics have plagued most parts of the world since the dawn of medicine. Although these outbreaks create worldwide public awareness, they are often forgotten in the annals of history. However, past epidemic control and preventive measures are brought to light and improved in the fight against new and resilient epidemics.

This is the story of most viral epidemics such as the Spanish flu, Avian flu, Swine flu, SARS (Severe Acute Respiratory Syndrome), MERS (Middle East Respiratory Syndrome) and currently COVID-19 (Coronavirus Disease 2019).

What then is the COVID-19 infection?

DEFINITION

COVID-19 is an acute, sometimes severe respiratory illness caused by the novel coronavirus SARS-CoV2. This virus is classified under a family of viruses known as the coronaviruses. Coronaviruses are enveloped RNA viruses which cause respiratory illness varying in severity from the common cold to fatal pneumonia.

Numerous coronaviruses were first discovered in domestic poultry which caused respiratory, gastrointestinal, and neurologic diseases in animals.
However, only 7 coronaviruses are known to cause disease in humans. These infections involve mild upper respiratory tract illness that causes symptoms of the common cold.

In addition, 3 of the 7 human coronavirus infections are much more severe and have recently caused major outbreaks of fatal pneumonia. These include:
• SARS-CoV2: A novel coronavirus that was first identified in Wuhan, China in late 2019 as the cause of coronavirus disease 2019 (COVID-19) and spread worldwide.
• MERS-CoV: Identified in 2012 as the cause of the Middle East respiratory syndrome (MERS).
• SARS-CoV: Identified in 2002 as the cause of an outbreak of severe acute respiratory syndrome (SARS).

The above coronaviruses can cause severe respiratory infections and are transmitted from animals to humans (zoonotic pathogens).

TRANSMISSION

Currently, research is still underway into the mode of spread of the virus. From recent reports in Wuhan, China; early infections of COVID-19 were linked to a live animal market in the city. This suggested that the virus was transmitted from animals being sold as exotic food to humans.

The virus is also thought to spread mainly from person-to-person; that is between people who are in close contact with one another (within about 6 feet) or through respiratory droplets produced when an infected person coughs or sneezes.

These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Persons who are symptomatic are the most contagious. Moreover, persons who are asymptomatic can spread the virus, however, this is not the main way the virus spreads.

EPIDEMIOLOGY

As of February 11th 2020, 43,118 laboratory-confirmed cases of COVID-19 have been reported globally with 1,018 deaths.

Currently, there are over 105,000 laboratory-confirmed cases of novel coronavirus (2019-nCOV) – infected pneumonia (NCIP) globally with over 3,500 recorded deaths.

Cases have been reported from 14 Asian countries, 9 European countries, 2 countries in North America, 1 country in Oceania and 7 countries in Africa.

Currently, the death toll has risen outside of China with Italy and Iran having over 100 recorded deaths.

All reported cases are confirmed by a real-time reverse transcriptase-polymerase chain reaction.

SIGNS AND SYMPTOMS

Most persons infected with COVID-19 have mild symptoms or no symptoms at all, but some become severely ill and die. Symptoms usually include fever, cough and shortness of breath.

Symptoms usually appear about 2 to 14 days after people are infected.

Majority of affected persons already have chronic illnesses, therefore making them susceptible to the virus and present with fever, chills, cough and shortness of breath.

Another group of patients mostly present with bilateral lobar pneumonia noticed on chest CT and x-rays. The most common causes of death are multiple organ failure and fatal acute respiratory syndrome.

DIAGNOSIS

The gold standard for COVID-19 diagnosis is based on real-time reverse transcriptase-polymerase chain reaction (RT-PCR) testing of upper and lower respiratory secretions.

Diagnostic testing currently is being done by clinicians through public health laboratories in their jurisdiction. Although clinical specimens from both lower and upper respiratory tracts are taken, additional specimen types such as stool or urine may be collected and stored.

For biosafety reasons, CDC (Center for Disease Control and Prevention) recommends local institutions not to attempt to isolate the virus in cell culture or do initial characterization of viral agents in patients suspected of having COVID-19 infection.

Health practitioners can suspect COVID-19 in people who have flu-like symptoms and have travelled to or live in an area where they could have been exposed to the virus or who have had recent close contact with someone who may have had COVID-19.
Chest CT and x-rays may also be requested to confirm the presence of bilateral lobar pneumonia in affected patients.

TREATMENT

Currently, there is no specific antiviral treatment recommended for COVID-19.People with COVID-19 receive supportive care to help relieve symptoms.

This normally involves acetaminophen or a non-steroidal anti-inflammatory drug (NSAID) such as ibuprofen to relieve fever and muscle aches. Some people who are severely ill may need to be treated with mechanical ventilation to assist their breathing.

Anyone who thinks they may have been exposed to COVID-19 should contact their nearest healthcare provider immediately.

PREVENTION

There is as yet no vaccine that could prevent further spread of COVID-19 and no specific antiviral drug for it.

However, researchers worldwide are working effortlessly to develop a cure.

Attempts have been made to test drugs such as Kaletra, a combination of two protease inhibitors, lopinavir and ritonavir, used to treat HIV/AIDS, chloroquine, an antimalarial, and remdesivir, a nucleotide analog that was originally tested against Ebola. Organizations such as the Chinese Center for Disease Control and Prevention, University of Hong Kong, University of Queensland, NIH (National Institute of Health) and several pharmaceutical companies are using published genomes to develop possible vaccines against SARS-CoV2.

Rapid vaccine and drug development could mitigate the evolution of COVID-19 into a pandemic.

However, as a reminder, CDC always recommends everyday preventive actions to help prevent the spread of respiratory diseases, which are:

• Avoid close contact with people who are sick.

• Avoid touching your eyes, nose, and mouth.

• Stay home when you are sick.

• Use a tissue to cover your mouth and nose when coughing or sneezing, then throw the tissue into a dustbin.

• Clean and disinfect frequently touched objects and surfaces using a regular household cleaning spray or wipe.

• CDC does not recommend that persons who are well wear a facemask to protect themselves from respiratory diseases, including COVID-19.

• Facemasks should be used by people who show symptoms of COVID-19 to help prevent the spread of the disease to others. The use of facemasks is also crucial for health workers and people who are taking care of persons in close settings (at home or in a health care facility).

• Wash your hands often with soap and water for at least 20 seconds, especially after going to the bathroom; before eating; and after blowing your nose, coughing or sneezing. If soap and water are not readily available, use an alcohol-based hand sanitizer with at least 60% alcohol. Always wash hands with soap and water if hands are visibly dirty.