Explainer: What you need to know about coronavirus

The worsening outbreak of a little known strain of coronaviruses has sent health officials across the world scrambling as countries remain on high alert.

There are now fever checks at airports and other ports of entry in most countries as experts fear that the situation may worsen before it gets better.

With the death toll and number of new infections rising, Japan and the United States have started evacuating hundreds of their citizens from Wuhan, the city at the centre of the epidemic.

More than 56 million people in almost 20 Chinese cities, including Wuhan, have been prevented from travelling, underlining the gravity of the crisis.

As Kenyans wait to know the fate of a student who arrived at the Jomo Kenyatta International Airport (JKIA) with coronavirus-like symptoms yesterday, it is important to understand the basics of how the virus works in order to avert panic.

Here's what you need to know about the current coronavirus epidemic.

What are coronaviruses?

It is a family of viruses that can cause a range of illnesses in humans including common colds and more severe forms like Severe Acute Respiratory Syndrome (SARS-CoV) and Middle-East Respiratory Syndrome (MERS-CoV) which are life-threatening.

The name coronavirus comes from the Latin word corona, meaning crown or halo. Under an electron microscope, the image of the virus resembles the solar corona.

The current strain has been named 2019-nCoV.

How did the epidemic start?

The World Health Organisation (WHO) was alerted on December 31, 2019 to several cases of pneumonia in Wuhan City, Hubei Province, China. The virus did not match any other known virus, which raised concerns.

A week later on January 7, Chinese authorities confirmed that they had identified a new virus of the coronavirus family. The new virus was temporarily named Novel coronavirus-2019 (2019-nCoV). It had not been previously identified in humans.

Where did it come from?

Scientists suspect the virus may have originated in bats or snakes. According to theories based on genetic analysis of coronavirus, bats were found to be the native host and that there was likely an intermediate host between the flying mammals and humans. It's not yet clear who the intermediate host is and how the infection was transmitted from animals to humans.

However, early reports pointed the finger at a game food market in Wuhan where snakes, rats, wolf puppies, live foxes, crocodiles, giant salamanders, peacocks, porcupines, and other wildlife are available for sale.

Previous Coronavirus cases

In 2003, 774 people died from SARS-CoV outbreak. As of 2015, there were no further reports of cases of SARS.

About 858 people died from MERS-CoV, which first appeared in 2012 in Saudi Arabia and then in other countries in the Middle East, Africa, Asia and Europe.

In April 2014, the first American was hospitalised for MERS-CoV in Indiana and another case was reported in Florida. Both had just returned from Saudi Arabia.

In May 2015, there was an outbreak in Korea, which was the largest outbreak outside of the Arabian Peninsula.

What are the symptoms?

According to WHO, the main clinical signs and symptoms reported in this outbreak include fever, difficulty in breathing, and chest radiographs showing bilateral lung infiltrates.

In more severe cases, it can lead to pneumonia, severe acute respiratory syndrome, kidney failure and even death. The incubation period of the coronavirus remains unknown.

WHO notes that not enough is known about the epidemiology of 2019-nCoV to draw definitive conclusions about the full clinical features of disease, the intensity of human-to-human transmission, and the original source of the outbreak.

How it spreads

According to the US Centres for Disease Control and Prevention (CDC), there is still a lot to learn about this new strain and how it is transmitted, with investigations still ongoing.

According to WHO, coronaviruses in general are zoonotic, meaning they are transmitted between animals and people. Several known coronaviruses are circulating in animals that have not yet infected humans.

Once people are infected, coronaviruses such as SARS and MERS - which the 2019-nCoV resembles - mainly spread via respiratory droplets produced when an infected person coughs or sneezes, just like colds and flu.

In the past week, the number of confirmed infections has more than tripled and cases have been found in 13 provinces in China, as well as the municipalities of Beijing, Shanghai, Chongqing and Tianjin.

The virus has also been confirmed outside China, in Hong Kong, Macau, Japan, Nepal, Singapore, South Korea, Taiwan, Thailand, the US, Vietnam, France, Germany and Canada.

As at Wednesday, the virus had killed 132 people and infected nearly 6,000.

Prevention

According to WHO, standard recommendations to prevent infection spread include regular hand washing, covering the mouth and nose when coughing and sneezing, and thoroughly cooking meat and eggs.

Avoid close contact with anyone showing symptoms of respiratory illness such as coughing and sneezing.

Additionally, it is recommended that you use a separate bathroom if living with and caring for someone who is infected.

If infected, you should restrict activities outside your home, except if going to get medical care. Do not go to work, school, or public areas, and do not use public transportation or taxis, the CDC advises.

People with symptoms of acute respiratory infection should practise cough etiquette, that is, maintain distance, cover coughs and sneezes with disposable tissues or clothing, and wash hands.

Hygiene

You should wash your hands often and thoroughly with soap and water for at least 20 seconds, the CDC says.

You shouldn't share dishes, drinking glasses, towels, bedding, and other items with other people in your home once infection is suspected.

Is it safe to travel to China?

The Ministry of Foreign Affairs advised Kenyans against all but necessary travel to China as a precaution.

Kenya Airways says it will not suspend its flights to China as it monitors the situation, even as British Airways suspended flights to Beijing and Shanghai on Wednesday.

The CDC also issued a Level 3 Warning to Americans to avoid all non-essential travel to China.

Chinese authorities are imposing quarantines and restricting travel throughout the country.

If you absolutely must travel to China, you should:

•Avoid contact with sick people.
•Discuss your travel plans with your healthcare provider. Older adults and travellers with underlying health issues may be at risk for more severe disease.
•Avoid animals (alive or dead), animal markets, and products that come from animals (such as uncooked meat).
• Use an alcohol-based hand sanitiser if soap and water are not available.

If you travelled to China in the last 14 days and feel sick with fever, cough, or difficulty breathing, you should:

•Seek medical care right away. Before you go to a doctor’s office or emergency room, call ahead and tell them about your recent travel and your symptoms.
•Avoid contact with others.
•Not travel while sick.
•Cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing.
•Wash hands often with soap and water for at least 20 seconds. Use an alcohol-based hand sanitiser if soap and water are not available.