What is a coronavirus?
Coronaviruses are a family of common viruses, so called because of the spikes on their surface which form a sort of crown. They can cause diseases ranging from the common cold to more severe respiratory syndromes such as Mers (Middle Eastern respiratory syndrome) and Sars (severe acute respiratory syndrome). In 2003, Sars infected more than eight thousand people, and 774 died of it. The current epidemic, which broke out in Wuhan, a Chinese city of 11 million inhabitants in the province of Hubei, is caused by a hitherto unknown coronavirus, called 2019-nCoV.
What are the symptoms of the new virus?
Especially fever and cough, and in some cases breathing difficulties. Symptoms appear to occur between two days and two weeks after the person has been exposed to the virus. A research, published in the medical journal The Lancet, analyzed data for 99 patients hospitalized at the Jinyintan hospital in Wuhan between 1 and 20 January.
It has been seen that 49 had been to the Huanan market, from which the epidemic was initially thought to have started. The average age of the patients was 55.5 years, including 67 men and 32 women. Just over half had pre-existing chronic disease. Other reported symptoms include muscle pain (11 patients), mental confusion (9) and headache (8). Only four also had a cold. Seventeen patients developed acute respiratory distress syndrome (ARDS) and, among these, 11 worsened rapidly and died. Overall, the disease therefore seems to affect older males with other diseases to a greater extent.
How is the virus diagnosed and treated?
Chinese health authorities recreated the virus in the laboratory, sequenced its genome and shared the sequence with the international scientific community. The virus was also recreated by a group of Australian researchers, who made it available to the World Health Organization (WHO). There are no specific antivirals for the infection, only symptomatic or antiviral treatments usually used for other infections. There is currently no vaccine, but scientists have identified the virus quickly and developed a diagnostic test in less than a month. Advances in technology could allow testing a 2019-nCoV vaccine within three months. However, switching from testing to mass production can take years.
How is it transmitted?
Wuhan’s coronavirus is most likely transmitted through coughing and sneezing, like the flu. But infection by infected people without symptoms or during the incubation period is not excluded. Scientists are trying to understand the degree of transmission. A second The Lancet study, this time on a family, suggests that the virus passed from one sick relative to six others; only two had had contact with the initial patient. The study was the first confirmation of person-to-person transmission of the virus.
How contagious is the virus?
It is still not clear. It is known that it is transmitted from person to person. Chinese authorities have presented evidence of fourth generation cases in Wuhan and second generation infections outside the city. Preliminary calculations on the average number of infections that each infected person can cause, known as R0, indicate that they are 1.4 to 2.5 per infected person. But the data is uncertain. Seasonal flu usually has an R0 of about 1.3.
Where does the virus come from?
WHO is still working on this aspect. Many of the first confirmed cases (but not all) concerned people who, in December 2019, had been in a market in Wuhan where live animals are also sold. A recent genetic analysis suggests that the new coronavirus resembles viruses that affect bats and snakes. According to Kristian Andersen, a biologist from the Scripps research institute, which analyzed the 2019-nCoV sequences, the first infection could have occurred weeks or months earlier, and the virus would have come to the market later. Humans have always taken diseases from animals, in fact most of the new infectious diseases come from wildlife. The evolutionary survival of bacteria and viruses depends on the infection of new hosts, and jumping from one species to another is one way to do it. But climate change is accelerating this process. In addition, the increase in travel and people living in the city means that when a new disease emerges, it can spread more quickly.
Where has the virus spread so far?
Of the over fourteen thousand confirmed cases, more than 98 percent are located in China, especially in Wuhan, but also in Beijing, Shanghai and Guangdong. In addition to the recorded cases, it is estimated that there are other tens of thousands of infected people. Among the more than one hundred people infected in the rest of the world (in over twenty countries, including Italy), almost all came from Wuhan or other Chinese cities. Cases of person-to-person transmission that occurred outside of China were recorded in Vietnam, Japan, Germany, France, the United States and Taiwan.
How deadly is it?
So far 305 deaths (all in China, except one registered in the Philippines of a Wuhan man) have been linked to the virus, suggesting a mortality rate of around 2 percent. Actually the rate could be lower, because there could be many people infected with the virus who did not have symptoms severe enough to go to the hospital and therefore were not counted. In comparison, normal flu has a mortality rate of 0.14 percent (about one in a thousand people). The death rate of Sars is 11 percent, that of Mers is 30 percent. Every year, normal seasonal flu affects millions of people worldwide. Between three and five million have complications and between 250 thousand and 500 thousand die.
Why did the WHO decree the global health emergency?
WHO has proclaimed the epidemic of the new coronavirus a global health emergency (Public health emergency of international concern or Pheic). The concern is, in particular, that coronavirus may spread to countries with weak health systems. The declaration aims to raise the level of attention and improve international coordination. It allows the WHO to recommend measures on travel, trade, quarantine, screening, treatment. For the moment, the organization does not recommend introducing restrictive travel and trade measures (which have limited effectiveness and can be counterproductive), but the recommendations are not binding on the states. The Philippines, Australia and the United States have decided to prohibit foreign nationals who have recently been to China from entering their respective countries.
How is the epidemic contained?
The Chinese government has taken unprecedented measures to stem the infections: it has prolonged the New Year’s holidays, closed the stock exchange and schools until further notice. The areas most affected by the virus have been quarantined: public transport and private traffic have been suspended. The measures affect over fifty million people in at least 17 cities. Hong Kong has stopped rail links with mainland China. Many airlines, such as British Airways and Lufthansa, have suspended all flights with China. Italy has closed air traffic with China. The United States, the European Union, Australia and Japan have organized special flights to repatriate their citizens.
How to protect yourself?
If you have not recently been to China or in contact with someone infected with the virus, there is no cause for alarm. In the case of coughing or other symptoms such as chest pains it is preferable to call your doctor and not go in person. To reduce the risk of infection, WHO recommends:
- wash your hands often, with soap and water for 20 seconds or with alcoholic solutions;
- sneezing or coughing in a tissue or in the crook of the elbow;
- avoid touching your eyes, nose or mouth without washing your hands;
- avoid close contact with people who are sick or show symptoms of respiratory diseases;
- stay home if you have symptoms;
- pay attention to what you eat (avoid raw or undercooked meat, unwashed fruit and vegetables);
- clean and disinfect objects and surfaces that may have been contaminated.
Are masks needed?
Many infectious disease experts say that cheap disposable masks, which cover the nose and mouth, can help prevent infection if worn and used properly. But they admit that there isn’t much scientific evidence of quality about their effectiveness outside of healthcare facilities. In fact, most of the studies concern the use of surgical masks in the hospital setting. Experts fear that the mask gives a false sense of security. Furthermore, most people do not change it every day and do not use it correctly: they put their hand under the mask to scratch their face or rub their nose bringing contaminants in contact with the nostrils and the mouth or remove it, for example, if he receives a call. The masks tend to block the larger saliva droplets, but not the nebulized ones, which can be produced by the normal breathing of the infected person. The most important precaution remains that of not touching your face with your hands, washing them often and avoiding contact with the sick.