Even as new cases are being reported from countries outside China such as India, Iran and Republic of Korea, the novel coronavirus continues to confound experts. A new virus means more data is needed to fully understand many of its characteristics, experts concede. “The situation is still evolving and the true picture will emerge only after a few months,” a public health expert working with the government told THE WEEK. The expert requested not to be named because of health ministry protocol on information related to coronavirus.
It is now well known that COVID-19 belongs to a family of coronavirus; the family includes viruses that caused the SARS and MERS outbreaks in the past. Unlike influenza viruses, COVID-19 causes acute respiratory distress or pneumonia. It also spreads faster—among close contacts— than SARS, but causes milder symptoms.
However, experts in epidemiology told THE WEEK that it is still not known how fast the virus spreads; the number of people one patient of coronavirus can infect ranges from 1.5-4 persons.
As of now, the risk of infection among close contacts of a patient is 5 per cent, and among household members is 11 per cent, an expert said, citing CDC estimates on the subject.
Even the exact incubation period — the time period between acquiring the infection to showing symptoms — is not known exactly. “What we know is that the average incubation period is 5 days; the range of incubation period is 2 – 14 days. The government is following the 14 day time period for quarantine to be on the safe side,” the expert said.
We also don’t know the exact case fatality rate or deaths caused due to the virus — the average is 3.5 per cent. In China, the case fatality or death rate stands at 4 per cent, whereas outside of China, the rate is 1.8 per cent. Experts say that as of now, the final outcome of the disease is also not known—this can only be studied after substantial numbers of patients who are treated, recover, as well as those who succumb to the disease are studied.
The infection spreads through microdroplets in the air when a patient sneezes or coughs, as well as fomites [any inanimate object, that when exposed to infectious agents such as pathogenic bacteria, viruses or fungi, can transfer disease to a new host]. “Further studies will reveal how long the virus can survive on the inanimate objects,” the expert said. Data is also needed on how many people can one patient infect, and further, how many persons can acquire the infection from these people that one patient passed on the virus to, he added.
In light of what is known, experts say that N95 masks are required only if people have respiratory symptoms. The virus spreads through micro-droplets and hence masks should be used only to prevent the spread of the infection. Besides, public health experts warn that N95 masks are a precious commodity at this stage and must not be “wasted”.
Though the question of whether the virus can survive warmer climates is still up in the air, experts are hoping that with a change in season, the infections might come down. However, there’s no evidence as yet to prove that temperature affects its virulence. For instance, an outbreak of Middle East Respiratory Syndrome (MERS), a viral respiratory illness caused by one among the family of coronaviruses, was reported in Saudi Arabia in May, 2013. Most people infected with MERS-CoV developed severe respiratory illness, including fever, cough, and shortness of breath. Many of them have died.
However, most experts say that given the mild symptoms and low death rate in the current COVID-19 outbreak, there is enough cause for concern, and not panic. Preventive measures such as hand hygiene (washing hands with soap and water) and following coughing and sneezing etiquette must be adhered to. Besides, the Union health ministry has also asked citizens to report any signs or symptoms of the disease to the designated state and central helplines.