Wuhan coronavirus: Is this outbreak worse than the SARS and MERS outbreaks?
On December 31, 2019, the World Health Organization (WHO) was first informed of the many cases of pneumonia detected in Wuhan City in the Hubei province of China. Since then, the disease caused by coronavirus has killed 26 and sickened over 800, leading to questions and speculations as to how dangerous it is.
WHO says that the illness is not yet a global health emergency. Tedros Adhanom Ghebreyesus, Director-General of WHO, also tweeted: “I am not declaring the new #coronavirus outbreak a public health emergency of international concern today. The Emergency Committee was divided over whether the outbreak represents a PHEIC (Public Health Emergency of International Concern). This is an emergency in China, but it has not yet become a global health emergency.”
According to numbers till January 23, the proportion of deaths in currently reported cases is 4% -- 17 of 557.
The third WHO novel coronavirus (2019-nCoV) situation report, released on January 23, said: “WHO assesses the risk of this event to be very high in China, high at the regional level and moderate at the global level.”
(Salvatore Di Nolfi/Keystone via AP)
The CDC, which is also closely monitoring the outbreak, says that based on current information, the immediate health risk from 2019-nCoV to the general American public is considered low at this time.
Coronaviruses are a large family of viruses, some causing illness in people and others that circulate among animals, including camels, cats, and bats.
According to a report in The Conversation, four other human coronaviruses (HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1) cause colds, flu-like illnesses and more severe respiratory diseases such as pneumonia. Newborns, the elderly, immunocompromised people and those with underlying disease are at particular risk.
Rarely, animal coronaviruses can evolve and infect people and then spread among people such as has been seen with Middle-East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS), says the CDC.
“Both MERS and SARS have been known to cause severe illness in people. The situation with regard to 2019-nCoV is still unclear. While severe illness, including illness resulting in a number of deaths, has been reported in China, other patients have had milder illness and been discharged. There are ongoing investigations to learn more,” says CDC.
Wuhan coronavirus may be less severe than SARS
Experts say that the Wuhan coronavirus seems to be less severe than the SARS coronavirus.
“The new Wuhan coronavirus seems to cause less severe disease than the SARS coronavirus, which is now extinct after its single dramatic outbreak in 2002-04. MERS was less severe than either unless the patient was already burdened with underlying disease,” say experts from the University of Queensland.
They add: “Because we are at such an early stage of discovery and characterization of the new Wuhan virus, it’s very difficult to compare it to other viruses or to draw any strong conclusion about how it transmits, and its impact on humans.”
According to WHO, in the case of the Wuhan coronavirus, there have been very few reports of hospital outbreaks or infections of health care workers, which is a prominent feature of MERS and SARS.
Patients with confirmed 2019-nCoV infection have reportedly had mild to severe respiratory illness with symptoms of fever, cough, and shortness of breath. In more severe cases, the infection can cause pneumonia, severe acute respiratory syndrome, kidney failure, and even death.
“CDC believes at this time that symptoms of 2019-nCoV may appear in as few as two days or as long as 14 after exposure. This is based on what has been seen previously as the incubation period of MERS viruses,” say experts.
Not yet clear how easily it spreads
Experts say currently it is unclear how easily or sustainably this virus is spreading between people.
“Investigations are ongoing to learn more, but person-to-person spread of 2019-nCoV is occurring. It’s important to note that person-to-person spread can happen on a continuum. Some viruses are highly contagious (like measles), while other viruses are less so. It’s not clear yet how easily 2019-nCoV spreads from person-to-person. It’s important to know this to better assess the risk posed by this virus,” says CDC experts.
The agency, however, cautions that more cases are likely to be identified in the coming days, including more cases in the US. “Given what has occurred previously with MERS and SARS, it’s likely that some person-to-person spread will continue to occur,” it says.
Researchers from the Penn State University College of Medicine, and the National Institute of Allergy and Infectious Diseases, National Institutes of Health, write that the ultimate scope and effect of this outbreak is unclear at present as the situation is rapidly evolving.
“So far, it appears that the fatality rate of 2019-nCoV is lower than that of SARS-CoV and MERS-CoV; however, the ultimate scope and effects of the outbreak remain to be seen,” says the JAMA report.
The researchers add, “Human coronaviruses (HCoVs) have long been considered inconsequential pathogens, causing the “common cold” in otherwise healthy people. However, in the 21st century, 2 highly pathogenic HCoVs — SARS-CoV and MERS-CoV — emerged from animal reservoirs to cause global epidemics with alarming morbidity and mortality... The emergence of yet another outbreak of human disease caused by a pathogen from a viral family formerly thought to be relatively benign underscores the perpetual challenge of emerging infectious diseases and the importance of sustained preparedness.”