Fatality rates
The focus right now is China. The outbreak has spread beyond Wuhan to other parts of the country, and there’s evidence of fourth-generation spread.
Transportation into and out of Wuhan and other cities has been curtailed, Lunar New Year festivals have been canceled, and the Shanghai Disneyland has been closed, among other measures taken by Chinese officials.
The government could be taking drastic measures in part to prevent the public criticism it took in the early 2000’s for the delayed response and lack of transparency during the global outbreak of another wildlife market coronavirus epidemic, severe acute respiratory syndrome (SARS). In a press conference Jan. 22, WHO officials commended the government’s containment efforts but did not say they recommended them.
According to WHO, serious cases in China have mostly been in people over 40 years old with significant comorbidities and have skewed towards men. Spread seems to be limited to family members, health care providers, and other close contacts, probably by respiratory droplets. If that pattern holds, WHO officials said, the outbreak is containable.
The fatality rate appears to be around 3%, a good deal lower than the 10% reported for SARS and much lower than the nearly 40% reported for Middle East respiratory syndrome (MERS), another recent coronavirus mutation from the animal trade.
The Wuhan virus fatality rate might drop as milder cases are detected and added to the denominator. “It definitely appears to be less severe than SARS and MERS,” said Amesh Adalja, MD, an infectious disease physician in Pittsburgh and emerging infectious disease researcher at Johns Hopkins University, Baltimore.
SARS: Lessons learned
In general, the world is much better equipped for coronavirus outbreaks than when SARS, in particular, emerged in 2003.
Dr. Amesh Adalja
WHO officials in their press conference lauded China for it openness with the current outbreak, and for isolating and sequencing the virus immediately, which gave the world a diagnostic test in the first days of the outbreak, something that wasn’t available for SARS. China and other countries also are cooperating and working closely to contain the Wuhan virus.
“What we know today might change tomorrow, so we have to keep tuned in to new information, but we learned a lot from SARS,” Dr. Shaffner said. Overall, it’s likely “the impact on the United States of this new coronavirus is going to be trivial,” he predicted.
Dr. Lucey, however, recalled that the SARS outbreak in Toronto in 2003 started with one missed case. A woman returned asymptomatic from Hong Kong and spread the infection to her family members before she died. Her cause of death wasn’t immediately recognized, nor was the reason her family members were sick, since they hadn’t been to Hong Kong recently.
The infection ultimately spread to more than 200 people, about half of them health care workers. A few people died.
If a virus is sufficiently contagious, “it just takes one. You don’t want to be the one who misses that first patient,” Dr. Lucey said.
Currently, there are no antivirals or vaccines for coronaviruses; researchers are working on both, but for now, care is supportive.
This article was updated with new case numbers on 1/26/20.