Some infectious disease experts are warning that it may no longer be feasible to contain the
new coronavirus circulating in China.
Failure to stop it there could see the virus spread in a sustained way
around the world and even perhaps join the ranks of respiratory viruses
that regularly infect people.
“The more we learn about it, the greater the possibility is that
transmission will not be able to be controlled with public health
measures,” said Dr. Allison McGeer, a Toronto-based infectious disease
specialist who contracted SARS in 2003 and who helped Saudi Arabia
control several hospital-based outbreaks of MERS.
If that’s the case, she said, “we’re living with a new human virus,
and we’re going to find out if it will spread around the globe.” McGeer
cautioned that because the true severity of the outbreak isn’t yet
known, it’s impossible to predict what the impact of that spread would
be, though she noted it would likely pose significant challenges to
health care facilities.
The pessimistic assessment comes from both researchers studying the
dynamics of the outbreak — the rate at which cases are rising in and
emerging from China — and infectious diseases experts who are parsing
the first published studies describing cases to see if public health
tools such as isolation and quarantine could as effective in this
outbreak as they were in the 2003 SARS epidemic.
And the warnings come as the United States reported over the weekend
finding three more cases, the country’s third, fourth, and fifth. Two
were diagnosed in California. One is a traveler from Wuhan, where the
outbreak is believed to have started, who was diagnosed in Orange
County. The other is someone who visited Wuhan who was diagnosed in Los
Angeles County. The fifth case was diagnosed in Arizona and is a student
at Arizona State University; the person had also traveled to Wuhan.
Infections within China climbed over the 2,000 mark Sunday and the death toll rose to 56.
China’s health minister, Ma Xiaowei, warned Sunday that the virus
seems to be becoming more transmissible and the country — which has
taken unprecedentedly draconian steps to control the virus — was
entering a “crucial stage.”
China’s actions — which include shutting off flights and trains from
some affected cities and effectively putting tens of millions of people
into quarantine — may not be enough to stop the virus, experts said.
“Despite the enormous and admirable efforts in China and around the
world, we need to plan for the possibility containment of this epidemic
isn’t possible,” said Neil Ferguson, an infectious diseases epidemiology
at Imperial College London who has issued
a series of modeling studies on the outbreak.
There may be as many as 100,000 cases already in China, Ferguson
told The Guardian newspaper
on Sunday, adding the model suggests the number could be between 30,000
and 200,000 cases. “Almost certainly many tens of thousands of people
are infected,” he told the British newspaper.
The Bill and Melinda Gates Foundation announced Sunday it is donating
$10 million to the response to the virus. Half the money will be given
to Chinese groups to help them in containment efforts. The other half
will be given to the African Center for Disease Control to fund its
efforts to help African countries prepare to have to cope with the new
infection.
Also on Sunday, World Health Organization Director-General Tedros Adhanom Ghebreyesus
tweeted that he is traveling to Beijing to meet with Chinese authorities to offer support and to learn more about the outbreak.
The WHO so far has not declared the outbreak a global health
emergency, though Tedros, as he is know, has said the spread of the new
virus is a crisis for China and a risk to countries beyond it. The WHO
declined to label the outbreak a global health emergency of
international concern on the advice of a panel of experts who met
Wednesday and Thursday, though those experts were split on whether a
PHEIC should be declared.
This outbreak is caused by a virus —
currently known as 2019-nCoV
— that belongs to the same family as the viruses that caused the SARS
outbreak and which cause sporadic flare-ups of cases of MERS on the
Arabian Peninsula.
The SARS virus caused an explosive outbreak in late 2002 and early
2003, infecting more than 8,000 people around the globe and killing
nearly 800 before it was contained. MERS has never caused a sustain
global outbreak, though a number of large hospital-based outbreaks
— including one in South Korea sparked by a businessman who contracted
the virus in the Middle East — have been recorded.
One of the luckiest breaks the world got with the SARS outbreak was
the fact that the virus did not transmit before people developed
symptoms.
With some diseases, like influenza and measles, people who are
infected but who are not yet feeling sick — people who are still going
to work or school, taking public transit, shopping in malls, or going to
movies — can pass the viruses to others.
Tools like quarantine and isolation — which were key to controlling
SARS — are unlikely stop spread of a virus that can transmit during the
period from infection to symptoms, experts say.
Dr. Nancy Messonnier, director of National Center for Immunization
and Respiratory Diseases at the Centers for Disease Control and
Prevention, said the agency knows transmission of the virus within the
United States may be on the horizon.
“We’re leaning far forward. And we have been every step of the way
with an aggressive stance to everything we can do in the U.S.,” she told
STAT. “And yet those of us who have been around long enough know that
everything we do might not be enough to stop this from spreading in the
U.S.”
To date, at least 14 countries and territories outside of mainland
China have reported nearly 60 cases. There have been no reports yet of
unchecked spreading from those imported cases to others.
“In hours where I’m feeling optimistic I think about the fact that
none of the other countries, including the U.S., have seen significant
sustained chains of transmission,” Messonnier said. “But that doesn’t
mean that it’s not coming.”
It also appears that the incubation time — the time from infection to
the development of symptoms — may be a bit shorter than that of SARS,
McGeer said, citing a
paper published Friday
that described transmission within a family in Hong Kong. With SARS,
most people developed symptoms about four or five days after infection,
she said.
A short incubation period gives health authorities less time to track
down and quarantine people who have been exposed to the virus and who
are en route to becoming infectious.
Scientists who have been studying the
genetic sequences
of viruses from China and a few other of the countries that have
recorded cases have calculated what is known as the reproductive rate of
this outbreak — the number of people, on average, that each case will
infect.
An outbreak with a reproductive number of below 1 will peter out. But
a number of groups have calculated a reproductive rate for this current
outbreak — known by the term R-naught or R0 — in the range of 2 to 3 or
beyond.
Trevor Bedford, a computational biologist at the Fred Hutchinson
Cancer Research Center in Seattle, suggested the estimates are sobering
and point to continued spread.
“If it’s not contained shortly, I think we are looking at a
pandemic,” Bedford said, though he cautioned that it’s impossible to
know at this point how severe that type of event would be.
Dr. Tom Inglesby, director of the Center for Health Security at Johns Hopkins School of Public Health,
urged countries
to start planning to deal with global spread of the new virus. Such
plans need to include far more aggressive efforts to develop a vaccine
than have already been announced, he suggested.
“I’m not making a prediction that it’s going to happen,” Inglesby
said, though he noted the mathematical modeling, the statements from
Chinese authorities, and the sharply rising infection numbers make a
case for this possible outcome. “I think just based on those pieces of
limited information, it’s important for us to begin some planning around
the possibility that this won’t be contained.”
Containing new coronavirus may not be feasible, experts say, as they warn of possible sustained global spread
