Too soon to tell if new virus is as dan­ger­ous as SARS

The News & Observer (Sunday) - - News - BY LAURAN NEERGAARD AND MARIA CHENG The As­so­ci­ated Press Health and Sci­ence De­part­ment re­ceives sup­port from the Howard Hughes Med­i­cal In­sti­tute’s De­part­ment of Sci­ence Ed­u­ca­tion. The AP is solely re­spon­si­ble for all con­tent.

The new virus from China has the world on edge be­cause it’s a close cousin to viruses that killed hun­dreds in sep­a­rate outbreaks. While it’s too early to tell if this lat­est threat will prove as deadly, health au­thor­i­ties are draw­ing on lessons from that grim past.

WHAT’S THE LINK

The new virus comes from a large fam­ily of coro­n­aviruses, some caus­ing noth­ing worse than a cold. But in late 2002, a coron­avirus named SARS erupted in south­ern China, caus­ing a se­vere pneu­mo­nia that rapidly spread to other coun­tries. It in­fected more than 8,000 peo­ple and killed 774 — and then it dis­ap­peared, thanks to pub­lic health mea­sures.

In 2012, an­other coron­avirus dubbed MERS be­gan sick­en­ing peo­ple in Saudi Ara­bia. It’s still hang­ing around, caus­ing small num­bers of in­fec­tions each year: The World Health Or­ga­ni­za­tion has counted nearly 2,500 cases of MERS in the Mid­dle East and be­yond, and more than 850 deaths.

So far, deaths from the new virus have been a small frac­tion of the roughly 1,300 con­firmed in­fec­tions, most of those cases in China.

WHERE DO TH­ESE VIRUSES COME FROM?

SARS and MERS came from an­i­mals, and this new­est virus al­most cer­tainly did, too. The first peo­ple in­fected vis­ited or worked at a seafood mar­ket in the Chi­nese city of Wuhan.

SARS ini­tially was traced to civet cats sold in a live an­i­mal mar­ket, but later sci­en­tists de­cided it prob­a­bly orig­i­nated in bats that in­fected the civets. Peo­ple can catch MERS from in­fected camels, although again, bats likely first spread that coron­avirus to camels.

That an­i­mal-to-hu­man jump is a huge con­cern for all kinds of viruses. Ev­ery so of­ten, new strains of bird flu make the jump from Asian live poul­try mar­kets to peo­ple, for ex­am­ple.

“Th­ese wildlife mar­kets are a risk,” said Dr. Ian Lip­kin of Columbia Univer­sity, who as­sisted the WHO and China dur­ing the SARS out­break and ad­vises Saudi Ara­bia about MERS.

HOW SIM­I­LAR ARE THEY?

Ex­perts can’t yet tell whether the new virus called 2019-nCoV — it stands for “novel coron­avirus” — is more like SARS or MERS.

Ge­net­i­cally, they’re all closely re­lated but “they re­ally are dif­fer­ent viruses,” said Dr. An­thony Fauci, in­fec­tious dis­eases chief at the U.S. Na­tional In­sti­tutes of Health.

One in­di­ca­tion of a virus’ dan­ger is how eas­ily it spreads from per­son to per­son.

Un­like SARS, “it looks like it doesn’t trans­mit through the air very eas­ily and prob­a­bly trans­mits through close con­tact,” said Dr. David Hey­mann, who headed WHO’s global re­sponse to SARS.

And while it’s too soon to be sure, Hey­mann said the new virus ap­pears most dan­ger­ous to older adults who have other health prob­lems. .

Com­pli­cat­ing mat­ters, if this new virus is fairly mild, it may be harder to stem the spread. That’s be­cause peo­ple who aren’t sick enough to see a doc­tor and thus don’t learn they should be iso­lated could keep spread­ing it, noted Neil Fer­gu­son of Im­pe­rial Col­lege Lon­don, who has con­sulted for WHO. Nor is there any way to know yet how of­ten peo­ple be­come in­fected but show no ob­vi­ous symp­toms.

“We may see more mild cases as the sur­veil­lance in­ten­si­fies,” WHO spokesman Tarik Jasare­vic said Fri­day in Geneva. “So the is­sue is not so much re­ally num­bers that we know will go up.”

IT’S FLU SEA­SON IN THE NORTH­ERN HEMI­SPHERE — HOW WILL PEO­PLE KNOW THE DIF­FER­ENCE?

Since symp­toms are sim­i­lar — fever, cough and in more se­vere cases short­ness of breath or pneu­mo­nia — it’ll take a med­i­cal test to tell. There is one, but health au­thor­i­ties in China, the U.S. and else­where are work­ing to make it more widely avail­able.

Given that it is flu sea­son in China, too, it’s “all the more im­pres­sive that they were able to rec­og­nize this out­break quickly,” Dr. Brian Garibaldi of Johns Hop­kins Univer­sity said.

Pre­cau­tions that hos­pi­tals of­ten use for flu sea­son and for other in­fec­tious dis­eases should help for this, too, Garibaldi added. For ex­am­ple, in many U.S. hos­pi­tals peo­ple are given masks if they ar­rive with a fever and cough dur­ing flu sea­son.

HUNT­ING VAC­CINES

While there is no vac­cine — or spe­cific treat­ment — for SARS or MERS, Fauci said it is tech­ni­cally pos­si­ble to cre­ate a vac­cine against this new virus. NIH did de­velop a po­ten­tial vac­cine can­di­date for SARS. It proved safe in a small first-step study in peo­ple but never was tested fur­ther be­cause by then, the out­break was end­ing.

This time around, sci­en­tists have more of a head start. Just weeks af­ter the first un­usual pneu­mo­nias were re­ported, Chi­nese sci­en­tists mapped the genes of the vi­ral sus­pect and shared them with world health au­thor­i­ties.

Now, NIH is among sev­eral groups work­ing to cre­ate a vac­cine for the new virus, us­ing newer and faster tech­nol­ogy than was avail­able dur­ing SARS.

DAKE KANG AP

A staff mem­ber moves bio-waste con­tain­ers past the en­trance of the Wuhan Med­i­cal Treat­ment Cen­ter in Wuhan, China, on Wed­nes­day.

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