New bird-flu strain in Asia found re­sis­tant to vac­cines

The Washington Times Weekly - - National - By Joyce Howard Price

A new strain of bird flu in Asia is re­sis­tant to the vac­cines be­ing used to pro­tect poul­try against the dis­ease, and sci­en­tists are less cer­tain that this virus poses no threat of spread­ingdi­rectly­be­tween­hu­mans.

“The pre­dom­i­nance of this virus [among birds] over a large ge­o­graph­i­cal re­gion within a short pe­riod di­rectly chal­lenges cur­rent dis­ease con­trol mea­sures,” sci­en­tists at the Univer­sity of Hong Kong, who dis­cov­ered the new vi­ral strain, said inare­port­inPro­ceed­ing­soft­heNa­tional Academy of Sci­ences.

Karen La­courciere, pro­gram of­fi­cer for the Na­tional In­sti­tute of Al­lergy and In­fec­tious Dis­ease, said the “rapid spread” of the H5N1 virus the re­searchers de­scribed in their re­port was “sur­pris­ing.”

“It was a pow­er­ful pa­per the way they made their point that we must de­tect this early on, so we can ap­pro­pri­ately ad­just our in­ter­ven­tions and pre­pared­ness for a pan­demic,” she said.

Dr. Yi Guan and the other au­thors of the re­port are not ready to dis­miss the pos­si­bil­ity that the new virus can spread di­rectly be­tween hu­mans, rather than only from birds to hu­mans, a de­vel­op­ment that would make a ma­jor hu­man epi­demic pos­si­ble. The new virus has pro­duced 22 con­firmed hu­man in­fec­tions in 14 Chi­nese prov­inces since Novem­ber 2005.

“Some of those cases were res­i­dents of metropoli­tan ar­eas re­mote from poul­try farms [. . . ] fur­ther­more,therew­erenoob­vi­ous­poul­try out­breaks re­ported to neigh­bor­ing mar­kets or farms be­fore or af­ter theon­setofthose­hu­man­in­fec­tions,” the Chi­nese sci­en­tists wrote. “There­fore, whether those peo­ple were in­fected lo­cally and di­rectly from af­fected poul­try, or other sources, in­clud­ing hu­mans, is still un­known.”

Dr. Yi and his col­leagues said their sur­veil­lance of live-poul­try mar­kets and the use of ge­netic test­ing in­di­cate the “emer­gence and pre­dom­i­nance” of the “Fu­jian­like” H5N1 strain over other avian-flu viruses.

This de­vel­op­ment of re­sis­tance “may­be­as­so­ci­at­ed­with­vac­ci­na­tion in poul­try,” they ob­served.

Mrs. La­courciere said it’s too ear­ly­to­knowwhetherthis­new­bird­flu­virus­might­cause­a­ma­jorhu­man epi­demic, but she thinks there may “even­tu­ally be a pan­demic.” Be­cause the Fu­jian­like strain is “dom- inant in China and South­east Asia,” sur­veil­lance of the strain is needed in those places, she said.

Brian Ep­stein, a spokesman for the World Health Or­ga­ni­za­tion (WHO), said on Oct. 30 that he had not yet read the re­port but ad­vised against pan­ick­ing about the Fu­jian­like H5N1 virus.

He­saidthe­vari­antseem­sto­sidestep cur­rent vac­cines against avian fluin­poul­tryandthat“means­more chick­ens­maybe­sus­cep­ti­ble”tothis form of avian flu, “but it does not nec­es­sar­ily mean more peo­ple will get it.”

“There is bird flu all the time. Th­e­se­virus­escon­stant­ly­change­and mu­tate.This­does­not­mean­itwillbe trans­mit­ted to hu­mans,” he said.

While some ar­gue there have been no known cases of hu­man-to­hu­man trans­mis­sion of H5N1, the au­thors of the new re­port cited re­cent “sus­pected cases of hu­man-to­hu­man trans­mis­sion in­volv­ing mem­bers of an ex­tended fam­ily in In­done­sia.”

The au­thors of the NAS re­port fur­ther held that ge­netic test­ing showed the Fu­jian­like virus was re­spon­si­ble for the “in­creased preva­lence of H5N1 in poul­try since Oc­to­ber 2005 and re­cent hu­man in­fec­tion cases in China.” This has oc­curred, they said, even though China has re­quired flu vac­ci­na­tion of all poul­try for more than a year.

What’s more, they said, the Fu­jian­like virus “has al­ready caused poul­try­out­breaksinLaos,Malaysia and Thai­land, and hu­man dis­eases in Thai­land.”

In 2005, WHO con­firmed 97 hu­man bird flu cases in eight Asian or African coun­tries and 42 deaths in­five­oftho­se­n­a­tions.Bu­ta­sofOct. 16, the agency said, 109 hu­man cas­esal­ready­had­been­con­firmedin nine na­tions and 73 deaths in eight of them.

AP

Deadly or de­light­ful? A bird sits on a wire in Green­wich, Conn. on Oct. 31.

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