An­swers sought from West Nile surge

Health work­ers seek clues to 2012’s deadly out­break in ef­fort to pre­vent deaths.

Austin American-Statesman - - FRONT PAGE - By Jamie Stengle

With the mos­quito pop­u­la­tion dec­i­mated by the cooler weather, ex­perts have turned their at­ten­tion to learn­ing lessons from the lat­est round of deadly West Nile cases.

DAL­LAS — West Nile deaths mounted quickly this sum­mer as mos­qui­toes spread the virus across the coun­try. The sit­u­a­tion was es­pe­cially dire in Texas, where some ar­eas re­sorted to ae­rial spray­ing for the first time in decades to curb what be­came one of the worst such out­breaks in U.S. his­tory.

Na­tion­ally, more than 240 peo­ple died from the mos­quito-borne ill­ness — about a third of them in Texas, and at least six in Travis County.

Now with the mos­quito pop­u­la­tion dec­i­mated by the colder weather, health ex­perts have turned their at­ten­tion to learn­ing lessons from the lat­est round of deadly cases. Fed­eral health au­thor­i­ties are col­lect­ing and ex­am­in­ing data, while Dal­las County — the epi­cen­ter of the out­break — has be­gun year-round mos­quito sur­veil­lance and test­ing.

What re­mains un­clear is whether ex­perts will be able to shed light on what caused the out­break, why parts of Texas were so se­verely af­fected and whether they can forecast the next ma­jor surge in the ill­ness.

“I don’t think that we’re ever go­ing to to­tally be able to sort it out,” said Dr. Lyle Petersen of the U.S. Cen­ters for Disease Con­trol and Preven­tion. “For one rea­son, the ecol­ogy in the United States is ex­tremely var­ied, so a fac­tor that may af­fect an out­break in Colorado may be dif­fer­ent than a fac­tor that causes an out­break in Louisiana. The con­di­tions in an ur­ban area may be dif­fer­ent than a sub-

ur­ban area.”

West Nile virus is be­lieved to have first ap­peared in the U.S. in 1999 in the New York City area and then grad­u­ally spread across the coun­try.

Mos­qui­toes get the virus from feed­ing on in­fected birds, and then the in­sects spread it to peo­ple they bite. Most in­fected peo­ple show no symp­toms, but the most se­vere form of the disease, called neu­roin­va­sive, can cause coma, con­vul­sions, mus­cle weak­ness, paral­y­sis and death.

The Texas De­part­ment of State Health Ser­vices re­ported more than 835 neu­roin­va­sive cases in Texas this year with 86 deaths, led by Dal­las County’s 18 fa­tal­i­ties. The na­tional death toll this year ap­proached record num­bers from 2002, when 284 peo­ple died from the disease.

Petersen said the CDC is try­ing to de­ter­mine what caused the lat­est out­break by look­ing at fac­tors such as heat, rain­fall and the num­ber of mi­grat­ing birds that trans­mit the virus to mos­qui­toes.

The agency is also re­search­ing the ge­net­ics of the virus to see if it might have mu­tated, but that doesn’t seem to have hap­pened.

The sit­u­a­tion be­came so se­vere in North Texas that the state paid for ae­rial spray­ing in ar­eas of Dal­las County and nearby Denton County. Dal­las County hadn’t con­ducted such an op­er­a­tion since 1966 when en­cephali­tis was blamed for more than a dozen deaths.

“If you look at this out­break, it came upon us very sud­denly,” Dal­las County Judge Clay Jenk­ins said. “We might have the same sit­u­a­tion in the fu­ture where, by the time peo­ple know there is a risk out there, dozens of peo­ple have al­ready been in­fected.”

Dr. Don Read has made a mis­sion of spread­ing the word about tak­ing pre­cau­tions. The 70-year-old Dal­las colon and rec­tal sur­geon con­tracted the neu­roin­va­sive form in 2005 and still wears leg braces from the or­deal.

“I tell peo­ple it’s some­thing you don’t want to have,” said Read, who formed a sup­port group of sur­vivors. “Ini­tially, my legs were com­pletely par­a­lyzed. My arms were partly par­a­lyzed. I couldn’t talk. I couldn’t hear. I couldn’t write.”

There’s no way to tell how bad West Nile will be or where it will strike, but Dal­las County has added two mi­cro­bi­ol­o­gists to han­dle year­round mos­quito test­ing, said Zachary Thompson, di­rec­tor of Dal­las County Health and Hu­man Ser­vices. Jenk­ins added that they can now get test re­sults in one day in­stead of seven.

Thompson said they will also start ad­vis­ing res­i­dents ear­lier in the year to ap­ply in­sect re­pel­lent; dress in long sleeves and long pants when out­side; stay in­doors from dusk to dawn; and drain stand­ing water on their prop­erty.

Jenk­ins noted: “Per­sonal re­spon­si­bil­ity is im­por­tant be­cause we can’t pos­si­bly kill ev­ery West Nile mos­quito.” dis­cov­ery was ini­tially in­ves­ti­gated as a homi­cide, a po­lice of­fi­cial said Tues­day. The of­fi­cial also had said the body ap­peared to have suf­fered “ob­vi­ous trauma.” How­ever, au­thor­i­ties said Wed­nes­day that report was in­cor­rect. An au­topsy was per­formed and the death is no longer con­sid­ered sus­pi­cious, of­fi­cials said. An of­fi­cial cause of death has not been made, of­fi­cials said, adding that a fi­nal rul­ing will be made fol­low­ing tox­i­col­ogy tests.

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