Skip to comments.West Nile Virus Will Sweep Across Whole US
Posted on 08/06/2002 2:16:20 PM PDT by blam
West Nile virus will sweep across whole US
18:15 06 August 02
NewScientist.com news service
West Nile virus is continuing to sweep westwards across the US, with 88 confirmed cases and five human deaths so far in 2002. The mosquito-borne disease was first recorded in the US in New York in 1999 and experts think it will have swept across the entire continent by the end of this summer, or the next.
But climate-based "risk maps" are helping public health officials predict precisely which areas will be hit. "These are a big advance on what we had," says zoologist David Rogers at Oxford University, UK, where the maps are being created.
"Before, we had to wait for an infected bird to fall down and be recorded, sent to the lab and tested for the virus," he told New Scientist. "These spatial maps can predict the areas at risk in advance. Public health services could then go out and look for infection and control it, by mosquito spraying, for example."
In 2001, the team created their first prediction maps for New York State. This year, they added data from Delaware, Florida, Louisiana, South Carolina and Virginia to create risk maps for the whole US.
The maps pinpointed high risk areas in two states that had never previously recorded the virus, Mississippi and Louisiana. And on Friday, the governor of Louisiana declared a state-wide emergency, after 58 human cases and five deaths had been recorded in the state since June. Mississippi has reported 22 cases this year, 14 in the past week.
The 2002 risk maps also highlighted areas in South Carolina, for example, which has not yet recorded infection. Rogers' team has informed the state of the risk.
The researchers analyse all available data on mosquito, bird or animal infections. They also analyse satellite images showing temperature and vegetation conditions in precise areas where the infections were recorded. The vegetation data is used as an indicator of rainfall.
Next, they look for similar climate characteristics in areas as yet unaffected by the virus. Taking into account migratory patterns of birds known to harbour the virus, they combine all the information to produce risk maps for each state.
But the rapid spread of the virus - from 23 states in 2001 to 34 so far in 2002 - makes it very difficult to predict exactly which areas will be hit next. States such as South Dakota, with very different environmental conditions to past West Nile hotspots, have reported infection for the first time, Rogers points out.
The difficulty, he says, is that the virus can be transmitted by 40 species of mosquito and it can be harboured by about 70 species of bird. The birds in particular are adapted to a wide variety of environmental and climactic conditions. So the viral spread is not restricted to the same extent as viruses transmitted by only a few species of mosquito, for example.
One prediction Rogers will make is that the virus will reach California through warmer, southern states, rather than across the northern US.
But California residents can at least be reassured that local public health officers are on standby. Blood from about 2000 sentinel chickens in coops across the state is analysed each week for the West Nile virus.
I can't tell you how REASSURED I feel. Local public health officers on standby: Praise the Lord!!
< /sarcasm >
"Pass me the Super Sauce, Fred ..."
There is a grave yard here in Old Mobile (Church street, I believe) where (almost) everyone buried there died of Yellow Fever. (Joe Cain, the father of US Mardi Gras is buried there also)
Ofcourse I'm convinced I have the virus because I have a mosquito bite and my arm is sore (muscle soreness is a sign of WNV). I'm actually going to get my blood tested to be reassured.
In my opinion I think that the West Nile Virus is terrorist related just because WNV originates from the land of the Religion of Peace.
Secondly, if chickens can be used as sentinels, then chickens can be infected with the virus. Does this mean that humans can be infected by eating infected chickens? Are we about to see whole chicken farms having to be destroyed to "control" this virus?
Our government and the press have been strangely silent on this virus. Are they trying to hide something?
Yellow fever was brought home to me when I ran a farm near Lowndesboro, AL on the Alabama River. When we bought the place, once a substantial plantation, there was an overgrown graveyard on top of the hill. We cleaned it out and discovered 14 graves, dated twelve years apart (1821-1833, as I recall), all one family, all yellow fever.
It turns out the sole survivor was a daughter, who moved into town, continued to personally manage the plantation (plus a second plantation in South Carolina), and whose descendants remain prominent in the area to this day.
One thing that visitors to the South should note. Virtually every small town is built on a hill -- or what might pass for a hill. Yellow fever is the reason why all settlements avoided the lowlands.
Living where you do, I'm sure you're familiar with this phenomenon.
Yup. Cottage Hill and Spring Hill in Mobile are the affluent sections. Years ago the affluent would retreat to the cottages on the hills during the summer months.