News / Health

US Reports Record Outbreak of West Nile Virus

Carol Pearson
The United States has just had its worst year ever for West Nile virus, according to the Centers for Disease Control and Prevention.  As of September 11, more than 2,500 cases have been reported and 118 people have died from the ailment.
 
West Nile virus is now endemic to the United States.  The seasonal epidemic flares up around June and continues until about October.
 
Dr. Lyle Peterson of the U.S. Centers for Disease Control and Prevention says there have been more than 2,500 cases of the mosquito-born disease so far this year.  "The number of people who have become ill with West Nile virus disease continues to go up and we expect the virus to continue until October," he said.
 
The virus has been reported in every state except Alaska and Hawaii.  But Peterson, who heads the CDC’s division of vector-born infectious diseases, says most of the cases have occurred in just a handful of states. "Two-thirds of all cases have been reported from six states: Texas, Louisiana, South Dakota, Mississippi, Michigan and Oklahoma.  And 40 percent have been reported from Texas," he said.
 
The CDC reports that most people who contract the virus will have no symptoms, but some will go on to develop West Nile neuroinvasive disease.  In these cases, patients can have seizures, muscle weakness and paralysis.  The disease can be fatal. 
 
Peterson said the number of neuroinvasive cases is the highest to date since the virus was first detected in the United States 13 years ago. “Of the 2,636 cases, 1,405 or 53 percent were classified as neuroinvasive disease such as meningitis or encephalitis."  
"We consider the number of neuroinvasive disease to be the best indicator of the scope of the epidemic since these cases are most consistently reported," he said.
 
Although the number of cases is up 35 percent from last week, Peterson suggests the worst is over. "We've turned the corner on the epidemic.  West Nile virus outbreaks in the United States tend to peak in mid to late August," he said.
 
That's when days get shorter and mosquitos become less active.
 
While the West Nile virus will soon go dormant, scientists will be analyzing data to find out why it was so virulent in Texas. They will look at factors that include the number of mosquitos in an area, how fast the virus replicates in the mosquitos, and they'll also look at climate.
 
"There's a very complicated relationship of temperature and rainfall and all of these factors in West Nile virus transmission," said Peterson.
 
So far, scientists have not been able to figure out how those relationships help the virus spread.  Peterson says it may take several more years before they uncover the clues.  
 
In the meantime, there is no vaccine to protect people from this sometimes deadly illness.

You May Like

In China, Mixed Signals on Ebola Controls

How authorities are monitoring at-risk individuals remains unclear, including whether there are quarantines for Chinese health workers returning from West Africa More

Video Women Voters Anxious Ahead of US Elections

Analysts say if women are focused on national security, it could be bad news for Democrats More

Solar's Future Looks Brighter

New technology and dropping prices are contributing to a surge in solar power More

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Women Voters Anxious Ahead of US Electionsi
X
October 31, 2014 4:10 AM
Public opinion polls show American voters are deeply dissatisfied with their government and anxious about threats from abroad. This is especially true for a key voting group both Republicans and Democrats are trying hard to win over: women. Analysts say if women are focused on national security, it could be bad news for Democrats, with majority control of the Senate at stake. VOA’s Cindy Saine looks at the crucial role women voters will play in deciding the elections.
Video

Video Women Voters Anxious Ahead of US Elections

Public opinion polls show American voters are deeply dissatisfied with their government and anxious about threats from abroad. This is especially true for a key voting group both Republicans and Democrats are trying hard to win over: women. Analysts say if women are focused on national security, it could be bad news for Democrats, with majority control of the Senate at stake. VOA’s Cindy Saine looks at the crucial role women voters will play in deciding the elections.
Video

Video Victorious Secularists Face Challenge to Form Government in Tunisia

Official results from Tunisia show the Islamist Ennahda party has failed to win the second free election since the so-called "Arab Spring" uprising in 2011. Ennahda, which handed power to a government of technocrats pending the elections, lost out to the secular party Nidaa Tounes. Henry Ridgwell reports from London that the relatively peaceful poll offers some hope in a volatile region.
Video

Video Africa Tells its Story Through Fashion

In Africa, Fashion Week is a riot of colors, shapes, patterns and fabrics - against the backdrop of its ongoing struggle between nature and its fast-growing urban edge. How do these ideas translate into needle and thread? VOA’s Anita Powell visited this year’s Mercedes Benz Fashion Week Africa in Johannesburg to find out.
Video

Video Smugglers Offer Cheap Passage From Turkey to Syria

Smugglers in Turkey offer a relatively cheap passage across the border into Syria. Ankara has stepped up efforts to stem the flow of foreign fighters who want to join Islamic State militants fighting for control of the Syrian border city of Kobani. But porous borders and border guards who can be bribed make illegal border crossings quite easy. Zlatica Hoke has more.
Video

Video China Political Meeting Seeks to Improve Rule of Law

China’s communist leaders will host a top level political meeting this week, called the Fourth Plenum, and for the first time in the party’s history, rule of law will be a key item on the agenda. Analysts and Chinese media reports say the meetings could see the approval of long-awaited measures aimed at giving courts more independence and include steps to enhance an already aggressive and high-reaching anti-corruption drive. VOA’s Bill Ide has more from Beijing.
Video

Video After Decades of Pressure, Luxembourg Drops Bank Secrecy Rules

European Union finance ministers have reached a breakthrough agreement that will make it more difficult for tax cheats to hide their money. The new legislation, which had been blocked for years by countries with a reputation as tax havens, was approved last week after Luxembourg and Austria agreed to lift their vetoes. But as Mil Arcega reports, it doesn’t mean tax cheats have run out of places to keep their money hidden.
Video

Video Kobani Refugees Welcome, Turkey Criticizes, US Airdrop

Residents of Kobani in northern Syria have welcomed the airdrop of weapons, ammunition and medicine to Kurdish militia who are resisting the seizure of their city by Islamic State militants. The Turkish government, however, has criticized the operation. VOA’s Scott Bobb reports from southeastern Turkey, across the border from Kobani.

All About America

AppleAndroid