Alarming increase seen in West Nile Virus: Know the Signs and Symptoms Says CDC

Aug 23, 2012

ATLANTA (AP) — U.S. health officials reported Wednesday three times the usual number of West Nile cases for this time of year and one expert called it “one of the worst” outbreaks since the virus appeared in this country in 1999.

So far, 1,118 illnesses have been reported, about half of them in Texas, according to the Centers for Disease Control and Prevention. In an average year, fewer than 300 cases are reported this early. There have also been 41 deaths.

“We’re in the midst of one of the largest West Nile outbreaks ever seen in the United States,” said Dr. Lyle Petersen, a CDC official.

Never before have so many illnesses been reported this early, said Petersen, who oversees the CDC’s mosquito-borne illness programs.

Most infections are usually reported in August and September, so it’s too early to say how bad this year will end up, CDC officials said.

They think the mild winter, early spring and very hot summer have fostered breeding of mosquitoes that pick up the virus from birds they bite and then spread it to people.

West Nile virus was first reported in the U.S. in 1999 in New York, and gradually spread across the country over the years. It peaked in 2002 and 2003, when severe illnesses reached nearly 3,000 and deaths surpassed 260. Last year was mild with fewer than 700 cases.

Only about one in five infected people get sick. One in 150 infected people will develop severe symptoms including neck stiffness, disorientation, coma and paralysis.

In recent years, cases have been scattered across the country. Hot spots are usually in southeast Louisiana, central and southern California, and areas around Dallas, Houston, Chicago and Phoenix.

Those areas seem to have a combination of factors that include the right kinds of virus-carrying mosquitoes and birds, along with large numbers of people who can be infected, health officials say.

The best way to prevent West Nile disease is to avoid mosquito bites. Insect repellents, screens on doors and windows and wearing long sleeves and pants are some of the recommended strategies. Also, empty standing water from buckets, kiddie pools and other places to discourage breeding.

Source: By MIKE STOBBE, Associated Press

Symptoms of West Nile Virus

Q. What are the symptoms of West Nile virus (WNV) infection?
A. Infection with WNV can be asymptomtic (no symptoms), or can lead to West Nile fever or severe West Nile disease.

It is estimated that about 20% of people who become infected with WNV will develop West Nile fever. Symptoms include fever, headache, tiredness, and body aches, occasionally with a skin rash (on the trunk of the body) and swollen lymph glands. While the illness can be as short as a few days, even healthy people have reported being sick for several weeks.

The symptoms of severe disease (also called neuroinvasive disease, such as West Nile encephalitis or meningitis or West Nile poliomyelitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. It is estimated that approximately 1 in 150 persons infected with the West Nile virus will develop a more severe form of disease. Serious illness can occur in people of any age, however people over age 50 and some immunocompromised persons (for example, transplant patients) are at the highest risk for getting severely ill when infected with WNV.

Most people (about 4 out of 5) who are infected with West Nile virus will not develop any type of illness (an asymptomatic infection), however you cannot know ahead of time if you’ll get sick or not when infected.

Q. What is the incubation period in humans (i.e., time from infection to onset of disease symptoms) for West Nile disease?
A. Usually 2 to 15 days.

Q. How long do symptoms last?
A. Symptoms of West Nile fever will generally last a few days, although even some healthy people report having the illness last for several weeks. The symptoms of severe disease (encephalitis or meningitis) may last several weeks, although neurological effects may be permanent.

Q. What is meant by West Nile encephalitis, West Nile meningitis, West Nile poliomyelitis, “neuroinvasive disease” and West Nile fever?
A. The most severe type of disease due to a person being infected with West Nile virus is sometimes called “neuroinvasive disease,” because it affects a person’s nervous system. Specific types of neuroinvasive disease include: West Nile encephalitis, West Nile meningitis, West Nile meningoencephalitis and West Nile poliomyelitis. Encephalitis refers to an inflammation of the brain, meningitis is an inflammation of the membrane around the brain and the spinal cord, meningoencephalitis refers to inflammation of the brain and the membrane surrounding it, and poliomyelitis refers to an inflammation of the spinal cord.

West Nile Fever is another type of illness that can occur in people who become infected with the virus. It is characterized by fever, headache, tiredness, aches and sometimes rash. Although the illness can be as short as a few days, even healthy people have been sick for several weeks.

Q. If I have West Nile Fever, can it turn into West Nile encephalitis?
A. When someone is infected with West Nile virus (WNV) they will typically have one of three outcomes: No symptoms (most likely), West Nile fever (WNF in about 20% of people) or severe West Nile disease, such as meningitis or encephalitis (less than 1% of those who get infected). If you develop a high fever with severe headache, consult your health care provider.

West Nile fever is characterized by symptoms such as fever, body aches, headache and sometimes swollen lymph glands and rash. West Nile fever generally lasts only a few days, though in some cases symptoms have been reported to last longer, even up to several weeks. West Nile fever does not appear to cause any permanent health effects. There is no specific treatment for WNV infection. People with West Nile fever recover on their own, though symptoms can be relieved through various treatments (such as medication for headache and body aches, etc.).

Some people may develop a brief, WNF-like illness (early symptoms) before they develop more severe disease, though the percentage of patients in whom this occurs is not known.

Occasionally, an infected person may develop more severe disease such as “West Nile encephalitis,” “West Nile meningitis” or “West Nile meningoencephalitis.” Encephalitis refers to an inflammation of the brain, meningitis is an inflammation of the membrane around the brain and the spinal cord, and meningoencephalitis refers to inflammation of the brain and the membrane surrounding it. Although there is no treatment for WNV infection itself, the person with severe disease often needs to be hospitalized. Care may involve nursing IV fluids, respiratory support, and prevention of secondary infections.

Source: CDC

CDC says U.S. deaths from West Nile virus jump to 43

The number of West Nile virus cases in the U.S. jumped dramatically in one week, increasing to 1,221, with 43 deaths, the Centers for Disease Control and Prevention reported today.

The report marked a substantial increase from last week’s tally of 693 cases and 26 deaths.

Approximately 75% of the cases have been in five states: Texas, Mississippi, Louisiana, South Dakota and Oklahoma, the CDC said.

Texas has been hardest hit, accounting for almost half of all cases.

As of Wednesday, 23 deaths and 640 cases had been reported there, said Christine Mann with the Texas Department of State Health Services.

“The number of West Nile cases in people has risen dramatically in the last few weeks and indicates that we are in one of the biggest West Nile virus outbreaks we have ever seen in this country,” said Lyle Petersen, director of the CDC’s Division of Vector-borne Infectious Diseases.

So far this year, 47 states have reported West Nile virus in humans, birds or mosquitoes, the CDC said. Thirty-eight states have reported cases of the human disease.

The 1,221 cases are the highest number of West Nile virus disease cases reported to the CDC through the third week in August since the virus was first detected in the United States in 1999, the agency said.

Up to 20% of people who contract West Nile virus develop symptoms that include fever, headache, body ache, swollen lymph glands and occasionally a rash on the trunk of the body. Symptoms appear within two to 15 days and then disappear within a few days.

About 80% of people infected with the West Nile virus have no symptoms.

Of those who develop a fever, fewer than 1% develop West Nile neuroinvasive disease which causes inflammation of the brain, spinal cord or the tissue surrounding the brain. About 10% of those will die, said Marc Fischer, medical epidemiologist with CDC’s mosquito-borne illness division in Ft. Collins, Colo.

People older than 50 and those with compromised immune systems are more likely to develop this form.

The West Nile virus first appeared in the United States in 1999, from Africa.

Here are five things you need to know about West Nile virus:

1. Most mosquitoes do not carry West Nile.

In areas where mosquitoes carry the virus, only about one in 500 mosquitoes is infected, according to the Connecticut Mosquito Management Program.

2. Most people bit by West Nile mosquitoes do not get sick.

About 80% of people bit by a mosquito infected with the West Nile virus do not get sick, according to the CDC. About 20% will have relatively mild symptoms, such as fever, headache and vomiting. Symptoms can last for as short as a few days or as long as a few weeks. About one in 150 people infected with West Nile will develop a severe illness, which can include paralysis, coma or death.

3. You can help prevent West Nile with the “four Ds.”

• Use mosquito repellent with DEET

• Dress in long pants and long sleeves

• Be especially careful at dusk and dawn

• Drain any standing water, such as kiddie pools or bird fountains, where mosquitoes like to breed.

4. People over 50 are most vulnerable.

Those older than 50 are the most likely to become severely ill with West Nile and should take special care to avoid mosquitoes, according to the CDC.

5. Seek medical care immediately if you have severe headaches or confusion.

If you develop symptoms of severe West Nile virus illness, such as unusually severe headaches or confusion, seek medical attention immediately, according to the CDC. Severe illness usually requires hospitalization. Milder cases improve on their own and do not necessarily require medical attention.

Source: OnDeadLine

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