It looks like 2012 in the United States is shaping up to be the worst year for fatalities caused by the West Nile virus since it first appeared here in 1999, as you may have heard on hyperbolic TV reports the past week.
The virus, as of Aug. 22, has killed 47 people and infected people across 38 states.
But WebMD Health News reports that not all infected people develop West Nile disease, however. The U.S. Center for Disease Control (CDC) reports that 1,118 people in the U.S. have contracted the disease this year.
WebMD reported its grim news after a teleconference on Aug. 22 with Dr. Lyle R. Petersen, the CDC’s director of the vector-borne disease division.
"The number of West Nile disease cases in people has risen dramatically. We are in the midst of one of the largest West Nile outbreaks ever seen," Petersen, who also holds a master’s degree in Public Health Administration, told WebMD.
The adding to the bad news is that the U.S. is in the middle of its mosquito season, and nearly all West Nile infections come from mosquito bites. Petersen expects to see the number of cases rise through September.
Only three states haven’t detected the virus in mosquitoes, birds or people: Alaska, Vermont and Hawaii.
Fortunately, here have been no reported cases of West Nile disease in Nevada this year. But the Southern Nevada Health District (SNHD) reported its first West Nile-positive mosquitoes in the Las Vegas area on Tuesday, Aug. 28.
“With the identification of positive mosquitoes in one area of Clark County it is likely that West Nile virus-infected mosquitoes are present throughout the valley and precautions against the disease are recommended for all residents and visitors,” the SNHD said.
You may have heard that Texas has suffered the most with half the cases and half the fatalities. The Texas state health commissioner, David L. Lakey, calls the outbreak a “disaster.”
Since the West Nile virus spread nationwide in 2003, most of the seasonal outbreaks have been relatively mild. “Why is this year suddenly so bad?” WebMD asked Petersen.
"We really don't know," he answered. "Many major outbreaks in Europe and Africa and now in the U.S. have appeared during abnormally hot weather. Hot weather, in lab tests, does increase transmissibility of the virus from mosquitoes, and that may be one factor."
But, he added, there’s also concern the virus may have mutated into a more virulent form, although there isn’t any evidence of a super-strain virus quite yet.
As it is now, only about one in five people infected by the West Nile virus develop West Nile disease. But Petersen, who was himself infected in 2003, cautions because of West Nile disease’s flu-like symptoms, many cases likely go unreported. After being bitten by an infected mosquito, the victims develop the symptoms anywhere from three days to two weeks after the bite, but once they begin, they develop suddenly.
In his case, Petersen said, "I was out for a jog, and in one mile I went from perfectly normal to the point where I could barely walk. That is probably the norm."
He notes the disease is hardly ever mild or short term.
"Those who get more ill with West Nile fever will be laid up in bed for days or a week, followed by a period of just feeling awful,” Petersen explained. “And there can be a fatigue syndrome where people remain fatigued for weeks or months. It lasts longer than we used to think.” But the disease can develop into something worse
In about one in 150 people who develop the disease from the one in five who are infected, the West Nile virus can infect the brain, the spinal cord or connecting nerves, which can cause paralysis. That’s one in every 750 who become infected face the potential complications.
Petersen added that Baylor University researchers may have discovered another risk. For some patients, the West Nile virus doesn't always go away. The Baylor study, which has yet to be confirmed by other laboratories, suggests that the virus can hide in the kidneys and may cause kidney disease over time.
Most serious cases of West Nile disease occur in people over 50. According to the CDC so far in 2012, 61 percent of the cases have occurred in people over 50 and 39 percent in people of 60.
Infants don’t seem to be at high risk with only one case reported this year. WebMD says although there have been some reports that pregnant women have passed the virus on to their unborn children, it’s been very rare.
The West Nile virus also has the potential to be transmitted by blood transfusion. But blood testing has discovered only 242 infected samples in the U.S., and there are no reported cases of the disease due to transfusions.
Mosquitoes are the threat. Spraying to kill the adult mosquitoes does little to stop the spread. The larvae must also be destroyed.
Brackish water can be mosquito breeding grounds, a serious problem in Las Vegas where many homes with pools are in foreclosure. Pools pose a serious problem in Las Vegas besides mosquitoes: so far in 2012 there have been four drownings in pools, three of them in private pools. Three of the victims were under 4. There have been 31 near drownings, with 83 percent of the victims under 4. Pools may pose a greater threat to life than mosquitos.
The CDC advises that to protect yourselves from mosquitoes (which the SNHD says could be West Nile carriers) when going out of doors wear long pants and shirts with long sleeves, especially near dawn or dusk. And use mosquito repellant containing DEET.
But while protection from mosquitoes and the West Nile virus is advisable, is the 2012 West Nile disease season really a “disaster,” as the Texas health commissioner reports?
While 1,118 Americans have become sick with West Nile disease and 47 have died so far in 2012, 32,885 people died on the nation’s highways in 2011, according to the National Highway Traffic Safety Administration (NHTSA). The NHTSA does not report on the number of non-fatal injuries, the number hospitalized nor the number of people disabled in auto crashes.
And, according to the National Center of Health Statistics (NCHS), the leading killers of Americans continue to be the non-infectious and often preventable diseases like heart disease, strokes and lung diseases. Smoking cigarettes or eating a high-fat, low-fiber diet puts you in far more jeopardy than a squadron of mosquitoes.
Each year the NCHS publishes its list of the 15 top killers in the nation. But, for the first time since 1965, homicides aren’t in the top 15.
Heart disease has the honor of topping the latest list, for the year 2010, followed by cancer.
Heart disease killed 595,444 of us with cancer accounting for 573,855 deaths.
Lung disease, such as chronic bronchitis, emphysema and asthma were ranked a distant third with 137,789 deaths. Strokes were the fourth top killer, at 129,180.
Highway fatalities are included in the all accidental deaths category with a total of 118,043.
Alzheimer’s disease was ranked sixth with its 83,308 deaths, followed by diabetes at 68,905 deaths. Kidney disease killed 50,472 while 50,003 Americans perished because of pneumonia or the flu.
Suicides accounted for 37,793 deaths with blood poisoning in 11th place with 34,843 killed.
Chronic liver disease took 31,802 lives with hypertension claiming 26,577.
Parkinson’s disease was ranked as the 14th top killer with 21,963 lives lost.
“The 15th leading killer is pneumonitis due to solids and liquids, an illness more likely to strike the elderly,” the NCHS reported. “This is inflammation of the lungs due to inhaling substance inside the lung such as dust, mold or inhalants.”
All other causes of death in 2010, the last year reported by the NCHS, totaled 488,954.
That year 2,465,932 Americans died of all causes.
So, by all means, protect yourself and your loved ones from West Nile infection.
But do avoid the fear some news and government reports seem determined to generate. The disease causes about 0.000019 percent of the nation’s deaths.