WASHINGTON, D.C. — While the number of reported cases of West Nile virus (WNV) continues to be down nationally, and with few cases reported in this region so far this year, health officials warn the disease likely will be on the rise in coming years in large part because of significant federal funding cuts.

Through July 19, a total of 25 cases of mosquitoes or dead birds found to be carrying the disease had been identified in Illinois and 14 reported in Ohio, for example, but no cases of human or horse infections have been reported this year, state health officials said.

The disease, first discovered in the United States in 1999, reached a record in 2003 with nearly 10,000 reported cases and 264 people who died, but the number of cases steadily decreased with increased mosquito prevention measures and public awareness. Last year there were a reported 5,674 cases and 286 deaths, according to the Centers for Disease Control and Prevention (CDC).

It is transmitted primarily by mosquitoes, which pick up the disease from infected birds. There is now a vaccine for horses, but not for humans – and no known cure.

“The mosquito bites a diseased house sparrow or other bird and then bites a human, infecting them with the virus,” said University of Illinois extension entomologist Phil Nixon.

“Most people might not even know they have the virus, may have an immunity built up to it or may experience mild flu-like symptoms, but for infants and seniors, a bite from an infected mosquito can cause serious disease, including muscle weakness, inflammation of the brain (encephalitis), stiff neck, stupor, disorientation, tremors, convulsions, paralysis, coma or death.”

According to the CDC, about four in five people bitten by an infected mosquito won’t exhibit any symptoms, either because they are immune or have a strong enough immune system to eventually fight it off.

Symptoms usually show within 4-15 days and can include fever, headache, body aches, nausea or skin rashes; they can last several weeks to several months. One in about 150 people will require hospitalization, and if symptoms include high fever, severe muscle weakness and neck soreness, people are advised to see their doctor immediately.

Prevention measures remain the best recipe against contracting WNV, Nixon said, not only using mosquito repellant, but also keeping areas with standing water dry, particularly gutters. Also, regularly replace birdbaths and pet drinking dishes with fresh water.

Nixon noted using outdoor fans around decks and backyards helps. “Mosquitoes are not very good at flying, so they need air to be still in order to land and bite. Keep the air circulating with a fan blowing over the area where your guests are outside,” he said.

One of two studies published last week in the Journal of the American Medical Association suggested the number of WNV cases likely will increase during the next five years in light of federal funding cuts, as well as longer, hotter summers.

Stephen Ostroff, a former CDC director, noted the CDC’s Epidemiology and Laboratory Capacity program – which distributes money to states and large cities for use against mosquito-borne diseases – saw its funding drop from nearly $35 million in the early 2000s to less than $10 million this year.

In Ohio, for instance, the CDC had been helping to pay for statewide WNV testing with a $265,000 grant for several years. But the grant was reduced to $87,500 this year, so the state’s mosquito surveillance program was scaled back, said Tessie Pollack, spokeswoman for the Ohio Department of Health.

Ostroff attributed the funding cuts in part to a growing apathy toward WNV, in that most people believe it is declining. “It seemed like the problem had gone away, and it was an easy place to cut,” he said.