Elizabeth Weise, USA TODAY
The number of reported deaths in this year's West Nile virus outbreak rose 19% this week to 219 nationwide, the Centers for Disease Control and Prevention says.
The overall number of cases was up 4% to 4,725.
A complete report of cases and deaths may not be available until "well into next year," says Marc Fischer, a medical epidemiologist who studies West Nile virus at CDC's Fort Collins, Colo., laboratory. "It takes a lot of time for them to trickle from the local doctor to the local hospital to the state health department to the CDC."
Almost 70% of the cases have been in eight states: Texas, California, Louisiana, Mississippi, Illinois, South Dakota, Michigan and Oklahoma. More than one-third were in Texas.
This year is the second worst on record for West Nile, the CDC says. It's still possible 2012 could top 2003, the nation's worst year since the virus was found here in 1999, in terms of deaths. In 2003, there were 9,862 cases with 264 deaths.
West Nile virus tests were first commercially available in 2003, "so some states, in particular in the West, tested a lot of patients, so there's a disproportion number" of reported cases that year, Fischer says.
This year the peak of the disease appears to have hit at the end of August, he says. Now that the weather is turning colder, mosquito activity is waning and the number of infections has almost stopped.
Most people infected with West Nile virus will not have any signs of illness, but 20% will experience mild symptoms such as fever, headache, body aches and, in some cases, a skin rash on the trunk of the body and swollen lymph glands.
People older than 50 and those with compromised immune systems are most at risk. About one in 150 people will get more severe symptoms: headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.