As of Tuesday, there have been 2,636 confirmed human cases, including 1,405 cases of neuroinvasive disease, the highest number for the second week of September since West Nile appeared in the U.S. in 1999.
There have been 118 deaths so far and it is tracking to eclipse the previous record of 284 deaths in 2002, said Dr. Larry Petersen, the director of the Division of Vector-Borne Infectious Diseases at the Centers for Disease Control and Prevention.
Officials believe “this year’s outbreak is the largest to date and certainly the most serious,” he said.
While those numbers are expected to increase through October, the peak of the outbreak likely has already happened, he said.
“We believe in most areas of the country the epidemic probably peaked around the end of August,” Peteresen said. Officials are still trying to understand why a larger outbreak occurred this year but one theory is it has been “abnormally hot” in many areas of the country and that tends to create greater transmission of the virus, he said.
“The longer the weather stays warm, the more transmission is going to occur,” Petersen said. In the South, for instance, transmission can occur throughout the year, he said.
So far, neither Georgia nor South Carolina has been hard hit by West Nile. Georgia has had 29 human cases and three deaths; South Carolina has had eight cases, but the CDC has not been notified of a death of an elderly Aiken County man.
Complaint calls have decreased slightly to Richmond County Mosquito Control this week, from about 60 a day to 30-40 a day, operations manager Fred Koehle said. Mosquito Control, which had been a week behind, is now three or four days behind in responding to those complaints but is hopeful the cooler and drier weather will work in their favor, he said.
“We’re almost able to stay afloat at this point,” Koehle said.