NEW ORLEANS (AP) — Louisiana’s West Nile virus season is off to a late start, probably because the cool spring apparently kept mosquito populations down, says Louisiana’s state epidemiologist.
A seriously ill Caldwell Parish resident whose diagnosis was confirmed Monday is the first person known to be ill from the virus this year, state epidemiologist Raoult Ratard said Tuesday. The patient has the worst form the disease, affecting the nervous system.
By this time last year, 31 people had been diagnosed with such neuroinvasive West Nile virus.
“This year is probably going to be very light. Probably. We may have maybe 10 or 12 cases of neuroinvasive disease this year. We’ll see,” Ratard said.
Last year was the worst since the state’s more serious outbreak in 2002. Department of Health and Hospitals records show that 160 people had neuroinvasive West Nile in 2012, compared to 204 in 2002. There had been fewer than 100 cases a year from 2006 through 2011, when there were only six.
“The winter was mild and the spring was a little bit warmer” than usual last year, so there were more mosquitoes, Ratard said.
About 90 percent of all people bitten by mosquitoes that carry the virus never show any symptoms. About 10 percent develop flu-like West Nile fever, and fewer than 1 percent develop encephalitis or meningitis, the neuroinvasive forms.
Last year’s cases included 191 of West Nile fever. Another 46 people were diagnosed without any symptoms, 34 of them after giving blood.
The virus has been present statewide for years, so everyone should use mosquito protection, Ratard said.
That includes wearing long pants and long-sleeved shirts when outside for any length of time, using mosquito repellant on exposed skin and eliminating standing water around homes to keep mosquitoes from breeding there.
West Nile virus: http://dhh.louisiana.gov/index.cfm/page/539