It may be too soon to say for certain, but there appears to be at least a temporary waning of the numbers of cases of West Nile Virus (WNV) in Mississippi with no deaths reported thus far this year.
WNV virus is contracted from mosquito bites, and causes only flu-like symptoms in most people who are infected. But for some people, especially the elderly or those with compromised immune systems, the illness can be severe leading to meningitis or encephalitis. Sometimes it is fatal.
“We’ve had 14 cases of WNV reported so far this year,” said State Epidemiologist Dr. Mary Currier. “Last year at this same time we had 20 cases. Although we don’t have as many reported cases as we did last year at this time, we need to continue to take precautions to get rid of mosquito breeding places and to prevent mosquito bites in ourselves and our loved ones.”
Mississippi, with high average rainfall amounts and warm weather that can make ideal habitat for mosquitoes, has traditionally been in the top 10 in incidences of WNW. Since WNV was first noted in Mississippi in 2002, the state has had case counts among the top 10 states in the US, except in 2003 when the state ranked 16th.
Mississippi saw 136 cases of WNV in 2007, 184 cases in 2006 and 70 cases in 2005.
The state has also had three cases of LaCrosse encephalitis (LAC) so far this year, one each in Adams, Hinds and Yazoo counties. LAC is transmitted through mosquitoes (Culeseta melinura, or the “treehole mosquito”). Currier said LAC is a virus that affects children more than adults, and can have some of the same symptoms as WNV such as headache and fever, and additionally can cause seizures.
Three horses in Jackson County have been diagnosed with eastern equine encephalitis, another virus transmitted by mosquitoes that can sometimes affect humans.
The areas of the state most impacted by WNV so far this year are Clarke, Forrest, Harrison, Hinds, Jones, Lawrence, Lincoln, Madison, Monroe, Neshoba and Pearl River counties. A map of the counties with WNV cases can be found at www.msdh.state.ms.us.
“Remember, people who live in areas with no reported cases should also take precautions, as absence of reported cases is not evidence does not mean the virus is not present in the area,” Currier said.
State medical entomologist Dr. Jerome Goddard said businesses that want to make sure their outdoor workers are protected should primarily be concerned about night workers.
“Most outdoor workers who work in the daytime should have nothing to worry about,” Goddard said. “The main carrier mosquito for West Nile predominantly flies at night from about 7 p.m. until 10 p.m.”
Goddard recommends businesses make sure they have tight-fitting doors and windows to keep mosquitoes outs
Contact MBJ contributing writer Becky Gillette at firstname.lastname@example.org.