Mosquito season brings threat of West Nile
After 17 years of warnings about the West Nile virus, no one will be surprised to learn that Louisiana and Mississippi are among the states with the highest rate of human infection with the mosquito-borne disease.
But you might be surprised to learn that the other leading states are not associated with either the West Nile virus or ravenous mosquitoes. They include Colorado, the Dakotas, Nebraska and Wyoming.
No matter where you live, spring means that it’s time to eliminate sources of standing water where mosquitoes breed and to think about using a mosquito repellent, especially in late afternoon and early evening.
Jessie Boudreaux of Cajun Mosquito Control has warned that the warm, wet winter may mean more mosquitoes this year.
“We are seeing increased mosquito proliferation in the municipalities of Franklin, Patterson, Baldwin, St. Mary Parish Mosquito Abatement District No. 1 and both upper and lower St. Mary Parish at this time,” Boudreaux said in a press release.
The virus is usually found in birds and is transmitted among them by mosquitoes carrying the virus, according to the Centers for Disease Prevention and Control. West Nile is monitored by trapping mosquitoes and testing for the virus in bird populations.
Eighty to 90 percent of humans who test positive for West Nile will develop no symptoms, the CDC said.
Some infected people will contract a condition called West Nile fever, marked by fever, headache, fatigue, a rash, swollen lymph glands and eye pain.
One in 150 infected people develop conditions the CDC classifies as neuroinvasive. These include West Nile meningitis, the symptoms for which include fever, a headache and a stiff neck.
The other neuroinvasive condition is West Nile encephalitis. The symptoms can include “changes in consciousness ranging from mild (sluggishness) to severe (mental confusion, convulsions, or coma),” as well as fever, tremors and even paralysis in the limbs.
Neuroinvasive West Nile can be fatal. The CDC has recorded more than 2,100 West Nile deaths across the country since 1999.
The disease became well-known in Louisiana during the 2002-03 outbreak, when the national rate of neuroinvasive disease incidence rose to 1 per 100,000 members of the population. The concern reached a peak here in 2003, coinciding with the search for the South Louisiana Serial Killer. Bumper stickers warned that Louisiana women were “wearing DEET and packing heat.”
DEET is an ingredient in some mosquito sprays and is recommended by health officials as a repellent.
Also according to the CDC:
—The rate of neuroinvasive incidence begins to rise in May and peaks in September.
—The rate of West Nile neuroinvasive disease incidence in Louisiana from 1999-2017 was 1.23 per 100,000 people. Colorado (1.35), Mississippi (1.33), Nebraska (1.91), North Dakota (2.8), South Dakota (3.4) and Wyoming (1.68) had higher rates.
—St. Mary’s rate from 1999-2017 is in the 0.01 to .49 rate range, a testament to the attention paid to mosquito control here.
—The rate of neuroinvasive disease incidence is roughly proportional to age. The lowest infection rate is in children 10 and younger. The highest rate is among those over 70.