St. Charles Herald-Guide

West Nile cases on the rise

By Jonathan Menard - August 24, 2012

The number of West Nile virus cases has spiked across the country this year and 26 people in Texas have died of the disease. In St. Charles Parish, seven chicken and mosquito samples have tested positive for West Nile compared with two positives in 2011.

The positive samples in St. Charles have come from Luling, Hahnville, Destrehan and Ama, according to Steve Pavlovich, an entomologist with Mosquito Control.

Pavlovich said that the mosquitoes transmitting West Nile are called southern house mosquitoes and they prefer to live in some nasty areas.

"These particular mosquitoes are not ones that are going to be associated with being in the marsh or woods. They are associated with septic areas such as broken pipes, ditches and broken containers," he said. "We encourage people to help us help them by removing containers from outside their homes and other places that are breeding mosquitoes."

The only good thing about southern house mosquitoes is that they are not very aggressive.

"The ones that come after rain in the marsh or woods are very aggressive, but these are docile in comparison," he said.

Though there have been more positive samples in St. Charles this year when compared to last year, Pavlovich said the West Nile virus tends to be cyclical.

"We had more positive samples in 2002, 2003 and 2004 and this year seems to be mirroring those years," he said. "We have years with a lot of activity followed by several years with less activity. (The virus) is not necessarily going to be on the rise because of climate change or warming or anything like that."

The national increase in reported West Nile cases seems to have been brought on by the mild, wet winter.

"That probably changed something in the behavior of the birds that brought the virus. They brought it sooner and they were able to perpetuate the disease," he said. "One hypothesis is that when they came to this area they were able to better transfer the disease."

Pavlovich said that Mosquito Control has increased spraying across the parish and has even been spraying during the weekends.

Though no one in St. Charles has contracted West Nile, nationwide there have been at least 693 cases and 28 deaths, according to the CDC and state numbers released last week.

Thirty-two states have had cases of West Nile, the CDC says.

Louisiana has had six deaths in 68 cases, Oklahoma one death in 55 cases, and Mississippi one death in 59 cases. In Arizona, there has been one death in seven cases.

California had 23 cases, one of which was fatal, and South Dakota had one fatality in 37 cases.

About 80 percent of the people who are infected with the West Nile virus never know it because they donít display any symptoms. Twenty percent to 30 percent develop West Nile fever, with headaches, fever, joint pains, vomiting or diarrhea.

Less than 1 percent of those infected with the virus develop West Nile neuroinvasive disease involving inflammation of the brain, spinal cord or the tissue surrounding the brain. About 10 percent of those will die. People over 50 and those with compromised immune systems are more likely to develop this form.