“One of the best defenses against West Nile Virus and mosquitoes is to beef up prevention,” said Sandy Kachur, spokesperson for Harris County Public Health and Environmental Services. “There currently are no cases in the county, but our battle is in the beginning stages and surveillance operations are underway.”
She said recent heavy rains have resulted in a bumper crop of mosquitoes in the area and that increases the risk that one of the critters could be carrying the deadly virus.
What is West Nile virus?
West Nile virus is an arthropod-borne virus (arbovirus) most commonly spread by infected mosquitoes. The virus can cause febrile illness, encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord).
West Nile virus transmission has been documented in Europe and the Middle East, Africa, India, parts of Asia, and Australia. It was first detected in North America in 1999, and has since spread across the continental United States and Canada, according to the Centers for Disease Control.
Kachur said the Harris County Mosquito Control Division is responsible for monitoring the mosquito populations, does surveillance and checks across 1,800 square miles of the county.
During surveillance, the county collects samples of mosquitoes to get a snapshot of the virus and keeps traps in 268 locations above and below ground where mosquitoes are known to thrive in the county.
In 2013, Harris County reported 9 human cases of West Nile Virus and 147 of the traps tested did test positive.
A positive test increase the level of urgency and results in spraying of any area affected by the positive test.
“It was a lighter year, but the disease was still around,” she said. “We hope we can keep the numbers down this year too.”
How do people get infected with West Nile virus?
Most people get infected with West Nile virus by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread the virus to humans and other animals.
In a very small number of cases, West Nile virus has been spread through blood transfusions, organ transplants, and from mother to baby during pregnancy, delivery, or breastfeeding.
Kachur said Harris County has 56 different species of mosquitoes. Of those one in particular is a nuisance to human health- the CULEX Mosquito is the primary carrier of the virus in Harris County.
“These the mosquitoes that primarily come out at dusk and dawn to feed on us,” she said. “They are pesky and determined and during the night time hours, these biters who can make your life miserable.”
What are the symptoms of West Nile virus disease?
No symptoms in most people. Most people (70-80%) who become infected with West Nile virus do not develop any symptoms.
Febrile illness in some people. About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.
Severe symptoms in a few people. Less than 1% of people who are infected will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). The symptoms of neurologic illness can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis.
Recovery from severe disease may take several weeks or months. Some of the neurologic effects may be permanent. About 10 percent of people who develop neurologic infection due to West Nile virus will die.
How can people reduce the chance of getting infected?
Kachur said one of the most effective way to avoid West Nile virus disease is to prevent mosquito bites:
Use insect repellents when you go outdoors. Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide longer-lasting protection.
Wear long sleeves and pants from dusk through dawn when many mosquitoes are most active.
Install or repair screens on windows and doors. If you have it, use your air conditioning.
Help reduce the number of mosquitoes around your home. Empty standing water from containers such as flowerpots, gutters, buckets, pool covers, pet water dishes, discarded tires, and birdbaths.
Another is for Neighborhoods to launch an early strike attack on the critters by ensuring all water bowls and eliminating stagnant water locations making sure the areas are dumped and remain dry.
“It does not take much for them to breed,” she said. “They will even breed in standing water inside your home so be aware and do not help their cause.”
Increased vigilance will help eliminate potential breeding sites, since mosquitoes can grow from egg to adult in as little as seven days. Breeding sites for mosquitoes include stagnant swimming pools, stagnant ponds, pet water dish, birdbaths, potted plants, tires, empty containers, toys and clogged gutters and drains, she said.
She also noted that problem areas that harbor mosquitoes and can help spread nurture more are storm drains and gutters.
“Don’t feed the problem by feeding storm drains with grass clippings and clean gutters completely,” she said. “They can will and do breed there.”
Communities can also help cut down on chances for a West Nile Virus infestation by eliminating high weeds, high grass and other standing waters in neighborhoods.
Kachur said rising temperatures will bring on more mosquitoes, but hopes the public will step up and do their part to help hold down mosquitoes breeding and the increased chances that someone will contract the disease.
She added that any citizens in neighborhoods across the county that experience issues with mosquitoes should contact the mosquito control division and ask for a division officer to come investigate the problem.