Control district and health department urges precautions
By Suzanne Schmidt
Recent mosquito related deaths in northern Hillsborough County and Brandon have health officials encouraging residents to take extra precautions.
The Pasco County Mosquito Control District, The Hillsborough County Mosquito Control District and the Pasco County Health Department are releasing information about what people can do to protect themselves and the area around their homes.
Deanna Krautner, public information officer for Pasco County Health Department, said she encourages people to avoid mosquito bites.
“Our concern is we want people to take precautions,” Krautner said. “We want people to follow the five Ds.”
Dennis Moore, director of the Pasco County Mosquito Control District, said even though both deaths were in Hillsborough County, it is still a problem for Pasco residents. Due to privacy laws the names of the people who died of equine encephalitis (EEE) in northern Hillsborough County and the infant who died in Valrico will not be released.
“The truth is mosquitoes are able to transmit the diseases and the disease is out there,” Moore said. “The reality is that the whole region should take precautions.”
In the last month, two horses have died of equine encephalitis in Dade City.
“The increased activity has caused some additional concern as far as how mosquitoes spread disease across the state,” Moore said. “We use sentinel chickens to test for the presence of EEE and the west Nile virus. With the horse case, we have 16 confirmed horse cases due to mosquito bites this year with seven since June 23. That causes some concern.”
Viruses circulate among bird species and once a mosquito bites a bird it contracts the disease. The mosquito will then lay eggs and go out looking for its next victim. The next person or animal the mosquito bites will then contract the disease.
Typically the time of greatest activity for mosquitoes is during dusk.
“Most people encounter mosquitoes at that time,” Moore said. “If you are running or on a bicycle, there is too much air movement and they can not get a blood meal, but if you are just sitting there not being active then you are a perfect target. Mosquitoes are able to sense the CO2 (carbon dioxide) when you exhale and they also home in on body temperature.”
Females take blood meals to reproduce.
It is important to drain the standing water around a home due to the way mosquitoes reproduce. Once an egg is laid in water, it takes five to seven days for the mosquito to fully mature. During that time the developing mosquito must be immersed in water to survive.
“One mosquito can lay up to 100 to 150 eggs at a time,” Moore said. “If you have a dozen mosquitoes attach their eggs to the sides of a flower pot, you could have a couple thousand mosquitoes come from that single flower pot. Even something as simple as a Frisbee can work. As long as the item holds water for five to six days, it can be a breeding ground for mosquitoes.”
A female mosquito typically lives a few weeks. During that time she can lay at least two or three batches of eggs. Eggs can even lie dormant for up to six months waiting for a large rainfall.
Even though the disease is present, Moore said there is an upside in the fact that there is not much mosquito activity.
“The mosquito population is not high enough that we will be aggressively spraying,” Moore said. “The mosquito population rises with heavy rainfall events, but we haven’t had many of those so far. We are doing our best to keep the numbers down. If we see a large number of mosquitoes we will step up our spraying.”
The spraying by the mosquito control district might seem erratic, but Moore said there is logic behind it all.
“We trap mosquitoes in 42 different locations every single night,” Moore said. “We have to identify the mosquitoes that are collected. We look at the numbers and we listen to what we have been hearing from the public and our investigators. We do the treatments based on those collections.”
Spraying is more complicated than most people realize.
Many people have probably noticed the trucks driving through neighborhoods spraying, but what most people probably do not realize are the trucks alternate spraying malathion and permethrin in order to prevent the mosquitoes from building up a tolerance.
“We are only putting out small amounts,” Moore said. “The trucks create an aerosol spray so that the material drifts for about 300 to 400 feet. With how the streets in neighborhoods are set up, the coverage is pretty good. The material is very low in volume. We spray in the safest environmental way we can.”
The district will also attack mosquitoes in other ways by dropping materials that will kill mosquito larvae. They also use helicopters and roadside ditch trucks to spray standing water where the trucks cannot drive.
“BTI is a very safe product that infects the stomach lining of mosquitoes when they eat it,” Moore said. “It is a naturally occurring bacteria and it only affects mosquitoes and other types of biting flies. So we are doing an integrated approach to catch the mosquitoes at different life stages. Ideally we will one day be able to just treat the larvae.”
The Hillsborough County Mosquito District is also taking the necessary precautions with 25 staff members taking a fleet of trucks, helicopters, a plane, airboats and ATV’s completing integrated pest management. The unit operates 15 sentinel chicken sites with 90 chickens and 74 mosquito surveillance traps throughout the county.
Since the beginning of the year, the staff has sprayed more than 32,000 acres with its trucks, more than 15,000 acres with its helicopters and almost 70,000 with its fixed-wing airplane.
For more information about Hillsborough County, visit www.hillsboroughcounty.org.
For more information about Pasco County, visit www.pascomosquito.org.
The five D’s are:
–Avoid being outside at dusk and dawn when the mosquitoes are biting.
–Dress and wear clothing that covers most of the skin.
–Use repellants containing DEET, picaridin, oil of lemon eucalyptus or permethrin.
–Check around the home to make sure there is proper drainage and no standing water.
