West Nile Virus podcast transcript - July 31, 2007
Doug Schultz, MDH Communications
Dave Neitzel, MDH epidemiologist
Doug: Welcome to this Minnesota Department of Health podcast on current public health issues. Mid-July thru September is the peak time of year for West Nile Virus in Minnesota, when the risk of getting the virus from the bite of an infected mosquito is highest, say state health officials. While West Nile Virus has been found in all Minnesota counties, since it was first detected here in 2002, there are regions of the state where the risk of West Nile infection is greater. Those regions are the open agriculture areas of western and central Minnesota, where the primary carrier of West Nile Virus in Minnesota, the Culex tarsalis mosquito thrives. This year unusually warm weather in June led to an early spike in the numbers of these mosquitoes in western and southwestern Minnesota, fueling concerns that a greater potential for disease could exist in those areas. As of July 24th, three human cases of West Nile Virus had already been reported. Here to talk with us about West Nile Virus is Dave Neitzel, an MDH epidemiologist, specializing in diseases carried by mosquitoes and ticks. Thanks for being here Dave.
Dave: Thanks for having me.
Doug: So what exactly is the concern in western and central Minnesota?
Dave: This year we’re seeing much higher numbers of the type of mosquito that can transmit West Nile Virus and we’re seeing very high numbers in western Minnesota.
Doug: Haven’t we known before that western Minnesota was a higher risk area for West Nile?
Dave: Western and central Minnesota is our traditional high risk area. The vast majority of cases of West Nile that have been reported in Minnesota have come from these areas, but we’re seeing much higher mosquito numbers, much earlier in the year, which could lead to higher disease risk in from July thru September.
Doug: Okay, does this mean that residents in the metro area should not be concerned about West Nile Virus?
Dave: Well clearly the risk of West Nile Virus infections is much lower in the metropolitan area. However, metro area residents still need to be aware of West Nile Virus and take some simple precautions against the virus.
Doug: Okay, so the Metropolitan Mosquito Control District doesn’t really eliminate the risk of West Nile Virus?
Dave: The Metropolitan Mosquito Control District helps. They do a lot of mosquito monitoring and mosquito control work, but it can be kind of hard to find this particular type of mosquito that transmits West Nile, so they’re not going to eliminate all the risk.
Doug: Okay. What is the best way then for people to eliminate that risk or to prevent getting West Nile Virus?
Dave: The first thing is really important is knowledge, knowing when and where you’re at risk, knowing that dusk and dawn is the primary time that this mosquito feeds on people and that the risk is much higher out in the agricultural parts of Minnesota, more open agricultural landscapes of western and central Minnesota. And the easiest way to protect yourself is to use mosquito repellant. Minnesotan’s are used to using the mosquito repellant when the mosquitoes get bad, but just keep that can of mosquito repellant handy. Repellants that contain DEET up to a 30% solution is what we recommend and for people that don’t feel comfortable using DEET, we recommend repellants containing either picaridin or lemon oil of eucalyptus.
Doug: Okay, so there are some options out there.
Doug: Well let’s say I use a mosquito repellant and I wear long sleeves and so forth, but despite those efforts you know I become infected with West Nile Virus. What could happen then? What should I be looking for?
Dave: Well the good new is that about 80% of people that are bitten by West Nile infected mosquito are able to fight off the virus without any symptoms whatsoever, you fight off the virus and you’re fine. Almost everybody else gets what we call West Nile Fever, a real bad headache, fever, rash, other symptoms like that and only about 1 out of every 150 people that are bitten by a West Nile infected mosquito develop a real severe illness, West Nile, encephalitis or meningitis and unfortunately about 10% of those people end up being fatal cases.
Doug: Okay. Are there some people who are more likely to become seriously ill from West Nile Virus than others?
Dave: Yes, when we talk about West Nile Virus infections in people, people of any age can be infected and show illness, but the severe illness is much more common in elderly people, aging and elderly folks and you know this is a disease should be thinking about the elderly, as opposed to other types of encephalitis, where children are at more risk.
Doug: Are there certain types of activities that puts some people more at risk than others?
Dave: Well certainly you know since we’re talking about a disease that’s more common out in agricultural country, you know farmers that are out working in their fields or working around their buildings at dusk or dawn are certainly at risk, but other than that Minnesotans that are out enjoying the little bit cooler weather that we have in the evenings, any activities that put you outside at dusk or dawn will put you at risk for West Nile.
Doug: Okay. If someone thinks they have West Nile Virus what should they do? How do you know when it’s time to see the doctor, rather than just take pain relievers?
Dave: Well certainly you know some of the initial symptoms, the headache and the fever you can get a headache and a fever from several different diseases or conditions, but if it’s a real severe headache and a real bad fever and certainly if you start showing signs of disorientation, it’s time to see the doctor.
Doug: Okay. Is there a treatment for West Nile Virus?
Dave: There’s no treatment for the virus itself, but doctors can offer supportive care, you know the medication that will reduce the severity of the symptoms.
Doug: Okay, if anyone wants more information about West Nile Virus, where can they get it?
Dave: Well we try and keep the Minnesota Department of Health website updated with West Nile information. That’s at www.health.state.mn.us, also the National Centers for Disease Control website www.cdc.gov and the Minnesota Department of Health also has a phone line that if people have questions, they can give us a call at 1-877-676-5414 and that’s a toll free number.
Doug: Great, thanks very much Dave, appreciate it.Dave: Thank you.