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Know Before You Go: Tools to Prevent West Nile Virus · Healthier Together: Larimer County's Public Health Podcast

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  Welcome to Healthier Together, Larimer County's
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  public health podcast, where we come together
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  for healthier lives, connected communities, and
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  real conversations. From your local public health
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  team, I'm your host, Tom. And I'm Joanna. As
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  we make plans to enjoy the outdoors this summer,
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  a common risk we run into in Larimer County is
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  West Nile virus. This week, we're joined by Allison
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  Barbee, Communicable Disease Epidemiologist here
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  at the Health Department. Here to tell us a bit
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  more about West Nile virus and the steps we can
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  take to protect ourselves and our loved ones.
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  Allison, thank you so much for joining us. Yeah,
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  thank you so much for having me be here. Can
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  you tell us what West Nile virus is? West Nile
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  virus is a vector -borne disease that's commonly
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  spread by infected mosquitoes. It was originally
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  introduced to the U .S. in 1999 and Colorado
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  in 2002, before we had a really big outbreak.
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  Culex mosquitoes that are able to transmit West
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  Nile virus are found locally and in many other
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  parts of Colorado. These look like medium -sized
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  mosquitoes. They typically feed around dawn and
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  dusk, and some of them have like a zebra stripe
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  pattern on them. Do you know where West Nile
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  virus got its name, why we call it West Nile
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  virus? This is a fun fact. West Nile virus was
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  first isolated from a patient who was from the
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  West Nile district of Uganda in 1937. If you
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  do get West Nile virus, what are the symptoms?
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  Yeah, so for people who do develop symptoms,
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  it usually feels like a mild flu. So some of
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  those symptoms could be a fever, headaches, body
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  aches, tiredness, generalized weakness. I do
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  want to also add that one in 150 people who develop
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  symptoms from West Nile virus will get seriously
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  ill. So some of those symptoms can include a
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  stiff neck, altered mental status, seizures,
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  encephalitis, and polio -like paralysis, a sudden
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  onset of muscle weakness, and loss of reflexes.
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  Recovery from these severe illnesses can take
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  several weeks or even months. Additional information
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  for symptoms is they usually start about two
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  to six days after you've been bit by an infected
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  mosquito. But it can range from about 2 to 14
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  days after being bit. Majority of people who
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  experience symptoms will recover completely,
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  but may experience some fatigue, weakness, or
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  other symptoms that can last for weeks. Most
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  people who get West Nile virus won't even know
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  they have it. About 80 % of people show no symptoms
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  at all. What are those cases that do experience
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  more severe symptoms? Do they usually start with
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  those same sort of flu -like symptoms as other
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  cases? That's a great clarification. Yes. So
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  people who have that neuroinvasive illness can
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  also experience those fever, headaches, body
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  aches, and then they progress. And who is most
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  at risk for those more serious cases of West
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  Nile? People with health conditions such as cancer,
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  diabetes, high blood pressure, kidney disease.
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  or individuals who take medications that suppress
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  their immune system. You're at a higher risk
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  for serious illness if you're over the age of
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  55. One in 50 people in this age group will get
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  severely ill if they're infected with West Nile
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  virus. I also want to note that severe illness
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  can occur in people of any age. So what can people
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  do to protect themselves from West Nile virus?
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  The best way to avoid a West Nile virus infection
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  or disease is to prevent mosquito bites. If you
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  have planned outdoor activities during peak mosquito
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  biting times, which is between that like dawn
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  and dusk time, we really do recommend using EPA
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  registered insect repellent and or wearing loose
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  fitting clothes, long sleeve shirts and pants.
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  So what can homeowners do then to kind of protect
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  against mosquitoes? So homeowners can protect
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  themselves against mosquitoes by installing and
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  repairing screens on windows, doors. Even using
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  air conditioning rather than opening their doors
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  to give that lovely breeze, which I also really
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  love, especially in the spring. This time of
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  year, it's delightful in the morning. But we
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  recommend using those screens to help prevent
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  mosquitoes from getting indoors. We also recommend
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  that they empty standing water from containers
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  around their home at least once a week. This
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  includes anything from flower pots, gutters,
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  buckets, pool covers, those pet water dishes
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  you leave outside and you forget about. At the
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  community level, a number of municipalities in
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  Larimer County spray to help control mosquitoes.
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  Can you tell us a little bit more about that
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  process? Specifically, what is the protocol for
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  spraying and who decides when we spray? Larimer
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  County does not currently run its own mosquito
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  control program. However, many local municipalities
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  work with Vector Disease Control International,
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  also known as VDCI, to manage those mosquito
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  control. and they use that adulticide spraying
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  or other larvicide application to help minimize
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  mosquito population. What's actually being sprayed
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  when municipalities spray and what does it do?
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  They use EPA -registered adulticides, which are
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  used during those spray events or also known
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  as fogging events, to minimize those adult mosquito
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  populations. These products have been extensively
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  tested for human environmental safety before
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  they're used. Also, the method of applying this
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  adulticide is called ultra low volume spraying.
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  Now, this method is a common industrial mosquito
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  spray technique that is primarily done from the
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  back of a truck. The primary benefit of this
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  type of method of spraying is it requires very
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  little product and it treats a large area of
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  land. So to put it to scale, typically about
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  an ounce of adulticide is... is enough for one
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  acre of land. And is there a way that people
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  can know if there's going to be spraying in their
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  area? Fort Collins offers a text alert service
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  to notify residents about spraying. And to sign
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  up, you can either text or go online. To text,
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  you can simply text FCWNV to 888 -777 to receive
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  those text updates. Otherwise, this information
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  is also available on our website. So tell us,
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  what kind of work the health department does
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  that's related to West Nile virus? Our communicable
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  disease team monitors and responds to all reported
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  human cases of West Nile virus infection in Larimer
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  County. These cases are reported to public health
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  from physicians or laboratories when a patient
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  receives a positive blood test result. Once we
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  receive a new West Nile virus case, our team
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  will interview individuals to determine their
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  case classification through the individual's
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  clinical presentation, illness onset, and what
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  their illness outcome is. We also provide education
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  on the most effective way to prevent West Nile
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  virus infection and disease and help to refer
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  people for more treatment or care as necessary.
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  Our team also provides weekly public health recommendations
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  to the City of Fort Collins on areas that have
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  a higher risk of people becoming sick with West
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  Nile virus. when an area has a high number of
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  mosquito traps with mosquitoes that are infected
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  with West Nile virus. That kind of brings me
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  to my next question. I'm interested in the data
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  collection process. You mentioned mosquito traps.
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  Can you explain what those are? BBCI conducts
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  most of the mosquito surveillance program in
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  our community. They help with the data collection
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  side of it. And this includes everything from
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  mapping out potential mosquito breeding sites.
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  They also use these traps that you just asked
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  me about. for adult mosquito activity that they
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  start around June and end in September. So how
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  many of these traps are there then in Larimer
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  County? Larimer County has approximately 104
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  traps that are located within Fort Collins, Loveland,
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  and Berthoud. So what happens then when the mosquitoes
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  are collected? What is the process then to determine,
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  oh, there's West Nile in this area, it was captured
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  in this trap. How does that work? Sure. Once
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  mosquitoes are collected by BDCI, they're ID'd
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  for their species and their sex, and then they're
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  tested by CSU for West Nauvars and St. Louis
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  encephalitis. So how do you translate that data
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  into risks for specific areas? Right now, different
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  municipalities and groups use what we call the
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  vector index. The abbreviation is VI. This is
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  a measurement tool that has proven to be a useful
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  predictor of human risk of West Nile virus infection
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  and helps to guide public health recommendations
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  for mosquito management practices. So the VI
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  measures how many female Culex mosquitoes are
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  infected with West Nile virus in a given area,
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  so within those traps. Studies have shown that
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  when the VI is above 0 .5, the risk of human
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  infection increases. What does that testing process
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  look like? How do you test a mosquito to know
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  if it has West Nile? We partner with the Ebel
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  Lab at Colorado State University, and they also
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  partner with other local municipalities within
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  Larimer County to test the mosquitoes. They essentially
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  take the mosquitoes and then they process them
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  and analyze them in the lab through the use of
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  a test called the polymerase chain reaction,
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  also known as a PCR test. Like a COVID test uses
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  PCR. Yeah, that's a great comparison. This season,
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  you helped build a new dashboard where Larimer
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  County residents can see West Nile virus data.
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  Can you tell us about the dashboard and the data
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  that it shares? So this dashboard provides weekly
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  maps of the current and prior week of mosquito
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  trap data for all of Larimer County. These maps
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  are interactive and they highlight mosquito traps
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  that have positive Culex mosquitoes. during that
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  current and previous week of trapping. You'll
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  see on the map that there's a one -mile radius,
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  which is highlighted in red, from a mosquito
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  trap, which represents the immediate risk of
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  being bitten by a mosquito infected with West
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  Nile virus. We also have a search function in
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  these maps that you can use to identify if your
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  home or the place that you're going to recreate
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  may fall within this area of risk. We also have
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  information about human case data. cool. I'm
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  biased, but we have some pretty cool graphs that
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  show the 2025 -2026 seasons of West Nile virus
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  cases in comparison to the five -year average.
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  We also have a cumulative West Nile virus graph
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  that shows each of the past five years of human
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  cases of West Nile virus in Larimer County and
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  seeing if the trends Are they how close they
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  are together? What years were higher? What years
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  were lower? And it kind of just helps people
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  see what is this year looking like compared to
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  last year or the year before that. What did the
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  development process look like on the back end
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  for that dashboard? It began at the end of the
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  2025 season where our communicable disease team
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  was working. on better methods of mapping out
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  where positive mosquito traps were located in
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  Fort Collins and trying to provide evidence of
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  areas we would recommend a deltacide spraying.
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  I then created a time -lapse application through
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  our programming software that helped to visualize
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  the positive trap data throughout the 2025 season,
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  showing the immediate risk to West Nile virus
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  and the dispersal range of Culex mosquitoes and
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  how it kind of fluctuated week to week. It was
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  interesting to learn, but Culex mosquitoes typically
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  don't fly long distances. They have been recorded
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  to fly up to eight miles or even can disperse
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  up to 20 miles depending on environmental factors.
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  But after consultation with a number of professionals
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  within our community for West Nile virus, we
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  did kind of land on that one mile radius of immediate
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  risk in comparison to a mosquito trap here in
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  Larimer County. After creating this, These visualizations
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  led to further conversations with other West
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  Nile virus stakeholders and public health groups
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  that had a greater interest in seeing that week
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  -to -week data on the local positive pools and
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  help demonstrate that flight path range through
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  buffer zone visualization. Essentially, just
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  helping people see what's going on, what do they
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  need to do, and help understand the impacts to
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  people and how many people are getting sick.
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  What can they do as the viewer of the dashboard
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  can best protect themselves during a current
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  season? So it sounds like the dashboard offers
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  really hyper -local information so that you can
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  plan activities throughout Larimer County if
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  you need to shift from one area to another based
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  on risk level. Yeah, I think that's a good way
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  of putting it. The data is collected the week
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  prior, so we're kind of working on a one -week
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  delay, but... We're able to best understand,
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  especially if there is no spray events happening
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  in your community, to know that if there's positive
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  mosquitoes one week, there is a greater likelihood
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  that there might be positive mosquitoes that
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  current week that you're seeing. If people would
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  like to explore the dashboard or learn more about
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  West Nile virus, where can they go? There is
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  a link to the West Nile virus surveillance dashboard
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  on Larimer County's main West Nile virus page.
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  Awesome. Allison, thank you so much for joining
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  us. Thank you both so much. This was a pleasure.
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  Do you have a question about public health in
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  Larimer County or a topic you'd like us to discuss?
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  Let us know. Email us at healthiertogetheratlarimer
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  .org. Thanks for listening, Larimer County. Until
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  next week, stay well, stay connected, and remember,
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  we really are healthier together. Bye. Bye.