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WEST NILE VIRUS   What is West Nile Virus?     West Nile Virus is a mosquito-born virus that can cause encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord) in humans and horses. Mosquitoes that acquire it from infected birds transmit the virus. This virus was first discovered in the United States in New York in 1999 and has quickly spread throughout the U.S. Surveillance has confirmed the presense of West Nile virus in 44 states of the U.S. in 2002. Previously, West Nile Virus had only been seen in Africa, Asia and southern Europe.  Nebraska Cooperative Extension: West Nile Virus Guidlines for Horse Owners   How could a horse get West Nile Virus?     Horses become infected with West Nile virus after being bitten by an infected mosquito. The mosquito acquires the virus by feeding on an infected bird and then the mosquito transmits the virus when it feeds on a horse, human or other mammal. Horses and humans are considered "dead end hosts," meaning they cannot transmit the West Nile virus to other horses, birds or people.      For the year 2002, there was 15,257 horse cases in 40 states For the year 2003, 5,181 horse cases. For the year 2004, 1,406 reported horse cases For the year 2005, 1,075 reported horse cases. For the year 2006, 1,086 reported horse cases. USDA: Current Status of West Nile Virus   What are the signs and symptoms of West Nile encephalitis in horses?     In horses that do become clinically ill, the virus infects the central nervous systems and causes symptoms of encephalitis. Clinical signs can include: loss of appetite, depression, fever, weakness of hind limbs, paralysis of hind limbs, impaired vision, ataxia, head pressing, aimless wandering, convulsions, inability to swallow, circling, hyperexcitability or coma. Many of these symptoms are similar to horses with rabies, Equine Protozoal Meylities (EPM) equine encephalitis and other serious neurological diseases. If symptoms are present, a veterinarian should be contacted immediately.    Is there a vaccine for West Nile virus?     In 2001, a vaccine was conditionally approved for horses, which must be administered by a veterinarian. The initial vaccine is a two-injection series given three weeks apart. Both injections must be given to provide protection from West Nile virus. Foals may be vaccinated at 12 weeks of age and require a second dose three weeks later. If foals are vaccinated prior to 12 weeks of age, a three-dose series is recommended. Other equine "encephalitic" diseases (sleeping sickness, eastern equine encephalitis, western equine encephalitis, and Venezuelan equine encephalitis) belong to another family of viruses for which there is not cross-protection. Therefore, horses should be vaccinated specifically for West Nile virus. There is no vaccine for humans.    Is there a treatment for West Nile encephalitis in horses?     There is no specific treatment for West Nile virus other than supportive veterinary care standard for animals infected with a viral agent. Data suggest that most horses do recover from the infection.    Are humans at risk for getting West Nile encephalitis?     All residents of areas where virus activity has been identified are at risk of getting West Nile encephalitis; persons older than 50 years have the highest risk of severe disease.      For the year 2005, there have been 2,949 human cases and 116 human deaths in 48 states and the District of Columbia as of December 31st. Centers for Disease Control West Nile Virus Home Page   What are the symptoms of West Nile encephalitis in humans?     A bite from an infected mosquito will not always make a person sick, in fact, most people with West Nile Virus either have no symptoms or experience mild illness. Most infections are mild, and symptoms include fever, headache and body aches, occasionally with skin rash and swollen lymph glands. More severe infection may be marked by headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, paralysis and rarely death.    What is the incubation period in humans (i.e, time from infection to onset of disease symptoms) for West Nile encephalitis?     Usually 3 to 15 days.    Do birds infected with West Nile virus die or become ill?     In the 1999 New York area epidemic, there was a large die-off of American crows. Through October 2002, West Nile virus has been identified in at least 110 species of birds found dead in the United States. Most of these birds were identified through reporting of dead birds by the public.    How can I report a sighting of dead bird(s) in my area?     In Washington County, please contact the Mosquito Abatement District at (435) 652-5842.    What kind of information is needed along with the dead bird?     All birds can potentially carry West Nile Virus, but ravens, crows, magpies, jays and birds of prey (i.e., hawks, falcons, eagles, and owls) tend to be more likely than other birds to die when they become infected with the virus. If you find one of these birds and it is dead or appears to be very ill - it may be unable to fly or appear to be wobbling or staggering - please call and report this to your local health department, your local mosquito abatement district, or the Office of Epidemiology. Some of these birds may be collected for testing. Please have as much of the following information ready as possible when you call:      What kind of bird is it? If you are not sure what kind of bird it is, please be ready to describe its size (length from beak to tail), coloring, and anything else you notice about the bird. Where and when did you see this bird? Was the bird dead when you first saw it? If not, did you see the bird behaving strangely in any way before it died? If the bird was dead when you first saw it, please look at it to see how fresh it is. Dead birds that are rotten cannot be tested but you are still encouraged to report these deaths. How can we get in touch with you if we need additional information?     Source:  Utah Department of Health WNV Prevention Information   What other things should I consider when watching for dead birds?     If you notice large numbers of dead birds suddenly appearing in a small area (e.g., more than three dead birds in your backyard overnight), these birds may have been poisoned. Please contact your local Wildlife Resources office to report this. If you have a bird feeder, please read the following paragraphs for instructions on how to clean your feeder. Also, if birds are dying near your feeder, the feeder may need to be cleaned.   Source: Utah Department of Health WNV Prevention Information     For routine cleaning: Clean feeders once a week using a bleach solution - use one part bleach to nine parts water. Rinse feeder thoroughly with water after cleaning and allow it to dry completely before refilling it with fresh seed. Remove waste grains from below feeders. If you have had birds die near your feeder: Use a stronger bleach solution to clean your feeder - one part bleach to three parts water. Rinse feeder thoroughly with water after cleaning and allow it to dry completely before refilling it with fresh seed. Also, remove waste grains from below feeders and empty water for 7-10 days after an incident where birds have died near your feeder.     How do I safely handle and dispose of dead birds?     For every dead bird: Avoid direct contact with the dead bird. Use rubber gloves or put a double plastic bag over your hand. (Grocery bags will do if they are in good shape.) Invert the bags over your hand, grab the bird, wrap it up and tie off or seal the bags. If you are using gloves, place the dead bird into a double plastic bag, wrap it up and tie off or seal the bags. For birds that are to be discarded: Throw the double bagged and dead bird into an OUTSIDE garbage container and wash your hands thoroughly with soap and water. If you are asked to collect the bird so it can be picked up later: Place the double-bagged dead bird in either a refrigerator or freezer that is not used for food, or in an ice cooler with a generous amount of ice or ice packs. Place the bird in a Ziploc-type bag if available (to prevent leakage). If the bird is double-bagged in a sealed and intact Ziploc-type bag, it could probably be safely stored in a refrigerator or freezer used for food (as long as it is clearly labeled!). Once the bird is stored properly, wash hands with soap and water. If you do not want to touch the bird (and someone has told you it is going to be collected): Pour a generous quantity of ice on the bird and cover it with an ice cooler, garbage can, or other container.   Utah Department of Health Disposal of Dead Birds   How can I prevent mosquitoes from affecting my horses?     There are some easy steps you can take to prevent mosquitoes from affecting your horses: House horses indoors during peak periods of mosquito activity (dusk and dawn). Avoid turning on lights inside the stable during the evening and overnight. Place incandescent bulbs around the perimeter of the stable to attract mosquitoes away from the horses. Remove all birds, including chickens, that are in or close to the stable. Eliminate areas of standing water on your property. Topical preparations containing mosquito repellants are available for horses. Read the product label before using and follow all instructions. Fogging of stable premises can be done in the evening to reduce mosquitoes; read directions carefully before using.    How can I reduce the number of mosquitoes around my home?     Reduce the amount of standing water available for mosquito breeding. Dispose of tin cans, plastic containers, ceramic pots or similar water-holding containers on your property. Remove all discarded tires. Drill holes in the bottom of recycling containers left outdoors. Clean clogged roof gutters. Turn over plastic wading pools when not in use. Turn over wheelbarrows and don't let water stagnate in birdbaths. Aerate ornamental pools or stock them with fish. Clean and chlorinate swimming pools when not in use. Use landscaping to eliminate standing water that collects on your property.    What is Utah doing to prevent a West Nile virus outbreak?     The Utah Public Health Laboratory is capable of testing birds and mosquitoes for the presence of the virus. If the virus is located within the state a warning will be made to allow people to take measures to protect themselves and their horses.      Utah had many positives in 2007.  USGS: West Nile Virus Maps - 2007       GENERAL   Why do mosquitoes bite?     Mosquitoes belong to a group of insects that requires blood to develop fertile eggs. Males do not lay eggs, thus, male mosquitoes do not bite. The females are the egg producers and "host-seek" for a blood meal. Female mosquitoes lay multiple batches of eggs and require a blood meal for every batch they lay. Few people realize that mosquitoes rely on sugar as their main source of energy. Both male and female mosquitoes feed on plant nectar, fruit juices and liquids that ooze from plants. The sugar is burned as fuel for flight and is replenished on a daily basis. Blood is reserved for egg production and is imbibed less frequently.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   Why do mosquitoes leave welts when they bite?     When a female mosquito pierces the skin with her mouthparts, she injects a small amount of saliva into the wound before drawing blood. The saliva makes penetration easier and prevents the blood from clotting in the narrow channel of her food canal. The welts that appear after the mosquito leaves is not a reaction to the wound but an allergic reaction to the saliva injected to prevent clotting. In most cases, the itching sensation and swellings subside within several hours. Some people are highly sensitive and symptoms persist for several days. Scratching the bites can result in infection if bacteria from the fingernails are introduced to the wounds.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   Why are some people more attractive to mosquitoes then others?     Scientists are still investigating the complexities involved with mosquito host acceptance and rejection. Some people are highly attractive to mosquitoes and others are rarely bothered. Mosquitoes have specific requirements to satisfy and process many different factors before they feed. Many of the mosquito's physiological demands are poorly understood and many of the processes they use to evaluate potential blood meal hosts remain a mystery. Female mosquitoes use the CO2 we exhale as their primary cue to our location. A host seeking mosquito is guided to our skin by following the slip stream of CO2 that exudes from our breath. Once they have landed, they rely on a number of short range attractants to determine if we are an acceptable blood meal host. Folic acid is one chemical that appears to be particularly important. Fragrances from hair sprays, perfumes, deodorants and soap can cover these chemical cues. They can also function to either enhance or repel the host seeking drive. Dark colors capture heat and make most people more attractive to mosquitoes. Light colors refract heat and are generally less attractive. Detergents, fabric softeners, perfumes and body odor can counteract the effects of color. In most cases, only the mosquito knows why one person is more attractive than another.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   How long do mosquitoes live?     Mosquitoes are relatively fragile insects with an adult life span that lasts about 2 weeks. The vast majority meet a violent end by serving as food for birds, dragonflies and spiders or are killed by the effects of wind, rain or drought. The mosquito species that only have a single generation each year are longer lived and may persist in small numbers for as long as 2-3 months if environmental conditions are favorable. Mosquitoes that hibernate in the adult stage live for 6-8 months but spend most of that time in a state of torpor. Some of the mosquito species found in arctic regions enter hibernation twice and take more than a year to complete their life cycle.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   Where do mosquitoes go in the winter?     Mosquitoes, like all insects, are cold blooded creatures. As a result, they are incapable of regulating body heat and their temperature is essentially the same as their surroundings. Mosquitoes function best at 80o F, become lethargic at 60o F and cannot function below 50o F. In tropical areas, mosquitoes are active year round. In temperate climates, adult mosquitoes become inactive with the onset of cool weather and enter hibernation to live through the winter. Some kinds of mosquitoes have winter hardy eggs and hibernate as embryos in eggs laid by the last generation of females in late summer. The eggs are usually submerged under ice and hatch in spring when water temperatures rise. Other kinds of mosquitoes overwinter as adult females that mate in the fall, enter hibernation in animal burrows, hollow logs or basements and pass the winter in a state of torpor. In spring, the females emerge from hibernation, blood feed and lay the eggs that produce the next generation of adults. A limited number of mosquitoes overwinter in the larval stage, often buried in the mud of freshwater swamps. When temperatures rise in spring, these mosquitoes begin feeding, complete their immature growth and eventually emerge as adults to continue their kind.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   Can mosquitoes carry diseases?     Any insect that feeds on blood has the potential of transmitting disease organisms from human to human. Mosquitoes are highly developed blood-sucking insects and are the most formidable transmitters of disease in the animal kingdom. Mosquito-borne diseases are caused by human parasites that have a stage in their life cycle that enters the blood stream. The female mosquito picks up the blood stage of the parasite when she imbibes blood to develop her eggs. The parasites generally use the mosquito to complete a portion of their own life cycle and either multiply, change in form inside the mosquito or do both. After the mosquito lays her eggs, she seeks a second blood meal and transmits the fully developed parasites to the next unwitting host. Malaria is a parasitic protozoan that infects the blood cells of humans and is transmitted from one human to the next by Anopheles mosquitoes. Encephalitis is a virus of the central nervous system that is passed from infected birds to humans by mosquitoes that accept birds as blood meal hosts in addition to humans. Yellow fever is a virus infection of monkeys that can either be transmitted from monkey to human or from human to human in tropical areas of the world. Dog heartworm is a large filarial worm that lives in the heart of dogs but produces a blood stage small enough to develop in a mosquito. The dog heartworm parasite does not develop properly in humans and is not regarded as a human health problem. A closely related parasite, however, produces human elephantiasis in some tropical areas of the world, a debilitating mosquito-borne affliction that results in grossly swollen arms legs and genitals.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   Can mosquitoes transmit AIDS?     The HIV virus that produces AIDS in humans does not develop in mosquitoes. If HIV infected blood is taken up by a mosquito the virus is treated like food and digested along with the blood meal. If the mosquito takes a partial blood meal from an HIV positive person and resumes feeding on a non-infected individual, insufficient particles are transferred to initiate a new infection. If a fully engorged mosquito with HIV positive blood is squashed on the skin, there would be insufficient transfer of virus to produce infection. The virus diseases that use insects as agents of transfer produce tremendously high levels of parasites in the blood. The levels of HIV that circulate in human blood are so low that HIV antibody is used as the primary diagnosis for infection.        Source:  New Jersey Mosquito Control Association  New Jersey Mosquito Control Association   What is the UMAA? What is the AMCA?     The UMAA stands for the Utah Mosquito Abatment Association.        The AMCA stands for the American Mosquito Control Association.