WNV Treatment and Control

There is no specific treatment for West Nile viral illnesses.  Because West Nile infections are caused by a virus, antibiotics are not an effective treatment and no antiviral drugs have been successfully used.  Therefore, treatment is supportive.  It is aimed at improving the symptoms of an infected person but does not shorten the course of illness.  Main treatment concerns involve lowering fever, avoiding dehydration, decreasing brain swelling or dealing with a loss of automatic breathing activity.  Mild symptoms will usually resolve in a few days.  In more severe cases, intensive supportive therapy is indicated, such as hospitalization, intravenous (IV) fluids and nutrition, airway management, ventilatory support (ventilator) if needed and prevention of secondary infections (pneumonia, urinary tract, etc.).

Treatment for pets and horses is similar to that in humans.  It is essentially supportive and consistent with standard veterinary practices for animals infected with a viral agent.  Treatment in horses may include anti-inflammatory medications, intravenous fluid administration, parenteral nutrition, and physical support if the animal is extremely weak or prone to recumbency.

Currently, two different vaccines are available for prevention of WNV-associated disease in horses.  One vaccine, the West Nile Innovator^TM, was developed by Fort Dodge licensed for use in 2003.  RecombiTEK^TM was developed by Merial and released in 2004.  The two vaccines work in completely different ways and cannot be used interchangeably.  Both vaccines are only available through a licensed veterinarian. For more information regarding these equine WNV vaccines, click here.   In addition to the equine vaccine, simple insect control measures should be utilized.  Consider the use of insect repellents, and place horses in barns/stables under fans during dusk, dawn, and other times when mosquitoes are present.  Eliminate opportunities for mosquito breeding by draining wet areas of pasture, draining puddles, repairing eve troughs and gutters, clearing any containers that might hold even small pools of water, and draining water tanks one or twice weekly.

There is no vaccine available for pet mammals or birds.  Owners are advised to protect their pets in the same way that they would protect themselves: keep pets indoors around dusk and dawn when mosquitoes are most active, keep windows screened, and eliminate mosquito-supporting habitat around the home.  There are veterinarian approved insect repellents that may be used on dogs, however these products are not approved for use on other species such as pet birds or cats.  These products are commercially available from veterinarians and protect against mosquito bites, which can transmit WNV and heartworms; and ticks bites, which can transmit Lyme Disease. Safe use requires closely following label directions.  DEET-based repellents, which are recommended for humans, are not approved for veterinary use (largely because animals tend to ingest them when licking.) Talk with your veterinarian for advice about the appropriate product for use on your pet.

There are no commercially available human vaccines for the prevention of West Nile virus. Prevention of arboviral diseases like West Nile virus centers around controlling exposure to mosquitoes and avoiding mosquito bites as well as public health measures to reduce the populations of infected mosquitoes.

Measures to prevent WNV infection in humans include:

• Reduce time outdoors, especially at dusk, during mosquito seasons
• Wear light weight long sleeves and long pants if you are outdoors
• If outdoors, apply insect repellent exposed skin or clothing that contains the active ingredient, DEET. Repellents containing Picaridin or Oil of Lemon Eucalyptus have recently become EPA approved and recommended for use by CDC.  (Be sure to follow the manufacturer's instructions).  For more information on mosquito repellents, click here.
• Maintain window and door screens to keep mosquitoes out of buildings
• See the section under the Mosquito Control link to the left about Homeowner Mosquito Control (or click here). Drain standing water in the yard because they are potential mosquito breeding sites. Empty standing water from flower pot bases, pet bowls, clogged rain gutters, swimming pool covers, discarded tires, buckets, barrels, cans, etc.