The same way humans become infected—by the bite of infectious mosquitoes. The virus is located in the mosquito's salivary glands. When mosquitoes bite or "feed" on the horse, the virus is injected into its blood system. The virus then multiplies and may cause illness. The mosquitoes become infected when they feed on infected birds or other animals.

Clinical signs of WNV in horses include stumbling, depression, incoordination, and weakness of limbs (partial paralysis or inability to stand), and muscle twitching. However, some infected horses may not show any signs. Although about two-thirds of infected horses that become ill will survive and have a full recovery, West Nile virus can and has caused deaths in horses.

These diseases are transmitted by infectious mosquitoes. There is no documented evidence of person-to-person or animal-to-person transmission of WNV or EEE. Normal veterinary infection control precautions should be followed when caring for a horse suspected to have these or any viral infection.

The main route of human infection with West Nile and EEE virus is through the bite of an infected mosquito. Neither virus can be passed between people by coughing, sneezing, shaking hands, sharing food, etc. Additional routes of human infection were identified for WNV during the 2002 West Nile epidemic. It is important to note that these other methods of transmission represent a very small proportion of cases.

No. There are approximately 42 different species of mosquitoes in Maine. Some of them have habitats that overlap, and others have separate habitats based on their specific breeding requirements. Some mosquitoes feed on birds, some on mammals, and a few on both birds and mammals. The mosquitoes of most concern are those that feed on both birds and mammals; these are called “bridge” vectors.

No. WNV and EEE are NOT transmitted from person-to-person. For example, you cannot get either virus from touching or kissing a person who has WNV or EEE, or from a health care worker who has treated someone with either disease.

The Maine Center for Disease Control has developed an Arboviral Surveillance system to track the occurrence of WNV and EEE in Maine, generally beginning in mid-June and lasting through to mid-October. Surveillance efforts include adult mosquito trapping and testing, collecting dead bird data, testing dead birds, llamas, alpacas, and horses, and testing people who are ill with symptoms similar to those of an arbovirus infection.

Horses are not killed. Infected horses or donkeys are simply quarantined until they return to full health. Quarantine is critical to help prevent the disease from spreading.

Besides birds, the virus has been identified in horses, cats, bats, chipmunks, skunks, squirrels, and domestic rabbits. Just recently it has been found in dogs. WNV is transmitted by infectious mosquitoes. There is no documented evidence that the virus is transmitted from animal to person.

No. There is no documented evidence that WNV is transmitted between horses. However, horses with suspected WNV should be isolated from mosquitoes, if possible.

People are infected with WNv by being bitten by an infected mosquito. The risk level in the province is expected to vary by region and to flare up in the summer and fall depending on climate conditions. The public will be notified by public health officials if birds or mosquitoes in the province test positive for the virus. When people are exposed to mosquitoes in an area the WN virus has been detected they are at risk for infection.

Contact your health care provider if you have concerns about your health. If you or your family members develop symptoms such as high fever, confusion, muscle weakness, and severe headaches, you should see your doctor immediately.

There is no specific treatment for WNV or EEE. In more severe cases, intensive supportive therapy is indicated, often involving hospitalization, intravenous fluids, airway management, respiratory support (ventilator), prevention of secondary infections (pneumonia, urinary tract, etc.), and good nursing care.

There are WNV and EEE vaccines available for equines. Please note that the vaccines offer NO cross-protection; i.e., the WNV vaccine does not protect against EEE, and vice versa. To be protected, horses must be fully vaccinated or boostered at least two weeks before exposed to mosquitoes. Please consult your veterinarian for more information.

The cycle of infection begins when roundworm eggs are passed out in the droppings and develop into immature worms in the dung. These then climb up blades of damp grass and are eaten by the horse.

The principle route of human infection with West Nile virus is through the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds, which may circulate the virus in their blood for a few days. The virus eventually finds its way into the mosquito's salivary glands. During subsequent blood meals, the virus may be injected into humans and animals, where it can multiply and possibly cause illness.

Experimentally, it was found that this may be possible. However, there has been no evidence to indicate transmission of WNV to cats or dogs that carry or consume infected animals has occurred naturally. Dogs and cats can get infected by the bite of a mosquito, thus minimizing their exposure to mosquitoes is recommended.

There is no evidence West Nile virus can be transmitted to humans through consuming infected birds or animals. In keeping with overall public health practice, and due to the risk of known food-borne pathogens, people should always follow procedures for fully cooking meat from either birds or mammals.

There is no specific treatment for WNV infection. Full recovery from the infection is likely. Treatment would be supportive (managing symptoms, if present) for animals infected with a viral agent. There is no documented evidence of dog or cat-to-person transmission of West Nile virus. The evidence suggests that dogs do not develop enough virus in their bloodstream to infect more mosquitoes.

Preliminary studies have not been able to detect virus in the saliva of infected dogs. This suggests that dog bites pose a low risk, if any, of transmission of WNV from dogs to other animals or people.

Since 1999, large numbers of North American crows and other birds have become seriously ill and died. Many other species of birds become infected, develop a high viremia and then immunity, but do not become ill.

of Boulder County residents are at risk for contracting West Nile virus ? that includes children, grandparents, and YOU!

People become infected by the bite of a mosquito infected with WNV. Mosquitoes get WNV from birds. Most mosquito bites will not transmit the disease, but it only takes the bite of one mosquito carrying the WNV to potentially cause an infection. There is an incubation time of 5-15 days between the time a person is bitten and the onset of illness.

A. There are no human vaccines to prevent WNV infection at this time, but several companies are working towards developing a vaccine. Avoid spending time outside when mosquitoes are most active, from dusk until dawn. Wear loose fitting, long-sleeved shirts and long pants when outdoors. Mosquitoes can bite through thin clothing tight fitting clothing. Treat clothing with repellents containing permethrin or DEET.