West Nile Virus

 

How do people and animals get West Nile virus?

West Nile virus is transmitted to people and animals (birds and horses) by infected mosquitoes. Only certain species of mosquitoes carry the virus and very few mosquitoes are actually infected.

 

Are there other ways of getting West Nile virus?

In rare instances, West Nile virus can be transmitted through blood transfusion, organ transplants, and from mother to fetus and breast feeding infants. Pregnant and nursing mothers are encouraged to avoid mosquitoes. Consult a physician for additional information.

 

What are the symptoms?

Most people who are infected with West Nile virus have no symptoms. Of those who become ill, symptoms may include fever, headache, body aches, nausea, skin rash, and/or swollen lymph nodes. Symptoms will generally last a few days. In severe cases, encephalitis (inflammation of the brain), meningitis (inflammation of the membrane surrounding the brain) or inflammation of both the brain and the membrane may occur. Severe symptoms may include high fever, headache, neck stiffness, disorientation, coma, tremors, paralysis, and possibly death. Neurological damage may be permanent. At greatest risk are people over the age of 50, the elderly, and those who have weakened immune systems. Incubation period: the time between the mosquito bite and the onset of illness ranges from 3-15 days in humans. It is estimated that 1 in 150 who are infected with West Nile virus will require hospitalization.

 

Is there a vaccine for humans? No, but a British vaccine maker Acambis PLC and called ChimerVax-West Nile, represent the first positive data on a human West Nile vaccine. The vaccine probably wouldn't come to market before 2007.

 

Which animals get West Nile virus?

An infected mosquito can bite any animal, but not all animals will become infected. The disease most often affects birds (crows, ravens, magpies, and jays), but occasionally causes disease in other animals as well.

 

If you find a dead bird, particularly a crow or other corvids (i.e. raven, jay, or magpie) please call the California Department of Health Services hotline at 1-877-WNV-BIRD. Not all birds will qualify for testing; however, they will record all reports of dead birds.

 

To move or discard a carcass, wear rubber or latex gloves. If gloves are not available, use a plastic bag turned inside-out over your hand and invert the bag to surround the bird. Seal and discard in the trash if the bird will not be picked-up for testing.

 

Horses are also susceptible to West Nile virus. The disease does not seem to be specific to a particular breed or age of horse. Many horses infected with West Nile virus will not develop any illness. Of those that do become ill, approximately 30% die or must be destroyed. In 2003, there were nearly 5,000 confirmed cases of equine West Nile virus reported in the U.S. If your horse becomes infected, it is not contagious to you or to other horses. Clinical signs are: lack of coordination, stumbling, circling, falling, weakness or partial paralysis of limbs, muscle twitching (especially around nose and lips), an inability to rise, and grinding teeth. Vaccination: two different vaccines are available for horses. The timing of these vaccines is critical because they must be administered prior to disease exposure. Contact a veterinarian for advice.

 

Does West Nile virus affect dogs and cats?

Dogs and cats only rarely show illness if infected with West Nile virus. The National Animal Poison Control Center warns that insect repellant should not be used on pets. Cats are highly sensitive to the chemicals, and both dogs and cats lick themselves and could ingest toxins from the repellents. So far, cats and dogs have been fairly resistant to the virus.

 

What can you do to help?

Mosquitoes breed in standing water. Eliminate standing water on your property by dumping or draining water in neglected swimming pools, ponds, rain barrels, discard tires, buckets, or anything holding water for more than few days. This will stop the mosquito life cycle.

 

How to protect yourself and your family



Summary of WNV Positives For 2007
  GLACVCD CA State
Humans 32/3 deaths 378/16 deaths
Horses 0 28
Dead Bird Surveillance 115 1,395
Mosquito Pools 88 1,007
Sentinel Chickens 14 510

*Updated January 8, 2008

Summary of WNV Positives For 2006
  GLACVCD Los Angeles County CA State
Humans 7/0 deaths 13/0 deaths 272/6 deaths
Horses 0 0 57
Dead Bird Surveillance 58 93 1,404
Mosquito Pools 78 78 833
Sentinel Chickens 18 38 640

*Updated January 10, 2007

Summary of WNV Positives For 2005
  GLACVCD Los Angeles County CA State
Humans 22/0 deaths 47/0 deaths 935/18 deaths
Horses 5/3 deaths 10/6 deaths 456/200 deaths
Dead Bird Surveillance 135 173 3,044
Mosquito Pools 179 218 1,242
Sentinel Chickens 6 flocks (16 chickens) 77 793

*Updated Dec. 19, 2005

2005 West Nile Virus Positive Dead Birds Within GLACVCD

Date Confirmed City
2/11/05 Valencia (1)
2/16/05 Valencia (1)
4/6/05 Woodland Hills (1)
5/26/05 Long Beach (1)
6/6/05 Pico Rivera (1)
6/29/05 LA (Van Nuys) (1)
7/7/05 Pico Rivera (1)
7/14/05 Pico Rivera (1)
7/25/05 West Hills (1)
7/27/05 Carson (1)
7/27/05 Long Beach (1)
8/1/05 Castaic (1)
8/1/05 Santa Clarita (1)
8/2/05 Santa Clarita (1)
8/5/05 Santa Clarita (1)
8/8/05 Canyon Country (2)
8/8/05 La Mirada (1)
8/8/05 San Pedro (1)
8/8/05 Castaic (1)
8/8/05 Santa Clarita (1)
8/8/05 Santa Clarita (1)
8/9/05 Santa Clarita (1)
8/9/05 Valencia (1)
8/10/05 Santa Clarita (1)
8/10/05 Stevenson Ranch (1)
8/11/05 Valencia (1)
8/11/05 Santa Clarita (1)
8/11/05 Reseda (1)
8/12/05 Stevenson Ranch (1)
8/12/05 Santa Clarita (1)
8/15/05 Newhall (1)
8/15/05 Chatsworth (1)
8/15/05 Val Verde (1)
8/16/05 Newhall (1)
8/16/05 Van Nuys (1)
8/17/05 Van Nuys (1)
8/17/05 Tarzana (1)
8/18/05 Woodland Hills (1)
8/18/05 Santa Clarita (1)
8/22/05 Santa Clarita (3)
8/22/05 Valencia (1)
8/22/05 Castaic (4)
8/22/05 Gardena (1)
8/23/05 Norwalk (1)
8/23/05 Sherman Oaks (1)
8/24/05 Castaic (1)
8/24/05 Whittier (2)
8/25/05 Santa Clarita (1)
8/26/05 Encino (2)
8/29/05 Sunland (1)
8/29/05 Valenica (2)
8/29/05 Tarzana (1)
8/29/05 Newhall (1)
8/29/05 Woodland Hills (1)
8/29/05 Chatsworth (2)
8/29/05 Long Beach (1)
8/29/05 Canyon Country (1)
8/29/05 Castaic (2)
8/29/05 San Fernando (1)
8/29/05 Santa Clarita (1)
8/30/05 Van Nuys (1)
8/31/05 Newhall (1)
8/31/05 Northridge (1)
9/1/05 Winnetka (1)
9/6/05 Canyon Country (1)
9/6/05 North Hollywood (1)
9/6/05 Santa Clarita (3)
9/6/05 Sylmar (1)
9/6/05 Woodland Hills (1)
9/7/05 Santa Clarita (1)
9/8/05 Santa Clarita (1)
9/9/05 Santa Clarita (1)
9/9/05 Encino (1)
9/12/05 Sunland (1)
9/12/05 Canyon Country (1)
9/12/05 Santa Clarita (6)
9/12/05 Castaic (1)
9/12/05 Sylmar (1)
9/14/05 Santa Clarita (5)
9/14/05 North Hollywood (1)
9/19/05 West Hills (1)
9/19/05 Castaic (1)
9/20/05 Encino (1)
9/26/05 Chatsworth (1)
9/26/05 Sunland (1)
9/28/05 Santa Clarita (3)
9/29/05 North Hills (1)
10/3/05 Canyon Country (1)
10/3/05 Newhall (2)
10/3/05 Northridge (1)
10/3/05 Sun Valley (1)
10/3/05 Valencia (1)
10/3/05 Norwalk (1)
10/3/05 West Hills (1)
10/3/05 Chatsworth (1)
10/4/05 Santa Clarita (1)
10/5/05 Castaic (1)
10/5/05 Santa Clarita (2)
10/6/05 Santa Clarita (1)
10/10/05 Mission Hills (1)
10/10/05 West Hills (1)
10/10/05 Newhall (1)
10/11/05 Canyon Country (1)
10/11/05 Santa Clarita (1)
10/31/05 Santa Clarita (1)
11/7/05 Castaic (1)
11/7/05 Northridge (1)
12/7/05 Santa Clarita (2)
Total 135

2005 West Nile Virus Postive Mosquito Pools Within GLACVCD

Date Confirmed City
May Cerritos (1)
June Long Beach (35)
July Long Beach (28)
July Cerritos (1)
July Lakewood (3)
July LA (Canoga Park) (1)
July LA (Encino) (1)
July LA (Chatsworth) (3)
July LA(Griffith Park) (1)
July Hawaiian Gardens (1)
July Los Angeles City (1)
July Bell (1)
July Granada Hills (2)
July Sunland (1)
July North Hills (1)
Aug. Long Beach (10)
Aug. Pico Rivera (2)
Aug. Lakewood (2)
Aug. Cerritos (1)
Aug. Los Angeles (5)
Aug. Santa Clarita (3)
Aug Wilmington (2)
Aug Rowland Heights (3)
Aug Hawaiian Gardens (1)
Aug Canoga Park (2)
Aug Chatsworth (11)
Aug Encino (7)
Aug Valencia (1)
Aug Canyon Country (1)
Aug Sunland (3)
Aug Granada Hills (6)
Aug Long Beach (1)
Aug Chatsworth (1)
Aug Northridge (4)
Aug Winnetka (5)
Aug Santa Clarita (1)
Aug Carson (1)
Sept Pico Rivera (2)
Sept Long Beach (1)
Sept Wilmington (1)
Sept Sunland (3)
Sept Sylmar (2)
Sept Encino (3)
Sept Van Nuys (2)
Sept Downey (2)
Sept Hawaiian Gardens (1)
Sept Woodland Hills (1)
Sept LA City (1)
Sept Sunland (1)
Sept Chatsworth (1)
Oct Long Beach (2)
Oct Santa Clarita (1)
Dec Santa Clarita (1)
Total 179

2005 West Nile Virus Postive Sentinel Chickens Within GLACVCD

Date City # of positive chickens
6/18/05 Long Beach 1
6/20/05 Long Beach 1
7/5/05 Long Beach 1
7/18/05 Long Beach 3
8/15/05 Encino 3
8/15/05 Harbor City 1
8/31/05 Valencia 1
8/30/05 Chatsworth 1
8/29/05 Rowland Heights 2
9/12/05 Rowland Heights 1
9/26/05 Long Beach 1
Total   16

2005 West Nile Virus Warning Signs Posted

Date City Location
6/14/05 Cerritos Coyote Creek bike trail
6/14/05 Cerritos Cerritos Regional Park
6/17/05 Longe Beach Bixby Village Golf Course
6/17/05 Long Beach Alamitos LLC Power Plant
6/17/05 Long Beach McFarland Oil Fields
6/24/05 Long Beach Long Beach Marketplace
7/8/05 Long Beach Wardlow Park
7/8/05 Long Beach Los Altos Park
7/8/05 Long Beach Bouton Park
7/8/05 Long Beach Wahley Park
7/8/05 Long Beach El Dorado Park West
7/8/05 Long Beach El Dorado Park Golf Course
7/8/05 Long Beach Skylinks Golf Course
7/8/05 Long Beach Los Altos Market Center
7/27/05 Lakewood Jose San Martin Park
7/27/05 Lakewood Jose Del Valle Park
7/27/05 Lakewood Rynerson Park
7/27/05 Lakewood Monteverde Park
7/27/05 Lakewood Mae Boyer Park
8/12/05 LA City Hansen Dam Recreational Area
8/17/05 Santa Clarita Vista Valencia Golf Course
8/17/05 Santa Clarita Valencia Meadows Park
8/17/05 Santa Clarita Old Orchard Park
8/25/05 Chatsworth Chatsworth Oaks Park
8/25/05 Chatsworth Chatsworth Park North
8/25/05 Chatsworth Mason Recreational Center

Summary of WNV Positives For 2004
  GLACVCD Los Angeles County CA State Nationwide
Humans 180/ 4 deaths 331/ 14 deaths 830/ 28 deaths 2,470 human cases/ 88 deaths
Horses 8/5 deaths 16 / 8 deaths 540/ 230 deaths 1,305 cases
Dead Bird Surveillance 645 840 3,232 7,074
Sentinel Chickens 44 166 805 1,429 (flocks)
Mosquito Pools 341 408 1,136 8,263