West Nile Virus Update

  

 

Los Angeles County West Vector

& Vector-Borne Disease Control District

6750 Centinela Avenue, Culver City CA 90230

Ph: 310-915-7370 ext. 223; Fax: 310-915-9148

Email: rsaviskas@lawestvector.org

West Nile Virus

Public Health Update & Advisory

Period: 1-1-14 thru 7-27-14

First WNV Positive Dead Birds (LA City & Rancho Palos Verdes) within the Los Angeles County West Vector & Vector-Borne Disease Control District.

This is the first West Nile virus (WNV) update and public health advisory for 2014 for all cities and unincorporated county areas within the Los Angeles County West Vector & Vector-Borne Disease Control District.  Cities and areas within the District are: Agoura Hills, Beverly Hills, Calabasas, Culver City, El Segundo, Hawthorne, Hermosa Beach, Hidden Hills, Inglewood, Lawndale, Lomita, Malibu, Manhattan Beach, Palos Verdes Estates, Rancho Palos Verdes, Redondo Beach, Rolling Hills, Rolling Hills Estates, Santa Monica, Torrance, West Hollywood, Westlake Village, and portions of Los Angeles City and Los Angeles County.

About West Nile Virus (WNV) & Current Conditions:

Currently, WNV activity is low compared to the same time period in 2013. WNV is endemic (constantly present) throughout all areas of Los Angeles County, whether shown on the map or not, individuals should follow all recommendations listed below on reducing their risk of infection regardless of where they live.

Human Cases and Positive Indicators

1.         Nationally:

2014:           35 Human Cases;       1 Death(s) (as of 7-27-14)

2013:       2465 Human Cases;   119 Death(s) (entire year)

2.         California:

            2014:          15 Human Cases;   0 Death(s) (as of 7-27-14)

2013:             4 Human Cases;   0 Death(s) (as of 7-27-13)

3.         LA County:

            2014:             0 Human Cases;     0 Death(s) (as of 7-27-14)

2013:         165 Human Cases;     9 Death(s) (entire year)

4.         Human Cases w/i LA Co. Hlth. Dept. Service Planning Areas (SPA)* (1-1-14 thru 7-27-14):

            SPA 1: Antelope Valley:          0 New human case(s) for this period:     0 Total case(s) YTD

SPA 2: San Fernando:            0 New human case(s) for this period:     0 Total case(s) YTD

SPA 3: San Gabriel:                0 New human case(s) for this period:     0 Total case(s) YTD

SPA 4: Metro:                          0 New human case(s) for this period:     0 Total case(s) YTD

            SPA 5: West:                           0 New human case(s) for this period:     0 Total case(s) YTD

SPA 6: South:                          0 New human case(s) for this period:     0 Total case(s) YTD

SPA 7: East:                            0 New human case(s) for this period:     0 Total case(s) YTD

            SPA 8: South Bay:                  0 New human case(s) for this period:     0 Total case(s) YTD

            * Map of SPAs is attached

                                   

5.         New WNV Positive Indicators inside the District’s Boundaries (7-21-14 thru 7-27-14):

            (WNV indicators are positive dead birds, sentinel chickens, mosquitoes, or squirrels)

LA City:                                    DB (1): Zip 90045

Rancho Palos Verdes: DB (1): Zip 90275

Types of Positives:

(DB) Dead Bird(s):                  This is a dead bird tested for West Nile virus (WNV)

(MP) Mosquito Pool(s):           This is a group of trapped adult mosquitoes tested for WNV

(SC) Sentinel Chicken(s):       This is the testing of chickens housed in sentinel chicken flock coops located throughout the District designed to monitor WNV activity

(DS) Dead Squirrel(s):            This is a dead squirrel tested for WNV

How do WNV infections occur:

Mosquitoes become infected when they first bite an infected bird and then transfer the virus to other birds and humans as they bite again. A wide variety of wild birds, including the American crow, are the reservoir for West Nile virus.

Most mosquitoes do not carry the virus and most people bitten by a mosquito are not exposed to the virus. The virus is not spread through person-to-person contact, or directly from birds to humans.

In most cases, people who are infected with West Nile virus never become sick, or have only very mild symptoms that include fever, headache, nausea, body aches, and a mild skin rash. Symptoms of WNV could appear within 3 to 12 days after infection.

Fewer than 1 in 150 people who are bitten by an infected mosquito become severely ill, according to the Centers for Disease Control and Prevention (CDC).  The elderly and those with weakened immune systems are most at risk for developing severe symptoms, which may require hospitalization. There is no specific treatment for this disease.

Positive Dead Birds:

WNV is endemic (constantly present) throughout Los Angeles County, California and the United States. With respect to positive indicators (dead birds, sentinels chicken flocks, mosquitoes, and dead squirrels), dead birds are the least reliable with respect to where the birds were actually infected.  This is due to the fact that 90-95% of all dead birds that are positive for WNV are American crows which have extensive daily travel patterns.

American crows routinely travel as many as 10-20 miles each day from their nighttime nesting and roosting locations to feed and scavenger before returning to their original location in the evening.  Infected mosquitoes bite the birds in the evening and at night as they roost and sleep. Because of these daily flight and roosting patterns, American crows may travel and die as far as 20 miles away from the location where they were actually bitten and infected by a mosquito.

This is particularly true the last two years as the crows have been travelling further west to the coastal cities during the days to escape the hotter inland temperatures to the east.

Positive American crows collected in a specific area are significant only with respect to trends on a more regional or countywide basis.  It does not indicate that a specific zip code, city, or location was the site where the actual mosquito bite and infection occurred because of the bird’s extended daily travel patterns.

However, positive results for mosquito pools and sentinel chicken flocks are very specific with respect to the locations where positive mosquitoes exist and can transmit disease since the locations of the traps and chickens are fixed.

How to decrease your risk of infection:

1.   DEET & other repellents: Apply insect repellent according to the label.  Repellents containing DEET, picaradin, IR3535, and oil of lemon eucalyptus are the longest lasting and most effective.  Repellents keep the mosquitoes from biting you.

2.   DAWN AND DUSK:  Mosquitoes that carry WNV primarily bite in the early morning and evening so it is important to wear repellent at this time.

3.   MOSQUITO PROOF YOUR HOME:  Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes.  Repair or replace screens with tears or holes.

4.   DRAIN STANDING WATER:  Mosquitoes lay their eggs on standing water.  Eliminate all sources of standing water on your property, including flowerpots, old car tires, rain gutters and pet bowls. Ensure that swimming pools, spas, and ponds are properly maintained.

5.   INOPERATIVE POOLS AND SPAS:  If your pool or spa is inoperative and still has any amount of water in it, the District will treat or plant mosquito fish in it at no cost. This service is confidential. You can call for service or make arrangements to pick up free mosquito fish at the District by calling 310-915-7370.

Reporting & Picking Up Dead Birds: 1-877-WNV BIRD (1-877-968-2473):

The public is encouraged to report dead birds to help with West Nile virus surveillance and control efforts. Dead birds should be reported to the toll-free hotline number at 1-877-WNV BIRD (1-877-968-2473).  Dead birds must be less than 24 hours old to be tested for West Nile virus.  If the bird is rigid or decomposed, it cannot be used for testing.

Disposal of Dead Birds:

General Disposal: For birds that are too old, determined not to be in a condition to accurately test, or outside of the testing cycle, they can be disposed of in your normal weekly trash pickup by taking the following steps:

1) Take a plastic garbage bag and inserting your hand in the open end;

2) Grab the dead bird and pull it into the garbage bag using an “outside-to-inside” pulling motion;

3) Tie off the bag with the bird inside and place it in your regular trash for disposal.

District: Please note that the District does not pick up or disposed of dead birds that are not collected for testing.

Symptoms of West Nile Virus:

People infected with WNV can experience a variety of symptoms that may include: no symptoms, West Nile Fever, or West Nile Neuroinvasive disease. Symptoms usually occur 3-12 days after infection.  If you suspect you have contracted WNV, consult your physician for testing and care.

Symptoms of “West Nile Fever” can include:

• Headaches

• High fever

• Tiredness and body aches

• Skin rash and swollen lymph glands

(These symptoms may last from several days to several weeks)

Symptoms of “West Nile Neuroinvasive Disease” can include:

• Severe Headache

• High Fever

• Stiff neck

• Stupor

• Disorientation

• Tremors, convulsions, muscle weakness

• Paralysis and/or Coma (with possible long term or permanent damage to the brain)

Important Numbers:

For mosquito problems or to pick up mosquito fish:  Call 1-310-915-7370 Monday through Friday, 8:00 a.m. – 3:30 p.m.

For additional information on WNV and the Los Angeles County West Vector & Vector-Borne Disease Control District:  Please visit the District’s website at www.lawestvector.org.

New results are posted weekly.

Questions:  If you have any questions, please contact Robert Saviskas, Executive Director, at (310) 915-7370 ext. 223 or at rsaviskas@lawestvector.org.