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Lyme Disease in Los Angeles

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Presentation on theme: "Lyme Disease in Los Angeles"— Presentation transcript:

1 Lyme Disease in Los Angeles
Birds are the long distance carriers Pockets of foci Tick testing in one area may not reflect other areas

2 Lyme Disease An infectious disease transmitted by ticks
Caused by a spirochete Characterized by EM arthritis neurologic and cardiac symptoms


4 Diagnostic Issues with CA Focus
In CA, 70% do not recall tick bite 97% of vector borne disease Only 56.8% have EM 41% exposed outside county of residence 22% exposed outside of state EM not seen on dark skin In CA less than 60% of population is white, but ~ 90% of reported cases are white People who work as gardeners, contractors, field workers, park rangers, fire fighters are at high risk

5 Nymphal ticks transmit most LD
Smaller than a poppy seed Three blood meals Bite is painless In CA nymphal ticks have the highest rate of infection Humans incidental and end host

6 Lyme: Clinical diagnosis due to flawed testing

7 How do we determine risk?
Will the ecosystem support Lyme infected ticks? Are there ticks that can carry Lyme in the area? Are there ticks that do carry Lyme? Are people exposed to these ticks? Will the ecosystem support Lyme infected ticks? The question here is whether the known animal reservoirs that maintain Bb are in the environment? Here, we are talking about mice, rabbits, birds, squirrels, and deer. Actually, the deer are not believed to be a reservoir. However, the ticks do mate on deer. The next question is whether black legged ticks are in the area. Other ticks don’t seem to house Bb. If there are black-legged ticks, all that is required is that they feed on a reservoir animal to become infected. Then we ask if there actually are ticks in the area that are known to be infected? If so, we have a problem. This is why it is important to do tick testing. It is also important to recognize that there may be foci of infected ticks—which means that there tend to be pockets of ticks carrying Bb. This means that if you test a tick in one area and that pool is negative, a hundred yards over there may be infected ticks and if you don’t test them you won’t know. (In short, just because you don’t catch any fish doesn’t mean there aren’t any fish in the lake.) Finally, people have to be exposed to them. I know in my neighborhood, Los Feliz, its not uncommon to have deer, racoons, skunk, opossum, mice, rats all hanging out by the kitchen door.

8 How does Lyme disease risk spread?
Tick Transports Birds are the long distance carriers Pockets of foci Tick testing in one area may not reflect other areas


10 Awareness drives everything!

11 Lyme disease is throughout CA
Many doctors unaware that Lyme disease is in CA Most of the public are unaware that Lyme disease exists in CA Public is unaware that ticks are dangerous Do not take proper precautions Do not do tick checks Do not remove ticks properly Do not know that rash means they should go to the doctor

12 W. LA Vector Control District
Model website Information on ticks, prevention & coinfections. Regular flagging activity. Use the best labs in the state to test ticks Placer County Sonoma County

13 Number of cases in California
In one small rural community in Mendocino County 37% of the residents had definite or probable Lyme disease, while 24 % were seropositive. In 2001, estimates of the annual incidence of Lyme disease in California ranged from 920 (10 times the number of officially reported cases) to 1,500 cases (based on estimated lab reports) to 2,640 (based on physician estimates.

14 LA County Wilderness Areas
LA County: 13 million people (If state, the 9th most populated) 30% of land = state parks, national parks and agriculture Urban areas next to wilderness areas (Hollywood Bowl, Rose Bowl, the Greek Theatre) Black-legged ticks found throughout Hollywood Bowl (Hollywood Hills), Griffith Park, Angles National Forest, Santa Monica Mountains, Los Padres National Forest, San Gabriel Mountains, Santa Monica Mountains, Whittier Hills, La Puente Hills, Palos Verdes

15 Griffith Park Abundance of ticks
Largest urban wilderness in United States 10 million visitors a year Humans, horses, and dogs use trails

16 Los Angeles 6th out of 59 counties in Lyme cases from 1994-2003
Butte (9.7%) Sonoma (9.2%) Humboldt (8.6%) Mendocino (7.2%) San Diego (5.8%) Los Angeles (4.8%)

17 Local parks with infected ticks
Malibu (Tapia State Park,1998; Charmlee 2000) Pacific Palisades (Will Rogers State Park 2000) Topanga (Topanga State Park 2000) Palos Verdes (Bluff Cove 2000) Backbone trail connecting Will Rogers and Topanga State Park an unidentified Bb strain Crestview Hills Park (north of Brentwood)

18 Incidence in LA ≠ Disconnect
CDC (2004 & cumulative) LA Support Group (Current) Physician Estimates Lab Estimates (2004) LA: 5 annual So. Cal.: 200 (cum ) 262 ~ cum. 260 ~ cum. (2004) ?? Awareness Diagnosis Reporting Staffing 10 or 40 X ~ Annual? ~2,000-8,000 cum Chronic ~15% total (~1,744?) Joiners (~1,730?) 2 polled May be more than one test per year

19 Coinfections: Can be more common than Lyme?
Babesia Microti & WA-1 Ehrlichia HGE & HME Bartonella Spirochete Malaria like protozoa Gram neg. bacteria Gram. Neg. bacteria Average for nymphs 12% N. CA community study1 100 residents Microti: 0 WA-1: ~18% N. CA community study2 230 residents HGE: 0.4% HME: 4.6 % 19.2% * Santa Clara tick study3 (Chang 2001) 1. Lane RS, et al Risk factors for Lyme disease in a small rural community in northern California. Am J Epidemiol 136: 2. Fritz et al. 1997, Seroepidemiology of Emerging Tickborne Infectious Diseases in a Northern California Community. J Inf Dis 175:1432-9, 1997. 3. C. C. Chang et al. Molecular Evidence of Bartonella spp. in Questing Adult Ixodes pacificus Ticks in California J. of Clin. Microbiology, April 2001, 39(4):

20 What can be done? Alert public to Lyme risks, symptoms & precautions
Newsletter to physicians in LA Only ~68% with EM EM alone diagnostic Clinical diagnosis Surveillance definition not for diagnosis Make sure all physicians and labs aware of new mandatory lab reporting lab results Physician form verifying CDC criteria Compile data already being collected & add question to form re clinical diagnosis that does not meet CDC surveillance definition

21 California Lyme Disease Association
Vision Statement Every person who contracts Lyme receives a prompt diagnosis and ideal treatment to prevent the development of persistent Lyme disease. Every person with persistent Lyme disease receives readily accessible and sufficient medical treatment to preserve health by either curing or controlling the disease to improve the individual’s current quality of life, prevent the progression of disease, or extend life span. Every physician in the state receives adequate education regarding tick-borne diseases and is able to accurately diagnose and treat tick-borne diseases.

22 Lyme disease is now lab reportable
….Lyme disease has been made laboratory reportable, which means that a positive laboratory test for Lyme disease must be forwarded to the local health department, which will then follow up with the physician ordering the test to evaluate if the patient fits the surveillance case definition. Reportable Disease List to be Updated New Legislation Allows for Timely Changes Department of Health Services, Division of Communicable Diseases, Medical Board of California, Action Alert Report, July :8.

23 LA Has 5 Vector Control District—Only one is doing its job
The Greater LA District prevents and controls three vectors: mosquitoes, black flies, and midges. Covers Los Feliz area. The Antelope Valley Mosquito & Vector Control District concentrates on mosquitoes and Africanized Honey Bees only. San Gabrial Valley: Vectors of concern in the San Gabriel Valley include mosquitoes, black flies, midges, rodents, …Africanized honey bees and other stinging insects. May test ticks? Website has no public information on ticks. Long Beach Health Dept – LBHDVCP No mention of ticks

24 2000 Vector Report for West LA
“These positive results represents an unusually high infection rates of Lyme spirochete in southern California ticks, occupying a wide area from Pacific Palisades to the west of Malibu close to Ventura county and as far south as Palos Verdes.”

25 New relapsing fever type strains found in California
Bissett identified a new strain in California similar to reported European strains with antigenic variation similar to that seen in the Borrelia spp. that causes relapsing fever Bissett, ML and W. Hill, Characterization of Borrelia burgdorferi Strains Isolated from Ixodes pacificus Ticks in California. J Clin. Microbiology, Dec. 1987, 25 (12): Novel relapsing fever group spirochete also detected in Ixodes pacificus ticks in CA. Detected in Sonoma, Placer, Monterey, San Luis Obispo, Riverside,?? . Quintana, U.S. Army Center for Health Promotion & Prevention Medicine West.

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