Los Angeles County Department of Public Health Veterinary Public Health and Rabies Control Program

Transcription

1 Dr Emily Beeler, DVM Los Angeles County Department of Public Health Veterinary Public Health and Rabies Control Program RABIES, WEST NILE VIRUS, AND MORE: A PUBLIC HEALTH UPDATE

2 RABIES

3 Common Thoughts and Myths We don t have rabies anymore. Squirrels and rats are the #1 carriers of rabies. I have a strong immune system so I can t get sick. Even though I was bitten by a bat, I feel fine so I do not have to worry about rabies. Rabies shots are given in the belly and can kill you as easily as rabies can. The doctor can just test me to see if that animal gave me rabies.

4 What is rabies? RNA virus Family: Rhabdoviridae Genus: Lyssavirus Species-specific variants Spread in saliva, by bites Not blood, urine, feces Causes brain inflammation In mammals Fatal once any symptoms appear. Kills 55,000 people per year worldwide. Most by dog bites In USA: by bat bites (1-3/year) Thousands of Americans get treatment for rabies exposure annually 1 1 Blanton et al, 2005

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6 Rabies variants and reservoirs Certain mammals are Rabies Reservoirs In US reservoirs are: BATS skunks, raccoons, foxes, and coyotes (south Texas). Rodents, squirrels NOT rabies hosts. Opossums CAN have rabies 5 opossums with rabies in state in 10 years.

7 Human Rabies Symptoms Pain Back, chest, abdomen, etc Numbness, tingling of bitten body part Weakness Headache, flu-like signs Problems swallowing, drooling Fear of wind and water Agitation, confusion Problems talking Tremors, seizures Coma Death 99.9% Fatal Treatment must start long before symptoms appear! No tests work until too late

8 Rabies Symptoms - Animals FURIOUS: Aggressive, attacking drooling, unafraid. DUMB: Weak, paralyzed, unafraid, drooling. No treatment euthanize, test brain. Photo utexas.edu

9 Photos Courtesy CDC Public Health Image Library

10 Rabies suspect LA County 2009 Photo courtesy T. Walker

11 November 2008, Missouri Bat flew into house- Family of animal lovers Began handling, feeding bat Father bitten on ear Family decided to watch bat for 2 days to see if looked sick with rabies. Bat seemed fine, they let it go. No rabies test of bat One month later First day Severe chest and back pain Second day Family mentioned bat bite. Rabies treatment started (way too late) Third day Weak arm, trouble walking, numb side of face, trouble swallowing Agitated, anxious Fourth Day CDC Public Health Image Library Severe agitation restraints, drugged Sixth day Rabies confirmed on tests. Ninth day Died

12 Human Rabies Survival 2004 Wisconsin Jeanna Giese, 15, animal lover Picked up bat in church, bitten, took outside Symptoms began: tiredness, double vision, vomiting, tingling in arm Experimental treatment: Medically-induced coma In hospital 80 days Recovered with neurological deficits Milwaukee Protocol YouTube: The Girl Who Survived Rabies Has failed on 4-5 others Success on 1 boy in Brazil Ms Giese has own YouTube Channel

13 Humble, Texas 2006 Zach Jones, 16, napping Awoke when bat flew in a brushed up against face Bat released, not tested Several weeks later: illness began Milwaukee Protocol tried Died zachjonesmemorial.org Also see on YouTube

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18 Raccoon Rabies Outbreak Centers for Disease Control and Prevention. (1993). Raccoon Rabies Epizootic-US CDC MMWR Surveill Summ 43(15):

19 Steven Baty (AZDPH) and Andrea McCollum (CDC) bat-associated Rabies Virus in Skunks and Foxes, Flagstaff, AZ, 2009 CDC Zoonotic Disease Conference Call. Nov 4, 2009

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21 Rabid skunks in California last rabid skunk detected in LA Co 2002 skunk rabies spread south into Santa Barbara Co ORV program in SLO Co could stop spread Sterner et al, 2008

22 Idea: ORV of skunks in California SLO SB Sterner et al, 2008

23 Rabies in California 2009 through October Bats 113 Los Angeles 9 San Luis Obispo - 1 Skunks 38 San Luis Obispo - 2 Gray Foxes 34 Humboldt County 31 El Dorado County 2 Santa Barbara County -1

24 Bats roosting in crevice between balcony and side of house, Woodland Hills, Bats and Rabies Most bats not rabid Fewer than 1/1000 Protected by law Rabid bats More likely to be On ground Flying in daylight Near people, pets

25 Bats and Minor Bat Exposure Most human rabies cases in the US are due to rabies from insect-eating bats. Insect-eating bats are small less than 20 grams with tiny needle-like teeth. Rabies-positive red bat (Lasuirus borealis) Eastern pipistrelle and Silver-haired bat Slide courtesy CDC

26 Bat bite on finger Slide courtesy CDC

27 Year Rabid Animals in Los Angeles County, Number rabid animals cat skunk dog bats

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29 rabid bats so far

30 Rabies Pre-exposure vaccination Pre-exposure treatment Recommended by CDC for those handling animals routinely Three rabies vaccines: Day 0, 7, and 14 or 28 No vaccine shortage Most insurance does not cover

31 Post-exposure Treatment Report bites (not rodents/rabbits) Was the person exposed? Answer lies in animal. Treatment needed before symptoms start. Injections NOT given in abdomen! Treatment for unvaccinated One treatment with immunoglobulin on first day Series of 4 vaccines given over 2 wks Day 0, 3, 7, 14 Usually covered by insurance. Treatment for pre-vaccinated Series of two vaccines given 3 days apart, ONLY. OLD WAY OF TREATMENT! Boy being treated For rabies exposure, LA County, 1950s.

32 Your Role Protecting the public Report all animal bites to people Legally required, moral obligation Report to your local health department Do not release biting animal Report progressively neurologic mammals Submit for rabies testing

33 Your Role Educating the public Which species carry rabies, which do not Rabies is rare, but is still here Rabies is fatal Not to feed wildlife Not to leave pet food out Not to touch wildlife

34 West Nile Virus

35 What is WNV? RNA virus Arbovirus Arthropod-borne virus Family: Flaviviridae Genus: Flavivirus Electron micrograph WNV - CDC

36 WNV History 1937 discovered - Africa Endemic in Africa, Asia, Europe, Australia 1998 Israel 1 st outbreak with avian mortality Israel NYC Crows, horses, people becoming ill Dr Tracey McNamara DVM, Bronx Zoo pathologist saw pattern There is one level of surveillance for species of economic value and another one entirely for wildlife. 2 Tracey McNamara Photo courtesy Western University 1 Lichtensteiger and Green, Interview with Tracey McNamara, 2002.

37 WNV History WNV in USA: WNV now most common cause of arthropodborne encephalitis in US 2 Largest arbovirus outbreak ever recorded 1 Biggest arbovirus-related avian mortality event 1 Most species diversity in any arbovirus outbreak 1 >300 avian spp 2, humans, horses, squirrels, alligators, dogs, cats, 1 skunk, 1 wolf, 2 sheep, a few bats, 1 alpaca, raccoons, and rabbits 1 1 Lichtensteiger and Green, CDC WNV Website

38 WNV transmission Humans/mammals: Mosquito bites Organ transplant & blood donation Transplacental- 1 human case 1 Necropsy Birds (additional means) Bird-to-bird oral-oral? fecal-oral? Consumption of infected prey 1 Trevejo and Eidson, 2008

39 WNV Symptoms - humans No symptoms 80% Moderate illness West Nile Fever ~20% fever, headache, body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Serious Illness West Nile Neuroinvasive Disease <1% high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. Fatality risk highest for elderly westnile.ca.gov

40 WNV - Reservoirs Virus in blood viremia Reservoirs Jays, finches, grackles, sparrows, crows, American Robin. NEW-sampling eye in dead crow best test 1 Non-reservoirs Pigeons, chickens, quail, budgerigars. 2 1 Lim et al, Trevejo and Eidson, 2008

41 WNV in House Sparrows Reservoir Sicker =higher viremia Protective immunity ~3 years. Chicks not immune No bird-to-bird transmission ~10-25% of infected become ill Handling = risk of illness Lethargy, fluffed feathers, leg rigidity, death Virus isolated from oral cavity, heart, kidneys, brain, spleen Immune birds=safer people Passer domesticus Nemeth et al, 2009

42 Presenting raptors 42% infected with WNV 67% of infected birds were ill WNV+ birds less likely to be released neuro signs prognosis Dehydration, emaciation, mental dullness, ataxia, head tilt, tremors, nystagmus, abnormal PLR, leg paresis/rigidity, increased aggression, hypersensitivity, circling, problems swallowing, blindness, seizures. WNV in Raptors Nemeth et al, 2006 and 2009

43 WNV in Raptors More likely neuro: Great-horned owls, Ferruginous hawks (severe) Less likely neuro Am Kestrels, Swainson s hawks, Barn owls Viremia potential reservoirs Myocarditis & encephalitis Arteritis & necrosis Nemeth et al, 2006 and 2009

44 Sequelae: Pinched-off feathers (starts within weeks, may be temporary or persist) Relapses in ataxia

45 WNV and Squirrels 2009 California 10/98 squirrels WNV + (Erin Parker CDPH) Fox Squirrels (Sciurus niger) experimental data Viremia <2 days in most 80% had levels high enough to infect mosquitoes No squirrel-squirrel transmission Incubation ~1-10 days Only 5-10% become ill Symptoms: tremors, head tilt, incoordination No gross lesions seen on necropsy Microscopic lesions in heart kidneys, brain, spinal cords, and liver. Oral and rectal shedding of virus for 7-22 days post exposure Oral transmission possible but not shown Virus in urine up to 17 days post exposure Platt et al, 2008 and Root et al, 2006

46 WNV and Eastern Grey Squirrels Experimental data No illness Low viremia Lesions in organs 1 aces.edu 1 Gomez et al 2008

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49 WNV Prevention-rehabbers Isolation of sick animals Avoid bird-to-bird spread Caution with discharges and secretions Hand washing often Wear gloves, +/- goggles and more Disinfect often Change clothes after working with animals Hand washing

50 WNV Prevention -General Avoid outdoors, dawn, duck, evenings Wear mosquito repellant if outside then Repair Screens on house Dump standing water 2x/week Mosquitofish for ponds Mosquito dunks for other standing water Report dead birds and squirrels

51 Your Role - Surveillance Report all dead birds and tree squirrels WNV-BIRD Location found species, current condition Online, birds only: If freshly dead, carefully bag, put aside Wear gloves, wash hands Keep carcass cool Keep carcass away from food Even if no test data helps

52 WNV movie maps

53 Additional Disease updates Distemper, heartworm, leptospirosis, murine typhus,

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58 References Baty S (AZDPH) and McCollum A (CDC) Bat-Associated Rabies Virus in Skunks and Foxes, Flagstaff, AZ, 2009 CDC Zoonotic Disease Conference Call. Nov 4, 2009 Blanton JD, Bowden NY, Eidson M, Wyatt J, Hanlon CA. (2005) Rabies Postexposure Prophylaxis, New York, Emerg Infect Dis 11(12): California Department of Public Health website: California West Nile Virus webpage Centers for Disease Control and Presentation Rabies website: Centers for Disease Control and Presentation WNV website: Centers for Disease Control and Prevention. (1993). Raccoon Rabies Epizootic-US MMWR CDC Surveill Summ 43(15): Green C and Rupprecht C. (2006). Rabies and Other Lyssavirus Infections. In C Green (Ed.) Infectious Diseases of the Dog and Cat (pp ). St Louis, MO: Saunders. Gomez A, Kramer L, Dupuis AP et al. (2008). Experimental Infection of Eastern Gray Squirrels (Sciurus carolinensis) with West Nile Virus. Am J Trop Med Hyg 79(3): Interview with Tracey McNamara. (Aug 2002). J Homeland Security. Available at: Default.aspx?oid=15&ocat=4. Accessed 11/19/09. Lichtensteiger and Green C. (2006). West Nile Virus Infection. In C Green (Ed.) Infectious Diseases of the Dog and Cat (pp St Louis, MO: Saunders. Lim AK, Dunne G, gurfield N (2009) Rapid bilateral intraocular cocktail sampleing method for West Nile Virus detection indead corvids. J Vet Diagn Invest. 21(4) Nemeth N, Gould D, Bowen R, and Komar N (2006). Natural and Experimental West Nile Virus Infection in Five Raptor Species. J Wildlife Dis. 42(1):1-13.

59 References Nemeth NM, Kratz GE, Bates R, et al (2009). Clinical Evaluation and outcomes of Naturally Acquired West Nile Virus Infectioon in Raptors. J Zoo Wildlife Med 40(1): Nemeth NM, Oesterle PT, and Bowen RA (2009). Humoral Immunity to West Nile VirusIs Long-Lasting and Protective in the House Sparrow (Passer domesticus). Am J trop med Hyg 80(5): Pavlin BI, Schloegel LM and Daszak P. (2009). Risk of Importing Zoonotic Disease through Wildlife Trade, United States. Emerg Infect Dis 15(11): Platt K, Tucker BJ, Halbur PG et al. (2008). Fox Squirrels (Sciurus niger) Develop West Nile Virus Viremias Sufficient for Infecting Select Mosquito Species. Vector Borne Zoonotic Dis. 8(1): Root J, Oesterle PT, Nemeth NM et al (2006) Experimental Infection of Fox Squirrels (Sciurus niger) with West Nile Virus. Am J Trop Med Hyg 75(4): Swartout HO and Harvey CO. (1942). Rabies Epidemiology and Control in Los Angeles County. Cal West Med 57(4): Available at: Vener HI (1939). Concerning the Incidence of Rabies in Los Angeles City and Los Angeles County. Cal West Med 48(6): 473. Available at: Sterner RT, Sun B, Bourassa JB, Hale RL, et al (2008). Skunk Rabies in California ( )- Implications for Oral Rabies Vaccination. J Wildl Dis 44(4): Trevejo R and Eidson M(2008). West Nile Virus. J Am Vet Med Assoc. 232(9):

60 Human Rabies Cases October 2004, Los Angeles Man goes to emergency room Very bad back pain given antibiotics for kidney infection Does not mention any animal bites Next day Pain is worse, behavior changes Pain medicine, sent home Next day Back pain spread to abdomen Problems swallowing Nausea Problems breathing More tests hospitalized and given more medicine Dies five days later in hospital Tests show he caught rabies from a dog in El Salvador 15 months before death.

61 California Human Rabies Cases Since 1990, 12 of 53 cases (23%) in U.S. were reported in CA residents. 1992: 11 yo male; Fresno Co.; dog bite in India 1993: 69 yo male; Contra Costa Co.; dog bite in Mexico 1994: 44 yo male; Alameda Co.; silver-haired bat variant 1995: 27 yo male; San Benito Co.; Mex. free-tailed bat 1995: 74 yo male; Butte Co.; silver-haired bat variant 2000: 49 yo male; Amador Co.; Mex. free-tailed bat variant 2001: 72 yo male; San Diego Co.; Philippine dog variant 2002: 28 yo male; Glenn Co.; Mex. free-tailed bat variant 2003: 66 yo male; Trinity Co.; silver-haired bat variant 2004: 28 yo male; Los Angeles Co.; El Salvador dog variant 2006: 9 yo male; San Joaquin Co.; Philippine dog variant 2008: 16 yo male; Santa Barbara Co.; Mexico, variant pending Courtesy Dr Ben Sun, CA State Public Health Veterinarian

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63 1941 Over 40 dogs attacked. Veterinary Public Health No map, however, can show that people still doubt the existence of rabies.. Downey Shelter Swartout and Harvey, 1942

64 Rabies Control History in LA County 1937 LA County Pound Dept 1956 Rabies vaccination required for dog licensing 1950s Mandatory rabies vaccination of dogs spread across US Before 1950s: human rabies per year Now: <3 human rabies cases per year. 1950s rabies vaccine clinic.

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66 New Potential Rabies Source: Smuggled Puppies from Mexico Many smuggled over Mexican border Mostly small, purebred puppies Sold at street corners, parking lots and flea markets sold for $300 - $1,000, or more, cash 10,000 puppies entering San Diego County over Mexico border per year. "Puppy peddling is better than selling drugs. The consequences are far less." Problems with rabies in dogs of Mexico. All imported puppies SUPPOSED to be quarantined at home until 5 months old.

67 Importing Zoonoses through wild mammals US world s largest importer of animals >1 billion ,537 raccoons Quarantine for only birds, primates, some ungulates Home confinement required for dogs. Ex: Ebola (primates), monkeypox (rodents) TOP 5 disease risks from wild mammals: Rabies, anthrax, tuberculosis, Echinococcus spp, leptospirosis. TOP 6 Genera Canis, Felis, Rattus, Equus, Macaca, Lepus/lagomorphs Country of origin often not clear Wildlife-human interface of key PH importance Pavlin et al, 2009

68 In 2008 in Los Angeles County there were 170 human cases and 6 human deaths.

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