Download Cindy P. Driscoll, DVM MD DNR State Wildlife Veterinarian Director

MOSQUITO AND VECTOR-BORNE DISEASES
(WITH THOUGHTS ON CLIMATE CHANGE)
Cindy P. Driscoll, DVM
MD DNR State Wildlife Veterinarian
Director, Fish & Wildlife Health Program
Cooperative Oxford Lab
Oxford, MD
What’s a Veterinarian Doing at a Mosquito Conference?
We are all connected:
humans, domestic animals,
wildlife, and fish in our
shared environment
Joshua Lederberg, 1997
ZOONOTIC DISEASES REPORTABLE IN
MARYLAND (AND MOST STATES)
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Anthrax
Brucellosis
Arboviral encephalitis*
Ehrlichiosis*
Leptospirosis
Lyme disease*
Mycobacteriosis (TB)
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Plague*
Psittacosis
Rabies
RMSF*
Salmonellosis
Trichinosis
Tularemia*
Vector-borne diseases*
ONE HEALTH AND DISEASE INTERFACES
Environment &
One
Health
USGS
ROUTES OF DISEASE TRANSMISSION
Contact - handling WL
Aerosol
contact
Tick & vector–borne dz
LD, WNV
Contact with
contaminated water
EMERGING INFECTIOUS DISEASES
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Globally, approx 60% of EIDs are zoonotic diseases
Of these, > 71% have wildlife origins
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Avian Influenza (HPAI)
SARS
WNV
Ebola
Wildlife as sentinels for early detection of emerging diseases,
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global environmental alterations, and climate change
Highlights the connection between human health, animal
health, and ecosystem health
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Emphasizes the need for a collaborative approach
EMERGING INFECTIOUS DISEASES
DISEASE POTENTIAL & THE
EPIDEMIOLOGIC TRIAD
3 Changing elements:
1) agent
2) host
3) environment
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Potential for disease is due to
continual change and evolution
New, emerging and re-emerging
diseases will always develop and
are the “norm” rather than the
exception
Epidemiologic Triad
AGENT
HOST
Virulence
Antibiotic susceptibility
Immune reaction
Distribution
Vectors
Survival characteristics
Host range
Antimicrobial resistance
ENVIRONMENT
Diet
Immuno-competence
Exposure status
Age
Concurrent disease
Activities
Human global travel
Climate
Demographics
Mgmt. practices
Culture
Exposure level
Stress
Disruption
Habitat loss
IMPACTS – WHY ARE DISEASES EMERGING?
 Impacts on human health, wildlife
health & global economies and
societies
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Global travel – spread of disease
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Within 24 hrs
Millions of people living with
infectious diseases globally
> 200 million poultry culled since
2003 as a result of H5N1 HPAI
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Spread of Influenza?
Cost to society?
National Fish, Wildlife & Plants Climate Change Adaptation Strategy
IMPACTS
 Impacts to wildlife
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New and emerging diseases
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White-Nose Syndrome in bats
Amphibian extinctions from chytrid
fungus
Chronic Wasting Disease
Re-emerging diseases….?
IMPACTS – CHANGING HABITAT
Hurricanes  wildlife?
Hurricane IRENE brings snakes out in
Montgomery County, MD
Could two snake-bitten Montgomery County,
Md., residents be among the casualties of
Hurricane Irene?
Both victims received anti-venom and
follow-up care at Shady Grove Adventist
Hospital after being bitten Tuesday night.
Two venomous snakes are native to
Maryland: copperheads and timber
rattlesnakes, according to the Maryland
Department of Natural Resources.
Copperheads are suspected in both cases.
The weekend weather may have lured the
snakes out of the woods, a hospital
spokesperson said. Some of there homes
flooded, too, so they are coming out of their
holes.
Tim Ryan, of ABC Wildlife Removal, said he
expects more snake calls. Snakes will be
looking for places to hibernate in the coming
months, and they might choose places like
attics and wood.
CLIMATE CHANGE
 Intergovernmental Panel on
Climate Change (2007):
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Predicts unprecedented rise in:
 Global temperatures, sea levels
 Altered precipitation patterns
 Will have significant impacts on
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animal and human diseases
Evidence of climate change
effects:
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Incidence and geographic
distribution of diseases
 Changes in migration patterns
CHESSIE THE MANATEE: IN SEARCH OF A
“CHANGE OF LATITUDE”
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1994 – Rescued Ches. Bay
1995 Traveled to RI/ CT
1996 --- 2012 found again in
the Chesapeake Bay
2009-10 Stranded manatee
died in Massachusetts;
rescued in NJ
New – or OLD migratory
ranges? – or global
warming?
DISEASE EXAMPLES
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Correlations in WTD HD:
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Higher winter and summer
temperatures increase vector
capacity and competence
Increase ability to acquire,
maintain, and transmit the
virus
Increase vector abundance,
survival, biting
Lower summer rainfall may:
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Improve or increase breeding
sites for midges
Increase physiological stress on
deer
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Decrease immune function &
prolong viremias
White Tailed Deer (WTD)
Hemorrhagic Disease (HD)
HD variation over time
CONSEQUENCES OF CLIMATE CHANGE
Before 1995
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Changes in:
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1
Geographic range and distribution
of wildlife diseases
Wildlife host-pathogen interactions
Pathogen virulence and genetic
diversity
Disease patterns in wildlife
2
After 1995
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1. Geographic range of lung parasite of
caribou, Parelaphostrongylus odocoilei, since
1995
2. Avian malaria Plasmodium relictum –
Hawaiian birds
- High elevations getting warmer
- Parasite proliferating (<1500 ft……now >
1500 ft??)
- Endangered populations - even more
critical
EMERGING INFECTIOUS DISEASES
Factors favoring disease emergence
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o
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o
New pathogen or more virulent existing pathogen
New host population or increase in host susceptibility
Extension in host-pathogen range
Increase in human/domestic animal/wildlife interface
Global travel (animals and humans) and trade
Antimicrobial resistance of pathogens
Habitat alteration or destruction
o
Climatic conditions change
o
Environmental contamination affects
WILDLIFE VECTOR-BORNE DISEASES
[TICK-BORNE DISEASES – ALREADY COVERED]
EEE, VEE, WEE, SLE,
Epizootic
WNV, LAC
hemorrhagic dz /
 Dengue, Malaria
Blue tongue
 Pox, Heartworm
 Vesicular stomatitus
“SPEED
DATING FOR WILDLIFE DISEASES”
 Fibroma deer &
 Anaplasmosis
squirrel
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Rabbit abdominal
worm
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Onchocerca cervalis
Leishmaniasis
Tularemia
[mechanical transmission – anthrax, dermatophilosis]
WILDLIFE VECTOR-BORNE DISEASES
WNV – STILL AROUND….
E. Miller
E. Miller
E. Miller
MID-ATLANTIC EEE
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~1831 - Equine epizootics - East Coast
1933 – EEE isolated, Mid-Atlantic equine
epizootic
1938 – EEE mortality in RN Pheasants - CT
1984 EEE killed 7 Whooping Cranes at
Patuxent Wildlife Research Center, Laurel,
Maryland
G. Olsen
EEE MORTALITY CASE - MARYLAND
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1984 - 7 whooping cranes
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July –Sept.
Birds ranged in age from 1
to 16 years
3 birds - clinical signs
Good body condition
Gross lesions – variable
Fluid in airsacs
Histopath – acute necrosis
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Most organs
G. Olsen
HABITAT & MONITORING
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Arboreal
Late summer and fall
Small puddles, such as
occur when trees
uprooted are used for
breeding
HISTORY OF EEE IN WHOOPING CRANES
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High virulence of
EEE in exotic birds
Benign disease in
native wild birds
Two forms
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Neurotropic
Viscerotropic
Current program - vaccination
EPIZOOTIC HEMORRHAGIC
DISEASE (EHD)
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Orbiviruses
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WTD, mule deer, pronghorn antelope, big
horn sheep and cattle susceptible to both
Elk only susceptible to BTV; cattle are the
BTV reservoir
Transmission
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EHDV (serotypes 1, 2, and 6)
Bluetongue/BTV (22 serotypes) – 2, 10, 11,
13,17
Vector: Biting midges (Culicoides spp)
10-20 d. after blood meal -viremic animal, can
infect new host.
Outbreaks in late summer, early fall
(often near water)
EPIZOOTIC HEMORRHAGIC DISEASE (EHD)
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Acute form
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Sub-acute form
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Severe edema of the head, neck, tongue, lungs
Fever, respiratory distress
Cyanotic mucous membranes
Rapid death
Less severe than acute
Lameness, ataxia
Secondary infections
Chronic form
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Fever, mild cyanosis, recovery
Sequelae- laminitis, stomatitis, rumenitis,
pneumonia
Sloughed hooves, deformed coronary band
growth
EPIZOOTIC HEMORRHAGIC DISEASE (EHD)
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Diagnosis
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Prevention and control
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Vector control
Recent outbreaks (2013) – 15
states!
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Virus isolation
Serology for chronic cases
EHDV 6: FL, IN, IA, MI, MO
Michigan reporting 10,000 dead
deer
Noted expansion to northern
Latitudes
New serotypes EHDV-6 and BTV
13 since 2006
DEER FIBROMA
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Cause: Papillomavirus
Hosts: WTD
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Signs: Benign tumors most
common:
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Highest incidence in young bucks
Proliferative, wart-like growths on
skin of eyes, neck, face, forelegs
Transmission: Scratching posts,
sparring & fighting insect bites
Diagnosis: By gross appearance
and skin biopsy
Significance: Size and location
may cause physical problems
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Spontaneous regression possible
TULAREMIA
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Bacterial zoonosis, Francisella tularensis
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Small, Gram-negative coccobacillus
2 subspecies with different virulence
Maintained and amplified in nature
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Vertebrate reservoirs
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Arthropod / insect vectors
100-200 cases annually in the U.S.
www.NWHC.usgs.gov
REPORTED CASES OF TULAREMIA
UNITED STATES, 1945-1999*
*1999 provisional
TRANSMISSION
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Highly infectious – 10-50 organisms
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Laboratory transmission
Exposure to infected tissues leading to direct
inoculation of wound or mucous membrane
Arthropod or insect bite - tick, deerfly, mosquito
Ingestion
Inhalation
Person-to-person NOT known to occur
CLINICAL PRESENTATION
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Extremely variable, varies
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Route of inoculation
Dose
Virulence
Incubation: 3-5 days (range: 1 – 14 d.)
Febrile illness
Chills, headache, myalgia, fatigue, sore
throat, cough, shortness of breath,
vomiting, diarrhea
Prominent lymphadenopathy
POX VIRUS
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Most strains –
species specific
Abscess-like tumors
that hemorrhage
readily
Cutaneous “dry”
form
Impair vision
Poor prognosis
POX VIRUS
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Transmission
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Mosquitoes, mites
Direct – open wound
Virus – latent (years)
Immune monthsyrs
Incubation – 7-9 days
VESICULAR STOMATITIS
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Rhabdovirus (New Jersey, Indiana serotypes)
Domestic hosts- swine, cattle, horse, donkeys, mules;
(rare in sheep and goats)
Wildlife hosts- deer, elk, bobcats, raccoons
Enzootic in North America (common is Southern Atlantic
and Gulf Coastal plains)
Transmission by insect vectors and direct contact
Incubation period 2-8 days
VESICULAR STOMATITIS
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Lesions similar to other “vesicular diseases”- SVD, VES,
and FMD. Need to differentiate!
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Vesicles on mucous membranes of lips, tongue, gums,
mouth, muzzle, nostrils, teats, soles of feet, coronary
band
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Diagnosis: Serology (ELISA, CF), VI, PCR
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No treatment
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Vector control by stabling horses, insect repellents; no
control for wildlife
HEARTWORM
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Dirofilaria immitis
Domestic dogs and cats
Sporadic in wild mammals
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Fox
Coyote
Wolf
Raccoon
Black bear
Beaver
Ferret
Harbor seal, Sea lion
All states including Alaska; Canada
Common in Atlantic and Gulf coasts, Mississippi
River valley
Mosquito vector transmission
HEARTWORM
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Life cycle:
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Adult worms live in heart, pulmonary arteries → microfilaria
circulate in blood →
Ingested by mosquito → develop to infective larvae and migrate to
mouthparts →
Infect next host by mosquito bite → further develop in SQ and
muscles → migrate to Right heart and mature
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Cough, fatigue, pulmonary thromboembolism, CHF
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Diagnosis by microfilariae in blood, Xray, necropsy
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Treatment for domestic animals, not wildlife
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Wild mammals not considered a reservoir
MD One Health
Bulletin
ADDITIONAL INFORMATION
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Maryland DNR
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www.dnr.maryland.gov
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www.dhmh.maryland.gov
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www.nwhc.usgs.gov
Maryland DHMH
USGS National Wildlife Health Center
Southeastern Cooperative Wildlife
Disease Study
www.scwds.org
 USFWS - www.fws.gov
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USDA APHIS Wildlife Services
www.aphis.usda.gov/ws
 CDC - www.cdc.gov
 WDA – www.wildlifedisease.org
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Important Phone Numbers
IMPORTANT NUMBERS
• To report wildlife illness or death (i.e. > 5 animals; not single bird) or to talk to a wildlife
professional about nuisance wildlife, call the DNR / USDA WS Call Center:
1-877-463-6497
• To find a wildlife rehabilitator (e.g. – if you find an injured bird, squirrel, etc.):
http://www.dnr.state.md.us/wildlife/wlproblems.asp
• For general fish or wildlife information: 1-877-620-8DNR: www.dnr.state.md.us
• Report fish kills, algal blooms, oil spills – call toll free: 1-877-224-7229
•MD DNR Wildlife & Heritage Service: 410-260-8540; Fisheries: 410-260-8325
• Report sightings or strandings of live or dead marine mammals or sea turtles:
1-800-628-9944
• State Wildlife Veterinarian: Dr. Cindy Driscoll – 410-226-5193; [email protected]
• For Domestic Animals/ Agriculture: 410-841-5810
Asst. State Ag. Veterinarian: Dr. N. Jo Chapman [email protected]
• For Zoonotic / human health information: www.dhmh.state.md.us
• St. Public Health Veterinarian: Dr. Katherine Feldman: [email protected]
DHMH Ctr for Zoonotic & Vector-Borne Disease Office: 1-410-767-5649
• Contact your personal physician or local health department
ZOONOTIC DISEASES
Maryland Department of Natural Resources
Cindy P. Driscoll, DVM
Maryland Department of Natural Resources
Fish & Wildlife Health Program
Cooperative Oxford Laboratory
904 South Morris Street
Oxford, MD 21654
O: 410-226-5193
F: 410-226-5925
E: [email protected]
All Wildlife Fisheries, Marine Mammal and Sea Turtle Issues:
24/7 Toll-free: 1-800-628-9944
Thanks for Your Attention!
Questions?