Update: New World Screwworm in Florida - Dr. Michael Short, State Veterinarian/Director, Division of Animal Industry, Florida Department of Agriculture and Consumer Services, from the 2017 NIAA Annual Conference, U.S. Animal Agriculture's Future Role In World Food Production - Obstacles & Opportunities, April 4 - 6, Columbus, OH, USA.
More presentations at http://www.trufflemedia.com/agmedia/conference/2017_niaa_us_animal_ag_future_role_world_food_production
2. Cochliomyia hominivorax
Only insect known to
consume living tissue
of warm- blooded
animals
Currently endemic in
South America and
some Caribbean
Islands, including Cuba
3. Female flies only mate once
Female flies attracted to blood or odors
Eggs laid near wound
First instar visible in ~3 days – discharge and
odor
Second instar and third instar ~4-12 days
Pupae drops from wound – burrows into ground
Hatch depends on environmental conditions
○ Mature in 3-5 days to mate
4.
5. 1852: First reports of New World
Screwworm
1958: Development of sterile male
technique (SIT)
1966: U.S. free of Screwworm
1991: Mexico declared free
2003: Sterile fly facility
established in Panama
6. Sterile Insect Technique (SIT) is the only
effective strategy for eliminating established
NWS fly populations.
Affected areas are inundated with sterile male
NWS flies.
Target is 10:1 ratio of sterile to wild type
The females only mate once in their lifetime, so
every female that mates with a sterile male has
no offspring.
7. Larvae visible in wound by 3 days
May be hundreds present
Bloody discharge
Foul-smelling odor
Depression
Off feed
Separation
Attempt to control discomfort
Can be fatal if not treated
8. Removal of larvae
Debridement, if necessary
Good hygiene
Topical Insecticides
Anti-parasitic drugs
Avermectins-Injectable, topical
Capstar (nitenpyram)
others
9. Contact from biologist at National Key Deer
Refuge (September 29, 2016)
Severe fly infestation with aggressive myiasis
Over 20 deer had been euthanized for myiasis
Big Pine Key & No Name Key
Original case – July 4, 2016 in deer
motor vehicle related injury
Larvae sample shipped to NVSL
high priority investigation
10.
11.
12. Administered by US Fish and Wildlife Service
Endangered Key Deer reside on multiple keys
~1000 deer; residing on ~20 keys
Reside on refuge and freely wander into
urban/residential areas
Significant urban/wildlife interface
2016 fawn crop was good and survival was good
Fawning season (Mid March – Late May)
13.
14.
15.
16. Deaths (July – September 2016)
July = 4
August = 7
September = 20
Male = 25
Female = 5
Unknown = 1 0
1
2
3
4
Female
Male
Unknown
Key Deer bucks had started rut by August
17. Unified Command – USDA, FDACS, Monroe
County Emergency Operations
Joint IMT deployed to Florida Keys
Multiagency
Declaration of Agricultural Emergency
○ Commissioner of Agriculture and Consumer Services
Official State Quarantine Area
Controlled Animal Movement from Monroe
County
○ Key Largo Interdiction Station
18. USDA APHIS Veterinary Services
FDACS
Monroe County EOC
US Fish Wildlife Services
USDA APHIS Wildlife Services
Florida Fish & Wildlife Commission
USDA ARS
USDA IS
COPEG – Panama Barrier Eradication Program
19. Prevent infestation from spreading to new areas
Disease surveillance to identify additional cases
Fly-trapping to determine the extent of infestation
Elimination of New World screwworm flies from
the affected Keys
Sterile fly release twice weekly at several locations
○ Approximately 7.2 million flies per week
Treat Key Deer
20. Yellow Border = Surveillance Zone, Red Border = Infested Zone, Orange Border = Barrier
Zone
As of 01/01/2017, barrier zone changed to Northern Surveillance Zone
21.
22.
23.
24. Baiting flies with liver, capturing adult flies
Entomologist evaluates
Wild type NWS Flies
Sterile NWS Flies (release flies)
27 Keys in the NWS Infested Zone
3 Keys in the NWS Barrier Zone
7 Keys in the NWS Northern Surveillance
Zone
6 Keys in the NWS Southern Surveillance
Zone
25.
26. Euthanasia and Disposal of infested Key
Deer
Treatment of Key Deer (>15,000 doses)
Oral preventative
○ Hand feeding
Topical Systemic preventative treatments
○ Treatment Stations
Immobilize and treat of clinical cases
31. Over 160 million flies
released to date
Shipments from
Panama on Monday &
Thursday
Releases on Tuesday
and Friday
29 release sites on 14
keys
Releases on keys with
infestation, and
Releases (4) in barrier
zone (ended on 12/26/16)
32.
33. Red border = Infested Zone; Orange border = Barrier Zone
34. Stray Dog found near Everglades National
Park entrance with myiasis
Picked up by Miami Dade Animal Services
Confirmed positive for NWS – 01/06/2017
Single male
NWS fly capture
in extensive
liver assessment
trapping
36. Confirmed positive NWS cases - 17
6 domestic animal cases and 11 wildlife cases
16 cases from infested zone (on 6 keys)
○ Last case confirmed Key Deer 01/10/2017
Confirmed negative investigations - 53
45 domestic animal cases and 8 wildlife cases
9 cases in Infested Zone and 39 from mainland
Also, 1 AL case, 2 GA case and 2 LA cases
37. 0
10
20
30
40
50
60
NWS Confirmed and Presumptive Cases
Key Deer Cases Confirmed Wildlife (non Key Deer)
Presumptive Domestic Animal Cases Confirmed Domestic Animal Cases
Index Case 09/29/2017 SIT began 10/11/2017 Deer Treatment began 10/26/2017
38. Closed Interdiction Station on March 18
Stopped releasing sterile flies in Homestead are
on March 24
Closed ICP on March 25
Releasing sterile flies in Lower Keys until April 24
Stopped deer treatment stations on March 16
USFWS stop hand treatments of deer on April 10
Stopped active surveillance on March 15
Continuing close surveillance of Key Deer
Continuing outreach and education
- Adult female flies are attracted to wounds as small as a tick bite.
- Will lay ca. 300 eggs on average at the side of the lesion, or may lay eggs next to mucous membranes of nasal cavity, eyes, prepuce, vulva, anus.
- Eggs hatch within 8-24 hours.
- 1st instar larvae burrow into lesion, may not be visible unless SQ tissues are exposed.
- Feed on SQ tissue, molting to 2nd and 3rd instar larvae over 4-12 days.
When released in large numbers twice a week over several life cycles (dependent on fly densities), the population declines rapidly and soon disappears.
Flies are sterilized by exposure to radiation (in this case, gamma rays), causing chromosome damage and non-viable sperm.
SIT has allowed eradication in US, MX and other Central American areas
Government and Private lands mixed over multiple keys, Multiple species on endangered list, Many are insects, Including , Bartram's, Hairstreak butterfly
Origination of the infestation. We don’t know for sure. Don’t have a good genetic bank. Don’t have good specimens from Cuba.
public outreach was key to the response efforts including surveillance reporting of cases, supporting fly releases and treating key deer.
Under disease surveillance: Important components are Active and Passive surveillance as well as and interdiction station.
Outreach, Veterinarians clinics,; 1-800-HELP-FLA; Posters/brochures, dedicated website, two large townhall meetings, Raido messages,, animal concentratuion points such as shclters, groomers, pet stores, state parks (people camping/visiting with pets); ; Marinas,
Also sent daily and then weekly summaries regarding the incident. The updates were in green font.
Located at mm 106 in Key Largo. Farthest key north coming out of the keys. Only one road into the keys and one out.
Veterinary Support and Animal: “Mandatory” inspection of all animals
Treatment required for all livestock
Companion Animals with wounds, close examination
Production is being ramped up in Panama and so the number of flies released will continue to increase as flies are available. Fly assessments will continue to determine need for additional release sites.
Two Strike formed of Panamanian technicians, FDACS/USDA facilitators
Some releases require boat transportation
Sterile Fly Release Plan based on: USDA ARS, USDA IS, COPEG Subject Matter Experts
Aerial and Ground Assessment for release sites used Mapping for habitat and access
Stray dog was taken to veterinary hospital who contacted FDACS.
The outreach activities are shown for the area around the location where the stray dog was found. Over 1400 visits.
102 vet hospitals, 138 farm or ranch facilities
Yellow boxes are fly release sites, Red X is site where dog was found, Inner circle is 3 miles, Outer circle is 10 miles, Blue and turquoise boxes are outreach visits – Blue are locations with animals; turquoise are locations with no animals