Sarcoptic Mange Sarcoptes scabiei mite ~1/64 of an inch long

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1 Sarcoptic Mange Sarcoptes scabiei mite ~1/64 of an inch long
Pearly white and oval-shaped Spines on bodies Year-round; winter Humans ("scabies"), canids, felids, bears, mustelids Common in red fox, wolves, and coyotes in N. America impacts on younger animals Highly contagious, direct transfer of mites at any stage of their development Indirect transfer of mites (mechanical transfer) – importance?

2 Sarcoptic Mange Highly specific to host type,
Life cycle completed in burrows within epidermis of host Adult mites mate in small pockets near the surface of skin Hatched larvae pass through a nymphal stage and continue migration through epidermis, becoming adults within 2 weeks

3 Sarcoptic Mange Female mites burrow into skin of host; use jaws and front legs to cut skin Female lays 2-3 eggs each day, up to 2 months Larvae hatch, 3-4 days Crawl onto surface of skin, use hair as shelter Both larvae and adults eat skin cells from hosts

4 Sarcoptic Mange Oily skin, crusting, hair loss, scab formation
Lesions - physical damage to skin, irritation caused by parasite excretions, and allergic response of host Hair loss in characteristic patterns (alopecia) Poor body condition, listlessness, abnormal behavior, increased scavenging May ultimately die from complications with mange infection or exposure; winter

5 Sarcoptic Mange Trichodectes canis Dog biting louse 2ndary infection

6 Sarcoptic Mange – WI Wolves
1st identified in a Great Lakes wolf, 1991 Since 1991, signs of mange detected in 27% of wolves High of 58% in 1993 = 11% decline in wolf population Some literature suggesting population impact most severe in 2nd or 3rd year of epidemic Impacts on annual pup survival?

7 Ticks Ixodes (e.g., deer tick; Lyme disease (Borrelia burgdorferi)
Dermacentor (Am. Dog tick & Rocky Mtn wood tick); Rocky Mountain spotted fever (Rickettsia rickettsii ) Amblyomma (e.g., lone star tick; Ehrlichiosis (Ehrlichia)

8 Ticks Winter tick (Dermacentor albipictus)

9 Ticks

10 Ticks Winter tick (Dermacentor albipictus)

11 Ticks Moose begin grooming in Jan (nymph stage) – mechanical and/or immunological irritation Extensive grooming through Mar-Apr = destroy winter coat Severe hair loss = gray coloration (undercoat) = "ghost moose".

12 Nasal Leeches Leech (Genus Theromyzon) feeds directly on blood from nasal passages, trachea and mucous membranes of eyes Spring/summer - leeches actively seeking potential hosts and reproducing Dabbling ducks (e.g., mallard, teal, wigeon, northern shoveler, etc.) and swans

13 Nasal Leeches Protruding from nares or attached externally
Resemble small sacks of blood Birds vigorously shaking heads, scratching bills or sneezing Nasal and respiratory tract infestations = labored breathing and gaping (similar to aspergillosis infection)

14 Nematodes = roundworms
Complete digestive systems Most species dioecious 2 main categories eggs are infective larva are infective

15 Gizzard Worm Parasitic nematode Genus Amidostomum or Epomidiostomum
10-35 mm, coiled, thread-like roundworm Beneath surface lining and grinding pads of gizzard waterfowl

16 Gizzard Worm

17 Gizzard Worm 1st exposure on breeding grounds
Large worm burdens; reduce vigor, couple with migration, etc… No field signs Poor growth/weight gain in young birds? Emaciation, general weakness Poor digestion

18 Raccoon roundworm - Baylisascaris procyonis

19 Raccoon roundworm - Baylisascaris procyonis
Life cycle is direct or indirect depending on age of raccoon Definitive host

20 Raccoon roundworm - Baylisascaris procyonis
Adults in intestines lay eggs

21 Raccoon roundworm - Baylisascaris procyonis
Eggs are shed with feces

22 Raccoon roundworm - Baylisascaris procyonis
Eggs are shed with feces – loads of ‘em

23 Raccoon roundworm - Baylisascaris procyonis
Sticky, proteinaceous outer coat

24 Raccoon roundworm - Baylisascaris procyonis
Over 2-4 weeks the eggs develop larvae

25 Raccoon roundworm - Baylisascaris procyonis
Can remain infectious for years

26 Raccoon roundworm - Baylisascaris procyonis
Embryonated egg with larvae is ingested by young raccoon -- Direct

27 Raccoon roundworm - Baylisascaris procyonis
Egg hatches in to larva

28 Raccoon roundworm - Baylisascaris procyonis
Larvae in intestines develop into egg-laying adults Infection rates in raccoons are high – as high as 70% of adults and over 90% of juveniles

29 Raccoon roundworm - Baylisascaris procyonis
Embryonated egg with larvae are ingested by intermediate hosts

30 Raccoon roundworm - Baylisascaris procyonis
Eggs hatch and release larvae into intestines  gut wall  migrate thru the various tissue (larval migrans) causing considerable damage and then encyst

31 Raccoon roundworm - Baylisascaris procyonis
In the eye  blindness

32 Raccoon roundworm - Baylisascaris procyonis
5-7% CNS disease

33 Raccoon roundworm - Baylisascaris procyonis
Dead intermediate is scavenged by adult raccoon – Indirect

34 Raccoon roundworm - Baylisascaris procyonis
Raccoons are ubiquitous in U.S. and urban adapted

35 Raccoon roundworm - Baylisascaris procyonis
Definitive host??

36 An emerging zoonotic especially of young children
Contact with raccoon feces Pica/geophagia Young age (less than 4) Male Developmental delay At any age – anyone exposed to raccoon feces – researchers, wildlife rehabilitators, etc – asymptomatic or subclinical, sometimes ocular migrans or encephalitis

37 Pathology Aggressive migration of larvae Molt and grow as migrate
Only 5-7% enter neural (or ocular) tissue – induce an inflammatory (eosinophilic) response  encephalitis Migrate extensively in brain before being walled off by host Post-inflammatory atrophy, necrosis, and impairment Very distinctive prominent alae excretory columns multinucleate

38 Encephalitis in an 11-month-old boy.
Abnormal high signal throughout most of the central white matter (arrows) compared with the dark signal expected at this age (broken arrows). Extensive evidence of raccoon activity and fecal contamination, including 21 latrine sites, were identified on the patient’s property and the adjacent vacant lot. 11 raccoon were necropsied, all were positive.

39 Raccoon Roundworm Single adult female worm = 115,000 to 877,000 eggs per day raccoon infected with multiple worms = shed up to 45,000,000 eggs daily

40 Raccoon Roundworm midwestern U.S. documented in 68–82% of raccoons; >90% juveniles

41 Raccoon Roundworm Prevalence, intensity of infection, avg # of larvae significantly higher in the highly fragmented landscape Probability of infection, intensity of infection, and avg # of larvae per mouse per patch varied as functions of forest patch area and isolation (DD)

42 Raccoon Roundworm A study conducted in Northern California tried to determine if a pattern existed to the preferred location of latrines. While latrines on the ground and on roofs appeared to be the most favorable, preferences varied by location.

43 Raccoon Roundworm Percentage of California properties that contained at least one raccoon latrine positive for Baylisascaris procyonis eggs (number of properties = 164).

44 Raccoon Roundworm Eggs ~ 65 microns in size
Household disinfectants (bleach) will not kill (remove coating) Fire/heat, boiling water, required to kill eggs

45 Raccoon Roundworm: Trophic-level Effects
Former range of the Allegheny woodrat (inside bold line), and regions where woodrats have disappeared in recent decades (stippled areas).

46 Raccoon Roundworm: Trophic-level Effects
Range of raccoon roundworm in Allegheny woodrat states