Protozoan Parasites: Lecture 20 Apicomplexans II Coccidia Part II & Cryptosporidium Pages 28-36

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1 Protozoan Parasites: Lecture 20 Apicomplexans II Coccidia Part II & Cryptosporidium Pages 28-36

2 Coccidia: Life cycle & treatment/control effectiveness? Asexual stages Sexual stages Prophylactic drugs Current drugs only work on asexual stages outside of host cells Sanitation : within hours i.e. before oocysts are mature & infective (sporulated oocyst) Supportive therapy - No current drugs kill/target sexual stages in cells

of Eimeria Prepatent period: 4-5 days Eimeria tenella

3 Eimeria acervulina Most common Mildly pathogenic Upper small intestine Avian Coccidiosis Chickens - 9 species of Eimeria Prepatent period: 4-5 days Eimeria tenella Most pathogenic (high mortality) Cecum Prepatent period: 7+ days

4 Pathogenesis Site of infection Small intestine to cecum depending on species involved Intestinal / cecal lesions range from minor to round, white/grey plaques to severe necrotic cores & hemorrhage with significant blood loss

5 Clinical signs Bloody droppings & hemorrhagic diarrhea beginning 4 days post infection Acute death High mortality rates Emaciation, pallor & inappetence

Control &Treatment $ 700 million/year loss Isolate sick birds treating sick birds is futile Treat healthy birds with anticoccidial medications

6 Control &Treatment $ 700 million/year loss Isolate sick birds treating sick birds is futile Treat healthy birds with anticoccidial medications Preventative medication in feed Ionophores (monensin, salinomycin, lasalocid) Amprolium Decoquinate... Resistance is widespread Rotate drugs or use "shuttle" program

Nebulizer/sprayer Feed additive Raise young chickens

7 Control &Treatment Vaccines have been developed but problems with administration Injectable Nebulizer/sprayer Feed additive Raise young chickens separate from older birds (segregation of industry) Proper hygiene/sanitation

meleagrimittis are all pathogenic Lesions < than in chickens, but

8 Avian Coccidiosis Turkeys 7 species of Eimeria infect turkeys E. adenoeides, E. gallopavonis, E. meleagrimittis are all pathogenic Lesions < than in chickens, but mortality rates high in young birds Ducks & Geese Renal coccidiosis - Eimeria truncata Intestinal coccidiosis - E. anseris

9 Bovine Coccidiosis 13 species infect cattle in North America Eimeria zuernii & Eimeria bovis Most pathogenic Mixed infections are the rule Calves Most susceptible 3 weeks to 6 months of age, Typically 2-6 months Also older calves housed in groups

10 First generation meronts (first asexual replication stage) grow to giant size & produce thousands of merozoites E. bovis - endothelial cells of lacteals in the villi E. zuernii - lamina propria of the ileum Prepatent period: days

11 Clinical signs Moderate infections: Diarrhea, listlessness, anorexia

become soiled with feces Secondary infections common

12 Clinical signs Severe infections: Explosive liquid bloody diarrhea, emaciation & tenesmus Hind quarters of calf can become soiled with feces Secondary infections common Pneumonia Calves that don t die in 7-10 days will usually recover

13 Calves 3-6 months Eimeria bovis Summer Coccidiosis Stress - first time on pasture Older cows carriers & infect the pasture Warm temperatures & high humidity Diarrhea to dysentery Tenesmus & projectile feces Dehydration & death if untreated

14 Diarrhea & tenesmus Severe cold weather Stress factors Weaning, shift from pasture to feedlot Eimeria zuernii Winter coccidiosis

15 Acute diarrhea Eimeria zuernii Nervous coccidiosis Muscular tremors, convulsions, blindness 50% mortality Pathogenesis is not understood but majority of cases occur during coldest months (stress?)

16 Control & Treatment General prevention: Reduce stocking rates, minimize stress, clean housing & feed Pasture management? Provide adequate colostrum Treatment & prevention?: Decoquinate, amprolium, monensin, sulfamethazine, sulfaquinoxaline, lasalocid

17 Control & Treatment Outbreak: Sick calves Isolate & provide supportive therapy & fluid replacement Healthy calves No clinical signs = treat with anti-coccidial drugs Clean & sanitize Housing between groups of calves Hot & dry = kills oocysts Do not mix calves of different ages Reduce stress

Ovine Coccidiosis 12 species of Eimeria infect sheep prepatent period ~ 14 days Lambs in feedlot or after shipping 12-21 days after arrival Watery diarrhea for

18 Ovine Coccidiosis 12 species of Eimeria infect sheep prepatent period ~ 14 days Lambs in feedlot or after shipping days after arrival Watery diarrhea for several days-2 weeks Depression, inappetence followed by weight loss Mortality usually <10%, But significant weight loss can occur Soiled wool leads to Fly strike (myiasis)

19 Caprine Coccidiosis 6 species of Eimeria infect goats prepatent period ~ 14 days More susceptible than sheep Clinical signs of diarrhea typically follow weaning Heavily infected Usually die Recovered kids may fail to grow normally

20 Ovine / Caprine Coccidiosis Control & Treatment As in cattle Raise lambs on slatted floor pens Good sanitation

21 Equine Coccidiosis Eimeria leuckarti Coccidiosis is rare in horses Few reports of diarrhea or weight loss in infected horses micropyle = exit pore Oocyst with prominent micropyle

subclinical Young rabbits most susceptible Anorexia, weight

22 Rabbit Coccidiosis Eimeria stiedae Liver Bile duct epithelium Biliary hyperplasia & cirrhosis resulting in diarrhea Often subclinical Young rabbits most susceptible Anorexia, weight loss, distended abdomen, icterus & rough hair coat Sudden death - infrequent

23 Rabbit Coccidiosis Eimeria intestinalis & Crypts of small intestine Eimeria flavescens Cecum Often subclinical Anorexia, weight loss, & rough hair coat Denuding of the epithelium & severe diarrhea Death

24 Control & Treatment Prophylactic administration of sulfonamides or lasalocid Reduce stress Intestinal form occurs even in well cared for bunnies Prevent contamination of feeders, waterers, cages, hutches... Proper management

25 Swine Coccidiosis Isospora suis Severe disease in nursing piglets Wherever pigs are farrowed in confinement 15-20% of piglet diarrhea

26 Swine Coccidiosis Isospora suis Enterocytes of the small intestine & occasionally cecum & colon Prepatent period 4-5 days Patent period 2 weeks

27 Clinical signs Piglets 1-2 weeks Yellow- grey pasty diarrhea Diarrhea smells like "soured milk Blood not present unless other disease agents involved e.g. rotavirus Depressed weight gains, high morbidity, moderate mortality

28 Clinical signs Piglets 5-6 weeks Post-weaning diarrhea Depressed weight gains, high morbidity, moderate mortality

29 Control & Treatment Anti-coccidials are not effective Nursing piglets do not eat or drink enough for drugs added to feed or water to be effective Sanitation to reduce the number of infectious oocysts in environment Reduce stress

30 Canine Coccidiosis Isospora (Cystoisospora) canis Largest oocysts in dogs (~40 µm) Lamina propria of distal small intestine & may cause diarrhea associated with weaning stress Concurrent bacterial or viral infections?

31 Canine Coccidiosis Isospora (Cystoisospora) ohioensis complex I. ohioensis, I. burrowsi & I. neorivolta All have small oocysts (~20 µm) Enterocytes in the small intestine, cecum & colon Diarrhea in puppies is: Associated with stress Concurrent bacterial or viral infections?

Feline Coccidiosis Isospora felis (~40 µm) Isospora rivolta (~20 µm) Develop in the enterocytes of small intestine & can cause diarrhea & enteritis in

32 Feline Coccidiosis Isospora felis (~40 µm) Isospora rivolta (~20 µm) Develop in the enterocytes of small intestine & can cause diarrhea & enteritis in kittens Newborn - 4 weeks old Stress factors likely involved e.g. other disease agents Rare unless other disease agents present Isospora rivolta Isospora felis

Canine & Feline Coccidiosis Paratenic hosts Infections in dogs & cats can be acquired through a paratenic host Mice, cattle, sheep & other herbivores Ingest the oocysts &

33 Canine & Feline Coccidiosis Paratenic hosts Infections in dogs & cats can be acquired through a paratenic host Mice, cattle, sheep & other herbivores Ingest the oocysts & sporozoites invade the extra-intestinal tissue Mesenteric lymph nodes, brain, muscle Sporozoites become encysted within tissue & are released when ingested by cats or dogs

Canine & Feline Coccidiosis Control & Treatment Sanitation to reduce exposure to oocysts Ensure sufficient colostrum Reduce stress Reduce opportunity for hunting Re: paratenic

34 Canine & Feline Coccidiosis Control & Treatment Sanitation to reduce exposure to oocysts Ensure sufficient colostrum Reduce stress Reduce opportunity for hunting Re: paratenic host Clinical cases Supportive therapy Sulfonamides or amprolium to reduce patent period? Value? Response to treatment is seldom dramatic Treatment of dams prior to parturition?

35 Super Role Model Barbie says, Prompt disposal of feces is the key to controlling coccidia!

epithelial cells lining the gastrointestinal & respiratory tracts of

36 Cryptosporidiosis Zoonosis Gregarine parasite of the Genus Cryptosporidium Many species Infect the microvillous region of epithelial cells lining the gastrointestinal & respiratory tracts of many different vertebrates Intracellular, extra-cytoplasmic parasites of epithelial cells

.. Very important cause of neonatal diarrhea in calves

37 Cryptosporidiosis Mammals Cryptosporidium parvum Infects small intestine Cats, dogs, horses, cattle & humans... Very important cause of neonatal diarrhea in calves Zoonotic Cryptosporidium hominis ONLY Infects small intestine of humans Causes diarrhea

38 Cryptosporidiosis C. andersoni Infects the abomasum of ruminants (cattle) Older calves (>1 month) & mature cattle May lead to sub-par performance in cattle Milk production & weight gain Life-long infections?

39 Cryptosporidiosis C. bovis Found in the small intestine Primary infection in postweaned cattle BUT: No clinical signs Life-long infections? Morphologically identical to C. parvum, therefore confounder...

40 Cryptosporidiosis C. suis Morphologically identical to C. parvum Small & large intestine of swine Host adapted -infects pigs of all ages No clinical signs One report in humans Life-long infections?

41 Cryptosporidiosis Birds C. baileyi Respiratory tract & cloaca of chickens & turkeys C. meleagridis & C. galli Small intestine of chickens & turkeys

42 Cryptosporidiosis Reptiles Cryptosporidium serpentis Intestinal infections Fish Cryptosporidium molnari Intestinal infections

43 Morphology Sporozoites, Merozoites, Meronts & Gamonts Similar to coccidia but it is a gregarine Oocysts C. parvum - round & very small 4-6 µm C. andersoni - slightly larger 6-8 µm All are sporulated when passed in feces Immediately infective Oocysts contain 4 "naked" sporozoites no sporocysts

44 Source: CDC

45 Cryptosporidium life cycle

concentrations fail to kill Ethanol, methanol, sodium hypochlorite,

46 Epidemiology Transmission Oocysts Immediately infective, highly resistant & remain viable for months Standard disinfectant concentrations fail to kill Ethanol, methanol, sodium hypochlorite, isopropanol... Methods that work 6% hydrogen peroxide VIM High pressure steam cleaning...

47 Epidemiology Transmission Direct: fecal-oral route is common in confinement

48 Waterborne outbreaks are the most common source for human infections Epidemiology Transmission

49 Epidemiology Transmission Milwaukee Kelowna & Cranbrook 1996 Chilliwack 1998 North Battleford Kamloops 2002 Kansas 2003 Wausau Wisconsin-2007 Globally, many every year...

50 Worldwide Infections common Epidemiology Prevalence Young animals, neonates & immunocompromised Dogs & Cats Reported prevalence of 5-10% Underestimated...

51 Epidemiology Prevalence Livestock Prevalence up to 100% in calves Calves <3 weeks of age & co-infection rotavirus, coronavirus & E. coli Dairy > Beef feedlot > Beef on range Calves: prepatent period is 4-6 days, patent period 7-14 days Canadian survey 17% of horses 11% of pigs 23% of sheep ON PEI Beef herds 80% Adults 35%, calves 80% Dairy herds 55% Adults 45%, calves 55% Swine herds 86% Adults 9%, weanlings 40%

52 Poultry Epidemiology Prevalence Common wherever birds are raised commercially i.e. disease of confinement 27% reported in broilers

53 Pathogenesis Intestinal cryptosporidiosis Enterocytes of the distal small intestine-ileum C. parvum - villous atrophy, villous fusion, crypt hyperplasia & enterocyte sloughing Increased epithelial turnover Immature population of absorptive cells Malabsorptive diarrhea

54 Pathogenesis Intestinal cryptosporidiosis C. baileyi infects the cloaca & bursa of Fabricius in chickens & turkeys C. meleagridis intestinal infections

55 Pathogenesis Abomasal cryptosporidiosis C. andersoni Infects gastric peptic glands Causes dilation of gland & may impact performance

56 Pathogenesis Respiratory Cryptosporidiosis C. baileyi Inhalation or aspiration of oocysts Impairs mucociliary elevator in trachea & bronchi Few to no cilia found in heavy infections Accumulation of mucus & sloughed epithelial cells Results in air sacculitis & pneumonia

Clinical signs Intestinal cryptosporidiosis Diarrhea Typically pasty-yellow in calves, occasionally with blood or mucus Mild & intermittent or severe profuse & watery May last up to

57 Clinical signs Intestinal cryptosporidiosis Diarrhea Typically pasty-yellow in calves, occasionally with blood or mucus Mild & intermittent or severe profuse & watery May last up to two weeks General signs of enteritis & dehydration Anorexia, abdominal cramping... Low mortality unless other pathogens or stress factors (severe cold & poor management) are involved

58 Clinical signs Respiratory cryptosporidiosis Sneezing, coughing & other signs of respiratory distress

59 Diagnosis Histopathology Various stages in sections of ileum as round "blebs" on the microvilli border Parasitophorous vacuoles

60 Diagnosis Fecal exam Sugar-centrifugal fecal flotation C. parvum oocysts Round & very small 4-6 µm C. andersoni oocysts Slightly larger 6-8 µm Both float just under the cover slip Difficult to see, requires experience Confused with the abundant yeast Oocysts may take on a pink refractile appearance

& iodine used on wet mounts Immunofluorescence antibody

62 Diagnosis Fecal exam Staining Acid fast stain of fixed smears Oocysts stain red, yeast stain green Methylene blue & iodine used on wet mounts Immunofluorescence antibody stain Specific & sensitive Limited to diagnostic & research labs

63 Treatment & Control No treatment currently available Nothing licensed Halofuginone & azithromycin some efficacy Necessary? Sanitation & good management Reduce exposure to oocysts Supportive care Fluids, electrolytes & reduce stress

Treatment & Control Adequate nutrition Important, administer in small volumes so as not to overload the gut Absorptive capacity is reduced during

64 Treatment & Control Adequate nutrition Important, administer in small volumes so as not to overload the gut Absorptive capacity is reduced during infection Adequate colostrum Calves, lambs... Can be a chronic disease of the immunocompromised & can be life threatening AIDS patients & immunosuppressive therapy

Apicomplexa of Intestinal Pathology

LECTURES #4, #5 & #6: APICOMPLEXA 1 Apicomplexa of Intestinal Pathology Cryptosporidium, Eimeria, Cystoisospora General Characteristics of Apicomplexa A. Morphology by stage Zoite o Tear-shaped (cylindrical