trichinella student seminar presentation jam65

TRICHINELLOSISIBERS student conference

(CDC, 2012)

Copyright © Jessica Moult 2015

Trichinellosis

• Life cycle• Prevention• Control

(CDC, 2012)Copyright © Jessica Moult 2015

What is trichinellosis?• Infection by the larvae of a species of worm

called Trichinella


What is trichinellosis?• Female- 3-4.8mm length• Male smaller 1.5-1.6mm length• New born larvae (NBL) 80-120um in length

(Nolan, 2008) (Nolan, 2008)

(Kociecka et al., 2003)


Why is it important?• Infection common and usually caused by ingestion of

undercooked pork. • Cases are associated with eating raw or undercooked

wild game meats.• Infection is now relatively rare. • Public awareness of the danger of eating raw or

undercooked pork products.


(Pozio, 2014)

T. spiralis (from 12 current species) is better adapted to and more frequently detected in swine


Recent outbreaks• Thailand (Khumjui, 2006)• United states (Roy et al., 1997)• Italy (1975) (Pozio & Murrell, 2006)

(http://www.animalpictures123.org/wild-boar/)

(http://www.thaiturtles.org/)Copyright © Jessica Moult 2015

Life Cycle

• Encysted larvae in muscles first seen 1821- was not associated with disease in humans

(Tiedemann, 1821)

• Adult worms discovered 1859 (Virchow, 1859)

• Discovered Infection from pork (Kean, et al., 1978, Zenker, 1860)

(Cox, 2002)


Life Cycle


Life Cycle

(Nockler & Kapel, 2007)

(A)Cellular infiltrates

(B)collagen capsule of a “nurse cell”

(C)intersected muscle larva


Life Cycle• Larvae ingested, surrounding tissue

digested (Capo, 1996)• Migration predominately to blood and

lymphatic system• Muscle penetration may involve enzymes

(Despommier, 1983)• New born larvae (NBL) enter skeletal muscle• ~20 days of growth and development

(CDC, 2012)


Life Cycle

• ‘Sylvatic Cycle’ oscillates between wildlife hosts and also includes all Trichinella species and genotypes (Gottstein, 2009)

• Important in persistence (Burke, 2008)

(Beiting, 2007)


Other sources of infection

Broad host spectrum (Gajadhar, 2009)• Horse meat (Boireau, 2000)• Crocodile (Pozio, 2005)• Red fox (Dupouy-Camet,2008)• Walrus (Jean-François, 2002)

• Worldwide – not reported in Antarctica (Pozio, 2007)

(http://en.wikipedia.org/wiki/Saltwater_crocodile)


Prevention• The best way to prevent trichinellosis is to cook meat

to safe temperatures. • For Whole Cuts of Meat (excluding poultry and wild

game) – Cook to at least 145° F (63° C).

• For Ground Meat (excluding poultry and wild game)– Cook to at least 160° F (71° C); ground meats do

not require a rest time. (CDC, 2012)


Prevention• For Wild Game (whole cuts and ground)– Cook to at least 160° F (71° C).

• For All Poultry (whole cuts and ground)– Cook to at least 165° F (74° C), and for whole poultry

allow the meat to rest for three minutes before carving or consuming.

• Curing (salting), drying, smoking, or microwaving meat

alone does not consistently kill infective worms.

(CDC, 2012)

(http://www.wildlifeupclose.co.uk/birds/pheasant/Pheasant.html)


Prevention

• Freeze pork less than 6 inches thick for 20 days at 5°F (-15°C) to kill any worms.

• Freezing wild game meats, unlike freezing pork products, may not effectively kill all worms because some worm species that infect wild game animals are freeze-resistant.

(CDC, 2012)


Control• Freeze pork less than 6 inches thick for 20 days at -

15°C (5°F ) to kill any worms.• Freezing wild game meats, unlike freezing pork

products, may not effectively kill all worms because some worm species that infect wild game animals are freeze-resistant.

• Wash your hands with warm water and soap after handling raw meat.

(CDC, 2012)


Prevention

• Clean meat grinders thoroughly after each use.

• Do not allow pigs or wild animals to eat uncooked meat, scraps, or carcasses of any animals.

(CDC, 2012)

(http://www.northerntool.com/)Copyright © Jessica Moult 2015

Control(Gottstein, et al., 2009)

(A) Main sources of Trichinella sp. infections for humans (B) Trichinella sp. cycle in the host body


Control• The original method using microscopy, and later

trichinoscopy, was limited to the investigation of individual animals.

• The pooled digestion method was introduced in the 1970s and is gradually replacing trichinoscopy.

• Pooled digestion test meets the requirements for more efficient, reliable and cheaper slaughter

(Nockler, et al., 2000)


Control• Cost effective surveillance • Target high infectious groups• Transmission exclusively meat borne• Private slaughtering

Economic cost (Alban, 2011)

• Controlled housing management• European food safety authority

(Alban, 2008)


Summary• Horse, walrus, bear, fox, wild boar, domestic pig• Worldwide (no reports Antarctica)• Socio-economics- higher prevalence• Undercooked meat• Meat scraps• Slaughter testing

(http://www.adfg.alaska.gov/)


References• Alban, L., Pozio, E., Boes, J., Boireau, P., Boué, F., Claes, M., A.J.C. Cook, P. Dorny, H.L. Enemark, J. van der Giessen, K.R. Hunte, M. Howell, M. Kirjusina,

K. Nöckler, P. Rossib, G.C. Smith, L. Snowe, M.A. Taylork, G. Theodoropoulos, I. Valléec, M.M. Viera-Pinto, I. & Zimmer, I. A. (2011). Towards a standardised surveillance for Trichinella in the European Union. Preventive veterinary medicine, 99(2), 148-160.

• Alban, L., Boes, J., Kreiner, H., Petersen, J. V. & Willeberg, P. (2008). Towards a risk-based surveillance for Trichinella spp. in Danish pig production. Preventive veterinary medicine, 87(3), 340-357.

• Boireau, P., Vallee, I., Roman, T., Perret, C., Mingyuan, L., Gamble, H. R. & Gajadhar, A. (2000). Trichinella in horses: a low frequency infection with high human risk. Veterinary parasitology, 93(3), 309-320.

• Bundy, D. A. P. & E. Michael (1996). Trichinosis, p. 310–317. In F. E. G. Cox (ed.), The Wellcome Trust illustrated history of tropical diseases. The Wellcome Trust, London, United Kingdom.

• Centers for Disease Control and Prevention, (2012). CDC - Trichinellosis. [online] Cdc.gov. Available at: http://www.cdc.gov/parasites/trichinellosis/ [Accessed 4 Feb. 2015].

• Cox, F. E. (2002). History of human parasitology. Clinical microbiology reviews,15(4), 595-612.• Despommier, D. D. (1983). Biology, p. 75–151. In W. C. Campbell (ed.), Trichinella and trichinosis. Plenum Press, London, United Kingdom.• Foster, W. D. (1965). A history of parasitology. Livingstone, Edinburgh, United Kingdom.• Dupouy-Camet, J. (2008). Trichinellosis still concerns Europe. Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca.

Veterinary Medicine, 63(1-2).• Gajadhar, A. A., Pozio, E., Gamble, H. R., Nöckler, K., Maddox-Hyttel, C., Forbes, L. B., Valle´e , I., Rossi, P., Marinculic, A. & Boireau, P. (2009).

Trichinella diagnostics and control: mandatory and best practices for ensuring food safety. Veterinary parasitology,159(3), 197-205.• Gamble, H. R., Brady, R. C., Bulaga, L. L., Berthoud, C. L., Smith, W. G., Detweiler, L. A., Miller, L. E. & Lautner, E. A. (1999). Prevalence and risk

association for Trichinella infection in domestic pigs in the northeastern United States.Veterinary parasitology, 82(1), 59-69.• Gottstein, B., Pozio, E. & Nöckler, K. (2009). Epidemiology, diagnosis, treatment, and control of trichinellosis. Clinical Microbiology Reviews, 22(1), 127-

145.• Grove, D. I. (1990). A history of human helminthology. CAB International, Wallingford, United Kingdom.• Jean-François, P., MacLean, J. D., Theresa, W. G., Daniel, L., Anne-Katrin, R., Bouchra, S., Forbes , L. & Alvin, A. G. (2002). Novel prevention program

for trichinellosis in Inuit communities. Clinical infectious diseases, 34(11), 1508-1514.


References• Kean, B. H., Mott, K. E. & A. J. Russell (ed.). (1978). Tropical medicine and parasitology: classic investigations. Cornell University Press, Ithaca, N.Y.• Kociecka, W., Boczon, K., Pozio, E., Knapen, F. van. (2003). International handbook of foodborne pathogens pp.637-658, Food science and technology,

125, Editors Miliotis M. D., Bier J. W., Marcel Dekker, inc. ISBN 0-8247-0685-4• Nöckler, K., Pozio, E., Voigt, W. P., & Heidrich, J. (2000). Detection of Trichinella infection in food animals. Veterinary Parasitology, 93(3), 335-350.• Nockler, K., & C. M. O. Kapel. (2007). Detection and surveillance for Trichinella: meat inspection and hygiene, and legislation, p. 69–97. In .• Nöckler, K. P., & Nolan, T. (2008). Parasitology Lab 3. [online] Cal.vet.upenn.edu. Available at:

http://cal.vet.upenn.edu/projects/parasit06/website/lab4.htm [Accessed 4 Feb. 2015].• OWEN, R. (1835). Description of a Microscophc Entozoon infesting the Muscles of the Human Body. The Transactions of the Zoological Society of

London, 1(4), 315-324.• Pozio, E. (2014). Searching for Trichinella: not all pigs are created equal. Trends in parasitology, 30(1), 4-11.• Pozio, E. (2007). World distribution of Trichinella spp. infections in animals and humans. Vet. Parasitol. 149:3–21.• Pozio, E., & Murrell, K. D. (2006). Systematics and epidemiology of Trichinella. Advances in parasitology, 63, 367-439.• Pozio, E., I. L. Owen, G. Marucci, and G. La Rosa. (2005). Inappropriate feeding practice favors the transmission of Trichinella papuae from wild pigs to

saltwater crocodiles in Papua New Guinea. Vet. Parasitol. 127:245–251.• Pozio, E., Voigt, W. and Heidrich, J. (2000). Detection of Trichinella infection in food animals. Veterinary Parasitology, 93(3-4), 335-350.• Pozio, E., (1995). Trichinellosis in the European Union: Epidemiology, ecology and economic impact. Parasitol. Today 14, 35–38.• RUITENBERG, E. and ELGERSMA, A. (1976). Absence of intestinal mast cell response in congenitally athymic mice during Trichinella spiralis

infection. Nature, 264(5583), 258-260.• Tiedemann, F. (1821). Weisse steinige konkremens in den meisten muskeln. Notiz. Geb. Nat. Heilkd. 3:column 64.• Virchow, R. (1859). Recherches sur le de´veloppement de la trichina spiralis (ce ver devient adulte dans l’intestin du chien). C. R. Seanc. Acad. Sci.

49:660–662.• Zenker, F. A. (1860). Ueber die Trichinen-krankheit des Menschen. Arch. Pathol. Anat. Physiol. Klin. Med. 18:561–572.


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trichinella student seminar presentation jam65