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Cryptosporidium sp

Cryptosporidium sp. What is it?. Cryptosporidium is an emerging coccidian protozoan parasite It is associated with municipal water supplies which causes diarrhea Cryptosporidium parvum causes the disease Cryptosporidiosis .

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Cryptosporidium sp

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  1. Cryptosporidium sp

  2. What is it? • Cryptosporidium is an emerging coccidian protozoan parasite • It is associated with municipal water supplies which causes diarrhea • Cryptosporidium parvum causes the disease Cryptosporidiosis. • During the past two decades, Cryptosporidium has become recognized as one of the most common causes of waterborne illness in the United States.

  3. What is it? • Definitive Host: Human • Reservoir Hosts: kittens, puppies, goats, calves, mice,etc • It is a zoonotic disease and can travel from animals to humans, and also from human to human • Transmission : fecal oral route  food and water • Cryptosporidium parvum has been recognized as a human pathogen since 1976.

  4. Prevalence • Found in most parts of the world • Most prevalent in Asia, Africa, Australia, South America • Antibody prevalence in Peru and Venezuela – 64% • 32% in Peace Corps workers • More prevalent in rural areas of U.S.  More animal contact

  5. Outbreak • In Milwaukee, WI water contamination from a sewage treatment plant killed 100 people and affected more than 400,000 in 1993. The parasite that caused the disease was determined to be cryptosporidium.

  6. Infectivity & Life Cycle • C. parvumhas a low ID50 (9-1000 oocysts) • Can be infected by just one oocyst • 10 billion oocysts per gram infected feces

  7. http://www.dpd.cdc.gov/dpdx/HTML/Cryptosporidiosis.htm

  8. Oocyst • Double walled, 4-6µm • Resistant to chlorine, drying, progressive freezing, salt water • Only stage in life cycle that can live ex vivo • Imbeds itself in gut epithelium and releases sporozoites • Reproduction continues sexually and asexually • Mature oocyst contain 4 sporozoites within

  9. Site of infection • Epithelial cells of the gastrointestinal tract • Has affected other tissues such as respiratory tract tissues and conjunctiva of the eye. • Cell death is a direct result of parasite invasion, multiplication, and extrusion or • Cell damage could occur through T cell-mediated inflammation, producing microvilli death and Cryptosporidium excess growth

  10. A scanning electron micrograph of Cryptosporidium lining the intestinal tract. (From: Gardiner et al., 1988, An Atlas of Protozoan Parasites in Animal Tissues, USDA Agriculture Handbook No. 651.)

  11. A scanning electron micrograph of a broken meront of Cryptosporidium showing the merozoites within.  (From: Gardiner et al., 1988, An Atlas of Protozon Parasites in Animal Tissues, USDA Agriculture Handbook No. 651.)

  12. Symptoms • Some individuals can be asymptomatic • Incubation period: 2-10 days • Symptoms include: • Stomach cramps, pain, watery diarrhea, dehydration, weight loss, vomiting, fever. • Immuno-competent individuals: 1-2 weeks • Immuno-compromised individuals: longer (months, even years!) • Patients excreting at least 2-25 liters of watery diarrhea per day  life threatening!

  13. LAB DIAGNOSIS • Microscopic exam • Modified acid fast stain of stool sample • Endoscopic biopsy of small intestine

  14. Cryptosporidium oocysts with acid-fast stain

  15. Cryptosporidium oocysts with acid-fast stain

  16. LAB DIAGNOSIS • Immunodiagnosis • Immunofluorescence assay (IFA) • Enzyme linked immunoabsorbant assay (ELISA) • Polymerase Chain Reaction (PCR) • Test of choice

  17. LAB DIAGNOSIS

  18. Treatment • No effective therapy, currently researching for a suitable prophylactic drug. • Immuno-competent individuals will recover with fluid and electrolyte replacement. • Nitazoxande for treatment of diarrhea. • For individuals with AIDS, anti-retroviral therapy will reduce oocyst excretion and decreases diarrhea.

  19. Control Methods • Water purification and filtration • Routine testing • Use of 1 micron filter to remove cysts • Boil water • Drink bottled water when traveling abroad • Educate public • Wash hands frequently • Avoid fecal matter during sexual activity

  20. INTERESTING FACT • There were 6 outbreaks between 1984 and 1994 in the US. • Cryptosporidium is resistant to chlorine. • Not protected in chlorinated pool. • In MO there were 26 confirmed cases from motel pools in 1994.

  21. INTERESTING FACT • Cattle alone produce about 4.57 tons of Cryptosporidium oocysts per year in the US BEWARE !

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