II. Epidemiology

  1. Natural Hosts: Young animals (e.g. calves)
    1. C. hominis only infects humans
    2. C. parvum infects both cows, sheep and humans
  2. Foodbourne illness (fecal-oral route transmission)
    1. Common cause of Traveler's Diarrhea worldwide
    2. Contaminated drinking water or uncooked foods
    3. Foods contaminated by an infected food handler
  3. Waterborne Illness outbreaks
    1. Milwaukee contaminated municipal water (n=400,000)
    2. Florida Summer Camp with contaminated outdoor faucet
    3. References
      1. N Engl J Med (1994) 331:161 [PubMed]
      2. MMWR (1996) 45:442-5 [PubMed]
  4. Sexually transmitted in Men who have Sex with Men
    1. Effects 10-20% of advanced HIV patients

III. Risk Factors

  1. Day care center attendance
  2. Human Immunodeficiency Virus (HIV) infection

IV. Pathophysiology

  1. Coccidian protozoan present in animal feces
    1. Farm animals
    2. Domestic pets
  2. Very low inoculum required: 10 Oocysts
  3. Immunocompetent host has only mild Diarrheal illness
  4. Immunocompromised host has potentially severe or even fatal illness (gastrointestinal and respiratory effects)
    1. AIDS patients
      1. CD4 Count <200: Chronic, persistent Diarrhea
      2. CD4 Count <140: More severe symptoms

V. Symptoms

  1. Normal Host
    1. Diarrhea
    2. Abdominal Pain
    3. Nausea or Vomiting
    4. Fever
  2. HIV Infection or other immunocompromised patient
    1. Chronic, persistent, secretory, watery Diarrhea
    2. Cough

VI. Labs

  1. Specific Ova and Parasite testing
    1. Cryptosporidium is not typically included on routine Ova and Parasite testing
    2. Request specific testing if higher index of suspicion
    3. May require multiple stool samples collected on several different days (intermittent excretion)
  2. Diagnostic modalities
    1. PCR (gold standard)
    2. Microscopy (wet mount, stains)
    3. Immunohistologic testing (immunoassay against oocyst wall)
  3. Sample sources
    1. Stool
    2. Duodenal aspirate
    3. Bile secretions
    4. Respiratory secretions

VII. Course

  1. Symptom onset delayed 2-10 days from exposure (up to 2 weeks)
  2. Normal host (self-limited)
    1. Diarrhea persists for 10 days in normal host (self limited)
    2. May relapse over weeks to months in some cases
  3. Immunocompromised host
    1. Severe course (may be fatal)
    2. Stools may exceed 21 stools per day for months (with secondary malabsorption and Failure to Thrive)

VIII. Complications

  1. Reactive Arthritis (associated with C hominis)
  2. Extra-intestinal infection (immunocompromised patients)
    1. Lungs are commonly affected (with secondary cough), esp. with C. hominis
    2. Chronic biliary tract disease (sclerosing Cholangitis) in patients with comorbid HIV Infection
    3. Other involvement
      1. Conjunctivitis
      2. Esophagitis
      3. Appendicitis
      4. Pancreatitis
      5. Intestinal perforation

IX. Management

  1. Symptomatic management
    1. See Acute Diarrhea
    2. Most immunocompetent patients recover without specific treatment
  2. Immunocompetent patients with severe or prolonged Diarrhea
    1. Nitazoxanide (Alinia) 500 mg orally twice daily for 3 days
    2. Paromomycin and Azithromycin are not thought to be effective
    3. Cure rate 72% with treatment, and resolves spontaneously in most cases
  3. Immunocompromised patients or HIV positive
    1. Nitazoxanide (Alinia) is no more effective than Placebo in immunocompromised patients
      1. However may be trialed in age over 1 year old
      2. Paromomycin and Azithromycin may be trialed in refractory cases (but low efficacy)
    2. Highly Active Antiretroviral Therapy in HIV eradicates intestinal Cryptosporidium (especially if CD4 >150 cells/mm3)
      1. Protease Inhibitors may have additional activity against Cryptosporidium

X. Prevention

  1. Avoid swimming for 1-2 weeks after exposure (oocyst sheddling continues after resolution)
  2. Water filters or boiling water (for at least one minute) reduces infection risk
  3. Cryptosporidium is very resistant to halogens (e.g. chlorination, Iodine)
    1. Swimming pool chlorination does NOT prevent transmission
    2. Cryptosporidium oocysts survive >10 days in swimming pools chlorinated to CDC recommended levels
    3. Shields (2008) J Water Health 6(4): 513-20 [PubMed]

XI. Resources

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Ontology: Cryptosporidiosis (C0010418)

Definition (MSH) Intestinal infection with organisms of the genus CRYPTOSPORIDIUM. It occurs in both animals and humans. Symptoms include severe DIARRHEA.
Definition (MEDLINEPLUS)

Cryptosporidiosis (crypto) is an illness caused by a parasite. The parasite lives in soil, food and water. It may also be on surfaces that have been contaminated with waste. You can become infected if you swallow the parasite.

The most common symptom of crypto is watery diarrhea. Other symptoms include

  • Dehydration
  • Weight loss
  • Stomach cramps or pain
  • Fever
  • Nausea
  • Vomiting

Most people with crypto get better with no treatment, but crypto can cause serious problems in people with weak immune systems such as in people with HIV/AIDS. To reduce your risk of crypto, wash your hands often, avoid water that may be infected, and wash or peel fresh fruits and vegetables before eating.

Centers for Disease Control and Prevention

Definition (MSHCZE) Střevní onemocnění způsobené prvokem Cryptosporidium parvum. Přenáší se fekálně-orální cestou (např. kontaminovaná voda), zdrojem bývají zvířata. Projevuje se vodnatými průjmy bez příměsí podobnými choleře. Závažný průběh je u imunokompromitovaných osob vč. nemocných s AIDS, u nichž má nemoc chronický průběh (enteritida, malabsorpce). Léčebně se ev. podávají některá antibiotika (např. paronomycin, spiramycin, nitrazoxanid), důležitá je symptomatická léčba, zejm. intenzivní rehydratace. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (CSP) intestinal infection with protozoa of the genus Cryptosporidium; occurs in both animals and humans; symptoms include severe diarrhea.
Concepts Disease or Syndrome (T047)
MSH D003457
ICD9 007.4
ICD10 A07.2
SnomedCT 186126003, 240370009, 58777003
LNC LA10448-1
English Cryptosporidioses, Cryptosporidiosis infection, cryptosporidiosis (diagnosis), cryptosporidiosis, Cryptosporidiosis, Cryptosporidia infections, Cryptosporidiosis [Disease/Finding], cryptosporidiasis, cryptosporidium infection, Intestinal cryptosporidiosis, Crypto, Cryptosporidiasis, Cryptosporidiosis (disorder), Infection by Cryptosporidium (disorder), Infection by Cryptosporidium, gastroenteritis; Cryptosporidium, infection; Cryptosporidium, Cryptosporidium; gastroenteritis, Cryptosporidium; infection, Infection by Cryptosporidium, NOS
Italian Infezioni da Cryptosporidi, Infezione da Criptosporidi, Criptosporidiosi
Swedish Kryptosporidios
Czech kryptosporidióza, Kryptosporidióza, Kryptosporidiózy
Spanish Criptosporidiosis infección, criptosporidiasis, criptosporidiosis (trastorno), criptosporidiosis, infección por Cryptosporidium (trastorno), infección por Cryptosporidium, Infecciones por cryptosporidium, Criptosporidiosis
Dutch cryptosporidiosis, cryptosporidiosisinfectie, Cryptosporidium; gastro-enteritis, Cryptosporidium; infectie, gastro-enteritis; Cryptosporidium, infectie; Cryptosporidium, Cryptosporidiosis, Cryptosporidia-infecties, Cryptosporidiose
Portuguese Infecção criptosporidiósica, Infecções a criptosporídios, Criptosporidiose
German Kryptosporidiose-Infektion, Cryptosporidia-Infektionen, Kryptosporidiose
Japanese クリプトスポリジウム症, クリプトスポリジウム感染, クリプトスポリジウムショウ, クリプトスポリジウムカンセン
Finnish Kryptosporidioosi
Russian KRIPTOSPORIDIOZ, КРИПТОСПОРИДИОЗ
Korean 와포자충증
Croatian KRIPTOSPORIDIOZA
Polish Kryptosporidioza, Kryptosporydoza, Kryptosporydioza
Hungarian Cryptosporidiosis fertőzés, Cryptosporidiosis, Cryptosporidialis fertőzések
Norwegian Kryptosporidiose, Cryptosporidiose
French Infections à Cryptosporidium, Cryptosporidiose

Ontology: Cryptosporidium parvum (C0085319)

Definition (MSHCZE) Prvok patřící k střevním kokcidiím, původce střevní kryptosporidiózy. Kosmopolitně rozšířený mikroorganismus o velikosti cca 2–6 μm s velmi odolnými oocystami. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (MSH) A species of parasitic protozoa that infects humans and most domestic mammals. Its oocysts measure five microns in diameter. These organisms exhibit alternating cycles of sexual and asexual reproduction.
Concepts Eukaryote (T204)
MSH D016785
SnomedCT 51504002
LNC LP35695-3
English Cryptosporidium parvum, parvums, Cryptosporidium, parvum, Cryptosporidium, Cryptosporidium parvums, parvum cryptosporidium, cryptosporidium parvum, CRYPTOSPORIDIUM PARVUM, Cryptosporidium parvum (organism)
Swedish Cryptosporidium parvum
Czech Cryptosporidium parvum
Finnish Cryptosporidium parvum
Russian KRIPTOSPORIDIIA MALAIA, CRYPTOSPORIDIUM PARVUM, КРИПТОСПОРИДИЯ МАЛАЯ
Polish Cryptosporidium parvum
Norwegian Cryptosporidium parvum
Spanish Cryptosporidium parvum (organismo), Cryptosporidium parvum
French Cryptosporidium parvum
German Cryptosporidium parvum
Italian Cryptosporidium parvum
Dutch Cryptosporidium parvum
Portuguese Cryptosporidium parvum

Ontology: Cryptosporidium hominis (C1489235)

Concepts Eukaryote (T204)
SnomedCT 417722006
LNC LP35796-9
Spanish Cryptosporidium hominis, Cryptosporidium hominis (organismo)
English Cryptosporidium hominis, Cryptosporidium hominis (organism)

Ontology: Cryptosporidium (C1744526)

Definition (MSHCZE) Prvok patřící k střevním kokcidiím, původce střevní kryptosporidiózy. Kosmopolitně rozšířený mikroorganismus o velikosti cca 2–6 μm s velmi odolnými oocystami. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ )
Definition (NCI) A genus of parasitic protozoa that is the cause of cryptosporidiosis.
Definition (MSH) A genus of coccidian parasites of the family CRYPTOSPORIDIIDAE, found in the intestinal epithelium of many vertebrates including humans.
Definition (CSP) genus of coccidian parasites of the family Cryptosporidiidae, found in the intestinal epithelium of many vertebrates including humans.
Concepts Eukaryote (T204)
MSH D003458
SnomedCT 83821001
LNC LP20006-0, MTHU008557
Swedish Cryptosporidium
English Cryptosporidium, Cryptosporidiums, Cryptosporidium Tyzzer, 1907, Genus: Cryptosporidium, Cryptosporidium (organism), Cryptosporidium, NOS, Genus Cryptosporidium
Czech Cryptosporidium
Finnish Cryptosporidium
Croatian CRYPTOSPORIDIUM
Polish Cryptosporidium
Norwegian Cryptosporidium
Spanish Cryptosporidium (organismo), Cryptosporidium, SAI, criptosporidio, género: Cryptosporidium, Cryptosporidium
French Cryptosporidium
German Cryptosporidium, Kryptosporidium
Italian Cryptosporidium
Russian CRYPTOSPORIDIUM
Dutch Cryptosporidium
Portuguese Cryptosporidium