Cryptosporidiosis in humans is caused by infection with a protozoan parasite Cryptosporidium parvum or Cryptosporidium hominis.

Cryptosporidiosis in Florida and the U.S. has a seasonal and cyclical trend. In 2021 there was an outbreak of Cryptosporidium linked to calves and no food or waterborne disease outbreaks due to cryptosporidium in 2022. Clusters of illness were reported and associated with person-to-person transmission, travel, daycares and contact with animals.

Transmission

Oocysts may be transmitted via contaminated food or water, by direct contact with infected livestock or pets, and from person to person by the fecal-oral route.

Cryptosporidium oocysts are present in most surface waters (e.g. rivers, streams, and lakes) throughout the U.S., and have shown resistance to chlorine. Oocysts are also difficult to remove by with filters.

Epidemiological studies have shown that municipal water supplies, camping, swimming, direct contact with feces while caring for an infected person, or association with kittens, puppies, and young livestock are the most frequently identified risk factors.

Symptoms

Oocysts, the infective stage of this parasite, cause an illness that presents as watery diarrhea with abdominal cramps, possibly accompanied by fever, nausea, vomiting, and myalgias. After exposure, the incubation period ranges from 1-12 days.

Duration of illness can range from days to months, but usually resolves within 2 weeks in otherwise healthy patients. Shedding of oocysts, however, can occur up to 2 weeks after the patient is clinically well.

Individuals at Increased Risk for Severe Illness

In people with HIV, the illness varies from asymptomatic carriage to severe watery diarrhea with weight loss, electrolyte imbalance, and dehydration.

Prevention

Practice Good Hygiene

  • Help keep yourself and your loved ones healthy by washing your hands often with soap and water, especially during key times when you are likely to spread germs.
  • Alcohol-based hand sanitizers are not effective against Crypto. Washing hands at key times with soap and water can help prevent infections.

Avoid Contaminated Food and Water

  • If you drink milk or apple cider, only buy if it has been pasteurized
  • Do not eat fruits and vegetables washed in water that might be contaminated
  • Do not drink untreated water or use untreated ice from lakes, rivers, springs, ponds, streams, or shallow wells.
  • Follow local drinking water advisories.
  • If the safety of the drinking water is in doubt (for example, if water source is unknown), use one of the following:
    • Commercially bottled water
    • Water that has been previously boiled for at least 1 minute and left to cool