Cryptosporidiosis: types, symptoms, causes, diagnosis & treatment

Last Updated on December 6, 2022 by Dr. Saqib Mueed

Cryptosporidium is a parasite that affects distal parts of the small intestine as well as the respiratory tract in individuals having autoimmune disorders as well as having normal immune systems. The parasitic attack leads to watery diarrhea. and it is called Cryptosporidiosis.

In individuals having autoimmune disorders, AIDS, or other immunity disorders, the parasitic attack of cryptosporidium can cause very severe and fatal symptoms. It may spread via the fecal-oral tract by contaminated water.

Evidence of recent research suggests that fomites in the secretion of the respiratory tract can also cause its transmission. In patients having HIV positive cryptosporidium is frequently found.

It is a common and world widely found waterborne disease. Consumptions of water or food which is contaminated with cryptosporidium can initiate cryptosporidiosis.


This disease occurs everywhere around the globe. It is the major cause of 50% of parasitic water-borne disorders. Cryptosporidium causes 8 to 19 percent of diarrhea disorders. Most of its victims are children of 1 to 9 years.

Types of Cryptosporidiosis

  1.   Cryptosporidiosis occurring in the distal part of the small intestine or any other part of the intestine is called intestinal cryptosporidiosis.
  2.   Cryptosporidiosis occurring in the respiratory tract is called respiratory cryptosporidiosis.

Symptoms of Cryptosporidiosis

In acute cryptosporidiosis which lasts less than two weeks, there is no clear symptom but symptoms appear again after a short recovery period. In chronic cryptosporidiosis which lasts longer than two weeks, there are very persistent and severe symptoms.

If the individual has a very compromised immune system then the infection can prove very fatal.

Symptoms that commonly occur in intestinal cryptosporidiosis are the following:

  •   Severe abdominal pain can cause cramps.
  •   Diarrhea.
  •   Loss of weight.
  •   Fever.
  •   Fatigue.
  •   Dehydration.
  •   Vomiting.
  •   Ascites.

Symptoms in case of respiratory cryptosporidiosis include the following:

  •   Sinuses inflammation.
  •   Inflammation of trachea and larynx
  •   Nasal mucosa inflammation.
  •   Change in voice.
  •   Cough and fever.
  •   Breath is shortened.
  •   Hypoxemia.

Causes of Cryptosporidiosis

It is caused by cryptosporidium which is the genus of Apicomplexa phylum. This genus is usually of the pathogenic protozoan. This cryptosporidium spread through polluted materials such as contaminated water, uncooked, and contaminated nutrition.

Risk factor

The following have a high risk of being a victim of cryptosporidiosis:

  •   Those parents who have children infected by cryptosporidiosis.
  •   People who work in child care centers.
  •   Caretaker of cryptosporidiosis patients.
  •   Swimmers who swim in contaminated water may swallow it.
  •   People having anal sex may be infected.
  •   Those cities which have improper and contaminated drinking water supplies are at higher risk of having cryptosporidiosis.

Chances of cryptosporidiosis are more in a patient who is immunocompromised as compared to a healthy person.


Diagnosis of cryptosporidiosis and identification of cryptosporidium responsible for it can be done in many ways. The diagnostic methods are as follows:

  •   Microscopy is used for the identification of cryptosporidium in feces. For better diagnosis, three samples must be inspected.
  •   FEA (Formalin Ethyl Acetate) is also used in diagnosis. This FEA actually makes the stool sample concentrated.
  •   Floatation techniques are also used in diagnosis which causes the oocysts to float.
  •   Some staining techniques are also used as diagnostic methods. Auramine stain, acid-fast stain, and H&E stains are some of the common stains used in the diagnosis of cryptosporidiosis.
  •   Detection of antigens by using DFA (Direct Fluorescent Antibodies) is also a method for the diagnosis of this disease.
  •  It can also be diagnosed by using PCR. PCR is one of the best diagnostic methods because it not just only identifies the presence of cryptosporidium but also tells the species of cryptosporidium.
  •   Ultrasonography is also used in the diagnosis of this disease.

Treatment of Cryptosporidiosis

If cryptosporidiosis has clear symptoms and treatment usually includes rehydration of fluid, replacement of electrolytes, and use of antimotility drugs. Supplementary zinc can also be used for the improvement of symptoms.


In immunocompetent persons who have a healthy immune system, cryptosporidiosis usually lasts for less than 14 days. If symptoms occur then treatment is required which includes antiparasitic medicines.

If symptoms are persistent and severe then the infection can occur again. For patients with cryptosporidiosis with a healthy immune system, nitazoxanide is the one and only effective drug. It can’t be used for immunocompromised individuals. 


Immunocompromised persons are those persons which have an immune system disorder for example patients with AIDS. In such individuals, it is resolved very slowly or it does not resolve at all and causes a persistent and very severe type of diarrhea which decreases the ability of nutrients absorption.

This may lead to dehydration, imbalance of electrolytes as well as malnutrition eventually resulting in a potential death.

The best treatment for the improvement of the immune system in immunocompromised patients is antiretroviral therapy. This is an inhibitor for HIV protease. Anti-parasitic medicines are also used it.

Preventions of Cryptosporidiosis

  •   Water treatment plants must remove cryptosporidium from the water before supplying it to the public for drinking. Chlorine dioxide and the treatment of water with Ozone make the cryptosporidium inactive. Hence reducing the chances of cryptosporidiosis. Modern researches show that UV rays are also very efficient in making cryptosporidium inactive.
  •   The drinking water must be boiled so boiling can remove water contaminating cryptosporidium completely.
  •   Good sanitation can also help in preventing cryptosporidiosis.
  •   The habit of washing hands before food and after using the bathroom can be very helpful to avoid the spreading of cryptosporidiosis.
  •   To avoid cryptosporidiosis people should not make any kind of contact with humans or any other animal fecal material.
  •   One must avoid the use of contaminated water or food.
  •   One should cut off sexual activities which can cause contact with the feces of his/her sex partner.
  •   People who have cryptosporidiosis must be very careful in public places such as swimming pools, parties, and others to gather where other peoples come in contact with them.
  •   In public health departments, different contaminated areas must be soaked with 3% H2O2 for about 15 to 20 minutes and then wash the area by rinsing them with water. It cleans the contaminated area and kills 99% of cryptosporidium along with other germs.[1] [2]PII: S1286-4579(02)01629-5 ( [3]Cryptosporidiosis Disease Fact Sheet ( [4] [5]

Reviewed by:
Dr. Shafaat Yar Khan  (Ph.D.) 
Medical University of Vienna, Austria 
Present: University of Sargodha, Pakistan

Our reviewers’ details, Click Here


2PII: S1286-4579(02)01629-5 (
3Cryptosporidiosis Disease Fact Sheet (

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