People can become infected with Cyclospora by consuming imported food or water contaminated with the parasite.
Cyclosporiasis symptoms may be more severe in people with a weakened immune system Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more , such as people with AIDS Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome (AIDS). HIV is transmitted... read more .
Symptoms vary but include watery diarrhea, abdominal cramping, fever, and weight loss.
Doctors diagnose the infection by identifying Cyclospora in a sample of stool.
Trimethoprim/sulfamethoxazole (TMP/SMX) is used to treat cyclosporiasis.
(See also Overview of Parasitic Infections Overview of Parasitic Infections A parasite is an organism that lives on or inside another organism (the host) and benefits (for example, by getting nutrients) from the host at the host's expense. Although this definition actually... read more .)
Cyclosporiasis is most common in tropical and subtropical climates where sanitation is poor. Residents and travelers to endemic areas are at risk. In the United States, outbreaks of this infection have been attributed to imported fresh produce, such as raspberries, basil, snow peas, mesclun lettuce, and cilantro.
Symptoms of Cyclosporiasis
The primary symptom of cyclosporiasis is sudden, nonbloody, watery diarrhea, and nausea. Other symptoms include fever, abdominal cramps, vomiting, fatigue, and weight loss. Symptoms in people with a normal immune system last from a few days to a month or longer. Relapses may occur.
In people with a weakened immune system, including people with AIDS Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome (AIDS). HIV is transmitted... read more , cyclosporiasis may cause severe diarrhea that may persist for a long time.
Diagnosis of Cyclosporiasis
To diagnose cyclosporiasis, a stool sample is examined under a microscope for Cyclospora eggs. Specialized techniques can be used to increase the chances of identifying the eggs. Molecular techniques are available in some reference laboratories to identify parasite DNA.
When stool examination does not reveal a cause of persistent diarrhea, doctors may use a flexible viewing tube ( endoscope Endoscopy Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope). Endoscopy can also be used to treat many disorders because doctors are able to pass instruments... read more ) to examine the upper part of digestive tract and obtain a sample of tissue (a biopsy) to be examined under a microscope and analyzed for parasite DNA.
Prevention of Cyclosporiasis
When outbreaks are reported, people should avoid eating potentially contaminated fruits or vegetables from the area. When traveling to tropical and subtropical areas where the infection is common, people should avoid eating uncooked foods, including salads and vegetables, and should avoid consuming potentially contaminated water and ice. Hand washing with soap and water is important. Drinking water that has been boiled is safe. Filtering water through a 0.1 or 0.4 micron filter can remove cysts of Cyclospora and other parasites, as well as bacteria that cause diseases.
Treatment of Cyclosporiasis
Infected people who have symptoms can be treated with trimethoprim/sulfamethoxazole (TMP/SMX) taken by mouth.
In people with AIDS More severe symptoms Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome (AIDS). HIV is transmitted... read more , it is very important that the HIV infection is treated as effectively as possible with antiretroviral drugs Drug Treatment of Human Immunodeficiency Virus (HIV) Infection Antiretroviral drugs used to treat human immunodeficiency virus (HIV) infection aim to do the following: Reduce the amount of HIV RNA (viral load) in the blood to an undetectable amount Restore... read more . Such treatment can strengthen the weakened immune system, which usually helps control the diarrhea and other symptoms. People with AIDS may benefit from a higher dose of TMP/SMX and a longer course of treatment.