Isospora—Isospora is a member of the Coccidia subclass in the family Eimeria , which also includes other medically important organisms such as Plasmodium species, Toxoplasma gondii, Cryptosporidium species, and Cyclospora species. Isospora belli can be transmitted directly from human to human via fecal contaminated food or water. It is not passed to humans from animals so is not zoonotic. The organism does infect animals and is endemic in certain tropical areas of the Western Hemisphere, but each animal has their own species of Isospora.
Common Sources of Infection–Water contaminated with infected feces.
Symptoms of Isospora: Isospora belli infection is most frequent in the immuno-compromised patient and can cause disease in both adults and children. The typical patient is HIV-positive and presents with watery, fowl smelling diarrhea, anorexia, fever, weakness and weight loss. These manifestations can last from days to years with chronicity being directly related to the degree of immuno-suppression present in the host. Cryptosporidiosis can have a similar clinical presentation but should be differentiated because Isospora can be effectively treated with antibiotics.
Diagnosis and Treatments for Isospora infection: The diagnosis of Isospora belli is made by seeing the oocysts in the fecal sample with special dyes and with using florescent microscopy. The patient needs to be shedding the organism is high numbers for this to be obvious.
Therapy: Trimethoprim-sufamethoxazole (sulfa drugs) are the standard therapy and usually leads to rapid improvement in symptoms. Although a cure can be obtained using antibiotics, severely immunocompromised patients are at increased risk for recurrence and maintenance antibiotics are usually indicated.
Prevention of Isospora: The key to prevention is proper sanitation to ensure that the environment is free of feces. Once the Isospora are passed in the feces, they can quickly develop into the infective stage, so rapid removal of the feces is very important. Mature oocysts of Isospora are resistant to most cleaning products and they can survive for months to years in the environment. However, the use of strong ammonia-containing compounds may be helpful in disinfection, and steam cleaning also helps kill the infectious oocysts.
Be sure to allow for adequate ventilation while cleaning the infected areas, as fumes from cleaning products can be harmful to animals and people. Dogs and cats should not be permitted to ingest rodents, since rodents may be carriers of the parasites. The treatment of infected canine and feline mothers soon after parturition may help prevent the spread of Coccidia to the young.
References for Isospora: