Epidemiology and Clinical Features ofCryptosporidiumInfection in Immunocompromised Patients

Abstract

SUMMARY Cryptosporidium spp. are a major cause of diarrheal disease in both immunocompetent and immunodeficient individuals. They also cause waterborne disease in both the United States and United Kingdom. Studies on the mechanisms of immunity to cryptosporidiosis indicate the importance of the T-cell response. The spectrum and severity of disease in immunocompromised individuals with cryptosporidiosis reflect this importance since the most severe disease is seen in individuals with defects in the T-cell response. The most commonly studied group is that of patients with AIDS. These patients suffer from more severe and prolonged gastrointestinal disease that can be fatal; in addition, body systems other than the gastrointestinal tract may be affected. The widespread use of antiretroviral therapy does appear to be having a beneficial effect on recovery from cryptosporidiosis and on the frequency of infection in human immunodeficiency virus-positive patients. Other diseases that are associated with increased risk of severe cryptosporidiosis, such as primary immunodeficiencies, most notably severe combined immunodeficiency syndrome, are also predominantly associated with T-cell defects. Of the remaining groups, children with acute leukemia seem to be most at risk from cryptosporidiosis. There is less evidence of severe complications in patients with other malignant diseases or in those receiving immunosuppressive chemotherapy.

The Human Immunodeficiency Virus Type 1 Tat Protein EnhancesCryptosporidium parvum-Induced Apoptosis in Cholangiocytes via a Fas Ligand-Dependent Mechanism

“…While a number of pathogens have been implicated, C. parvum is the single most common identifiable pathogen associated with this disease. Although biliary cryptosporidiosis is also seen in boys with X-linked immunodeficiency (18,22), in adults it has been reported only in patients with AIDS (12,17,21,25,30). In contrast, C. parvum infection of the intestine has been found in both immunocompetent and immunocompromised subjects (40).…”

“…In immunocompetent individuals, infection is usually limited to the intestine and causes an acute, self-limited disease. However, in immunosuppressed individuals, cryptosporidiosis may cause potentially fatal complications, including bile duct damage (12,17,21,25,30). AIDS cholangiopathy, a group of biliary disorders including secondary sclerosing cholangitis and acalculous cholecystistis seen in AIDS patients, causes significant morbidity and mortality (35,50).…”

Cryptosporidium parvum glycoprotein gp40 localizes to the sporozoite surface by association with gp15

“…are ubiquitous waterborne parasites responsible for outbreaks of diarrheal disease worldwide [1]. The infection is self-limiting in immunocompetent individuals, but in immunocompromised individuals the infection can develop into a chronic, debilitating, and sometimes life-threatening disease [2]. In malnourished children, cryptosporidiosis is associated with growth and developmental delays [1].…”

Intestinal Cryptosporidiosis and the Profile of the CD 4 Counts in a Cohort of HIV Infected Patients

“…in AIDS patients probably relates to the augmented risk of acquiring the infection from infected contacts and a prolonged excretion, which consecutively enhance the risk of subsequent transmissions. One therapeutic intervention that has a remarkable effect on the cryptosporidiosis in AIDS patients is antiretroviral therapy, which leads to recovery of the CD 4 counts [28].…”