Cryptosporidiosis as a cause of diarrhea following bone marrow transplantation

Colonic complications following human bone marrow transplantation

Background Human bone marrow transplantation (BMT) becomes an accepted treatment of leukemia, aplastic anemia, immunodeficiency syndromes, and hematologic malignancies. Colorectal surgeons must know how to determine and manage the main colonic complications.

Objective To review the clinical features, clinical and pathological staging of graft vs host disease (GVHD), and treatment of patients suffering with colonic complications of human bone marrow transplantation.

Patients and methods We have reviewed the records of all patients that received an allogeneic bone marrow transplant and were evaluated at our Colon and Rectal Surgery department due to gastrointestinal symptoms, between January 2007 and January 2012. The study was carried out in patients who developed colonic complications, all of them with clinical, histopathological or laboratory diagnosis.

Results The study group was constituted by 77 patients, 43 male and 34 female patients. We identified colonic complications in 30 patients (38.9%); five patients developed intestinal toxicity due to pretransplant chemotherapy (6.4%); graft vs. host disease was present in 16 patients (20%); 13 patients (16.8%) developed acute colonic GVHD, and 3 (3.8%) chronic GVHD. Infection was identified in 9 patients (11.6%).

Conclusions The three principal colonic complications are the chemotherapy toxicity, GVHD, and superinfection; the onset of symptoms could help to suspect the type of complication (0–20 day chemotherapy toxicity, 20 and more GVHD), and infection could appear in any time of transplantation.

Parasitic Infections of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient, Including Toxoplasmosis and Strongyloidiasis

Hematopoietic stem cell transplantation (HSCT) recipients may infrequently develop parasitic infections at the time of the procedure via contamination from allograft tissue or blood products, and in the post-transplantation period through the traditional route of infection or as a reactivation caused by immunosuppression related to the transplant. To reduce risk, efforts should be directed at performing a comprehensive history, maintaining a high index of suspicion, and adhering to preventive measures. Additional strategies for the prevention, screening and careful follow-up, identification, and pre-emptive treatment of parasitic infections are required to reduce morbidity and mortality in HSCT patients.

The evolution of respiratory Cryptosporidiosis: evidence for transmission by inhalation

The protozoan parasite Cryptosporidium infects all major vertebrate groups and causes significant diarrhea in humans, with a spectrum of diseases ranging from asymptomatic to life-threatening. Children and immunodeficient individuals are disproportionately affected, especially in developing countries, where cryptosporidiosis contributes substantially to morbidity and mortality in preschool-age children. Despite the enormous disease burden from cryptosporidiosis, no antiprotozoal agent or vaccine exists for effective treatment or prevention. Cryptosporidiosis involving the respiratory tract has been described for avian species and mammals, including immunocompromised humans. Recent evidence indicates that respiratory cryptosporidiosis may occur commonly in immunocompetent children with cryptosporidial diarrhea and unexplained cough. Findings from animal models, human case reports, and a few epidemiological studies suggest that Cryptosporidium may be transmitted via respiratory secretions, in addition to the more recognized fecal-oral route. It is postulated that transmission of Cryptosporidium oocysts may occur by inhalation of aerosolized droplets or by contact with fomites contaminated by coughing. Delineating the role of the respiratory tract in disease transmission may provide necessary evidence to establish further guidelines for prevention of cryptosporidiosis.

Infectious complications of stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment for a variety of hematologic malignancies. The profound immunosuppression these patients experience adversely affects their risk of infection. This risk is much higher than in the general population and requires aggressive diagnostic and therapeutic interventions. The chapter will outline the major infections after HSCT.

Infection with Cryptosporidium hominis and reinfection with Cryptosporidium parvum in a transplanted ileum

A transplanted ileum was found to be infected with Cryptosporidium hominis 6 days after transplantation. Although the infection resolved, the ileum was later found to be infected with Cryptosporidium parvum. The presence of the parasite was not always correlated with diarrhea. No other gastrointestinal symptom was ever detected. Treatment with azithromycin and paromomycin apparently failed.

Epidemiology and clinical features of Cryptosporidium infection in immunocompromised patients

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.

Respiratory cryptosporidiosis: case series and review of the literature

Five case of intestinal cryptosporidiosis with pulmonary involvement in patients with AIDS are reported. The diagnosis was based on the recognition of acid-fast oocysts in sputum or aspirated bronchial material and stool specimens. Coughing and excess secretions were present in all cases. Four patients had other associated pulmonary pathogens: two Mycobacterium tuberculosis, one Mycobacterium fortuitum and one Cytomegalovirus + Pneumocystis carinii; all of them had a previous (three cases) or simultaneous (one case) diagnosis of intestinal cryptosporidiosis, presenting with diarrhoea and vomiting. In the fifth patient Cryptosporidium was the only pulmonary pathogen found in a bronchial aspirate, and the onset of diarrhoea was 1 month after respiratory detection. Fifty-seven cases of respiratory cryptosporidiosis have been reported since 1980. In 17 of them, no other pathogen was found. Diarrhoea was present in 77% of the patients, cough in 77%, dyspnea in 58%, expectoration in 54%, fever in 45%, thoracic pain in 33%.

Intestinal and extraintestinal cryptosporidiosis in AIDS patients

In a prospective study in AIDS patients with chronic diarrhea, the overall prevalence of intestinal cryptosporidiosis was 15.6% (43/275). The prevalence was higher in homosexual patients (33.3%) than in intravenous drug abusers (10.6%) (p < 0.001). Extraintestinal infection was present in 30% (13/43) of the patients with known intestinal cryptosporidiosis. Eight of the 13 (61.5%) patients with extraintestinal cryptosporidiosis had Cryptosporidium in the bile and 7 of 13 (16.28%) had it in the sputum. Of the seven patients with Cryptosporidium in the sputum, four had respiratory symptoms and an abnormal chest radiograph, although another pulmonary pathogen was isolated simultaneously. Two other patients from whom Cryptosporidium was the sole respiratory pathogen isolated had no respiratory symptoms and normal chest radiographs. The seventh patient had pulmonary symptoms, interstitial infiltrate on chest radiograph and excessive activity on a pulmonary Gallium scan; Cryptosporidium was the only organism detected in induced sputum and bronchoalveolar lavage specimens. The mean CD4+ lymphocyte count in patients with extraintestinal cryptosporidiosis was 55 cells/mm3.

Effects of time and watershed characteristics on the concentration of Cryptosporidium oocysts in river water

Water samples were collected from four locations on two rivers in Washington State and analyzed by membrane filtration-immunofluorescence assay to establish Cryptosporidium oocyst concentrations. Sampling locations were selected to evaluate effects of watershed character, from pristine mountain to downstream agricultural, on oocyst concentrations. Samples were collected at six biweekly intervals from late June to early September, with two additional sets of five samples taken on separate days (one set taken at bihourly intervals and one set taken simultaneously). Cryptosporidium oocysts were found in 34 of 35 samples at concentrations ranging from about 0.2 to 65 oocysts per liter. Oocyst concentrations were highest early in the sampling period, when they were influenced by postrainfall runoff, and decreased through the summer months. Oocyst concentrations found in ten samples collected on two days (5 samples per day) showed no short-term variations. Oocyst concentrations and oocyst production per square mile (ca. 2.6 km2) of watershed found in water draining a controlled public water supply watershed were the lowest observed. The concentrations and production rates for drainage from an adjacent, comparable, but uncontrolled watershed were nearly 10 times higher. The concentration and production rates of the downstream area influenced by dairy farming were nearly 10 times higher than rates at the upstream stations. The data showed clearly that oocyst concentrations were consistently observed above the detection limit of the analytical method, about 0.1 oocysts per liter; that oocyst concentrations were continuous as opposed to intermittent; and that watershed character and management affected surface water oocyst concentrations significantly.

Cryptosporidiosis

Before 1982, only eight case reports of human cryptosporidiosis and fewer than 30 papers on Cryptosporidium spp. appeared in the biomedical literature. At that time, cryptosporidiosis was thought to be an infrequent infection in animals and rarely an opportunistic infection in humans. The concept of Cryptosporidium spp. as pathogens has changed dramatically within the past 8 years because of improved diagnostic techniques, increased awareness within the biomedical community, and the development of basic research programs in numerous laboratories. Presently, greater than 1,000 publications including over 400 case reports in the biomedical literature address Cryptosporidium spp. and cryptosporidiosis. Cryptosporidium parvum is now thought to be one of the three most common enteropathogens causing diarrheal illness in humans worldwide, especially in developing countries. It is likely that cryptosporidiosis was previously included in the 25 to 35% of diarrheal illness with unknown etiology. Because of the severity and length of diarrheal illness and because no effective therapy has been identified, cryptosporidiosis is one of the most ominous infections associated with AIDS. The role of C. parvum as an enteropathogen is well established; documentation of its role as a cause of hepatobiliary and respiratory diseases is now appearing in the literature. Our present understanding of the natural history, epidemiology, biology, and immunology of Cryptosporidium spp. as well as the clinical features, pathogenicity, and treatment of cryptosporidiosis are reviewed here.

Cryptosporidiosis: clinical features and diagnosis

Cryptosporidiosis is an infectious disease caused by the coccidian parasite Cryptosporidium spp. that primarily infects the gastrointestinal tract of animals. Prior to late 1982, only 11 cases of human infection had been reported, with the first human case reported in 1976. During the 1980s, the number of human cases began to rise dramatically. Most of these patients were immunodeficient, many of whom had the acquired immune deficiency syndrome (AIDS). Immunocompetent individuals can also acquire the infection with mild-to-severe diarrhea lasting from several days to weeks. Immunocompromised patients develop severe, irreversible diarrhea, often thought to be a significant contributing factor leading to death. Although many therapeutic compounds have been tried, none have proven to be very successful. The incidence of this infection is worldwide, with many published reports of infection in both immunodeficient and immunocompetent individuals. The diagnostic approach has been expanded to include stool examinations using modified acid fast procedures and fluorescent monoclonal antibody reagents. Although histological methods are still routinely used for biopsy specimens, the examination of stool has proven to be a very effective, noninvasive procedure. In addition to the gastrointestinal tract, other areas of the body that have been found to be infected with this organism include the respiratory tract and the biliary tree and gall bladder epithelium. Screening for this organism may become very important in known risk groups (animal handlers; children, staff members, and contacts of those who attend day care centers; travelers; and those who are immunodeficient), particularly if an effective therapy is found. Some laboratories screen every specimen submitted for an ova and parasite examination, while others have limited their testing to specific requests, risk groups, and those patients who are symptomatic.

Human cryptosporidiosis

Cryptosporidium is an enteric coccidial protozoan recognized in humans in 1976. Since its manifestation as an acquired immunodeficiency syndrome (AIDS)-related infection, new diagnostic techniques have improved recognition of Cryptosporidium oocysts, making apparent its true prevalence in human populations. Cryptosporidium represents 5 to 15% of all enteric pathogens in children in warm climate countries. It is responsible for both endemic and epidemic disease. Day-care center spread is well known, and evidence is strong for person-to-person transmission. The spectrum of illness caused by Cryptosporidium is broad, and while self-limited in immunocompetent individuals, gastrointestinal symptoms can be severe. Asymptomatic infection has been described in population surveys and outbreak investigations. Severe dehydration with malabsorption and failure-to-thrive in children from developing countries has been attributed to this organism. Intractable, incurable diarrhea can be fetal in immunosuppressed adults. Cryptosporidiosis in human immunodeficiency virus-infected individuals is declining in frequency in New York City, possibly reflecting changing sexual behaviors and comparatively low infectivity. No effective treatment for Cryptosporidium has been documented, but clinical trials are in progress.

Cryptosporidium spp. and cryptosporidiosis

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