Infectious diarrhea in human immunodeficiency virus

Multimethodological Approach to Gastrointestinal Microsporidiosis in HIV-Infected Patients

PURPOSE

Microsporidiosis is an opportunistic infection that produces chronic diarrhoea and cholangiopathy in patients with AIDS, mainly caused by two species of microsporidia, Enterocytozoon bieneusi and Encephalitozon intestinalis. The aim of this work was to develop an integral system for the diagnosis of microsporidiosis of the intestine and biliary tract in HIV-infected patients, comprising microscopic and molecular techniques.

METHODS

The study population comprised 143 adult patients of both sexes with diagnosis of HIV infection, with chronic diarrhoea, and with or without HIV-associated cholangiopathy. Stool studies for microsporidia identification of spores were performed on each patient. A video esofagogastroduodenoscopy with biopsy collection was also carried out for routine histology and semi-thin sections stained with Azure II. Species identification was carried out by transmission electron microscopy and/or polymerase chain reaction for the species E. bieneusi and E. intestinalis.

RESULTS

Out of the 143 patients a total of 12.6% (n = 18) were infected with microsporidia. Microsporidia species identified in most cases was E. bieneusi (16/18 cases), followed by E. intestinalis (4/18), all of these last ones in coinfection with E. bieneusi.

CONCLUSIONS

Clinical, imaging, microscopic and molecular analyses, when applied in a systematic and integrated approach, allow diagnosis and identification of microsporidia at species level in AIDS patients with chronic diarrhoea, and with or without HIV-associated cholangiopathy.

Enteric pathogens in HIV infected and HIV uninfected individuals with diarrhea in Pune

BACKGROUND

Diarrhea in HIV infected individuals is a common complication seen in about 90% of patients in developing countries. The objective of this study was to identify enteric pathogens in HIV infected and HIV uninfected individuals in Pune.

METHOD

This study was conducted from January 2009 to May 2010 on 331 consecutive patients presenting with diarrhea admitted at Naidu Municipal Corporation Hospital, Pune and processed using conventional methods.

RESULTS

Intestinal parasitic pathogens were detected in 60% (39/65) of HIV infected and 14.3 (38/266) of HIV uninfected individuals. Bacterial pathogens were detected in 34% (22/65) of HIV infected individuals and 28.2% (75/266) of the HIV uninfected individuals. The common enteric pathogens detected in HIV infected individuals were Cystoisospora belli (28%, 18/65) followed by Cryprotosporidium parvum (12%, 8/65). In HIV uninfected individuals Entamoeba histolytica (7.1%, 19/266) followed by Shigella flexnari (4.9%, 13/266) were the most common pathogens. The difference in detection of enteric parasites in HIV infected individuals and HIV uninfected individuals was found to be significant (p < 0.01).

CONCLUSIONS

Intestinal parasitic pathogens are more common in HIV infected antiretroviral therapy naïve patients. Early detection of enteric pathogens by routine examination of stool samples will help in the management and to improve the quality of life for HIV infected individuals.

Impact of highly active antiretroviral therapy (HAART) on the incidence of opportunistic infections, hospitalizations and mortality among children and adolescents living with HIV/AIDS in Belo Horizonte, Minas Gerais State, Brazil

The impact of highly active antiretroviral therapy (HAART) can be evaluated using indicators, such as rates of opportunistic infections, hospitalizations by cause of infection, and associated death. This study aimed to estimate the impact of HAART on the incidence of these indicators, in children and adolescents with HIV/AIDS. It was a hybrid cohort study; 371 patients were followed from 1989 to 2003. In December 2003, 76% of the patients were still being followed, while 12.1% had died, 9.5% had dropped out, and 2.4% had been transferred. The overall rate of opportunistic infections was 18.32 infections/100 persons-year and 2.63 in the pre- and post-HAART periods, respectively. In the multivariate analysis, the risk of developing an opportunistic infection was 5.4 times greater and 3.3 times greater for hospitalization risk before HAART. Respiratory causes represented 65% of the hospitalizations and they were reduced by 44.6% with therapeutic intervention. The average hospital stay of 15 days was reduced to 9. There was a post-HAART decline in deaths of 38%. This study demonstrates the effectiveness of HAART in significantly reducing opportunistic infections, hospitalizations, and deaths in this Brazilian cohort.

Diarrhea in patients with AIDS

Diarrhea in patients with AIDS is a worldwide problem that can have a devastating impact on quality of life for the patient. Chronic diarrhea, usually defined as at least 4 weeks' duration, is more common in patients with low CD4-positive T-lymphocyte counts, signaling advanced immunosuppression. Some organisms, such as Microsporidia, usually cause diarrhea only in the immunosuppressed; others, such as Cryptosporidium, Salmonella, Shigella, and Campylobacter, which are capable of causing diarrhea in the immunocompetent population, produce more severe or prolonged infections in people living with AIDS. Familiarity with the most common pathogens in the clinician's region will help with diagnosis and treatment. Because treatment options vary widely depending upon the infectious agent, thorough microbiologic evaluation is warranted. A stepped diagnostic approach of stool cultures and specialized microscopy and stains for protozoa, followed by sigmoidoscopy or colonoscopy and duodenoscopy with biopsies for histopathological examination is recommended in all patients with persistent, disabling diarrhea who have a CD4 count of less than 200/mm3, and should be considered for those with higher counts on an individual basis. Treatment, tailored to the specific pathogen, may need to be prolonged in the most severely immunocompromised patients to prevent relapse or recrudescence. For patients taking antiretroviral therapy (especially protease inhibitors) in whom no infectious agent can be found, diarrhea may be due to the medications. Nonspecific antidiarrheal agents should be tried until one that suits the patient is found. The most essential component of any therapeutic strategy for a patient with AIDS-associated diarrhea is restoration of the underlying immunologic defect using highly active antiretroviral therapy.

Gastrointestinal parasites in the immunocompromised

PURPOSE OF REVIEW

Parasites and other infections have many effects on the gastrointestinal tract of individuals who are immunocompromised. Few reviews focus on parasitic infections, which are covered here.

RECENT FINDINGS

The review first examines recent advances in our understanding of the taxonomy, diagnosis and treatment of pathogens such as cryptosporidia, cyclospora, isospora and microsporidia, which are recognized causes of diarrhoea in the immunocompromised, and discusses possible links between amoebiasis and HIV. The complex interactions of both intact and abnormal immune systems with helminth infections such as hookworm and strongyloidiasis, and with trematode infections such as schistosomiasis, are receiving increasing attention. These are discussed, together with the novel concept of using live helminths to treat inflammatory bowel disease.

SUMMARY

Parasitic infections remain a significant problem for immunocompromised individuals in resource-poor settings, and further work is needed to develop accessible diagnostic tests and to improve our understanding and management of their pathogenic effects. New concepts about the interactions of helminths with host immunity suggest the need for collection of further epidemiological and clinical data to unravel the complexities of such immunological interactions.

Management of gastrointestinal disorders in children with HIV infection

A double scenario characterizes the epidemiology of HIV infection in children. In countries where highly active antiretroviral therapy (HAART) is available, the pattern of HIV infection is evolving into that of a chronic disease, for which control strictly depends on patients' adherence to treatment. In developing countries with no or limited access to HAART, AIDS is rapidly expanding and is loaded with a high fatality ratio, due to the combined effects of malnutrition and opportunistic infections. The digestive tract is a target of the disease in both settings. Opportunistic infections play a major role in children with severe immune impairment, with Cryptosporidium parvum being the leading agent of severe diarrhea. Several therapeutic approaches are effective in reducing fecal output, but the eradication of the parasite is rarely obtained. Other opportunistic infections may induce severe and protracted diarrhea, including atypical mycobacteria and cytomegalovirus. Diagnosis of diarrhea should be individually tailored based on presenting symptoms and risk factors. A stepwise approach is effective in limiting patient discomfort and minimizing the costs of investigations, starting with microbiologic investigation and proceeding with endoscopy and histology. Aggressive treatment of infectious diarrhea is required in severely immunocompromised children. However, antiretroviral therapy prevents the development of severe cryptosporidiosis. The liver and pancreas are also target organs in HIV infection, although functional failure is rare. The digestive-absorptive functions are impaired, with steatorrhea, nutrient malabsorption, and increased permeability occurring in 20-70% of children. Intestinal dysfunction contributes to growth failure and further immune derangement, leading to wasting, the terminal stage of AIDS. Nutritional management is crucial in HIV-infected children and is based on aggressive nutritional rehabilitation through enteral or parenteral routes and micronutrient supplementation.HIV may play a direct enteropathogenic role and is implicated in both diarrhea and intestinal dysfunction. This explains the efficacy of antiretroviral therapy in inducing remission of diarrhea and restoring intestinal function. Gastrointestinal side effects of antiretroviral drugs are increasingly observed; they are often mild and transient. Severe reactions are rare but require the withdrawal of drugs. In conclusion, severe enteric infections and intestinal dysfunction characterize the intestinal involvement of HIV infection. This is more common in, but not limited to, children who do not receive effective antiretroviral therapy. Diagnostic approaches include microbiologic and morphologic examinations and assessment of digestive processes, but immunologic and virologic data should be also carefully considered. Treatment is based upon specific anti-infectious drugs, antiretroviral therapy, and nutritional rehabilitation.

Conduite à tenir devant une diarrhée aiguë. Étiologies

Les diarrhées aiguës constituent un problème de santé publique du fait de leur grande fréquence. Leur origine est presque toujours infectieuse et leur évolution spontanément résolutive, le plus souvent en moins de 3 jours. Seul 1 % des diarrhées nécessite d'emblée des explorations complémentaires, notamment des examens de selles, car leur présentation clinique évoque une colite aiguë sous-jacente (selles sanglantes, douleurs abdominales circonscrites), du fait d'un terrain fragile sous-jacent avec un risque immédiat pour le malade, ou d'un contexte particulier (séjour sous les tropiques…). Ces examens de selles doivent être orientés afin de guider le biologiste et améliorer la rentabilité des prélèvements, qui s'avère sinon très faible et coûteuse à l'échelle d'une population. Une antibiothérapie empirique basée essentiellement sur les fluoroquinolones est ensuite licite dans ces cas sélectionnés, en attendant les résultats des examens. Ces explorations sont aussi justifiées lorsque la diarrhée persiste au-delà de 3 jours. Enfin, lorsque l'épisode se prolonge au-delà de 5 jours, avec des prélèvements de selles négatifs, un avis spécialisé est nécessaire. Ainsi, seule une petite proportion de ces diarrhées aiguës va nécessiter une endoscopie, permettant de parler ainsi de colite ou de rectocolite. Au plan thérapeutique, la réhydratation précoce chez l'enfant reste d'actualité car elle a prouvé son efficacité en termes de mortalité depuis plus de deux décennies, principalement dans les pays en voie de développement.

Cytomegalovirus ischemic colitis: a near-fatal presentation of HIV infection

Cytomegalovirus infection occurs in immunocompromised patients. We present a 45-year-old male with no prior medical history who presented to the hospital with weight loss and non-bloody diarrhea. During hospitalization, he developed severe hematochezia and hypotension. Colonoscopy revealed dusky, friable mucosa. The patient arrested and was resuscitated. Specimen from emergent colectomy showed ischemic changes secondary to cytomegalovirus infection of endothelium and small-vessel thrombosis. An HIV test was subsequently positive with CD4 count of 2 per microliter. The patient was treated with antiretroviral therapy and ganciclovir. He survived postoperative infections and was eventually discharged. In summary, this case of near-fatal cytomegalovirus colitis represents an unusual presentation of undiagnosed HIV infection. Cytomegalovirus infection should be included in the differential diagnosis of immunocompromised patients with gastrointestinal symptoms. Hematochezia may be from intestinal ulceration or severe ischemic damage. Antiretroviral therapy and ganciclovir or foscarnet should be initiated promptly. Surgery is indicated in life-threatening hemorrhage or obvious bowel necrosis.

Gastrointestinal infections in the immunocompromised host

Persons with HIV infection, leukemia, lymphoma, solid organ and bone marrow transplants, and inherited immune deficiencies as well as those on immunosuppressive drugs are at high risk for infections of the gastrointestinal tract. Pathogenic as well as opportunistic viruses, bacteria, fungi, and protozoa cause infections in the esophagus, stomach, small intestine, and large intestine. Symptoms may be mild but more often are severe and even life threatening. This article reviews what is new in the field of gastrointestinal infections in the immunocompromised host during the past year. I will place specific emphasis on articles that are most pertinent to clinical care.

The role of esophagogastroduodenoscopy in the diagnosis and management of upper gastrointestinal disorders

Esophagogastroduodenoscopy has revolutionized the clinical management of upper gastrointestinal diseases. Millions of EGDs are performed annually in the United States for many indications, such as gastrointestinal bleeding, abdominal pain, dysphagia, or surveillance of premalignant lesions. Esophagogastroduodenoscopy is very safe, with a low risk of serious complications such as perforation, cardiopulmonary arrest, or aspiration pneumonia. It is a highly sensitive and specific diagnostic test, especially when combined with endoscopic biopsy. Esophagogastroduodenoscopy is increasingly being used therapeutically to avoid surgery. New endoscopic technology such as endosonography, endoscopic sewing, and the endoscopic videocapsule will undoubtedly extend the frontiers and increase the indications for endoscopy.