Diarrheal diseases associated with HIV infection

Temporal and Spatial Distribution of Opportunistic Infections Associated with the Human Immunodeficiency Virus (HIV) in Uganda

The human immunodeficiency virus (HIV) remains one of the greatest challenges of the twenty-first century in the absence of an effective vaccine or cure. It is estimated globally that close to 38 million people are currently living with the HIV virus and more than 36 million have succumbed to this deadly virus from the time the first case was reported in early 1980s. The virus degrades the human body immunity and makes it more vulnerable to different kinds of opportunistic infections (OIs). However, with the introduction of highly active anti-retroviral therapy (HAART) in 2003, the pattern and frequency of OIs has been progressively changing though with variations in the different parts of the World. So this chapter discusses the temporal and spatial patterns of OIs in Uganda.

Global prevalence and associated risk factors of diarrheagenic Giardia duodenalis in HIV/AIDS patients: A systematic review and meta-analysis

Giardia duodenalis is one of the leading causes of diarrhea, mostly in underdeveloped nations of Africa and Asia. The present review provides insights into the prevalence, odds ratios (ORs) and associated risk factors of giardiasis in HIV/AIDS patients. Four major English databases (Web of Science, PubMed, Scopus, and Google Scholar) were excavated for relevant literature without time limitation until 20 November 2020. Next, meta-analysis was performed using a random-effects model and 95% confidence intervals (CIs). As well, heterogeneity among studies was evaluated using Cochran's Q and the I²-statistic. Totally, 19,218 HIV/AIDS patients in 130 studies were examined, showing a 5% (95% CI: 4.2%-6%) pooled prevalence. Also, the weighted random-effects OR of G. duodenalis infection among HIV/AIDS patients in comparison with their controls in 48 case-control studies was estimated as 1.71% (95% CI: 1.1%-2.66%, p = 0.016). Based on sensitivity analysis, there was no remarkable variation in the pooled OR upon omitting individual studies. Diarrhea was a potent risk factor, since HIV/AIDS patients with diarrhea were 3.8-times (95% CI: 1.6-8.9, p = 0.002) more prone to G. duodenalis infection than those without diarrhea. Moreover, the prevalence of the parasitic infection was 1.2-times higher in patients without antiretroviral therapy (ART) than those with ART (p = 0.312). Meta-regression was employed to evaluate the possible association between G. duodenalis frequency in HIV/AIDS patients and some variables such as sample size, publication year, and HDI. Additionally, the pooled prevalence of G. duodenalis infection was estimated based on several subgroups, including publication years, WHO regions, countries, continents, country incomes, and CD4⁺ T-cell levels. Altogether, the epidemiology of giardiasis in HIV/AIDS patients and its association with various risk factors is still open to question and requires more detailed and comprehensive investigations.

The Synergistic Relationship Between Climate Change and the HIV/AIDS Epidemic: A Conceptual Framework

Climate change and HIV/AIDS represent two of the greatest threats to human health in the 21st century. However, limitations in understanding the complex relationship between these syndemics continue to constrain advancements in the prevention and management of HIV/AIDS in the context of a rapidly changing climate. Here, we present a conceptual framework that identifies four pathways linking climate change with HIV/AIDS transmission and health outcomes: increased food insecurity, increased prevalence of other infectious diseases, increased human migration, and erosion of public health infrastructure. This framework is based on an in-depth literature review in PubMed and Google Scholar from June 6 to June 27, 2019. The pathways linking climate change with HIV transmission and health outcomes are complex with multiple interacting factors. Food insecurity emerged as a particularly important mediator by driving sexual risk-taking behaviours and migration, as well as by increasing susceptibility to infections that are common among people living with HIV (PLWHIV). Future interventions should focus on decreasing carbon dioxide emissions globally and increasing education and investment in adaptation strategies, particularly in those areas of sub-Saharan Africa and southeast Asia heavily impacted by both HIV and climate change. Environmentally sustainable interventions such as urban gardening and investing in sustainable agriculture technologies also have significant health co-benefits that may help PLWHIV adapt to the environmental consequences of climate change.

Anthropogenic landscapes increase Campylobacter jejuni infections in urbanizing banded mongoose (Mungos mungo): A one health approach

Background

Campylobacter is a common, but neglected foodborne-zoonotic pathogen, identified as a growing cause of foodborne disease worldwide. Wildlife and domestic animals are considered important reservoirs, but little is known about pathogen infection dynamics in free-ranging mammalian wildlife particularly in sub-Saharan Africa. In countries like Botswana, there is significant overlap between humans and wildlife, with the human population having one of the highest HIV infection rates in the world, increasing vulnerability to infection.

Methodology/Principal findings

We investigated Campylobacter occurrence in archived human fecal samples (children and adults, n = 122, 2011), feces from free-ranging banded mongooses (Mungos mungo, n = 201), surface water (n = 70), and river sediment samples (n = 81) collected in 2017 from the Chobe District, northern Botswana. Campylobacter spp. was widespread in humans (23.0%, 95% CI 13.9–35.4%), with infections dominantly associated with C. jejuni (82.1%, n = 28, 95% CI 55.1–94.5%). A small number of patients presented with asymptomatic infections (n = 6). While Campylobacter spp. was rare or absent in environmental samples, over half of sampled mongooses tested positive (56%, 95% CI 45.6–65.4%). Across the urban-wilderness continuum, we found significant differences in Campylobacter spp. detection associated with the type of den used by study mongooses. Mongooses utilizing man-made structures as den sites had significantly higher levels of C. jejuni infection (p = 0.019) than mongooses using natural dens. Conversely, mongooses using natural dens had overall higher levels of detection of Campylobacter at the genus level (p = 0.001).

Conclusions

These results suggest that landscape features may have important influences on Campylobacter species exposure and transmission dynamics in wildlife. In particular, data suggest that human-modified landscapes may increase C. jejuni infection, a primarily human pathogen, in banded mongooses. Pathogen circulation and transmission in urbanizing wildlife reservoirs may increase human vulnerability to infection, findings that may have critical implications for both public and animal health in regions where people live in close proximity to wildlife.

Campylobacter infections are increasing worldwide but we still know little about the true burden of disease in the developing world, and even less about the role of wildlife and environmental reservoirs in human exposure and infection. Here we take a one-health approach evaluating Campylobacter infections in humans, banded mongooses (Mungos mungo), and the environment. We found evidence of widespread infection with Campylobacter spp. infecting nearly a quarter of sampled adults and children (23.0%, n = 122, 2011), dominantly with C. jejuni. Banded mongooses live in close association with humans in the area and over half of the animals sampled were found positive for Campylobacter spp. (56%, n = 201, 2017). Infection with C. jejuni was greater among mongooses utilizing human-made structures as den sites than those using natural dens. These data suggest that wildlife utilization of anthropogenic landscapes may increase C. jejuni exposure and infection. In turn, pathogen circulation and transmission in urbanizing wildlife reservoirs may increase human vulnerability to infection, particularly impoverished populations, where greater environmental exposures are expected.

Diarrhea: Initial Evaluation and Treatment in the Emergency Department

Diarrhea generates a wide range of diagnostic considerations and has profound individual and public health significance. The setting and circumstances under which a patient presents with diarrhea drastically influences the concern brought to the encounter. Nausea, vomiting, and diarrhea are often provisionally labeled "gastroenteritis" with appropriate expectant management. In resource-poor countries, the significance of diarrhea is even greater. This review focuses on diarrhea and its initial evaluation and management in the emergency department.

Human Immunodeficiency Virus-Associated Diarrhea: Still an Issue in the Era of Antiretroviral Therapy

Over half of patients with human immunodeficiency virus (HIV) experience diarrhea that contributes negatively to quality of life and adherence to antiretroviral therapy (ART). Opportunistic infectious agents that cause diarrhea in patients with HIV span the array of protozoa, fungi, viruses, and bacteria. With global use of ART, the incidence of diarrhea because of opportunistic infections has decreased; however, the incidence of noninfectious diarrhea has increased. The etiology of noninfectious diarrhea in patients with HIV is multifactorial and includes ART-associated diarrhea and gastrointestinal damage related to HIV infection (i.e., HIV enteropathy). A basic algorithm for the diagnosis of diarrhea in patients with HIV includes physical examination, a review of medical history, assessment of HIV viral load and CD4+ T cell count, stool microbiologic assessment, and endoscopic evaluation, if needed. For patients with negative diagnostic results, the diagnosis of noninfectious diarrhea may be considered. Pharmacologic options for the treatment of noninfectious diarrhea are primarily supportive; however, the use of many unapproved agents is based on unstudied and anecdotal information. In addition, these agents can be associated with treatment-limiting adverse events (AEs), such as drug-drug interactions with ART regimens, abuse liability, and additional gastrointestinal AEs. Currently, crofelemer, an antisecretory agent, is the only therapy approved in the USA for the symptomatic relief of noninfectious diarrhea in patients with HIV on ART.

High prevalence of diarrhoegenic intestinal parasite infections among non-ART HIV patients in Fitche Hospital, Ethiopia

BACKGROUND

HIV infection has been modifying both the epidemiology and outcome of parasite infections. Hence, this study was undertaken to determine the prevalence of Cryptosporidium and other intestinal parasite infections among HIV positives with and without Antiretroviral Treatment(ART) and its association with CD4+ T-cell count.

METHODS

A cross-sectional study was conducted at Fitche hospital focusing on HIV positives who came to hospital for follow-ups. A total of 378 HIV positive persons with and without ART participated in the study. Data on socio-demographic factors and diarrhoea status were obtained by interviewing all 214 with ART and 164 without ART. Stool samples were collected from all patients and examined for intestinal parasites using direct, formol-ether and modified acid-fast staining techniques.

RESULTS

The prevalence of intestinal parasite infections in this study was significantly higher among HIV positive persons not on ART. Specifically, the rate of infection with Cryptosporidium species, Blastocystis spp., Giardia lamblia, and Entamoeba histolytica/E. dispar were higher, particularly in those with CD4+ T-cell counts less than 200 cells/µL. Fifty seven percent of the study participants were on ART. Out of these 164/378 (43%) of the non-ART study participants were infected with at least one intestinal parasite species. Significant association was observed between lower CD4+ T-cell count (<200 cells/µL) and the prevalence of Cryptosporidium spp. and Blastocystis spp. The two parasites were significantly more prevalent in HIV positive non-ART patients.

CONCLUSION

HIV infection increased the risk of having Cryptosporidium and other intestinal parasites and diarrhoea. Therefore, raising HIV positive's immune status and screening for intestinal parasites is important. This study showed that patients who are taking ART had a lower prevalence of diarrhoea causing parasites and Cryptosporidium suggesting that ART through improvement of immune status of the patients may have contributed to controlling diarrhoea-causing parasites in HIV positive patients.

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.

Enteric pathogens in HIV-positive patients with diarrhoea and their correlation with CD4+ T-lymphocyte counts

BACKGROUND AND OBJECTIVES

Opportunistic parasitic infections are among the most serious infections in human immunodeficiency virus (HIV) positive patients and claim number of lives every year. The present study was conducted to determine the prevalence of intestinal parasites and to elucidate the association between intestinal opportunistic parasitic infection and CD4 (CD4+ T lymphocyte) counts in HIV-positive patients.

MATERIALS AND METHODS

The study was done on 266 HIV-positive patients presenting with diarrhoea and 100 HIV-positive patients without diarrhoea attending the integrated counselling and testing centre (ICTC) of SMS hospital, Jaipur. Simultaneously, CD4+ T-cell count estimation was done to assess the status of HIV infection vis-à-vis parasitic infections. The identification of pathogens was done on the basis of direct microscopy and different staining techniques.

RESULTS

Out of 266 patients with diarrhoea, parasites were isolated from 162 (i.e. 60.9%) patients compared to 16 (16%) patients without diarrhoea. Cryptosporidium parvum (25.2%) was the predominant parasite isolated in HIV-positive patients with diarrhoea followed by Isospora belli (10.9%). Parasites were more commonly isolated from stool samples of chronic diarrhoea patients, (77% i.e. 128/166) as compared to acute diarrhoea patients (34% i.e. 34/100) (P<0.05). The maximum parasitic isolation was in the patients with CD4+ T cell counts below 200 cells/μl.

CONCLUSIONS

Chronic diarrhoea in HIV-positive patients with CD4+ T-cell counts <200/μl has high probability of association with intestinal parasitic infections. Identification of these parasitic infections may play an important role in administration of appropriate therapy and reduction of mortality and morbidity in these patients.

Enteric Bacterial Pathogens in HIV-Infected Children With Acute Diarrhea in Mulago Referral and Teaching Hospital, Kampala, Uganda

Objective. HIV-infected children develop severe bacterial infections. We set out to determine the enteric bacterial pathogens in HIV-infected children and HIV-negative controls with acute diarrhea and their antimicrobial sensitivities. Methods. Children below 5 years of age with acute diarrhea were screened for HIV and their stools were analyzed by culture and use of antisera and the sensitivities of the pathogens were determined using the Kirby Bauer disc diffusion method. Results. Of the 190 children, 47 were HIV positive. The prevalence rates of the pathogens in HIV-infected and -uninfected children were 19% (9/47) and 27% (38/143), respectively; odds ratio = 0.64 (95% confidence interval 0.20-1.97), P value .396. The pathogens in HIV-infected and -uninfected children were Escherichia coli, Salmonella, and Shigella species. Most isolates were resistant to cotrimoxazole. Conclusions. Escherichia coli, Salmonella, and Shigella species significantly cause acute diarrhea in HIV-infected and -uninfected children and they are highly resistant to cotrimoxazole.

Aeromonas sobria sepsis complicated by rhabdomyolysis in an HIV-positive patient: case report and evaluation of traits associated with bacterial virulence

Human infection with Aeromonas species is uncommon and most often due to trauma with exposure to contaminated water or soil. A 43-year-old HIV- and hepatitis C virus (HCV)-infected male, after a two-week course of corticosteroid therapy for an autoimmune anemia, developed diarrhea, dermatologic manifestations and a multiple organ dysfunction syndrome, resulting in death. Although stool samples were repeatedly negative, two sets of blood cultures obtained during a single peak of fever yielded the post-mortem isolation of a Gram-negative, oxidase-positive, beta-hemolytic bacillus that was identified as Aeromonas sobria. Empiric antibiotic therapy was unsuccessful. Evaluation of the virulence-associated traits of the clinical isolate (adhesion, cytotoxicity activity, biofilm production) showed that the strain was a poor producer of recognized virulence factors, thereby indicating that the unfortunate coexistence of HIV infection, HCV-related liver cirrhosis and corticosteroids played a key role in the clinical course.

Bacterial diarrhea in persons with HIV infection, United States, 1992-2002

BACKGROUND

To describe trends in bacterial diarrhea among human immunodeficiency virus (HIV)-infected persons during 1992-2002, we examined data from a longitudinal record review study of persons with HIV infection who were receiving medical care in >100 medical facilities in 9 major United States cities.

METHODS

An analysis was performed using data from 44,778 persons who were followed up for a mean of 2.6 years. We calculated incidence rates and rate ratios for bacterial diarrhea, by stage of HIV disease, and determined odds ratios (ORs) to compare bacterial diarrhea diagnosis in 2002 versus 1992.

RESULTS

The mean annual incidence of bacterial diarrhea was 7.2 cases per 1000 person-years. The incidence of Clostridium difficile-associated diarrhea, the most common bacterial cause of diarrhea, was 4.1 cases per 1000 person-years. Compared with persons without AIDS, persons with AIDS were more likely to have bacterial diarrhea (incidence rate ratio, 1.3-9.9, varying by clinical versus immunologic AIDS and type of bacterial diarrhea). Between 1992 and 2002, the overall rate of bacterial diarrhea in persons with clinical AIDS decreased (OR, 0.4; 95% confidence interval, 0.2-0.6). During the same period, bacterial diarrhea rates among other persons in the analysis did not significantly change.

CONCLUSIONS

C. difficile is the most common recognized cause of bacterial diarrhea among persons infected with HIV. The risk for bacterial diarrhea increases with increased severity of HIV disease. Health care professionals should be aware that patients with AIDS are at increased risk for bacterial diarrhea, and they should reinforce recommendations for decreasing the chances of acquiring bacterial diarrhea.

Ultrastructural study of the pancreas in AIDS

INTRODUCTION

Frequent histologic changes (90%) in the pancreas suggesting protein-energy malnutrition were found in a previous necropsy study of pancreas morphology in patients with AIDS. However, additional studies were required to clarify subcellular changes.

AIM

To ultrastructurally analyze pancreas changes in AIDS patients through transmission electron microscopy.

METHODOLOGY AND RESULTS

Pancreas specimens for necropsy were obtained from nine consecutive AIDS patients and four normal controls. A semiquantitative histologic and ultrastructural analysis of exocrine pancreas was carried out with the following findings: preserved pancreas structure with little autolysis, marked decrease in zymogen granules (100%), increased lipofuscin pigment (80%), augmented and dilated rough endoplasmic reticulum (100%), and increased number and size of mitochondria. The Golgi complex could be identified only in two cases. In all cases, acinar nuclei were decreased in size, with peripherally condensed chromatin and undulated membrane suggesting early apoptosis. In addition, immunohistochemical evaluation of the pancreas was carried out to detect opportunistic agents.

CONCLUSION

Decreased zymogen granules, acinar atrophy, increased lipofuscin pigment, and rarefying Golgi complex represent the morphologic substrate of protein-energy malnutrition in AIDS patients. The combination of rough endoplasmic reticulum and mitochondria changes could be due to the need for supplying vital plasma proteins rather than exportation protein synthesis associated, or not, with the deleterious effects of inflammatory cytokines and/or therapy for disease.

CMV DNA in blood and CSF of HIV infected patients

Cytomegalovirus (CMV) infection frequently affects the central nervous system in HIV infected patients. Varied clinical manifestations of CMV disease make virological detection of CMV essential for proper diagnosis and treatment. Thus, in patients in different stages of HIV-induced disease, we attempted to detect cell associated and free, non cell associated CMV DNA in cerebrospinal fluid (CSF) and in peripheral blood mononuclear cells (PBMCs). Twenty-six blood samples were collected from 22 patients included in the study. Nine of these blood samples were tested in pair with the concomitant CSF sample for the presence of CMV DNA by a commercial hybridization test. CMV serostatus and avidity of IgG antibodies were detected by a commercial ELISA test. CMV DNA was present in the cells found in CSF in all but one of the AIDS patients, independently of the presence of neurological symptoms, suggesting that it represented a marker of advanced immunodeficiency, rather than of the specific CMV-related disease. Cell-associated CMV DNA in CSF tested positive even in the samples negative for cell-free CMV DNA in the CSF, and with no detectable CMV DNA in the PBMCs of concomitant blood sample. We believe that searching for CMV DNA in different compartments of CSF merits further attention.

Colorectal disease in liver allograft recipients -- a clinicopathological study with follow-up

OBJECTIVE

To determine the spectrum and outcome of colorectal diseases occurring in adult liver allograft recipients.

DESIGN

A retrospective cohort analysis of clinical, microbiological and histopathological data regarding colorectal disease.

PATIENTS

Forty three out of 302 adult primary liver allograft recipients were transplanted and followed up (at median 42 months) at a tertiary referral centre/teaching hospital.

RESULTS

Out of 302 patients, 43 (14%) were investigated (by endoscopy and/or laparotomy) for symptoms of colorectal disease after orthotopic liver transplantation. The symptoms were: diarrhoea (n = 31); per-rectal bleeding (n = 5); and symptoms relating to pre-transplant ulcerative colitis (n = 7). Among the patients without known ulcerative colitis, per-rectal bleeding occurring early after orthotopic liver transplantation was most commonly caused by cytomegalovirus colitis and carried a poor prognosis. Excluding ulcerative colitis, the commonest causes of diarrhoea were Clostridium difficile, cytomegalovirus infection and medications, particularly during the first 2 months after orthotopic liver transplantation. No cases of colorectal graft-versus-host disease, cryptosporidiosis, amoebiasis, atypical mycobacterial infection or post-transplant lymphoproliferative disease were demonstrated. The activity of pre-transplant ulcerative colitis was unchanged or increased after orthotopic liver transplantation. Two further patients developed new-onset ulcerative colitis after orthotopic liver transplantation.

CONCLUSIONS

Ulcerative colitis, C. difficile, cytomegalovirus infection and medications are the commonest colorectal causes of morbidity after orthotopic liver transplantation. Adult liver allograft recipients are, however, unlikely to show certain large bowel diseases encountered in other immunosuppressed groups. Amongst non-ulcerative colitis patients, those presenting with diarrhoea show a good outcome with appropriate management, whereas those with per-rectal bleeding have a more guarded prognosis.

Life-threatening cytomegalovirus colitis in the immunocompetent patient: report of a case and review of the literature

Cytomegalovirus colitis in the immunocompetent patient is an unusual clinical entity. We describe a patient with life-threatening cytomegalovirus colitis in the absence of immune deficiency and review the medical literature available on this topic.

Infectious diarrhea in human immunodeficiency virus

Chronic HIV-associated diarrhea is currently a field in flux. Improved noninvasive diagnostic tests, improved pathogen-specific regimens, and better empiric therapies may change some of the assumptions used to select algorithms for diagnostic evaluation and management. Any shift in the cause of diarrhea from pathogen-associated to idiopathic or a reduction in the overall incidence of diarrhea would have considerable impact. It is unclear how significant the problem of pathogen relapse in previous responders will become. Existing studies reviewed in this article show that the high diagnostic yield of endoscopy when stool tests are negative, coupled with significantly better outcomes when pathogens are identified, support the current practice of routine endoscopic evaluation. There currently are scant data on the economic impact of HIV-associated diarrhea as it relates to pathogen-specific and empiric therapy in the era of protease inhibitors. Such data would be integral to future evaluation of the impact of diagnostic and therapeutic strategies.

The histopathology of 103 consecutive colonoscopy biopsies from 82 symptomatic patients with acquired immunodeficiency syndrome: original and look-back diagnoses

OBJECTIVE

To compare the primary diagnoses assigned by general surgical pathologists on a series of 103 consecutive colon biopsies from individuals infected with human immunodeficiency virus (HIV) with diagnoses rendered by a pathologist with extensive experience in gastrointestinal pathology in HIV/acquired immunodeficiency syndrome.

DESIGN

New sections were cut from paraffin blocks of 103 consecutive colon biopsies taken during colonoscopies of 82 different HIV-infected patients; all new sections were stained with hematoxylin-eosin. These individuals either had negative stool studies or had failed to respond to therapy and had chronic large bowel symptoms, such as frequent small volume-type diarrhea, tenesmus, and/or bright red blood per rectum. Immunohistochemistry for cytomegalovirus (CMV) was performed on 18 of 22 specimens originally diagnosed with CMV colitis.

RESULTS

The initial study yielded 70 (68%) negative or nonspecific diagnoses, 22 (21%) cases of CMV colitis, 5 (5%) Cryptosporidium diagnoses, 2 cases each of adenomatous polyps and Kaposi sarcoma, and 1 case each of spirochetosis and squamous cell carcinoma of the anorectum. Review of the recuts yielded 64 (62%) negative or nonspecific diagnoses, 12 (12%) new adenovirus infections (3 combined with CMV), and 11 (11%) lone CMV infections. Three attaching and effacing bacterial infections were diagnosed, 1 with adenovirus coinfection. A total of 4 spirochetosis cases were found on review. Seven (7%) of the biopsies showed at least 1 coinfection. Nine biopsies had features suggestive of inflammatory bowel disease.

CONCLUSIONS

Colonoscopy with biopsy after negative stool studies or failure to respond to therapy yielded a high proportion of negative or nonspecific diagnoses. Adenovirus and enteropathogenic bacterial infections had been totally overlooked on initial examination. It takes particular experience to evaluate gastrointestinal biopsies from HIV-infected patients.

Small Intestinal Infections

The differential diagnosis of small intestinal infections is broad, making the identification and management of these disorders challenging. The majority of cases of acute diarrhea are self-limited and do not require diagnostic evaluation or treatment. Most patients do not require specific therapy, and treatment should focus on fluid and electrolyte replacement. In patients with severe, persistent, or chronic diarrhea, a careful medical history and routine stool testing are helpful in determining the cause. Pathogen-specific therapy should be given in patients in whom a pathogen is identified. In those without an identifiable pathogen, antidiarrheal agents are helpful in reducing the number of bowel movements and preventing further dehydration. Endoscopy may be helpful in patients with severe diarrhea and a negative stool evaluation, particularly in HIV-infected patients with chronic diarrhea. Surgery has a limited role in the management of small intestinal infections, but may be lifesaving in patients with intestinal perforation or small bowel obstruction.

The changing etiology of chronic diarrhea in HIV-infected patients with CD4 cell counts less than 200 cells/mm3

PURPOSE

The purpose of this study was to evaluate the incidence and causes of chronic diarrhea in patients with AIDS over a period of time that included the pre-HAART (highly active antiretroviral therapy) era and the introduction of HAART.

METHODS

The study cohort was comprised of patients receiving primary care at a university-associated outpatient HIV clinic from January 1, 1995 to December 31, 1997. Patients were identified retrospectively through a clinical database and were included in the study if their diarrhea had persisted for longer than two weeks and their CD4 cell count at time of symptoms was <200 cells/mm3. Further data were obtained by chart review.

RESULTS

Over the 36-month period, the occurrence of chronic diarrhea did not change significantly, ranging from 8 to 10.5% per year in patients with CD4 cell counts <200 cells/mm3. The percentage of patients diagnosed with opportunistic infectious etiologies decreased over the three-year period from 53% (1995) to 13% (1997). The percentage of patients diagnosed with noninfectious causes increased from 32% to 70% over this same time period.

CONCLUSIONS

Over the three years of the study, the incidence of chronic diarrhea in AIDS patients in our clinic did not change. The etiologies of diarrhea did change significantly, with an increased incidence of noninfectious causes and a decreased incidence of opportunistic infectious causes. This shift in etiologies coincides with the introduction and increased use of HAART in our clinic population (1996).

Prevalence of intestinal parasitic infections in patients with acquired immunodeficiency syndrome in Brazil

OBJECTIVES

To evaluate the prevalence of intestinal parasitic infections and to investigate the possible associations of clinical status and laboratory findings with the different parasites found in stool samples.

METHODS

Each patient was provided with one standard fecal collection vial containing 10% formalin for detecting ova, larvae, and cysts. To detect Cryptosporidium parvum and Isospora belli, the acid-fast Kinyoun stain and fluorescent auramine-rhodamine stain were used.

RESULTS

A total of 200 patients with acquired immunodeficiency syndrome participated in this study; 40% were infected with at least one pathogenic species. The total prevalence of parasites was 16% for Giardia lamblia, 13% for Entamoeba coli, 7% for Cryptosporidium parvum, 3.5% for Endolimax nana, 2.5% for Ascaris lumbricoides, 2.5% for Strongyloides stercoralis, 2% for Isospora belli, and 0.5% for Blastocystis hominis. Results showed that diarrhea was significantly associated with cryptosporidiosis, giardiasis, and isosporiasis. However, no association was observed between the CD4+ cell counts and the manifestation of any particular parasite.

CONCLUSIONS

The data support the value of standard fecal examinations in human immunodeficiency virus-infected patients, even in the absence of diarrhea, since these examinations easily can be performed, with low costs, and frequently disclose treatable conditions.

Quality of life and self-care management strategies of PLWAs with chronic diarrhea

A case control design was used to examine quality of life and self-care management strategies in persons living with AIDS (PLWAs) with chronic diarrhea. PLWAs without chronic diarrhea (n = 20) as compared to those with chronic diarrhea (n = 20) reported significantly higher general health perceptions (p = .028). In contrast, comparisons on symptom status scores revealed that PLWAs without chronic diarrhea reported greater fatigue (p = .05), greater psychological distress (p = .005), and greater gastrointestinal discomfort (p = .01). Although the intensity of chronic diarrhea was reported as moderate to severe by 85% of the sample, no single category of self-care management strategies was used by more than 65% of respondents. The number of categories of self-care management activities was significantly correlated with general health perceptions. The study findings support the need to test nursing interventions aimed at improving symptom management in chronic diarrhea and facilitating self-care behaviors including those focused on increasing adherence to prescribed therapeutic regimens.

A multiple drug interaction study of stavudine with agents for opportunistic infections in human immunodeficiency virus-infected patients

The effects of multiple opportunistic infection medications on stavudine pharmacokinetics were evaluated. Ten patients with CD4 counts of less than 200 cells/mm3 received stavudine (40 mg twice daily) in combination with one to three other drugs used to treat opportunistic infections. Serial blood samples for stavudine concentrations were collected after 1 week of therapy on each regimen and assayed for stavudine by using a validated high-pressure liquid chromatography method. Although the maximum concentration of drug in serum was significantly decreased when the drug was given in combination with three opportunistic infection medications, the area under the concentration-time curve did not significantly differ across various treatment regimens. Stavudine exposure was not significantly altered by multiple concomitant medications. Side effects were minor throughout the 3-month study period. The tolerability of stavudine, combined with its lack of drug interactions, makes it an attractive agent for use as part of a combination regimen.

A prospective study of endoscopy in HIV-associated diarrhea

OBJECTIVE

Diarrhea commonly occurs in persons with human immunodeficiency virus (HIV) infection. The optimal use of endoscopic procedures remains poorly studied for patients with HIV-related diarrhea. The purpose of this study is to compare the diagnostic yield of a complete endoscopic work-up including an esophagogastroduodenoscopy and colonoscopy to a more limited approach of biopsies obtainable by flexible sigmoidoscopy.

METHODS

A prospective study of 79 patients with HIV-related diarrhea. Upper endoscopy and colonoscopy were performed with tissue biopsies labelled according to location within the colon or small intestine.

RESULTS

A new infection was diagnosed in 22 of 79 patients (28%). Biopsy of the left colon yielded an enteric pathogen in 17 of 22 patients (sensitivity: 77%) and in 15 of 15 patients with cytomegalovirus colitis (sensitivity: 100%). Combined left and right colonic biopsies had a sensitivity of 82%. Combined colonic and terminal ileum biopsies missed no pathogens. Duodenal biopsies yielded no additional pathogens beyond those identified by colonoscopy and terminal ileal biopsy. Patients with a new pathogen diagnosed had significantly lower CD4 lymphocyte counts as compared to patients without a new pathogen (p = 0.001).

CONCLUSIONS

For patients with CD4 counts < 100/mm3 and unexplained AIDS-related diarrhea, flexible sigmoidoscopy with biopsy is a sufficiently thorough endoscopic evaluation.

Prevalence of intestinal pathogens in HIV patients with diarrhea: implications for treatment

Patients infected with the human immunodeficiency virus (HIV) commonly experience diarrhea at some time during their illness. A variety of enteric pathogens are identified in 50-80% of these patients, depending on the intensity of the diagnostic work-up that is done. In addition to the common enteric pathogens, several unusual enteric pathogens are recognized to cause diarrhea especially in HIV patients. These include protozoan parasites such as Cryptosporidia, Isospora belli, Cyclospora cayatenensis and Microsporidium species bacteria such as enteropathogenic Escherichia coli and Mycobacterium avium-intracellulare, fungi including Candida albicans and Histoplasma capsulatum, and viruses such as astroviruses and caliciviruses. Diagnosis of these infections sometimes involves special procedures not readily available every where, and empiric therapy based on knowledge of the likely pathogens has been advocated for developing countries. This article reviews the currently available data on geographic variation of enteric pathogens in HIV patients with diarrhea and outlines a rational strategy for empiric therapy of these patients.