Clinical prediction model for differentiation of disseminated Histoplasma capsulatum and Mycobacterium avium complex infections in febrile patients with AIDS

Disseminated Mycobacterium avium-Intracellulare Complex Infection Presenting With Disseminated Intravascular Coagulation in an AIDS Patient

Disseminated Mycobacterium avium-intracellulare complex (MAC) infection is one of the relatively common opportunistic infections seen in severely immunocompromised AIDS patients. A constellation of clinical, laboratory, and pathological features involving multiple organ systems are often present in disseminated MAC infection but disseminated intravascular coagulation (DIC) has not been previously described in association with this condition. To our knowledge, this is the first reported case of DIC complicating disseminated MAC infection in an AIDS patient. In this article, we present the case of a 33-year-old AIDS patient with high viral load, CD4 lymphocyte count of 1/mm³, who presented with nonspecific symptoms, anemia, thrombocytopenia, and increased lactate dehydrogenase, alkaline phosphatase, and ferritin. She also had abnormal coagulation parameters and features compatible with chronic DIC. Bone marrow biopsy assisted in making the correct diagnosis. She also later grew MAC from blood and sputum cultures. There were no other factors identified after a complete workup to explain DIC in this patient. After commencement of appropriate MAC therapy, she initially had a good response with some improvement of her coagulation parameters. Few months later, however, probably attributable to poor medication compliance, her condition deteriorated with development of thromboembolism, full-fledged DIC, sepsis, and an eventual fatal outcome. This case illustrates the importance of including disseminated MAC in the differential diagnosis of DIC in an AIDS patient.

High Mortality and Coinfection in a Prospective Cohort of Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome Patients with Histoplasmosis in Guatemala

Histoplasmosis is one of the most common and deadly opportunistic infections among persons living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome in Latin America, but due to limited diagnostic capacity in this region, few data on the burden and clinical characteristics of this disease exist. Between 2005 and 2009, we enrolled patients ≥ 18 years of age with suspected histoplasmosis at a hospital-based HIV clinic in Guatemala City. A case of suspected histoplasmosis was defined as a person presenting with at least three of five clinical or radiologic criteria. A confirmed case of histoplasmosis was defined as a person with a positive culture or urine antigen test for Histoplasma capsulatum. Demographic and clinical data were also collected and analyzed. Of 263 enrolled as suspected cases of histoplasmosis, 101 (38.4%) were confirmed cases. Median time to diagnosis was 15 days after presentation (interquartile range [IQR] = 5-23). Crude overall mortality was 43.6%; median survival time was 19 days (IQR = 4-69). Mycobacterial infection was diagnosed in 70 (26.6%) cases; 26 (25.7%) histoplasmosis cases were coinfected with mycobacteria. High mortality and short survival time after initial symptoms were observed in patients with histoplasmosis. Mycobacterial coinfection diagnoses were frequent, highlighting the importance of pursuing diagnoses for both diseases.

Lymphnodal Co-infection of Cryptococcus and Histoplasma in a HIV-Infected Patient and Review of Published Reports

Human infection with Histoplasma capsulatum and Cryptococcus runs the gamut from asymptomatic illness to disseminated disease. Though both are the most prevalent systemic mycoses in HIV-infected patients, simultaneous infection by both the pathogens rarely occurs. We document the first case from Asian subcontinent with concurrent infection with disseminated cryptococcosis and histoplasmosis infections in a HIV-infected Indian patient diagnosed by morphological examination of fine-needle aspiration cytology samples obtained from the enlarged lymph nodes on light microscopy and were later confirmed by culture studies. A prompt, accurate and timely diagnosis of the disseminated form of dual mycosis (or either of the mycosis as well) is of utmost importance which has obvious impact on early initiation of treatment. Fine-needle aspiration cytology is a rapid, cost-effective and reliable method to identify infection with Cryptococcus and Histoplasma and is comparable with the essential culture studies.

Validation of an enzyme-linked immunosorbent assay that detects Histoplasma capsulatum antigenuria in Colombian patients with AIDS for diagnosis and follow-up during therapy

We validated an antigen capture enzyme-linked immunosorbent assay (ELISA) in Colombian persons with AIDS and proven histoplasmosis and evaluated the correlation between antigenuria and clinical improvement during follow-up. The sensitivity of the Histoplasma capsulatum ELISA was 86%, and the overall specificity was 94%. The antigen test successfully monitored the response to therapy.

Development and evaluation of an enzyme-linked immunosorbent assay to detect Histoplasma capsulatum antigenuria in immunocompromised patients

Histoplasma capsulatum infection causes significant morbidity and mortality in human immunodeficiency virus-infected individuals, particularly those in countries with limited access to rapid diagnostics or antiretroviral therapies. The fungus easily disseminates in persons with AIDS, resulting in progressive disseminated histoplasmosis (PDH), which can progress rapidly to death if undiagnosed. The availability of a simple, rapid method to detect H. capsulatum infection in less developed countries where the infection is endemic would dramatically decrease the time to diagnosis and treatment of PDH. We have developed an antigen-capture enzyme-linked immunosorbent assay (ELISA) to detect PDH antigenuria in infected patients. The assay uses polyclonal antibodies against H. capsulatum as both capture and detection reagents, and a standard reference curve is included to quantify antigenuria and ensure reproducibility. We evaluated this assay using specimens collected from patients with AIDS and culture-proven histoplasmosis in a Guatemalan clinic (n = 48), from healthy persons (n = 83), and from patients with other, nonhistoplasmosis diseases (n = 114). The ELISA demonstrated a sensitivity of 81% and a specificity of 95% in detecting H. capsulatum antigen in urine. This assay relies on simple technology that can be performed in institutions with limited resources. Use of this test will facilitate rapid diagnosis of PDH in countries where mortality is high, expediting treatment and likely reducing PDH-related mortality.

Fever in the recently returned HIV infected traveller

A 41 year old HIV infected man with an extensive travel history developed intermittent fever and weight loss shortly after returning from abroad. Extensive and prolonged investigation identified the cause.

Gastrointestinal infections in the immunocompromised host

The gastrointestinal tract is a common site of infection in the opportunistic host. Pathogens range from highly virulent organisms, which infect people with well functioning immune systems as well as people with poorly functioning immune systems, to opportunistic organisms, which infect only those with impaired immune systems. Viruses, bacteria, fungi, and protozoa lead to disease that can be especially severe, debilitating, and difficult to treat in the immunocompromised host. Yet in this era of highly active antiretroviral therapy for HIV-infected patients and strategies to reduce immunosuppression in transplant and oncology patients, appropriate diagnostic tests and treatment can both improve the quality of life and decrease mortality. In this article, I review the changing pathogenesis, epidemiology, clinical presentation, diagnosis, and treatment of gastrointestinal infections in the immunocompromised host.