Fulminant and fatal encephalitis caused by Acanthamoeba in a kidney transplant recipient: case report and literature review.

Acanthamoeba is the most common cause of granulomatous amebic encephalitis, a typically fatal condition that is classically described as indolent and slowly progressive. We report a case of Acanthamoeba encephalitis in a kidney transplant recipient that progressed to death within 3 days of symptom onset and was diagnosed at autopsy. We also review clinical characteristics, treatments, and outcomes of all published cases of Acanthamoeba encephalitis in solid organ transplant (SOT) recipients. Ten cases were identified, and the infection was fatal in 9 of these cases. In 6 patients, Acanthamoeba presented in a fulminant manner and death occurred within 2 weeks after the onset of neurologic symptoms. These acute presentations are likely related to immunodeficiencies associated with solid organ transplantation that result in an inability to control Acanthamoeba proliferation. Skin lesions may predate neurologic involvement and provide an opportunity for early diagnosis and treatment. Acanthamoeba is an under-recognized cause of encephalitis in SOT recipients and often presents in a fulminant manner in this population. Increased awareness of this disease and its clinical manifestations is essential to attain an early diagnosis and provide the best chance of cure.

Human rhinovirus infections of the lower respiratory tract in hematopoietic stem cell transplant recipients.

BACKGROUND: Human rhinoviruses (HRVs) are a common cause of upper respiratory infection (URI) in hematopoietic stem cell transplant (HSCT) recipients; yet, their role in lower respiratory illness is not well understood. METHODS: We performed a retrospective chart review of HSCT recipients with HRV infection from the time molecular detection methods were implemented at our institution in 2008. Factors associated with proven or possible HRV pneumonia at the first HRV detection were evaluated by univariate and multivariate analysis. We then characterized all episodes of proven and possible HRV pneumonia from the initial HRV infection through a 1-year follow-up period. RESULTS: Between 2008 and 2011, 63 HSCT recipients had ≥1 documented HRV infections. At first HRV detection, 36 (57%) patients had HRV URI and 27 (43%) had proven or possible HRV pneumonia; in multivariate analysis, hypoalbuminemia (odds ratio [OR] 9.5, 95% confidence interval [CI] 1.3-71.7; P = 0.03) and isolation of respiratory co-pathogen(s) (OR 24.2, 95% CI 2.0-288.4; P = 0.01) were independently associated with pneumonia. During the study period, 22 patients had 25 episodes of proven HRV pneumonia. Fever (60%), cough (92%), sputum production (61%), and dyspnea (60%) were common symptoms. Fifteen (60%) episodes demonstrated bacterial (n = 7), fungal (n = 5), or viral (n = 3) co-infection. Among the remaining 10 (40%) cases of HRV monoinfection, patients' oxygen saturations ranged from 80% to 97% on ambient air, and computed tomography scans showed peribronchiolar, patchy, ground glass infiltrates. CONCLUSIONS: HRV pneumonia is relatively common after HSCT and frequently accompanied by bacterial co-infection. As use of molecular assays for respiratory viral diagnosis becomes widespread, HRV will be increasingly recognized as a significant cause of pneumonia in immunocompromised hosts.

Reiter syndrome following protracted symptoms of Cyclospora infection.

Two large outbreaks of diarrheal illness associated with Cyclospora cayetanensis, a coccidian parasite, provided an opportunity to evaluate clinical syndromes associated with this enteric pathogen. Reiter syndrome, a triad of ocular inflammation, inflammatory oligoarthritis, and sterile urethritis, has been associated with enteric infections. We describe the first case of Reiter syndrome following protracted symptoms of Cyclospora infection.

Prophylaxis strategies for solid-organ transplantation.

In addition to the net state of immunosuppression, the risk of infection after transplantation is largely determined by the transplant recipient's epidemiologic exposures. Potential sources of infection in the transplant recipient include the environment and the recipient's endogenous flora. This article presents aspects of prevention of infection after solid-organ transplantation such as avoidance of epidemiologic exposures, antibacterial prophylaxis, prophylaxis for tuberculin-positive transplant recipients, and prophylaxis against infections with Pneumocystis carinii and Toxoplasma gondii.

Paromomycin: no more effective than placebo for treatment of cryptosporidiosis in patients with advanced human immunodeficiency virus infection. AIDS Clinical Trial Group.

To evaluate the efficacy of paromomycin for the treatment of symptomatic cryptosporidial enteritis in human immunodeficiency virus-infected adults, we conducted a prospective, randomized, double-blind, placebo-controlled trial before the widespread introduction of highly active antiretroviral therapy (HAART). Seven units under the auspices of the AIDS Clinical Trials Group enrolled 35 adults with CD4 cell counts of < or = 150/mm(3). Initially, 17 patients received paromomycin (500 mg 4 times daily) and 18 received matching placebo for 21 days. Then all patients received paromomycin (500 mg q.i.d.) for an additional 21 days. Clinical definitions of response were measured by an average number of bowel movements per day in association with concurrent need for antidiarrheal agents that was lower than that before study entry. There was no treatment response during the placebo-controlled phase of the study according to protocol-defined criteria (P=.88). Three paromomycin recipients (17.6%) versus 2 placebo recipients (14.3%) responded completely. Rates of combined partial and complete responses in the paromomycin arm (8 out of 17, 47.1%) and the placebo arm (5 out of 14, 35.7%) of the study were also similar (P=.72). The clinical course of cryptosporidiosis was quite variable. Paromomycin was not shown to be more effective than placebo for the treatment of symptomatic cryptosporidial enteritis. However, inadequate statistical power prevents definitive rejection of the usefulness of paromomycin as therapy for this infection.

Cyclosporiasis: clinical and histopathologic correlates.

Although the histopathologic changes associated with Cyclospora cayetanensis infection have been previously described, the histopathology and the appearance of various life cycle stages have not been correlated with severity, stage, and duration of clinical disease. We report a prospective clinical investigation of disease characteristics and histopathologic findings in three otherwise healthy, immunocompetent patients with symptomatic C. cayetanensis infection, the duration of which ranged from 6 to 60 days. Varying degrees of gross and microscopic gastrointestinal inflammation were seen before treatment. An electron-dense phospholipid membrane/myelin-like material was variably present both before and after treatment. The greatest amount of myelin-like material was seen in the patient with prolonged disease. The results of our study suggest that inflammatory changes associated with C. cayetanensis infection may persist beyond parasite eradication. It is intriguing to speculate that the myelin-like material is a marker for persistent inflammation, but further study and confirmation are needed.

Pedal giant cell tumor of tendon sheath.

The authors present a brief review of giant cell tumor of tendon sheath and three case reports. A discussion emphasizing the histologic characteristics of this lesion demonstrates the benign-to-malignant variability of these neoplastic growths. Special attention is directed to a case with aggressive histologic characteristics. Reexcision after surgery should be considered in cases where microscopic examination reveals a lesion with characteristics suggestive of potentially aggressive behavior.

A survey of risk factors for cryptosporidiosis in New York City: drinking water and other exposures.

We conducted a survey to determine the prevalence of known and theoretical exposure risks for cryptosporidiosis among selected New York City residents. Subjects were recruited from outpatients attending either a practice for persons with HIV infection (n=160), or other medical practices (n=153), at The New York Hospital-Cornell Medical Center. Despite a greater concern for waterborne infection, 82% of HIV-infected subjects reported consuming municipal tap water compared to 69% of subjects from other medical clinics (OR 2.1, 95% Cl 1.2-3.6, P=0.006). Although 18% and 31% of subjects, respectively, denied any tap water consumption at home or work, all but one from each cohort responded positively to having at least one possible alternate source of tap water ingestion such as using tap water to brush teeth or drinking tap water offered in a restaurant. 78% and 76% of subjects, respectively, had at least one potential risk for exposure other than municipal water consumption, such as swimming in pools or contact with animals. Our findings indicate that it is possible to stratify the population into subsets by the amount of tap water consumed. This suggests that an observational epidemiologic study of the risk of contracting cryptosporidiosis from everyday tap water consumption is feasible.

Cyclospora.

Although Cyclospora infection has been documented in humans worldwide since at least 1977, it is only in the past 2 years that this organism has come into prominence as a result of major foodborne outbreaks in the United States and Canada. Cyclospora causes significant gastrointestinal disease in immunocompetent and immunocompromised hosts and can be successfully treated with trimethoprim-sulfamethoxazole. The infection is under-recognized because our methods for diagnosis are rudimentary and insensitive. The mechanisms by which the parasite causes disease, the range of animal hosts, and the natural reservoir are unknown. Cyclospora is a unique coccidian parasite that has just begun to emerge; as yet, we have no clue as to where it comes from or where it hides.

Agents of diarrhea.

Diarrhea is a common problem for AIDS patients, and is chronic and debilitating. A thorough evaluation will reveal a pathogen in the majority of patients, and the organisms most frequently identified in AIDS patients with chronic diarrhea are Cryptosporidium, microsporidia, and Mycobacterium avium complex. Bacterial pathogens are more common in AIDS patients than in the general population and may present in different ways from infections in immunocompetent hosts. Other pathogens, including Cryptosporidium and microsporidia, are difficult to diagnose and have no effective therapy. Moreover, enteric viruses and HIV itself may contribute to the diarrhea. In addition to microbes, other factors such as medication, immune dysregulation, automatic dysfunction, and nutritional supplementation play a substantial role in diarrhea of AIDS patients.

Emerging Pathogens Associated with Tick-Borne Infections.

In recent years, several microbial agents have been identified that result in significant morbidity and mortality. The newly recognized tick borne infections, babesiosis and ehrlichiosis, may be transmitted by the same tick that transmits Borrelia burgdorferi and simultaneous infections may occur. Babesia are intraerythrocytic protozoa that may cause severe hemolytic anemia, whereas Ehrlichia, depending on the species, may infect either monocytes or granulocytes, with associated leukopenia, thrombocytopenia and anemia. Improved laboratory surveillance is urgently needed to assess the prevalence of these worldwide pathogens in order to institute appropriate infection control efforts.

Characterization of Encephalitozoon (Septata) intestinalis isolates cultured from nasal mucosa and bronchoalveolar lavage fluids of two AIDS patients.

Microsporidia are obligate intracellular protozoan parasites that can cause opportunistic infections in AIDS patients. Species from five genera of microsporidia are presently known to infect man. One species, Septata intestinalis originally was detected in stool specimens of individuals with chronic diarrhea and subsequently was found to disseminate to the kidneys, lungs, and nasal sinuses. This organism has since been reclassified as Encephalitozoon and in this study, we report the culture of Encephalitozoon intestinalis from a bronchoalveolar lavage specimen and a nasal mucus aspirate of two AIDS patients living in the USA. The bronchoalveolar and nasal microsporidian isolates grew in several continuous cell lines including RK-13, MDCK, HT-29, Caco-2, Vero, and I047. Transmission electron microscopy of the clinical and cell culture specimens revealed that the new isolates appeared to be E. intestinalis based on morphology and growth of organisms in septated membrane-bound parasitophorous vacuoles. The new E. intestinalis isolates were characterized and compared with the first isolated E. intestinalis that was cultured from stool to confirm their identity and to determine if there existed any minor differences, as seen in the closely related Encephalitozoon cuniculi strains. By the methods of sodium dodecyl sulfate-polyacrylamide gel electrophoresis staining for proteins and carbohydrates, Western blot immunodetection, and polymerase chain reaction-based methods with restriction endonuclease digestion, double-stranded DNA heteroduplex mobility shift analysis, and DNA sequencing of the ribosomal DNA intergenic spacer region, the new isolates were identical to each other and to the reference isolate of E. intestinalis. In addition, with any of these methods, the E. intestinalis organisms could be distinguished from the three E. cuniculi strains, Encephalitozoon hellem, and Vittaforma corneae, which is important for diagnostics, therapeutic strategies, and epidemiology.