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.

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.

Cryptosporidiosis. Traveler's diarrhea in two families.

Intestinal cryptosporidiosis was diagnosed in three infants (aged 6 to 21 months), one child (aged 3 years), and two adult members of two families after their return from travel to the African continent. Examination of stools from all patients revealed acid-fast cryptosporidial oocysts on direct fecal smears stained by the modified cold Kinyoun technique. Five of the six were symptomatic with watery diarrhea, anorexia, and abdominal pain. Elevated anticryptosporidial titers were detected in five patients, two of whom were asymptomatic. Cryptosporidiosis should be included in the differential diagnosis of traveler's diarrhea.

Bacterial invasion of pulmonary vessels. Pseudomonas bacteremia mimicking pulmonary thromboembolism with infarction.

Pseudomonas aeruginosa displays a curious propensity for invading blood vessels and causing vessel wall necrosis. This bacteremia-related "vasculitis" is often associated with hemorrhagic necrosis and infarction of surrounding organ parenchyma. With the exception of skin lesions, however, clinical manifestations of Ps. aeruginosa vasculitis seldom occur. In the patient we describe, fatal Ps. aeruginosa bacteremia was first manifested by a syndrome indistinguishable from pulmonary thromboembolism with infarction.

Cryptosporidiosis and isosporiasis in patients with AIDS.

Cryptosporidium and Isospora belli are coccidian protozoan parasites that were long recognized as pathogens of animals. They were brought to the attention of the medical community by the advent of AIDS. These parasites are associated with persistent, devastating enteritis in patients with AIDS and self-limited diarrheal illness in the immunocompetent host. Cryptosporidiosis appears to be more common than isosporiasis in both patients with AIDS and those who are not immunosuppressed. Clinically, cryptosporidiosis is indistinguishable from isosporiasis. Watery, noninflammatory diarrhea, abdominal cramping pain, and weight loss are the characteristic symptoms. Diagnosis is made by identification of the acid-fast organisms in stained fecal specimens. There is no known effective therapy for cryptosporidiosis, whereas patients with isosporiasis respond promptly to treatment with trimethoprim-sulfamethoxazole. Patients with AIDS and isosporiasis have a high frequency of recurrent infection and therefore should be maintained on suppressive therapy. Much more needs to be learned about these two fascinating and unique parasites to be able to intervene successfully in the management of infected patients with AIDS.

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.

Coccidian infections in AIDS. Toxoplasmosis, cryptosporidiosis, and isosporiasis.

Cryptosporidium sp. and Isospora belli are coccidian protozoan parasites that were long recognized as pathogens for many animal species. The medical community became acquainted with these organisms with the advent of AIDS. Both parasites are associated with persistent, debilitating enteritis and, in the case of Cryptosporidium, biliary tract involvement in patients with AIDS. For the immunocompetent host, infection with these two pathogens usually results in self-limited diarrhea. Cryptosporidiosis appears to occur more often than isosporiasis, but the true prevalence of both infections for various populations of humans is unknown. Clinically, cryptosporidiosis is indistinguishable from isosporiasis. Diagnosis is based on finding the acid-fast (red staining oocyst in stained fecal specimens). There is no known effective therapy for cryptosporidiosis, whereas patients with isosporiasis respond promptly to treatment with trimethoprim-sulfamethoxazole. Patients with AIDS and isosporiasis have a high relapse rate after achieving complete remission and therefore need to be maintained on suppressive therapy. Much more needs to be learned about these two fascinating, "newly recognized" parasites.

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.

Comparison of ceforanide and cephalothin prophylaxis in patients undergoing total joint arthroplasty.

One hundred one patients undergoing total hip and knee arthroplasty were randomly assigned to receive either two 1 gm doses of ceforanide or five doses of cephalothin perioperatively. Simultaneous plasma and cancellous bone specimens were obtained intraoperatively and assayed for antibiotic concentration. Ceforanide plasma and bone levels remained sustained over six hours. Cephalothin plasma and bone levels obtained three to four hours post administration were 91% lower than levels obtained one hour post-dose. Patients were examined for infection for up to 18 months following surgery. None of the patients developed an infected implant. The sustained plasma and bone levels achieved with ceforanide obviate the need for intraoperative dosing necessary with other agents.

Tumors of the nail and nail bed.

This article reviews the tumors that most frequently affect the nail and nail bed. Clinical appearance, histopathology, differential diagnosis, and treatment are discussed.

Applied biomechanics of bone: functional and clinical perspectives.

Proper locomotion depends on the presence of a strong, intact skeletal system that is able to withstand the stresses and strains of everyday life. In this article, the authors discuss the function of force on bones from a clinical and biomechanical viewpoint. As is presented, bone is a living, viable organ that responds to both external and internal stimuli.

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.

Cryptosporidium and cryptosporidiosis.

Cryptosporidium is a newly recognized human pathogen associated with severe enteritis and, perhaps, cholecystitis in immunocompromised patients, particularly those with the acquired immunodeficiency syndrome, and significant, though self-limited, diarrheal illness in the immunocompetent host. As more physicians look for this pathogen, the number of reported cases of cryptosporidiosis continues to increase. Although the prevalence of cryptosporidiosis in humans is not yet known, recent studies suggest that it is a common cause of diarrhea worldwide, particularly in young children. The pathogenic mechanisms by which Cryptosporidium causes enteritis and the factors of human host defense essential for eradication of this parasite have not been delineated. Acid-fast staining of stool is a quick and reliable way of diagnosing cryptosporidiosis. Although a vast array of therapeutic agents has been tried for this disease, there is currently no known effective therapy for cryptosporidial infection.

Three-step stool examination for cryptosporidiosis in 10 homosexual men with protracted watery diarrhea.

Cryptosporidiosis, a zoonosis caused by Cryptosporidium species, is a newly recognized coccidial protozoan infection causing severe protracted watery diarrhea in humans. In August 1981, the first case of cryptosporidiosis in a homosexual man with acquired immune deficiency syndrome (AIDS) was reported; diagnosis was determined by intestinal biopsy. It is necessary to adopt a simple laboratory diagnostic procedure to screen large numbers of suspected cases. A three-step stool examination was developed to demonstrate Cryptosporidium oocysts and the diagnostic and infective stages of the infection in 10 homosexual men with AIDS. This is a less invasive, less costly, and more sensitive test than intestinal biopsy and has been designed to prevent confusion caused by yeast cells that are frequently present in stool, leading to a false diagnosis. The examination consists of preliminary differential determination by iodine wet mount, definitive identification by modified Kinyoun acid-fast staining, and a more effective method of concentrating oocysts, by Sheather's sugar cover-slip flotation method.

Appendicitis with perforation: a reminder to internists.

Over a two-year period, four adults with appendicitis were admitted to the medical service with manifestations sufficiently atypical to obscure the correct diagnosis. Perforation of the appendix was found in each, and abscess formation occurred in two cases. One patient died. The experience with these cases reemphasizes the protean manifestations of complicated appendicitis.