Actinomycosis esophagitis in a patient with persistent dysphagia

Many causes of esophagitis exist in immunocompromised patients. Uncommon pathogens must be considered to facilitate timely and appropriate therapy. A limited number of cases of esophageal actinomycosis have been reported. This report describes an unusual case of esophageal actinomycosis in a patient with persistent dysphagia. The broad differential may have delayed definitive diagnosis in the case study patient. Biopsy and culture are essential for accurate diagnosis. Although actinomycosis is a rare disease, it should be included in the differential diagnosis of patients presenting with oral or esophageal complaints. It may also be considered as an opportunistic infection in immunocompromised patients. The treatment of choice is parenteral penicillin G, 18 to 24 million units for 2 to 6 weeks followed by oral therapy for 6-12 months.     

Viral Infections in Immunocompromised Hosts

Several viral infections have been shown to occur in immunocompromised hosts like tumour bearing hosts, transplant recipients and human immunodeficiency virus (HIV) infected individuals. In these categories of patients they cause severe morbidity and disseminated fatal infections if untreated. The viruses that are significantly associated with disease in immunocompromised hosts are the members of family Herpesviridae, others include Adenoviruses (Adenoviridae), JC virus and BK virus family (Papovaviridae) and certain members of Paramyxoviridae like Respiratory Syncitial Virus, metapneumovirus and parainfluenza viruses. Infections could be seen in individuals when their HIV disease is asymptomatic and more fatal infections are seen when HIV disease is symptomatic. Infections with Hepatitis A virus and Hepatitis E virus could be seen as community acquired infections among immunosuppressed patients. Early and specific detection of opportunistic viruses is possible today by using certain new techniques like real-time multiplex polymerase chain reaction. It is possible to intervene with antivirals which reduce morbidity and mortality if the diagnosis is achieved early in the course of disease.     

Community-acquired pneumonia in immunocompromised patients. Opportunistic infections to consider in differential diagnosis

Immunocompromised persons are at increased risk for a large group of infections that are either uncommon or much less severe in the immunocompetent host. These opportunistic infections broaden the diagnostic considerations in differential diagnosis of community-acquired pneumonia in patients with immunodeficiencies. This article highlighted epidemiologic factors, clinical presentations, and treatment options for four selected opportunistic infections that represent varied classes of pathogens: nematodes (S stercoralis), mycoses (C neoformans), bacteria (P aeruginosa in patients with HIV infection), and viruses (measles virus).     

Diagnostic methods for fungal infections in pediatric patients: microbiological, serological and molecular methods

Although invasive fungal infections (IFIs) are relatively rare, they are important causes of morbidity and mortality in immunocompromised pediatric patients. Early and precise diagnosis of IFI is important to allow antifungal treatment to be started in time and to reduce the unnecessary use of toxic antifungal agents. Although traditional approaches such as direct microscopic examination, histopathological evaluation and cultivation are still gold standard, the diagnosis of IFI is generally difficult because of inadequate sensitivity and specificity with these tests. Commercial systems detecting the Aspergillus cell wall antigen galactomannan and 1,3-β-D-glucan are seen as the most convenient nonculture methods for the diagnosis of the IFI and monitoring of antifungal treatment. Several molecular methods have been described for the diagnosis of opportunistic mycoses. However, they have not been standardized and have only been used in experimental studies.     

Stenotrophomonas maltophilia: emerging disease patterns and challenges for treatment

Stenotrophomonas maltophilia is a ubiquitous organism associated with opportunistic infections. In the immunocompromised host, increasing prevalence and severity of illness is observed, particularly opportunistic bloodstream infections and pneumonia syndromes. In this article, the classification and microbiology are outlined, together with clinical presentation, outcomes and management of infections due to S. maltophilia. Although virulence mechanisms and the genetic basis of antibiotic resistance have been identified, a role for standardized and uniform reporting of antibiotic sensitivity is not defined. Infections due to S. maltophilia have traditionally been treated with trimethoprim-sulfamethoxazole, ticarcillin-clavulanic acid, or fluoroquinolone agents. The use of combination therapies, newer fluoroquinolone agents and tetracycline derivatives is discussed. Finally, measures to prevent transmission of S. maltophilia within healthcare facilities are reported, especially in at-risk patient populations.     

Parasitic diseases. Diseases associated with acquired immunodeficiency syndrome

There are several protozoan infections that cause relatively benign illness in normal individuals but result in severe disease manifestations in patients with AIDS. These diseases include Pneumocystis carinii pneumonia, CNS toxoplasmosis, cryptosporidiosis, and isosporiasis. Pneumocystis carinii pneumonia (PCP) caused by Pneumocystis carinii, is the most common opportunistic infection in AIDS. It is seen in more than 80% of individuals with this syndrome. Although historically classified as a protozoan, this organism shares many biochemical characteristics with fungi. The onset of PCP may be insidious, and cough and dyspnea are the most common presenting symptoms. Auscultation of the lungs is often unremarkable, but diffuse infiltrates are commonly seen on chest radiographs. The diagnosis of PCP can be confirmed by identifying the organism on specimens obtained by sputum induction or bronchoalveolar lavage. Trimethaprim-sulfamethoxazole is the treatment of choice but is unfortunately associated with leukopenia and rash in many individuals. Both trimethaprim-sulfamethoxazole and aerosolized pentamidine are used prophylactically in patients at high risk for initial or relapsing infection. The appropriate use of these agents has resulted in improved survival for AIDS patients with PCP. Toxoplasmosis, due to Toxoplasma gondii, affects the central nervous system in patients with AIDS. Headache is a common presenting symptom, and both seizures and paresis can occur. A diagnosis of toxoplasmosis is strongly suspected in symptomatic individuals with ringed mass lesions noted on head CT. Patients with this condition are treated with a combination of sulfadiazine, pyrimethamine, and folinic acid. Cryptosporidiosis and isosporiasis are coccidian protozoan diseases that can result in severe, acute, and chronic diarrhea in immunocompromised individuals. Cryptosporidiosis is the more common of the two and is caused by an unknown species of the genus crytosporidium. Isosporiasis is due to infection with Isospora belli. Dehydration and weight loss are a common result of infection with either agent. A definitive diagnosis can be made by examining an acid fast stain of a diarrheal stool specimen and demonstrating oocysts that are specific for each of these organisms. Fluid replacement and general supportive care are essential in the treatment of both of these diseases. Spiramycin is an unproven treatment modality that is often used in patients with cryptosporidiosis. Isosporiasis responds to initial therapy with trimethaprim-sulfamethoxazole, followed by prophylaxis with pyrimethamine. The adoption of safe sexual practices that minimize fecal-oral contamination should decrease the future prevalence of these diseases and other enteric parasitic infections.     

Improved detection of Mycobacterium avium complex with the Bactec radiometric system

A reconsideration of the laboratory methods used for primary isolation of mycobacteria other than Mycobacterium tuberculosis is needed due to the increasingly recognized importance of such mycobacterial infections in immunocompromised patients. One example of this is the severe opportunistic infections caused by Mycobacterium avium complex among AIDS patients. In this study, the Bactec radiometric system was compared to conventional culture on solid medium for the detection of M. avium complex in 3,612 selected clinical specimens, mainly of extrapulmonary origin. Of a total number of 63 M. avium complex isolates, the Bactec system detected 58 (92%), compared to 37 (59%) for conventional culture. A much more rapid detection was attained with radiometric technique than with conventional culture. The mean detection time for the cultures positive with both methods was 7.1 and 28.3 days, respectively. The Bactec radiometric system achieves a rapid and significantly more sensitive detection and seems to be an excellent complement to conventional culture in the laboratory diagnosis of infections with the M. avium complex.     

Complications of hepatic hydatid cysts: Ultrasound,computed tomography,and magnetic resonance diagnosis

A total of 179 hepatic hydatid cysts (HHCs) were studied by ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). The diagnosis of HHC complications was established by US and CT, which permitted a distinction between intact cysts and those presenting with contained rupture, as demonstrated by a collapsed endocyst or a globally echogenic appearance. The diagnosis of HHC perforation into the main biliary tree was made by detection of a discontinuity in the cyst wall and/or the presence of hydatid material within the biliary system. Similarly, direct HHC rupture into different thoracoabdominal spaces was diagnosed by demonstrating cyst wall discontinuity and the presence of hydatid material within these spaces. Ruptured and infected cysts were difficult to distinguish from ruptured cysts with sterile content. The role of MRI is yet to be defined in the assessment of HHC complications.     

Obligate aerobic,gram-positive,weak acid-fast,nonmotile bacilli,Tsukamurella tyrosinosolvens: Minireview of a rare opportunistic pathogen

Tsukamurella species are obligate aerobic, gram-positive, weak acid-fast, nonmotile bacilli. They are found in various environments, such as soil, water, sludge, and petroleum reservoir wastewater, and belong to the order Actinomycetales. In 2016, there was a reclassification of species within the genus Tsukamurella, merging the species Tsukamurella tyrosinosolvens (T. tyrosinosolvens) and Tsukamurella carboxydivorans. Tsukamurella species are clinically considered to be a rare opportunistic pathogen, because most reported cases have been related to bacteremia and intravascular prosthetic devices and immunosuppression. To date, it has been isolated only from human specimens, and has always been associated with clinical disease; human infections are very rare. Reported infections have included pneumonia, brain abscesses, catheter-related bloodstream infections, ocular infections, bacteremia, and sepsis presenting with septic pulmonary emboli in patients who are immunocompromised. To date, there is no commercially available test for identification. On the other hand, sequence-based identification, including matrix-assisted laser desorption ionization time-of-flight mass spectrometry, is an alternative method for identifying clinical isolates that are either slow growers or difficult to identify through biochemical profiling. The golden standards for diagnosis and optimal management still remain to be determined. However, newer molecular biological techniques can provide accurate identification, and contribute to the appropriate selection of definitive therapy for infections caused by this organism. Combinations of several antimicrobial agents have been proposed for treatment, though the length of treatment for infections has yet to be determined, and should be individualized according to clinical response. Immunocompromised patients often experience severe cases due to infection, and life-threatening T. tyrosinosolvens events associated with dissemination and/or failure of source control have occurred. Favorable prognoses can be achieved through earlier identification of the cause of infection, as well as successful management, including appropriate antibiotic therapy together with source control. Further analyses of similar cases are required to establish the most adequate diagnostic methods and treatment regimens for infections.     

Pulmonary disease in the immunocompromised host. 1

With few exceptions, pulmonary complications in the immunocompromised host will proceed to death unless the clinician intercedes. The differential diagnosis of diffuse pulmonary disease in this setting includes (1) infection, most commonly from opportunistic organisms; (2) recurrence or extension of the basic underlying disease process to involve the lungs; (3) adverse pulmonary reaction to drugs; (4) a new, unrelated disease process such as cardiac pulmonary edema or pulmonary emboli; and (5) any combination of these categories. Up to a third of these patients have two or more complications, such as pneumonitis from two different opportunistic organisms or an opportunistic infection and a drug-induced pulmonary complication. An understanding of the host defense that is compromised enables the clinician to narrow the differential diagnosis. The most common types of impairment of defense mechanisms are reductions in the number of granulocytes, B-lymphocytes, or T-lymphocytes, and not uncommonly, two or all three of these types of cells are involved. Impairment of each of these cell types is associated with an increased frequency of infection by a particular group of organisms. Consequently, the clinician can be somewhat selective if empiric therapy is being considered. In the immunocompromised patient, most pulmonary complications, including drug-induced pulmonary disease and pulmonary emboli, are associated with fever that mimics an infection. Up to 25% of the pulmonary complications in these patients are noninfectious.     

Focal fatty liver lesions in alcoholic liver disease: A broadened spectrum of CT appearances

The CT examinations of 26 consecutive alcoholic patients with focal fatty infiltration of the liver were analyzed. Five different patterns of focal fatty infiltration were noted. In most alcoholic patients these appearances present no diagnostic problem and further confirmation can be obtained by repeating the CT scan within 1–2 weeks to see if interval resolution occurs following enforced abstinence. In select instances, more invasive and definitive procedures such as superselective angiography or liver biopsy may be necessary to differentiate these findings from other more serious diseases they may closely resemble, such as primary or secondary liver neoplasms.     

Hepatosplenic brucelloma: clinical presentation and imaging features in six cases

Background We conducted a retrospective analysis of the clinical presentation and the computed tomographic (CT) and ultrasound (US) findings in six episodes of hepatosplenic brucelloma in five patients.Methods In four episodes, the diagnosis was based on clinical history, serology, and characteristic imaging findings. In the other two episodes in the same patient, the diagnosis was suspected after a biopsy was taken. CT was performed in all six cases and US in five.Results On US, brucellomas were iso- or hypoechogenic with the liver. Hyperechogenic masses were seen in one patient. Brucellomas were very poorly defined and contained small scattered cystic areas. All lesions showed central or marginal gross focal calcification, except multiple lesions in one patient. Contrast-enhanced CT showed predominantly solid masses with irregular borders and fine or thick enhancing trabeculations separating hypodense solid areas and/or small cystic areas. Two patients showed transdiaphragmatic lung invasion by brucelloma, a complication not previously published.Conclusion In regions where brucellosis is endemic, brucelloma should be included in the differential diagnosis if a hepatic or splenic mass with irregular borders and central or marginal gross focal calcification is detected, and contrast-enhanced CT shows enhancing trabeculations that separate hypodense solid areas and/or small liquid collections.     

First report of survival in two patients with hematologic malignancy and Stenotrophomonas maltophilia hemorrhagic pneumonia treated with trimethoprim-sulfamethoxazole-based combination antibiotic therapy

Stenotrophomonas maltophilia has become a common cause of opportunistic infections in immunocompromised hosts and critical care patients. The most common disease manifestations are pneumonia and bacteremia, with a mortality ranging from 9% to 60.5% depending of the type of infection and host related underlying risk factors. Patients with hematological malignancies may develop a hemorrhagic pneumonia with a rapidly progressive and universally fatal disease course, despite appropriate treatment with trimethoprim/sulfamethoxazole or combination therapy. We report the first two patients with hematologic malignancies and hemorrhagic pneumonia due to S. maltophilia with successful treatment outcomes after early institution of combination therapy with TMP/SMX, polymyxin, and/or moxifloxacin.     

术前及术中超声、CT及术中触诊诊断肝肿瘤的一致性评价

目的 评价术前超声、CT及术中超声、术中触诊诊断肝肿瘤良恶性的一致性.方法 分析70例肝肿瘤患者的术前超声、术前CT检查、术中超声以及术中触诊结果,对四种检查结果与病理及随访结果诊断肝肿瘤良恶性的一致性进行评价.结果 术前超声与病理及随访结果诊断肝肿瘤良恶性的一致性为中等(Kappa值0.63),术中触诊与病理及随访结果的诊断一致性较低(Kappa值0.38),CT以及术中超声检查与病理及随访结果诊断一致性较高(Kappa值分别为0.71及0.89),而术中超声与CT检查之间诊断一致性也较高(Kappa值为0.53).而术前超声与术中超声以及术前超声与术中触诊之间诊断一致性均较低(Kappa值均为0.23).结论 在肝肿瘤诊断评价中,CT与术中超声具有较高的诊断一致性,虽然术前超声与术中触诊诊断结果一致性较低,但在临床工作中依然不可或缺,而若能将四者结合应用,将有助于肝肿瘤的诊断与治疗.     

Hepatocellular carcinoma with or without cirrhosis: A comparison of CT and angiographic presentations in the United States and Japan

We compared the computed tomographic (CT) and angiographic presentations of hepatocellular carcinoma (HCC) with or without cirrhosis in the United States and Japan. Tumors in the United States were advanced and less frequently associated with liver cirrhosis (association of cirrhosis: United States) 56.2%, Japan 91.0%. In patients with cirrhosis, the size of the tumor tended to be smaller, and nodular tumors (single or multiple) were frequent. In early stage of HCCs with cirrhosis, tumors were hypovascular without a capsule. In advanced stage, tumors were hypervascular and a capsule was frequently observed around the tumor both with CT and angiography. HCCs without cirrhosis were seen in younger patients. These tumors were large at the time of diagnosis. A massive or diffuse mass without a capsule was frequently seen. Most tumors were hypodense on precontrast CT and hypervascular on angiography. Lymph node enlargement was significantly frequent. The radiological characteristics of HCC in both countries were significantly different depending upon associated cirrhosis, as well as the time of the diagnosis.     

Pseudallescheriasis in the 21st century

Since its discovery as an agent of mycetoma nearly a century ago, Pseudallescheria boydii with its asexual (synanamorphic) form, Scedosporium apiospermum, is now recognized as an important emerging opportunistic pathogen causing invasive mycosis in immunocompromised patients. The clinical spectrum of pseudallescheriasis is wide. Invasive disease of the lung, CNS and dissemination are serious manifestations in immunocompromised patients. This organism responds poorly to amphotericin B, and its histopathologic resemblance to aspergillosis often results in a delay in diagnosis. In vitro data, animal models and accumulating clinical experience support the use of voriconazole as a primary treatment for pseudallescheriasis. This paper reviews the microbiology, ecology, epidemiologic trends, clinical manifestations and current treatment options of pseudallescheriasis.     

Trichosporon species infection in bone marrow transplanted patients

Trichosporon species are emerging as opportunistic agents that cause systemic diseases in immunocompromised patients. Patients undergoing bone marrow transplant are submitted to intense and prolonged periods of neutropenia and consequently to several risk factors to fungal infections as the use of broad spectrum antibiotics and invasive devices. Two cases of fungal infections caused by Trichosporon asahii var. asahii and T. inkin in patients with bone marrow transplant are described T. asahii var. asahii was responsible for fungemia and the identification of this microorganism was later performed. T. inkin caused vascular accesses infection and was recovered from an implanted Hickman-Broviac catheter. Both patients were under oral fluconazole prophylaxis. The patient with systemic infection died despite the therapy with amphotericin B and the patient with catheter-related infection recovered from the fungal infection after catheter removal. Difficulties in the identification of this microorganism lead to delays in treatment and post-mortem diagnosis.     

Antiviral therapy for respiratory viral infections in immunocompromised patients

Introduction: Respiratory viruses (influenza, parainfluenza, respiratory syncytial virus, coronavirus, human metapneumovirus, and rhinovirus) represent the most common causes of respiratory viral infections in immunocompromised patients. Also, these infections may be more severe in immunocompromised patients than in the general population. Early diagnosis and treatment of viral infections continue to be of paramount importance in immunocompromised patients; because once viral replication and invasive infections are evident, prognosis can be grave.

Areas covered: The purpose of this review is to provide an overview of the main antiviral agents used for the treatment of respiratory viral infections in immunocompromised patients and review of the new agents in the pipeline.

Expert commentary: Over the past decade, important diagnostic advances, specifically, the use of rapid molecular testing has helped close the gap between clinical scenarios and pathogen identification and enhanced early diagnosis of viral infections and understanding of the role of prolonged shedding and viral loads. Advancements in novel antiviral therapeutics with high resistance thresholds and effective immunization for preventable infections in immunocompromised patients are needed.     

Effects of azole antifungal drugs on the transition from yeast cells to hyphae in susceptible and resistant isolates of the pathogenic yeast Candida albicans

Oral infections caused by the yeast Candida albicans are some of the most frequent and earliest opportunistic infections in human immunodeficiency virus-infected patients. The widespread use of azole antifungal drugs has led to the development of drug resistance, creating a major problem in the treatment of yeast infections in AIDS patients and other immunocompromised individuals. Several molecular mechanisms that contribute to drug resistance have been identified. In C. albicans, the ability to morphologically switch from yeast cells (blastospores) to filamentous forms (hyphae) is an important virulence factor which contributes to the dissemination of Candida in host tissues and which promotes infection and invasion. A positive correlation between the level of antifungal drug resistance and the ability to form hyphae in the presence of azole drugs has been identified. Under hypha-inducing conditions in the presence of an azole drug, resistant clinical isolates form hyphae, while susceptible yeast isolates do not. This correlation is observed in a random sample from a population of susceptible and resistant isolates and is independent of the mechanisms of resistance. 35S-methionine incorporation suggests that growth inhibition is not sufficient to explain the inhibition of hyphal formation, but it may contribute to this inhibition.     

Opportunistic infections and pharmacology.

The most common acute complication in HIV infection is likely to be one of the many possible opportunistic infections caused by immunodeficiency. These infections may be the index diagnosis of AIDS or occur in previously diagnosed patients as additional problems. Monitoring for the symptoms of disease and monitoring patients while undergoing treatment are frequently included in nursing care. This article discussed the diagnosis and treatment of some of the more common of the major opportunistic infections seen in AIDS.