Overview of diagnostic and detection methods for legionellosis and Legionella spp.

Since 1977, the diagnostic tools for Legionnaires' disease have been based on culture and serological investigations. Both methods require considerable time to produce results and have 'low' to 'reasonable' sensitivity. Since the introduction of urinary antigen tests in the mid 1990s, underdiagnosis has diminished and mortality has declined, thanks to early diagnosis. To obtain the most accurate diagnosis, culture, serological investigation, and urinary antigen testing should all be performed. In the last decade, advances in polymerase chain reaction technology allowed the development of assays detecting Legionella nucleic acids in clinical and environmental samples. Thus far, only widely varying results with relatively small series have been reported. Furthermore, these assays which are still labour intensive and complicated are not yet practicable for the average medical and/or environmental microbiological laboratory.     

Dengue and Chikungunya Fever among Viral Diseases in Outpatient Febrile Children in Kilosa District Hospital,Tanzania

Introduction

Viral etiologies of fever, including dengue, Chikungunya, influenza, rota and adeno viruses, cause major disease burden in tropical and subtropical countries. The lack of diagnostic facilities in developing countries leads to failure to estimate the true burden of such illnesses, and generally the diseases are underreported. These diseases may have similar symptoms with other causes of acute febrile illnesses including malaria and hence clinical diagnosis without laboratory tests can be difficult. This study aimed to identify viral etiologies as a cause of fever in children and their co-infections with malaria.

Methods

A cross sectional study was conducted for 6 months at Kilosa district hospital, Tanzania. The participants were febrile children aged 2–13 years presented at the outpatient department. Diagnostic tests such as IgM and IgG ELISA, and PCR were used.

Results

A total of 364 patients were enrolled, of these 83(22.8%) had malaria parasites, 76 (20.9%) had presumptive acute dengue infection and among those, 29(38.2%) were confirmed cases. Dengue was more likely to occur in children ≥ 5 years than in <5 years (OR 2.28, 95% CI: 1.35–3.86). Presumptive acute Chikungunya infection was identified in 17(4.7%) of patients. We observed no presenting symptoms that distinguished patients with Chikungunya infection from those with dengue infection or malaria. Co-infections between malaria and Chikungunya, malaria and dengue fever as well as Chikungunya and dengue were detected. Most patients with Chikungunya and dengue infections were treated with antibacterials. Furthermore, our results revealed that 5(5.2%) of patients had influenza virus while 5(12.8%) had rotavirus and 2(5.1%) had adenovirus.

Conclusion

Our results suggest that even though viral diseases are a major public health concern, they are not given due recognition as a cause of fever in febrile patients. Emphasis on laboratory diagnostic tests for proper diagnosis and management of febrile patients is recommended.     

The use of ion exchange chromatography for demonstration of rubella-specific IgM antibodies

IgM and IgG immunoglobulins of human sera were separated by stepwise column chromatography in QAE-Sephadex A-25 ion exchanger gel bed. The procedure resulted within 30 min in a fraction suitable for direct titration of rubella-specific IgM antibodies by haemagglutination inhibition test. The method proved to be a useful diagnostic tool for primary rubella. Serum samples of 13 individuals with previously acquired immunity, 152 patients with a recent rubella-like illness, and 194 pregnant women exposed to rubella infection were tested for the presence of rubella-specific IgM antibodies. Sera of individuals with previous immunity proved to be negative for specific IgM antibodies. Specific IgM titre was demonstrated in the blood of all the 25 patients with significant titre-rise tested because of rubella-like illness, and also in the sera of additional 8 patients whose serum samples were taken too late for demonstration of a rise in titre. Significant titre-rises were found in 5 women exposed to rubella infection, but only two of them exhibited rubella-specific IgM antibodies. The absence of specific IgM antibodies refers presumably to subclinical reinfection in the other three cases.     

An Epidemiologic Study of 100 Cases of Toxoplasmic Uveitis: Implications for Diagnosis and Prevention

An epidemiologic study of 100 patients with active chorioretinitis, positive Sabin-Feldman methylene-blue dye-test, and favourable response to antitoxoplasmic drugs (spiramycin) was undertaken to establish a basis for rapid clinical diagnosis and institution of preventive measures for toxoplasmic uveitis. Eighty-two of the 100 patients, but only 19 of 100 controls, gave positive histories of exposure to likely sources of toxoplasmosis, such as hunting and handling of wild game, ingestion of raw meat, etc. Seventy-six of these 82 patients had positive toxoplasmin skin tests, but all subsequently had positive dye-tests. The important practical conclusion was reached that all cases with active chorioretinitis, positive toxoplasmin skin test, or history of exposure to known reservoirs of toxoplasmosis should be treated immediately, as dye-tests in such cases will almost invariably be positive. This clinical approach greatly improves the visual prognosis of toxoplasmic chorioretinitis, since specific therapy need not be delayed for several weeks until the result of the dye-test is known.     

Relative contributions of history-taking,physical examination,and laboratory investigation to diagnosis and management of medical outpatients.

To evaluate the relative importance of the medical history, the physical examination, and laboratory investigations in the diagnosis and management of medical outpatients some physicians recorded their diagnosis and a prediction of the method of managementafter reading the patient''s referral letter, again after taking the history, and againafter performing the physical examination. These diagnoses and predictions were compared with the diagnosis and method of management which had been adopted two months after the patient''s initial attendance. A diagnosis that agreed with the one finally accepted was made after reading the referral letter and taking the history in 66 out of 80 new patients; the physical examination was useful in only seven patients, and the laboratory investigations in a further seven. In only one of six patients in whom the physician was unable to make any diagnosis after taking the history and examining the patient did laboratory investigations lead to a positive diagnosis.     

Does autoantibody-negative Graves' disease exist? A second evaluation of the clinical diagnosis.

Advanced technical methods are essential for accurate diagnosis of Graves' or Basedow's disease (GD). Inadequate methods may lead to a false diagnostic conclusion. We have analyzed the clinical features and methodology aspects of cases diagnosed as GD with negative findings for TSH receptor autoantibodies. The initial diagnosis was based on clinical findings (patient record, hypermetabolic state, goiter palpation) and laboratory testing (fT4 and TSH). From a total of 255 newly registered patients with GD, fifty-one (20%) were negative in a conventional porcine TBII assay. All fifty-one patients were retested with 131I or 99mTc uptake tests, thyroid scintigraphy, and a second-generation TBII assay. Results disclosed twenty-one cases (8.3%) with diagnosis other than GD: ten cases of autonomous hyperthyroidism (Plummer's disease), seven cases of painless thyroiditis and four cases of euthyroid endocrine ophthalmopathy. All twenty-one patients remained negative in the second-generation TBII assay. Measurement by second-generation TBII assay was performed on the remaining thirty patients initially found negative for TBII. As a result of this reevaluation, only 234 of the original 255 patients had GD. Of those, 231 (204 according to porcine plus 27 according to human TRAb assay) had detectable TBII (98.7%). This investigation stresses the problem of correct diagnosis and the methodological limitations in the assessment of laboratory parameter validity in GD. Based on this work, TSH receptor autoantibody-negative GD is extremely rare.     

Fungal Thyroiditis: An Overview

The authors review the epidemiology, clinical manifestations, diagnosis, and treatment of fungal thyroiditis cases previously reported in the medical literature. Aspergillus was by far the most common cause of fungal thyroiditis. Immunocompromised patients, such as those with leukemia, lymphoma, autoimmune diseases, and organ-transplant patients on pharmacological immunosuppression were particularly at risk. Fungal thyroiditis was diagnosed at autopsy as part of disseminated infection in a substantial number of patients without clinical manifestations and laboratory evidence of thyroid dysfunction. Local signs and symptoms of infection were indistinguishable from other infectious thyroiditis and included fever, anterior cervical pain, thyroid enlargement sometimes associated with dysphagia and dysphonia, and clinical and laboratory features of transient hyperthyroidism due to the release of thyroid hormone from follicular cell damage, followed by residual hypothyroidism. Antemortem diagnosis of fungal thyroiditis was made by direct microscopy and culture of a fine-needle aspirate, or/and biopsy in most cases. Since most patients with fungal thyroiditis had disseminated fungal infection with delay in diagnosis and treatment, the overall mortality was high.     

Emergency toxicology in a general hospital.

A study of all cases of attempted suicide by drug ingestion over a 6-month period was undertaken to evaluate the use of an emergency toxicology service and to establish the role of the emergency toxicology laboratory in the diagnosis and management of cases of attempted suicide. A total of 235 requests for emergency toxicologic analysis involving 259 specimens was received. Results of toxicologic screening were positive for 58% of all cases (range, 49% for patients who were drowsy to 90% for patients who were deeply unconscious). Barbiturate blood values did not correlate well with either the level of consciousness or the clinical state of the patient. In almost all patients who were drowsy or who were unconscious but had normal reflexes and vital signs there was no deterioration in the clinical state and no active treatment was required. The study demonstrated the need to educate all personnel involved in the care of patients with attempted suicide to limit laboratory investigations to the management of patients who benefit from such analyses. Quantitative drug analyses have a limited contribution to the management of such patients and should be performed only for patients with mixed drug overdosage and when the drugs require dialysis for their elimination from the body.     

Unexplained hepatitis following halothane.

Full clinical and laboratory details of 203 patients with postoperative jaundice were submitted to a panel of hepatologists. All patients whose jaundice may have had an identifiable cause were excluded, which left 76 patients with unexplained hepatitis following halothane anaesthesia (UHFH). Hepatitis in 95% of these cases followed multiple exposure to halothane, with repeated exposure within four weeks in 55% of cases. Twenty-nine patients were obese, 52 were aged 41-70, and 53 were women. Thirteen patients died in acute hepatic failure. Rapid onset of jaundice after anaesthesia, male sex, and obesity in either sex were poor prognostic signs. Of the clinical stigmata of hypersensitivity, only eosinophilia was impressive. The UHFH group had a much greater incidence of liver kidney microsomal (LKM) and thyroid antibodies and autoimmune complement fixation than those patients whose jaundice related to identifiable factors. Thirteen of the 19 patients with LKM antibodies also had thyroid antibodies. In six patients retested two to three years later LKM antibodies had disappeared, although thyroid antibodies persisted. Rapidly repeated exposure to halothane may cause hepatitis, but such a complication is probably rare. Possibly obese women with a tendency to organ-specific autoimmunity may be more at risk. Nevertheless, the comparative risks of rapidly repeated halothane or non-halothane anaesthesia cannot be determined from the present data. If alternative satisfactory agents are available halothane should be avoided in patients with unexplained hepatitis after previous exposure, although in three to five patients with UHFH who were re-exposed to halothane jaundice did not recur.     

Utility of the tourniquet test and the white blood cell count to differentiate dengue among acute febrile illnesses in the emergency room

Dengue often presents with non-specific clinical signs, and given the current paucity of accurate, rapid diagnostic laboratory tests, identifying easily obtainable bedside markers of dengue remains a priority. Previous studies in febrile Asian children have suggested that the combination of a positive tourniquet test (TT) and leucopenia can distinguish dengue from other febrile illnesses, but little data exists on the usefulness of these tests in adults or in the Americas. We evaluated the diagnostic accuracy of the TT and leucopenia (white blood cell count <5000/mm(3)) in identifying dengue as part of an acute febrile illness (AFI) surveillance study conducted in the Emergency Department of Saint Luke's Hospital in Ponce, Puerto Rico. From September to December 2009, 284 patients presenting to the ED with fever for 2-7 days and no identified source were enrolled. Participants were tested for influenza, dengue, leptospirosis and enteroviruses. Thirty-three (12%) patients were confirmed as having dengue; 2 had dengue co-infection with influenza and leptospirosis, respectively. An infectious etiology was determined for 141 others (136 influenza, 3 enterovirus, 2 urinary tract infections), and 110 patients had no infectious etiology identified. Fifty-two percent of laboratory-positive dengue cases had a positive TT versus 18% of patients without dengue (P<0.001), 87% of dengue cases compared to 28% of non-dengue cases had leucopenia (P<0.001). The presence of either a positive TT or leucopenia correctly identified 94% of dengue patients. The specificity and positive predictive values of these tests was significantly higher in the subset of patients without pandemic influenza A H1N1, suggesting improved discriminatory performance of these tests in the absence of concurrent dengue and influenza outbreaks. However, even during simultaneous AFI outbreaks, the absence of leucopenia combined with a negative tourniquet test may be useful to rule out dengue.     

Diagnosis of gastric cancer.

A prospective comparison was made of the accuracy of different diagnostic methods for gastric cancer. The basis of the study was a consecutive series of 113 patients thought to have gastric pathology; cancer was the final diagnosis in 32. Endoscopy and radiology were the most accurate investigations, whereas biopsy, cytology, and clinical examination gave disappointing results. A wide range of clinical features and laboratory investigations were studied in all patients in an attempt to identify criteria suggestive of malignancy. Multifactorial computer analysis of these investigations failed to improve upon the radiological diagnosis. A systemic approach designed to make optimal use of limited endoscopic and histopathological resources in the diagnosis of gastric lesions is presented.     

Diagnosis and management of brain death.

Finland was the first country in which brain death was legally accepted. Since 1975, 37 cases of brain death had been recorded in a university hospital in Finland, and these were reviewed. The cause for brain death was intracranial bleeding in 32 cases, other cerebrovascular disorder in two, and intracranial neoplasm in three. In 21 brain death was diagnosed clinically. In 16 cases confirmatory investigations (electroencephalography, cerebral angiography) were needed. After brain death had been established artificial support was withdrawn in 15 patients and organ transplantation was carried out in 10. In 12 patients, however, diagnosis of brain death did not influence management, though the heart stopped beating on average 25 hours after diagnosis. The Finnish criteria for brain death seem to be reliable and suitable for routine use.     

Phenotypic diagnosis of primary immunodeficiencies in Antioquia,Colombia, 1994-2002

Recurrent infections are a frequent cause of medical visits. They can be due to a heterogeneous group of dysfunctions that increase the susceptibility to pathogenic and opportunistic microorganisms, such as immunological deficiencies. To define an opportune rational treatment and to guide the molecular diagnosis of primary immunodeficiency diseases, we establish a program for the phenotypic diagnosis of these illnesses in Antioquia, Colombia, including clinical and laboratory evaluations of patients who present recurrent infections with abnormal evolution. Between August 1, 1994 and July 31, 2002, phenotypic diagnosis of primary immunodeficiency was made in 98 patients. Similar to data reported in the literature, antibody deficiencies were the most frequent (40.8%), followed by combined deficiencies (21.4%). This phenotypic characterization has allowed for appropriate treatments for each patient and, in some cases, functional and molecular studies that can lead to a definite molecular diagnosis.     

GERIATRIC PATIENTS IN A MENTAL HOSPITAL

An intensive study was made of men 55 years of age and over admitted to Napa State Hospital with either senile or arteriosclerotic brain disease. A ward treatment program, combining both the medical and psychiatric approaches, was applied to one-half of such patients admitted to a state hospital, with the aim of determining what, if any, effect this program would have on the course of the illnesses.Special laboratory studies showed: (a) Serial electroencephalograms and hospital adjustment ratings appeared to be positively correlated with the patients'' clinical course; (b) In 35 per cent of cases the electrocardiographic tracings at the time of admittance were within normal limits; (c) A “pathological level” of blood bromides was found in only one of 340 consecutive admissions in this age group.Sociopsychiatric study of 100 consecutively admitted patients revealed that: (a) 35 per cent of the patients were from the middle, and 65 per cent from the lower classes of society; (b) Only 59 per cent were admitted because of activities specifically psychotic. (c) 63 per cent needed admittance to this state hospital for observation and diagnosis, but only 44 per cent needed to stay for care and treatment; (d) In 88 per cent, specific emotional stresses were present just preceding and coincident with the clinical appearance of the organic brain syndrome.     

乙型肝炎病毒e抗原定量检测的性能验证和临床应用探索

乙型肝炎病毒e抗原(hepatitis B e antigen, HBeAg)的定量检测对乙型肝炎临床诊疗具有一定的重要性,但其定量检测还未成为常规检验项目。本研究对HBeAg定量检测系统进行性能验证,比较HBeAg定量和定性检测的相关性和一致性,分析HBeAg定量结果和乙型肝炎病毒DNA(hepatitis B virus DNA, HBV DNA)的关系,为HBeAg定量检测在临床诊疗的应用提供依据。通过收集710例2019年3月至5月于复旦大学附属华山医院就诊的慢性乙型肝炎患者血清样本,参照美国临床实验室标准化协会(The Clinical & Laboratory Standards Institute, CLSI)相关文件的要求,对雅培ARCHITECTi4000SR全自动免疫分析仪检测的HBeAg定量试剂的精密度、分析灵敏度、线性范围/可报告范围、携带污染率进行验证和评价;采用化学发光微粒子免疫检测技术(chemiluminescence microparticle immuno assay, CMIA)对618例患者进行HBeAg定性和定量检测;采用荧光定量PCR对慢性乙型肝炎患者进行HBV DNA检测,比较HBV DNA和HBeAg定量结果的相关性。本研究证实HBeAg定量试剂检测性能验证结果良好;HBeAg定量和定性检测相关性良好;126例同时有HBeAg定量检测和HBV DNA定量检测的结果显示,两种方法呈正相关且一致性良好。HBeAg定量检测可用于常规实验室检测来辅助HBV感染的临床诊疗。     

Diagnosis of active tuberculosis in a university hospital

Active tuberculosis was diagnosed in 100 patients at Sunnybrook Medical Centre during the five-year period 1968-72. These cases were studied to find out if any delay had taken place in establishing the diagnosis and starting treatment. Delay was found most frequently when patients presented with atypical disease or when microbiological investigations were negative or misinterpreted. However, in nine patients with positive Ziehl-Neelsen smears the diagnosis was delayed more than one week. Usually such delays were caused by a failure to send specimens promptly for examination for acid-fast bacilli. Lack of communication between the laboratory and the clinician was found to be responsible for delays in starting treatment in several patients. It is essential that the clinician in a general hospital be alert to the possibility of tuberculosis and that there be close cooperation between the clinical staff and the diagnostic services.     

Adrenal and testicular function in 14 patients with adrenoleukodystrophy or adrenomyeloneuropathy

Testicular and adrenal function were evaluated in 12 patients with adrenoleukodystrophy and 2 patients with adrenomyeloneuropathy. Although only 5 subjects had clinical symptoms suggesting adrenal insufficiency, an additional 5 showed laboratory evidence of reduced adrenal reserve. 9 of the 14 patients developed neurological deficits prior to the onset of clinical or biological adrenal insufficiency. In the remaining 5 patients, adrenal insufficiency antedated the appearance of neurological symptoms; 2 of these 5 patients had only laboratory evidence of hypoadrenocorticism, and 3 had both clinical and laboratory abnormalities. None of the prepubertal patients had detectable signs of testicular insufficiency, while 3 of the 7 pubertal/adult patients had elevated serum LH or FSH levels. This mild testicular deficiency was seen only in association with clinical adrenal insufficiency and significant neurological impairment.     

Do emergency tests help in the management of acute medical admissions?

A two year combined retrospective and prospective study of 555 acute medical admissions to a district general hospital was carried out to assess the value of emergency biochemical, haematological, radiological, and electrocardiographic tests in diagnosis and treatment. For the study the tests were considered helpful only if they disclosed an abnormality and resulted in a definite diagnosis or change of treatment which would not have been possible from the history and examination alone. A total of 2372 emergency tests were carried out in the 555 patients who presented with 579 acute medical problems. Only 403 (17%) of the test results were abnormal and, of these, only one third helped in treatment and less than one third helped in diagnosis. The most useful diagnostic tests were serum amylase activity in abdominal pain, the electrocardiogram in chest pain, the chest radiograph in respiratory problems, and cerebrospinal fluid analysis in suspected meningitis or subarachnoid haemorrhage. The most useful tests in treatment were blood sugar value in diabetes, PCO2 in obstructive airways disease, and haemoglobin concentration in gastrointestinal haemorrhage. Of the tests requested by far the most often--blood urea and serum electrolyte concentrations--only 7% gave abnormal results and were rarely of any help in either diagnosis or treatment. Analysis of the reasons for the uncritical use of emergency tests by house officers suggested that better undergraduate training, regular audit by senior members of medical units, abolition of routine investigational procedures, and more selective laboratory reports would help to build up the house officer''s confidence in his own skills of history taking and physical examination without recourse to indiscriminate use of laboratory and other investigations.     

中枢神经系统真菌感染的诊断与治疗

分析中枢神经系统真菌感染患者的临床特征、预后及其影响因素。收集我院2001年1月至2009年12月收治的42例中枢神经系统真菌感染患者的临床资料,对患者的诊断与误诊、实验室和病原学检查、治疗与预后等进行回顾性统计分析。42例患者中合并其他疾病者29例,占69.0%;首诊误诊32例,占76.2%。两性霉素B(AmpB)治疗者25例,其中6例在疾病早期联合5-氟胞嘧啶治疗,15例单用氟康唑治疗。治愈20例,占47.6%;好转11例,占26.2%;死亡11例,占26.2%。中枢神经系统真菌感染误诊率高,各种原因所致的免疫缺陷是引发中枢神经系统真菌感染的主要危险因素,尽早明确诊断,联合AmpB与5-FC抗真菌治疗、积极控制颅内压是降低病死率及改善预后的关键。     

A Comparative Study of Clinical Presentation and Risk Factors for Adverse Outcome in Patients Hospitalised with Acute Respiratory Disease Due to MERS Coronavirus or Other Causes

Middle East Respiratory syndrome (MERS) first emerged in Saudi Arabia in 2012 and remains a global health concern. The objective of this study was to compare the clinical features and risk factors for adverse outcome in patients with RT-PCR confirmed MERS and in those with acute respiratory disease who were MERS-CoV negative, presenting to the King Fahad Medical City (KFMC) in Riyadh between October 2012 and May 2014. The demographics, clinical and laboratory characteristics and clinical outcomes of patients with RT-PCR confirmed MERS-CoV infection was compared with those testing negative MERS-CoV PCR. Health care workers (HCW) with MERS were compared with MERS patients who were not health care workers. One hundred and fifty nine patients were eligible for inclusion. Forty eight tested positive for MERS CoV, 44 (92%) being hospital acquired infections and 23 were HCW. There were 111 MERS-CoV negative patients with acute respiratory illnesses included in this study as “negative controls”. Patient with confirmed MERS-CoV infection were not clinically distinguishable from those with negative MERS-CoV RT-PCR results although diarrhoea was commoner in MERS patients. A high level of suspicion in initiating laboratory tests for MERS-CoV is therefore indicated. Variables associated with adverse outcome were older age and diabetes as a co-morbid illness. Interestingly, co-morbid illnesses other than diabetes were not significantly associated with poor outcome. Health care workers with MERS had a markedly better clinical outcome compared to non HCW MERS patients.