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Role of the virology diagnosis laboratory in the surveillance of rubella virus Cuba 1988/2000.

In Cuba, on the basis of Measles Elimination Program, the incidence of this disease decline, and was necessary to test rubella virus as a possible etiology agent that produce fever and rash illness. To reach this goal, Cuba developed rubella elimination strategies with integrated epidemiologic and laboratory surveillance. In the country, the vaccination program against rubella started in 1982 by vaccinating 12-14 years old females, with a special surveillance program with laboratory study of all suspected cases. Through 1988-2000, the Serology Diagnosis Laboratory in the Virology Branch of Pedro Kouri Institute had the responsibility to do the measles and rubella surveillance and play a key roll in the elimination strategies of these diseases. For confirmation of all suspected cases, 8566 serum samples with the suspected diagnosis of measles or rubella from different provinces in Cuba were studied in the laboratory using different techniques as haemagglutination inhibition test (HIA), ultra micro analytic assay (UMA); and in 1995 by the newly introduced IgM ELISA, which was used taken only one sample in the acute phase of the disease. These techniques allowed knowing that the annual number of reported rubella cases in the country decreased substantially after the implementation, in 1986, of the second vaccine policy, that of vaccinating women of childbearing age. However, in 1989, was detected an outbreak of rubella virus infection that had occurred in young adults male 15-19 age groups in Matanzas' province. The last three indigenous cases of this disease were confirmed by our laboratory in 1995, after national vaccine coverage over 95%.

Adolescent↗

Laboratory diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis.

The clinical course and laboratory diagnosis of peritonitis in patients undergoing continuous ambulatory peritoneal dialysis was studied in 32 consecutive episodes. Peritonitis was associated with a failure in aseptic technique in eight episodes and with an exit-site infection in four episodes. Intraperitoneal vancomycin and ceftazidime were safe, effective, and convenient. Most patients administered their antibiotics at home, and symptoms usually resolved by day 4. Culture of the deposit obtained by centrifugation of 50 ml of effluent after leukocyte lysis provided the best rate of recovery (84% culture positive) but was technically demanding. Filtration of the same volume without leukocyte lysis was simple to perform and almost as effective. Enrichment was less satisfactory (65% culture positive) owing to the presence of antibiotic or infection with fastidious microorganisms. Culture of 50 ml of effluent after concentration by a commonly used laboratory technique, centrifugation without leukocyte lysis, performed poorly (59% culture positive at 48 h), as this method caused sequestration and death of microorganisms within the leukocytes. Culture of nearly 1 liter of effluent from 33 asymptomatic patients by the same techniques yielded no microorganisms.

Bacteria↗

[Further study on the indexes of auxiliary laboratory diagnosis in the syndrome of hyperactivity of liver-yang].

The indexes of auxiliary laboratory diagnosis, including plasma norepinephine (NE) levels, plasma epinephrine (E) levels, mean blood flow velocity of the middle cerebral artery (MCA-Vm) and systolic blood flow velocity of the middle cerebral artery (MCA-Vs), were observed in patients with the syndrome of hyperactivity liver-yang. The results indicated that the levels of the 4 indexes were significantly higher in the patients with the syndrome of hyperactivity liver-yang than those in the controls. In hypertension patients with the syndrome of hyperactivity liver-yang, there was a positive correlation between symptomatic scores of the syndrome of hyperactivity liver-yang and diastolic pressure (Pd), plasma NE and E levels. The symptoms ameliorated, and the levels of the 4 indexes decreased correspondingly in 3 weeks after the treatment of Qianyangfang (a traditional Chinese herb).

Adult↗

Laboratory diagnosis of lymphocytic choriomeningitis.

Current laboratory methods for the diagnosis of lymphocytic choriomeningitis are discussed, mainly from the point of view of recent improvements. The use of sentinel guinea-pigs is suggested for the detection of lymphocytic choriomeningitis infection in animal colonies.

Animals↗

Epidemiological characteristics and laboratory diagnosis of fungal keratitis. A three-year study.

PURPOSE: To study the epidemiological characteristics and laboratory diagnosis of fungal keratitis seen at a tertiary eye care referral centre in South India. METHODS: A retrospective review of all culture-proven fungal keratitis seen over a 3-year period, September 1999 through August 2002. RESULTS: Fungal aetiology were confirmed in 1095 (34.4%) of 3183 corneal ulcers. The predominant fungal species isolated was Fusarium spp (471; 42.82%) followed by Aspergillus spp (286; 26%). Males (712; 65.08%) were more often affected (P<0.0001). A large proportion of the patients (732; 66.85%) were in the younger age group (21 to 50 years). A majority (879; 80.27%) came from rural areas (P<0.0001), and most patients (709; 64.75%) were farmers (P<0.0001). Ocular trauma (1009; 92.15%) was a highly significant risk factor (P<0.0001) and vegetative injuries (671; 61.28%) were identified as a significant cause for fungal keratitis (P<0.0001). 172 (15.71%) patients had concurrent diabetes mellitus. The sensitivity of 10% potassium hydroxide (KOH) wet mount preparation was higher (99.23%) than Gram-stained smear (88.73%) (P<0.0001). Incidence of fungal keratitis was higher between June and September. CONCLUSION: Agricultural activity and related ocular trauma were principal causes of mycotic keratitis. A potassium hydroxide (KOH) wet mount preparation is a simple, and sensitive, method for diagnosis

Adult↗

Laboratory diagnosis of Neisseria gonorrhoeae in St Petersburg, Russia: inventory, performance characteristics and recommended optimisations.

OBJECTIVES: To perform a comprehensive inventory of the number of samples, performance characteristics, and quality assurance of the laboratory diagnosis of Neisseria gonorrhoeae at five laboratories in St Petersburg and Leningradskaya Oblast, Russia, in 2004, and to recommend optimisations for an increased adherence to international evidence based recommendations of diagnostics. METHODS: Surveillance data were obtained with questionnaire and site visits. For evaluation of the culture media utilised at the laboratories, N gonorrhoeae reference strains (n = 29) were used. RESULTS: During 2004 the total numbers of N gonorrhoeae samples analysed at the five laboratories using microscopy of stained smears and culturing were 330 879 (407 positive) and 38 020 (420 positive), respectively. Four laboratories used a Russian non-selective culture medium-that is, Complegon, and one laboratory utilised Biocult-GC. Both media seemed suboptimal. Only two of the laboratories used any species confirmative assay. Antibiotic susceptibility testing of N gonorrhoeae was performed at only two of the laboratories and each year only occasional isolates were analysed. None of the laboratories comprised a complete laboratory quality assurance system. CONCLUSIONS: According to international recommendations, the diagnosis of N gonorrhoeae in St Petersburg and Leningradskaya Oblast, Russia, is suboptimal. More samples need to be analysed by culturing on a highly nutritious and selective medium and, furthermore, species confirmation and antibiotic susceptibility testing should be more frequently performed. In addition, the utilised methods for culturing and antibiotic susceptibility testing, including medium and interpretative criteria used, ought to be optimised, standardised, and quality assured using systematic internal and external quality controls.

Clinical Laboratory Techniques↗

[Immunological aspects of laboratory diagnosis of chronic urticaria].

High prevalence of allergic diseases necessitates search for new methods of laboratory diagnosis thereof. We studied the diagnostic significance of the count of cells expressing low-affinity receptors to IgE (CD23+ cells) and compared this test with skin tests with non-infectious allergens and measurement of total serum IgE. 104 patients with various forms of chronic relapsing urticaria were examined. The count of CD23+ cells was markedly increased in atopic urticaria. The increase in the count of these cells and correlation with the results of skin test were less expressed in infectious allergic urticaria. In other forms of chronic urticaria characterized by negative results of skin tests the count of CD23+ cells was normal. The level of total serum IgE was low virtually in all patients. Hence, the count of cells carrying low-affinity receptors to IgE is highly informative, detecting IgE-mediated reactions in the patients, though this parameter does not allow identification of the allergen. This test can be used in complex with other methods of allergodiagnosis, particularly in cases when skin tests are for this or that reason impossible.

Adolescent↗

Critical assessment of chitotriosidase analysis in the rational laboratory diagnosis of children with Gaucher disease and Niemann-Pick disease type A/B and C.

Laboratory diagnosis of lysosomal storage disorders, especially sphingomyelinase deficiency (Niemann-Pick disease type A/B) and Niemann-Pick disease type C (NPC) can be challenging. We therefore aimed to analyse the feasibility of first-step screening with specific chitotriosidase cut-off values in children </= 10 years of age with visceral organomegaly (hepatomegaly, splenomegaly, or hepatosplenomegaly) in whom a storage disorder was suspected. We conducted a retrospective, cross-sectional, referral, single-centre study to assess diagnostic test properties in 106 individuals. Median chitotriosidase activity was 12 655 nmol/h per ml (interquartile range 4693-20982) in Gaucher disease (GD); 780 (465-1298) in SMD (sphingomyelinase deficiency); 925 (319-1215) in NPC and 50 (29-54) in patients with miscellaneous diseases. To restrict the differential diagnosis to GD, SMD or NPC, chitotriosidase activity above 200 nmol/h per ml had a sensitivity of 96%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 95%. For GD alone, chitotriosidase activity above 4000 nmol/h per ml had a sensitivity of 77%, specificity of 100%, PPV of 100% and NPV of 92%. Of the 44 patients analysed, 4.5% were homozygous and 36.4% heterozygous for chitotriosidase gene duplication. Adjusting for the chitotriosidase genotype, chitotriosidase activities were higher in GD type III than in GD type I. We conclude that, in the above setting, the degree of elevation of chitotriosidase activity can be applied to increase the likelihood of GD, SMD, or NPC and guide the choice of the appropriate confirmatory assay.

Chemistry, Clinical↗

Laboratory diagnosis of cystic hydatic disease.

The main purpose of this article is to answer the questions about which test to perform for hydatic diagnosis and when. Several techniques for biologic diagnosis and follow-up of human cystic hydatidosis are reviewed. The specificity and sensitivity of immunologic reactions are reported. The differential diagnosis between Echinococcus granulosus and E. multilocularis is examined. The characteristics of the immunologic diagnosis according to the stage and the treatment of hydatidosis disease is discussed. Laboratory diagnosis of cystic hydatic disease is complementary to the clinical data. A judicious association of the usual techniques (indirect immunofluorescence assay, indirect hemagglutination assay, immunoelectrophoresis, co-electrophoresis with antigen 5 identification) confirms the diagnosis in 80% to 94% of hepatic hydatidosis cases and in 65% of pulmonary hydatidosis cases. Special techniques (enzyme-linked immunosorbent assay, Western blot, polymerase chain reaction) must be used for other localizations or when cysts are calcified. A serologic survey is necessary for the follow-up of operated medically treated patients. Despite poor standardization, purified antigens can distinguish between E. granulosus and E. multilocularis infections, although false-positive results are observed during other helminthiases, such as cysticerocosis.

Animals↗

[Laboratory diagnosis of mycobacterial infections].

Every 10 seconds, one person in the world dies of tuberculosis (TB). It is estimated that one third of the world's population is latently infected with Mycobacterium tuberculosis. The proportion of multidrug-resistant strains of M. tuberculosis is increasing at an alarming rate in some parts of the world linked in part with the human immunodeficiency virus epidemic. For these reasons, TB remains a major public health problem, both in less-developed countries and in many industrialized countries, with 8-10 million new cases and 2 million deaths yearly in the world. Clinical, radiological and histological signs are not specific for tuberculosis or for other mycobacterial infections and allow only a presumptive diagnosis. In the same way, the tuberculin skin test is useful if the reaction is strong or phlyctenular because this test depends on various factors as previous BCG vaccination, contact or primary infection and host immune responses. The diagnosis of mycobacterial infection is proved only when bacilli are present in biological samples. Nevertheless, only 50% of cases in adults and 30% in infants have a positive bacteriological result. It seems necessary to develop new methods for a rapid and efficient diagnosis to optimize the therapy and the control of the epidemic. Laboratory testing in the mycobacterium field is experiencing more changes today than ever before. Determining what assays will be most useful to the clinician is a challenge, and acceptance of the new technology is under discussion. Progress in future will be linked probably to the progress of the genomic area. However the incidence rate is higher in less-developed countries, it is also important to develop now techniques possible to use in these countries. This review focuses on the current state-of-the-art resources useful for accurate and rapid laboratory diagnosis of mycobacterial infections.

Bacteriological Techniques↗

Laboratory diagnosis of autoimmune cytopenias.

The past year's literature shows that little progress has been achieved in the laboratory diagnosis of autoimmune hemolytic anemia. The direct antiglobulin test is the only diagnostic test for autoimmune hemolytic anemia. Advantages of new techniques, such as the gel test, have to be determined. Today, cephalosporins are known to cause both drug-dependent and -independent autoantibodies. The diagnosis of idiopathic thrombocytopenic purpura is a clinical one. The new assays that measure antibodies against specific glycoproteins offer improved specificity. New laboratory advancements and accumulation of data on granulocytes' antigens and antibodies enabled us to recommend guidelines for the laboratory investigation of autoimmune neutropenia.

Anemia, Hemolytic↗

Laboratory diagnosis of intravascular catheter associated sepsis.

Many different methods have been employed to aid in the laboratory diagnosis of intravascular catheter associated infection. However, because of differences in patient populations, the definition of catheter sepsis and types of catheters, comparison of these studies is difficult. Of even more fundamental importance, the question of the pathogenesis of intravascular catheter associated sepsis (i.e. whether the microorganisms migrate to the intravascular space via the internal or external surface of the catheter) has not been resolved and is the subject of ongoing controversy. Semiquantitative culture of catheter tips would appear the easiest and most labour-efficient method available at present to diagnose catheter related infection. With central vein catheter tips, however, a cut-off level below 15 CFU per plate should be adopted as indicating a positive test result, particularly in patient populations with a high prevalence of catheter associated infection. Methods for non-quantitative broth culture of catheter tips are likely to be more sensitive than the semiquantitative method, but are less specific. Quantitative broth methods improve the specificity, but because of the labour costs involved appear not to offer much advantage over the semiquantitative method in the routine clinical laboratory. Many studies have shown that organisms are more frequently seen on staining than recovered by culture of intravascular catheters. Further studies of intravascular cathether sepsis should include a catheter staining method in addition to culture. Aspiration and culture of blood through an intravascular catheter appears to be reasonably specific in diagnosing the presence of infection on the catheter tip, but is only of low sensitivity (20-40%) in the absence of associated bacteremia.

Catheterization, Central Venous↗

[Laboratory diagnosis of subclinical forms of hypothyroidism in an endemic goiter focus].

The paper is concerned with laboratory diagnosis of thyroid function in the endemic focus in Gornaya Shoriya of the Kemerovo region. The diagnostic value of radioimmunoassays was emphasized. The authors proposed a compensation index characterizing the ratio of the thyroid hormones and promoting the diagnosis of subclinical forms of hypothyreosis in the endemic goiter focus.

Adolescent↗

Laboratory diagnosis of plague.

In response to an outbreak of a plague-like disease in India, the Public Health Laboratory Service (PHLS) in the UK distributed advice on the isolation and identification of Yersinia pestis. Some of the procedures outlined were evaluated using a number of isolates of Y. pestis, complemented with in-house techniques detecting virulence genes or their products. These laboratory investigations are limited in that they are either only indicative or they take too long (48 hours or more), and thus represent a serious delay to the patient. Successful patient management must be based on a case history, and therapy should be started immediately. Laboratory diagnosis will subsequently rule out most pathogens which cause similar infections, yet will still require confirmation by a reference laboratory.

Bacteriological Techniques↗