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PubMedDate not supplied

[Pneumocystis carinii pneumonia: laboratory diagnosis].

We worked with 51 samples, 7 bronchoalveolar lavages (BAL) and 44 sputa (S) of 31 AIDS patients with clinical and radiographic symptoms compatible with Pneumocystis pneumonia. With the aim of finding a specific sensitive methodology for the diagnosis of Pneumocystis carinii, we evaluated 4 coloration techniques (silver methenamine, its modification without gold chloride, toluidine blue and Giemsa). 35% of the patients studied were positive. P. carinii were observed in 18% of the 44 sputa. We observed that the analysis of a single sputum sample (S) has a very low sensitivity and that the processing of two or more samples is necessary since only one of the 14 patients who had sent a single sample was found P. carinii positive, while in the remaining ten who had sent more than one (S) sample, the microorganism was detected in 50%. 4 of the 7 BAL were positive. 4 BAL were preceded by the analysis of an (S) sample: in two cases the results were negative while BAL allowed us to make the diagnosis, thus demonstrating its greater efficacy. To enhance sensitivity each sample was centrifuged until exhaustion and 10 slides were prepared for coloration with the final sediment. The four techniques employed were specific and all the Pneumocystis pneumonia patients responded to the treatment. Silver methenamine, its modification without gold chloride, and toluidine blue were very sensitive, in contrast to of Giemsa. The stain to be chosen is either silver methenamine, or its modification, because both achieve the best contrast, allowing optimum P. carinii identification. We suggest the implementation of some of these techniques in laboratory routine.

AIDS-Related Opportunistic Infections↗

PubMed1991

[The work of the Department of Clinical Laboratory Diagnosis of the Ukrainian Institute for Advanced Medical Education over a period of 60 years].

The author reviews the training and research activities of the Chair over the 60 years of its existence and the contributions of the scientists who have worked there. Special attention is given to the activities of one of the heads of the Chair, Professor A. Ya. Althauzen (1890-1960), whose birth centennial was remembered in 1990.

Academies and Institutes↗

PubMed1993

Evaluation of three methods for laboratory diagnosis of Strongyloides stercoralis infection.

The direct smear, a modified Baermann technique, and the agar plate culture method were compared for cost and efficiency in recovering Strongyloides stercoralis larvae in a hospital setting in Honduras. Of 427 stool samples, 9 were positive by the direct smear and 33 additional ones were detected by the Baermann technique; the agar plate culture method disclosed 28 more cases for a total of 70 S. stercoralis infections. The modified Baermann method was 3.6 times more efficient than the direct smear, and the agar plate culture increased the modified Baermann efficiency by 0.8 times. Cost for materials alone was cheapest for the direct smear; it increased 4 times for the modified Baermann method and 15 times for the agar plate culture method. This last technique required a better equipped laboratory, more time to perform, and the best trained, most skillful laboratory personnel. In field studies, prevalence of infection should determine the cost-effectiveness of the agar plate culture method; in a clinical setting, when S. stercoralis infection must be ruled out, the agar plate culture method should be made available to the medical community.

Animals↗

PubMed2001

Laboratory diagnosis of Clostridium difficile-associated diarrhea and colitis: usefulness of Premier Cytoclone A+B enzyme immunoassay for combined detection of stool toxins and toxigenic C. difficile strains.

Detection of Clostridium difficile toxins A and B in stools by Premier Cytoclone A+B enzyme immunoassay (EIA) was compared with detection by stool culture for C. difficile followed by detection of toxigenic isolates using the same EIA. Chart reviews were performed to evaluate the likelihood of C. difficile-associated diarrhea and colitis (CADC) for all patients with at least one positive toxin assay. While the toxins were detected in 58 of 85 consecutive CADC patients by both assays, CADC in 5 patients was detected only by stool toxin assay, and in 22 patients CADC was detected only by toxigenic culture. Our results suggest that for laboratories using a rapid toxin A+B EIA, direct toxin detection in stools should be combined with toxigenic culture in cases in which there is a negative stool toxin assay.

Bacterial Proteins↗

PubMed1986

Unexpected laboratory diagnosis of latent urogenital coccidioidomycosis in a nonendemic area.

Dissemination of coccidioidomycosis beyond the respiratory tract is not uncommon, but involvement of the urogenital tract is rarely observed. Most, if not all, reported cases of urogenital infections caused by Coccidioides immitis have been diagnosed in areas considered endemic for the fungus, where suspicion of this illness and its extrapulmonary manifestations is high. In nonendemic regions, however, C immitis is not likely to be considered as a possible cause of genitourinary tract infections unless the organism is fortuitously identified by histologic, cultural, or serologic studies. We report the unexpected isolation of C immitis from routine bacterial cultures of a draining urethral-scrotal fistula from a patient residing in a nonendemic area of the United States. We also discuss the difficulties and potential hazards encountered during the laboratory evaluation of this case.

Aged↗

PubMedDate not supplied

[Laboratory diagnosis of infantile infections caused by the respiratory syncytial virus. Report of 9 cases].

Nine cases of respiratory infections caused by syncytial respiratory virus which were diagnosed by direct immunofluorescence with monoclonal antibodies are presented here. Six of them have been clinically diagnosed as bronchiolitis and the remaining three are diagnosed as obstructive bronchitis, upper respiratory cold and respiratory distress respectively. Seven are male and two are female. Their ages vary from 13 days to eleven months. Its usefulness is indicated given its speed and the current availability of specific antiviral therapeutics. The test would be especially indicated in atypical cases like nursing babies with apnea or those with congenital heart disease or other underlying lung diseases and also to prevent intrahospital epidemias. The conclusion is reached that direct immunofluorescence seems to be an attractive alternative for laboratories that do not have costly cell culture equipment.

Female↗

PubMed1996

[Laboratory diagnosis of HIV infection].

The diagnosis of HIV infection is generally lead using two different ELISAs to detect specific anti-HIV antibodies, the eventual reactivity must then be confirmed by a Western Blot The antibodies can be detected only 1-6 months after the infection; in fact in the earliest phases neither the antibodies, for their low titre, nor the specific antigens, for the antibodies could form immune complexes, can be detected by the achieved methods. Only the viral isolation can reveal the presence of the virus in this early phase, but the isolation must be conducted only in adequately safe laboratories (P3 laboratories). The only test able to replace the viral isolation is the Polymerase Chain Reaction (PCR). The PCR technique can be useful to reveal an HIV infection in its early phase and to monitor the infection progression and the efficacy of an antiretroviral treatment

English Abstract↗

PubMed1993

Laboratory diagnosis of perinatal infections.

The application of new technology to the diagnosis of infectious disease in neonates has markedly increased the potential for early clinical intervention. Although far from perfect, the new tests have increased knowledge of the nature of these diseases and give physicians the opportunity to apply current treatments more effectively as well as to develop new modes of therapy for this important class of diseases.

Bacterial Infections↗

PubMed1991

The laboratory diagnosis of HIV infection.

Testing for HIV is a procedure with possible dire consequences; hence, reports should not be rendered to the patient without appropriate counseling. And this must be based on firm information whether the individual is truly infected if the report is positive. The reactive results of the EIA screening test should always be confirmed by supplemental testing. However, it must be remembered that a nonreactive serum does not exclude the possibility of the individual being infected; only by additional research studies, such as the polymerase chain reaction, can one be sure that the patient is not in the phase in which antibodies have not yet developed but the virus is present and the patient can transmit the infection. Our studies have found that the accuracy of testing HIV serum specimens is excellent. The biggest problem may be the potential confusion caused by the laboratory reports. All clinicians (nurses, educators, and physicians) who counsel or test potential HIV patients must be sure that they understand their laboratory's report. If there is any doubt about the report content, it must be clarified by contacting the laboratory director. The results of HIV antibody testing are so important to the patient that the significance of the report must be crystal clear to the counselor and any possible ambiguity clarified.

AIDS Serodiagnosis↗

PubMed2004

[Laboratory diagnosis of patients with exanthematic or febrile syndromes occurring in the Zulia State, Venezuela, during 1998].

BACKGROUND: Exanthematic diseases are a group of syndromes mainly caused by acute viral infections. AIM: To obtain information about the viruses that cause exanthematic diseases in our region. PATIENTS AND METHODS: During 1998, 267 serum samples from patients with an acute rash or patients presenting a febrile syndrome accompanied by enlarged lymph nodes, headache and other symptoms, were collected. Specific antibody of the IgM class (anti-IgM) against Rubella, Measles, Dengue types 1-4 and Cytomegalovirus (CMV) were measured by immunoenzymatic assay (EIA). Epstein-Barr virus (EBV) antibodies were measured by immunofluorescence. RESULTS: An etiologic agent was detected in 208 cases (77.9%). Cases due to Dengue (40.6%) and Rubella (21%) viruses predominated, but the frequency of other agents was also high in specific age groups. The agreement between the clinical suspicion and the laboratory findings varied broadly, from a 100% for suspected Dengue to just a 14.8% for cases of suspected CMV infection. CONCLUSIONS: Dengue was the most common viral exanthematic disease in the Zulia State during 1998.

Acute Disease↗

PubMed2006

Laboratory diagnosis of contagious ecthyma: comparison of different PCR protocols with virus isolation in cell culture.

A new polymerase chain reaction (PCR) assay for rapid diagnosis of contagious ecthyma was designed and applied to 21 clinical samples from Greece. This assay, which detects a highly conserved gene from the parapox genome, was evaluated for its sensitivity and specificity in order to be considered as a useful diagnostic tool. A comparative study with two published PCR protocols one using primers PPP1-PPP3, PPP1-PPP4 which targets putative virion envelope gene B2L and the other using VIR1-VIR2 primers which amplifies ORF virus interferon resistant (VIR) gene, as well as cell culture virus neutralization assay was carried out. All samples tested were amplified successfully with the PCR protocol established in the laboratory. The combination of primers PPP1-PPP3 and PPP1-PPP4 in a semi-nested PCR gave a positive result in 20 of 21 samples while primers VIR1-VIR2 failed to amplify successfully 7 of 21 samples. The diagnostic value of parapox viral DNA amplification was also compared with the results of virus isolation by cell culture and was positive in three samples that the virus isolation was obtained.

Animals↗

PubMed2005

Improvement in laboratory diagnosis of wound botulism and tetanus among injecting illicit-drug users by use of real-time PCR assays for neurotoxin gene fragments.

An upsurge in wound infections due to Clostridium botulinum and Clostridium tetani among users of illegal injected drugs (IDUs) occurred in the United Kingdom during 2003 and 2004. A real-time PCR assay was developed to detect a fragment of the neurotoxin gene of C. tetani (TeNT) and was used in conjunction with previously described assays for C. botulinum neurotoxin types A, B, and E (BoNTA, -B, and -E). The assays were sensitive, specific, rapid to perform, and applicable to investigating infections among IDUs using DNA extracted directly from wound tissue, as well as bacteria growing among mixed microflora in enrichment cultures and in pure culture on solid media. A combination of bioassay and PCR test results confirmed the clinical diagnosis in 10 of 25 cases of suspected botulism and two of five suspected cases of tetanus among IDUs. The PCR assays were in almost complete agreement with the conventional bioassays when considering results from different samples collected from the same patient. The replacement of bioassays by real-time PCR for the isolation and identification of both C. botulinum and C. tetani demonstrates a sensitivity and specificity similar to those of conventional approaches. However, the real-time PCR assays substantially improves the diagnostic process in terms of the speed of results and by the replacement of experimental animals. Recommendations are given for an improved strategy for the laboratory investigation of suspected wound botulism and tetanus among IDUs.

Animals↗

PubMed1999

Laboratory diagnosis of the thrombophilic state in cancer patients.

Perturbations of coagulation in cancer patients have been described for a long time. In up to 90% of cancer patients "routine" blood tests are abnormal leading to a hypercoagulable state in these patients. Among these tests are an increase in clotting factors, fibrinogen, fibrinogen/fibrin degradation products, and thrombocytosis. Markers of the activation of coagulation have been developed, and levels of FPA, F1+2, TAT, and D-Dimer have been found higher in cancer patients. More specific procoagulant activities in cancer (CP and TF) have also been described and can be measured but none of them have any predictive value for the occurrence of venous thromboembolism in these patients. Consistent with this hypercoagulable state in cancer is the finding that most cancer patients have reduced plasma levels of inhibitors of coagulation. These complex abnormalities are clinically expressed as thrombosis, low-grade or fulminant DIC which can be assessed by different laboratory tests, and as hemorrhage when the fibrinolysis system is impaired. However, no studies have shown to date a relationship between these abnormalities of the coagulation tests and the clinical expression in any single individual. Because these patients are at high risk for thrombosis in special conditions such as surgery or during chemotherapy, prophylaxis with various forms of heparin are recommended.

Blood Coagulation↗

PubMed1992

Laboratory diagnosis of Clostridium difficile-associated gastrointestinal disease: comparison of a monoclonal antibody enzyme immunoassay for toxins A and B with a monoclonal antibody enzyme immunoassay for toxin A only and two cytotoxicity assays.

A total of 320 stool specimens obtained from 262 patients suspected of having Clostridium difficile-associated gastrointestinal disease were examined with two cytotoxicity assays (CTAs) and two commercially available enzyme immunoassays (EIAs). The CTAs were an in-house-developed procedure (University of Massachusetts Medical Center [UMMC], Worcester, Mass.) and a commercial test (Bartels CTA; Baxter Healthcare Corp., West Sacramento, Calif.). One EIA was a monoclonal antibody-based assay for C. difficile toxins A and B (Cambridge Biotech Corp. [CBC], Worcester, Mass.). The other EIA employed monoclonal antibodies directed against only toxin A (Meridian Diagnostics, Cincinnati, Ohio). True-positive and true-negative results were defined on the basis of the results of the four assays, clinical assessments of patients, and the results of other laboratory tests. The sensitivities of the four assays were as follows: Bartels CTA, 100%; UMMC CTA, 97.2%; CBC EIA, 84.5%; and Meridian EIA, 69.0%. The Bartels CTA demonstrated a specificity of 99.2%. The other three assays had a specificity of 100%.

Antibodies, Monoclonal↗

PubMed2005

Sexually-transmitted viral diseases in women: clinical and epidemiological aspects and advances in laboratory diagnosis.

Sexually transmitted diseases (STDs) have long been known, but they have only recently been recognized as causes of significant long-term morbidity, mainly as a result of increased knowledge concerning viral STDs. The relationship of these diseases with conditions such as anogenital cancer and acquired immunodeficiency syndrome (AIDS) has made viral STDs an important issue in the healthcare of women and infants, and in reproductive health. The evolution of the AIDS pandemic is now characterized by growing differences between rich and poor nations. New diagnostic tools include rapid tests of blood, urine and saliva samples. New techniques, such as computerized cytology, have been developed for the diagnosis of human papillomavirus (HPV). Women infected with HIV are at a greater risk of being co-infected with HPV, and they are also more prone to the progression and persistence of HPV lesions. The herpes simplex virus presents high rates of co-infection with HIV, and it plays a particularly important role in increasing transmission rates of this virus.

Acquired Immunodeficiency Syndrome↗

PubMed2006

Evaluation of lateral flow assays for the detection of botulinum neurotoxin type A and their application in laboratory diagnosis of botulism.

Four lateral flow assays (LFAs) were evaluated for the detection of purified botulinum neurotoxin A, toxin complex, and unpurified culture supernatant. They included the BioThreat (Tetracore, Rockville, MD), SMART (New Horizons Diagnostics, Columbia, MD), BADD (ADVNT Biotechnologies, Phoenix, AZ), and RAMP (Response Biomedical, Burnaby, BC, Canada) assays. BioThreat and SMART did not detect the purified toxin. The best sensitivity was achieved with the RAMP test (50 ng mL(-1)). BioThreat and SMART measured as low as 10 ng mL(-1) of the toxin complex. Specificity data differed among the tests. BADD gave false-positive signals with uninoculated bacterial culture medium. BioThreat and RAMP were further evaluated with clinical sample matrices (serum, gastric, and rectum contents from pigs). Because of matrix effects and a generally low positive response, the assays are unsuitable for the direct detection of the toxin. However, the LFAs can be a helpful tool in screening bacterial cultures for toxigenic Clostridium botulinum, if further validated according to the laboratory needs.

Animals↗

PubMed1996

Laboratory diagnosis and molecular epidemiology of an outbreak of hepatitis C virus infection among recipients of human intravenous immunoglobulin in Spain.

BACKGROUND: Passive transfer of antibody to hepatitis C virus (HCV) has been thought to occur after infusion of human intravenous immunoglobulin (IVIG), as anti-HCV and/or HCV RNA was commonly found in that product. Recently, however, HCV RNA was detected in the serum of recipients of IVIG. Establishment of a causal relationship between IVIG therapy and HCV infection in recipients was attempted. STUDY DESIGN AND METHODS: Anti-HCV and HCV RNA sequences were investigated in serum samples from 39 persons who received a human IVIG product in seven different hospitals in Spain. HCV RNA was also investigated in two batches of the IVIG shared by some recipients. All the viral RNA detected were characterized with a line probe assay, restriction fragment length polymorphism analysis of the 5'-noncoding and core regions, and sequencing of the nonstructural 5 region. RESULTS: On the basis of both clinical and laboratory data, a relationship could be established between the IVIG therapy and the acquisition of the HCV infection by the recipients. Several HCV strains were detected among the recipients, with most of the recipients coming from the same hospital presenting with closely related strains. Moreover, an HCV strain almost identical to the main strain detected among the recipients was found in one batch of the IVIG that probably was shared by most of them. Follow-up studies and evaluation of low-avidity anti-HCV IgG suggested that both acute primary infections and reinfections were produced. In one case, direct evidence of reinfection by a different HCV strain was obtained. CONCLUSION: The results did not exclude the possibility that a second HCV strain associated with a further, unidentified batch of the IVIG could have contributed to this outbreak.

Adolescent↗

PubMed1993

Routine laboratory diagnosis of hepatitis C virus infection.

Hepatitis C virus (HCV) is the major cause of parenterally transmitted non-A, non-B hepatitis. The analysis of the genomic sequence of HCV has facilitated the development of a number of diagnostic assays for testing circulating antibodies in serum from patients with HCV infection. Besides the first-generation ELISA and RIBA, which employed the C100-3 non-structural polypeptide, second-generation tests employing both structural and non-structural polypeptides are being rapidly introduced. Several coded panels were employed in a comparative study of HCV-SP ELISA (utilizing a new synthetic peptide whose sequence was derived from the structural region) along with first- and second-generation tests. On the basis of the results, evidently antigens corresponding to the structural components of the virus are more sensitive and specific for the early detection of HCV antibodies than tests using non-structural epitopes. Additionally epitopes of the structural region elicit a very strong antibody response in laboratory animals. An example of one such application is the detection of HCV specific antigens in semen from patients diagnosed with non-A, non-B (NANB) hepatitis. Semen samples from 9 patients clinically diagnosed as having NANB hepatitis were tested by an ELISA using antibodies against HCV-specific structural antigens. The semen from all 9 patients had HCV-specific structural antigens in comparison to semen from 5 healthy donors. Semen from 5 of the 9 patients had significant levels of the HCV-specific antigen. This approach to detecting HCV antigens could, if rigorously tested, evolve into promising new assays for detecting HCV.

Amino Acid Sequence↗