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Results for “infectivity evaluation”

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At least 91 records · Page 5Linked to original sources
PubMed1984

Hepatitis B e-antigen titres for evaluating infectivity during hepatitis B virus infection.

By means of an ELISA the level of hepatitis B e-antigen (HBeAg) titre was determined in 51 patients with acute and 123 patients with persistent hepatitis B virus (HBV) infection. We also investigated 120 sera of these patients for infectivity by detecting HBV-specific DNA polymerase (DNA-P). Additional determination of the HBeAg titre revealed that the detection of HBeAg at a dilution of at least 1:50 correlates with the detection of DNA-P in 95% of cases, while in sera with an HBeAg titre of 1:25 or less DNA-P is only detectable in up to 5% of cases. Since the detection of DNA-P indicates high infectivity, certain titres of HBeAg can be employed to differentiate three different degrees of infectivity: (1) Sera without HBeAg show no or only little infectivity; (2) sera containing HBeAg greater than or equal to 1:50 are highly infectious; (3) HBeAg titres up to 1:25 indicate a medium degree of infectivity. These three markers for different degrees of infectivity were applied to study the course of infectivity during acute and persistent forms of HBV infection. In acute hepatitis B the period for the elimination of HBeAg is independent of the HBeAg titre in the first serum sample. In all cases the elimination of HBeAg in acute hepatitis B did not exceed 4 months. Patients with persistent HBV infection and an initial HBeAg titre greater than or equal to 1:50 remained at this high degree of infectivity for at least 18-30 months in 70% of cases. Only 30% of this collective showed a decrease in infectivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2002

Tools from ecology: useful for evaluating infection risk models?

Despite the increasing number of models to predict infection risk for a range of diseases, the assessment of their spatial limits, predictive performance and practical application are not widely undertaken. Using the example of Schistosoma haematobium in Africa, this article illustrates how ecozonation and receiver-operator characteristic analysis can help to assess the usefulness of available models objectively.

Africa↗
PubMedDate not supplied

Computerized image analysis of nails affected by fungal infection: evaluation using digital photographs and manually defined areas.

Despite the relevant increase in clinical trials on the efficacy of various systemic and/or topical antifungal agents in onychomycosis therapy, the evaluation of the results is largely subjective. The aim of this study was to set up and ensure an objective, reproducible and reliable method to measure nail plate involvement in onychomycosis. In order to validate a specifically designed software for the computerized image analysis of affected areas of the nail, standardized clinical pictures of onychomycosis were prepared by six different clinicians using a sample of 11 affected nails. Diseased areas and total nail plates were measured both on the clinical pictures and on their drawings traced by the different clinicians on transparent tapes adhering to sample nails. The computerized procedure was undertaken by a trained operator who was not a dermatologist. The variation coefficients of measurements on clinical pictures (automatically detected) and on drawings were compared. In addition, the agreement between automatic evaluation and drawing was evaluated by means of Bland-Altman analysis. To consider the effect of possible variations linked to different operators using the computerized method, 11 clinical pictures (one for each clinical case considered) were selected and submitted to computerized image analysis by six different trained operators. The computerized detection of affected nail areas showed a coefficient of variation (vc=8.5%) lower than that observed on drawings (vc=14.7%). The two methods showed appreciable agreement, as demonstrated by Bland-Altman plot. The coefficient of variation of image analysis conducted by six different operators was very low for the total area calculation (vc=0.9%) and acceptable for pathological area detection (vc=4.8%). Based on the results obtained, we conclude that automatic evaluation is a reliable and helpful method for the measurement of the clinical involvement of the nail plate in onychomycosis and for the evaluation of therapies, since it can increase the objectivity and reproducibility of data. However, in a minority of difficult cases, expert dermatological evaluation is needed.

Humans↗
PubMed2004

[Approach to the diagnosis of pertussis infection: evaluation of cases suffering from prolonged cough symptoms].

This study was performed on cases admitted to Sami Ulus Pediatric Health and Diseases Training and Research Hospital because of cough lasting two weeks or more between November, 2001 and April, 2003. According to pertussis case definitions, patient's information of each 66 probable cases complied with clinical criteria from 0-15 age group were recorded on questionnaire and nasopharyngeal samples were taken. Specimens were sent to Refik Saydam National Hygiene Centre, Pertussis Reference Laboratory in order to perform specific culture, direct fluorescent antibody (DFA) and polymerase chain reaction (PCR). Bordetella pertussis was isolated on cultures of two cases (3%) and the same specimens were found positive by DFA. Direct PCR results of nasopharyngeal samples were not evaluated since false positive reactions were obtained with one or more negative controls in different series. Since a symptomatic contact of any culture proven case is also defined as confirmed case by the standard case definitions, three of 66 cases (4.5%) together with a symptomatic contact of one of the culture positives were classified as confirmed pertussis in this study.

Adolescent↗
PubMed1997

[Biological diagnosis of pneumocystis infection. Evaluation and value of a new direct immunofluorescent technique].

Opportunist disease in immunocompromised patients and prematured babies, Pneumocystis carinii pneumonia was rare. It represents today inaugural manifestation of SIDA in 35-40% of cases. The research of the parasite becomes a current analysis for a medical laboratory. Biological diagnosis is based on the show of the parasite in the sampling with classical coloration technics. The limits of these colorations have played a great part in the development of fluorescent monoclonal antibody stains. In this evaluation, we compared, on 100 bronchiolo-alveolar-lavage (BAL), the performances of a new direct fluorescent monoclonal antibody stain recently commercialized (Pneumo Cel IF test B.M.D. Laboratories) with those of two classical colorations: May-Grünwald-Giemsa and Gomori-Grocott. Standard colorations revealed 18 positive cases while direct immunofluorescence technic revealed 20 cases of pneumocystosis. This new test has showed reliability, sensitivity and high specificity due to the utilisation of a monoclonal antibody. The preparation and the reading of the slides are rapid and easy. In spite of a very higher price, direct immunofluorescent should become a choice method for the majority of medical analysis laboratories, by reason of its qualities and the many advantages it offers in comparison with classical colorations.

Bronchoalveolar Lavage Fluid↗
PubMed1981

Postoperative wound infection after appendicectomy. Evaluation of infection risk with qualitative and quantitative incisional wound culture.

The predictive value for postoperative infection of incisional wound cultures obtained at wound closure was studied in two series of appendicectomies, comprising 404 patients studied with qualitative swab cultures, and 491 patients studied with quantitative velvet pad imprint cultures. 17% and 19%, respectively, of the patients in the two series yielded cultures positive with Gram-negative enterobacteria. The postoperative wound infection rate among contaminated cases was 36.1% and 26.9%, respectively, which was a significantly higher rate (p less than 0.001) as compared to operations yielding negative cultures. Using quantitative culture technique, 63% of all infections was shown to occur in the 15% of all patients whose culture yielded two or more colonies of enterobacteria. Of these high risk patients, those who were given antibiotics at operation had an infection rate of 25%, and those not given antibiotics had a rate of 48%. The remaining 85% of the patients had an infection rate of less than 5%.

Appendectomy↗
PubMed1986

Infection stones. Evaluation and management.

Infection stones may be the cause of persistent or recurrent bacterial urinary infection. Evaluation of the infection and the character of the stones often aids in the selection of management and treatment options. The ultimate success of the treatment of infection stones should be measured, however, by control or removal of both the stone and the urinary infection.

Calcium Carbonate↗