Value of different cut-off points of tuberculin skin test to diagnose tuberculosis among patients with respiratory symptoms in a chest clinic.

OBJECTIVE: To assess the utility of various cut-off points of tuberculin skin test in making a diagnosis of tuberculosis in patients with respiratory symptoms. METHODS: Tuberculin skin test was conducted on consecutive new patients attending chest clinic for various respiratory symptoms. All subjects were then investigated to establish diagnosis, and categorized into tuberculous and nontuberculous groups. Receiver operating characteristic (ROC) curve was plotted to evaluate discrimination by tuberculin skin test. Sensitivity, specificity and predictive value were also calculated at various cut-off points. RESULTS: Of 250 patients, 59 (23.6%) had tuberculosis on clinical and microbiological criteria (other than the tuberculin test). Sensitivity and specificity of tuberculin test at readings greater than 5, 10 and 15 mm were 0.8136 and 0.7068, 0.6271 and 0.8901, and 0.2034 and 0.9738 respectively. Area under ROC curve for this test was 0.80. CONCLUSION: A cut-off point of 10 mm is likely to be useful in supporting a diagnosis of tuberculosis in patients with strong clinical suspicion of tuberculosis, in other patients, 15 mm cut-off may be more suitable.

Prevalence of tuberculin reacting and prevalence of risk factors for the development of active tuberculosis in a nursing home in Puerto Rico

A total of 91 nursing home patients were evaluated to determine the prevalence of tuberculous infection and the prevalence of risk factors for active TB in those with positive tuberculin reactions. Overall prevalence rate for positive PPD was 42.9 percent No association was found between revalence of positive PPD and time since admission to the nursing home. The most prevalent risk factors for active TB among PPD positive patients were diabetes mellitus (38.5percent), being 10 percent below ideal body weight (25.6 percent), chest X ray with fibrotic changes (13.2 percent), and carcinoma of oropharynx (5.1 percent). Twenty-one patients (53.8 percent) of patients with positive test) met criteria for prophylactic treatment with isoniazid. This study detected a high prevalence of positive PPD reactions in this nursing home population and a high prevalence of risk factors for the development of active TB in the group with positive reaction to PPD. Due to the high risk for the development of active tuberculosis in this population, aggressive screening and preventive therapy are mandatory

Value of Mantoux Test in diagnosis of tuberculosis in chronic illness.

Total 240 cases of 2-12 years age group who had contact of tuberculosis indirectly or directly and had chronic illness were screened for tuberculosis. Out of 240 cases, 180 cases were diagnosed as tuberculosis. Special emphasis was given on Mantoux Test (M.T.), though the battery of tests were done to diagnose tuberculosis. Out of 180 cases of Tuberculosis, M.T. was Positive in 97 cases (40.41%) and repeat M.T. was done after 3 weeks and was converted to Positive in 20 cases (8.33%). Thus only M.T. help in diagnosis of Tuberculosis in almost 50% of the cases.

Valor preditivo do teste tuberculínico padronizado em crianças vacinadas com BCG / The predictive value of the standard tuberculin test in BCG vaccinated children

A aplicabilidade do teste tuberculínico em crianças menores de 5 anos vacinadas com BCG é assunto controvertido. Visando contribuir para esclarecê-lo foi analisado o valor peditivo positivo do teste tuberculínico padronizado em populaçäo sob elevada cobertura vacinal e baixa prevalência de infecçäo tuberculosa. A partir da proporçäo de reatores fortes em latentes e escolares vacinados e näo vacinados, foram calculadas a razäo de declínio da alergia tuberculínica nos vacinados e a razäo de crescimento nos näo vacinados, o que possibilitou a estimativa dos respectivos valores nas idades intermediárias. A expectativa de falsos-positivos (FP) foi entäo calculada por diferença. Conhecidas a sensibilidade e a especificidade do teste (E=1-FP), a cobertura BCG e a prevalência de infecçäo, os valores preditivos (para a infecçäo tuberculosa) foram: 1,52 por cento, 4,22 por cento, 8,26 por cento, 14,86 por cento, 23,00 por cento do primeiro ao quinto ano de vida. Nessas condiçöes, a probabilidade de uma reaçäo forte ser devida ao BCG é grande, especialmente nos dois primeiros anos, o que reduz a aplicabilidade clínica e epidemiológica do teste.

Discussäo de alguns aspectos da padronizaçäo técnica do teste de Mitsuda em relaçäo ao teste tuberculínico / Discussion of some aspects of technical stardardization of Mitsuda's test in relation with tuberculin test

Estuda-se alguns aspectos dos testes tuberculinico e de Mitsuda, com o objetivo de avaliar a comparabilidade entre eles e discutir a padronizaçäo da técnica do teste de Mitsuda. Conclui-se serem os testes comparáveis entre si, nos diferentes aspectos estudados, excetuando-se a técnica de leitura do teste de Mitsuda, que näo se encontra descrita na literatura consultada.Sugere-se a padronizaçäo dessa leitura, nos moldes do teste tuberculínico, e o treinamento do pessoal como alternativa para garantir a uniformidade do procedimento

Significance of the tuberculin skin test in pulmonary tuberculosis in Jamaica: comparisons of culture-positive, culture negative and non-tuberculous patients

The results of tuberculin skin tests with PPDS-S done on patients with pulmonary tuberculosis seen over a three-year period (1979-1981) were compared with the results of similar tests done during the same period in a group of persons without tuberculosis. Ninety per cent of patients with culture-positive tuberculosis had positive tuberculin skin tests, compared to 83% of positive tests in the non-tuberculous group. The presence of such a large proportion of positive tuberculin reactions in persons without active disease indicates that the skin test reaction cannot be used on its own to establish the diagnosis of had negative sputum smears and cultures for acid-fast bacilli. Eighty-two per cent of these patients had positive tuberculin skin tests. Invasive diagnostic tests and newer serological diagnostic methods are likely to increase the yield of confirmed positive cases of tuberculosis in the future

Teste tuberculínico: diluiçäo padronizada do PPD Rt 23 no Brasil / Tuberculin test: standard dilution of the PPD Rt 23 in Brazil

A prova tuberculínica constitui-se em recurso importante para o diagnóstico da infecçäo tuberculosa. Para que a prova possa ser confiável, deve ser padronizada e, para que esta padronizaçäo seja alcançada, é necessário que se utilize um PPD de qualidade controlada. O Instituto de Tisiologia e Pneumologia da Universidade Federal do Rio de Janeiro (ITP/UFRJ) é o responsável pela diluiçäo do PPD concentrado, recebido do Statens Seruminstitut de Copenhagen, que é distribuída para todo o território brasileiro pela Divisäo Nacional de Pneumologia Sanitária do Ministério da Saúde (DNPS). Uma série de procedimentos técnicos säo necessários para a obtençäo de uma diluiçäo que atenda aos parâmetros internacionais. Descrevem-se tais procedimentos e apresentam-se os resultados do controle de qualidade a que foram submetidas 51 partidas de PPD diluído, no período de 1977 a 1983, que apresentaram atividade idêntica à do PPD produzido e diluído no Statens Seruminstitut de Copenhagen, confirmada mediante provas tuberculínicas pareadas. Conclui-se que o PPD diluído no ITP/UFRJ atende aos critérios exigidos pela Organizaçäo Mundial da Saúde