Prevalence of positive tuberculin skin test in a Brazilian sample of rheumatoid arthritis and spondylarthritis patients

SUMMARY OBJECTIVE: Patients with rheumatic diseases have an increased risk of infections, especially tuberculosis. In this study, we aimed to recognize the positivity rate of tuberculosis skin test in patients with rheumatoid arthritis and spondyloarthritis and the characteristics of the patients with positive results. METHODS: Retrospective study of tuberculosis skin test results in patients followed from 2004 to 2021 in a single rheumatology unit. Data related to clinical and epidemiological features, along with treatment information referring to the period in which the tuberculosis skin test was performed, were collected from patients' charts. RESULTS: A total of 723 tests were identified (448 tests in 269 rheumatoid arthritis patients and 275 in 174 spondyloarthritis patients). In the rheumatoid arthritis sample, 31/275 (11.5%) individuals had positive tests, and in the spondyloarthritis, 38/174 (21.8%) had positive tests. In the rheumatoid arthritis sample, patients with positive tuberculosis skin tests used a higher dose of methotrexate than those with negative results (median of 25 mg/week versus median of 20 mg/week respectively; p=0.02). In the spondyloarthritis sample, tuberculosis skin test positivity was associated with alcohol ingestion (13.1% versus 2.9% in users and non-users respectively; p=0.02) and sulfasalazine use (15.7% of positivity in users versus 5% in non-users; p=0.01). CONCLUSION: The tuberculosis skin test-positive prevalence in rheumatoid arthritis was lower than in the spondyloarthritis sample. Patients with rheumatoid arthritis using a higher dosage of methotrexate or with spondyloarthritis using sulfasalazine had more frequency of tuberculosis skin test positivity and should be carefully followed by the attending physician in order to avoid the appearance of full-blown tuberculosis.

Frecuencia de infección tuberculosa latente en estudiantes de Medicina en una universidad privada de Paraguay

Introducción: la infección tuberculosa latente es un estado de respuesta inmune tipo hipersensibilidad celular retardada del organismo a la estimulación por antígenos de Mycobacterium tuberculosis sin evidencia clínica y radiológica de tuberculosis. Puede ser diagnosticada mediante la prueba de tuberculina o derivado proteico purificado de tuberculina. Objetivos: determinar la frecuencia de infección tuberculosa latente en estudiantes de Medicina y las variables asociadas a una reacción positiva en la prueba de tuberculina. Metodología: se realizó un estudio descriptivo de corte transversal, en el cual se procedió a realizar la prueba de tuberculina por el método de Mantoux utilizando 0,1 ml de derivado proteico purificado de tuberculina Tubersol, en estudiantes de la carrera de Medicina de una universidad. Resultados: participaron 290 estudiantes. La frecuencia de infección tuberculosa latente fue 19,3%. Al relacionar las variables demográficas con la reacción positiva en la prueba de tuberculina, los hombres presentaron 1,895 veces mayor probabilidad de dar positivo a la prueba de tuberculina que las mujeres. Conclusiones: la frecuencia de infección tuberculosa latente en estudiantes de la carrera de Medicina fue 19,3% y la variable que presentó asociación estadística a la prueba de tuberculina positiva fue el sexo masculino.

Introduction: Latent tuberculosis infection is a state of delayed cellular hypersensitivity immune response of the organism to stimulation by Mycobacterium tuberculosis antigens without clinical and radiological evidence of tuberculosis. It can be diagnosed by tuberculin test or tuberculin purified protein derivative. Objectives: To determine the frequency of latent tuberculosis infection in medical students and the variables associated with a positive reaction in the tuberculin test. Methodology: A descriptive cross-sectional study was carried out, in which the tuberculin test was made by the Mantoux method using 0.1 ml of purified protein derivative of Tubersol tuberculin in students of the medicine career of a university. Results: Two hundred ninety students participated. The frequency of latent tuberculosis infection was 19.3%. When relating the demographic variables to the positive reaction in the tuberculin test, men were 1,895 times more likely to test positive for the tuberculin test than women. Conclusions: The frequency of latent tuberculosis infection in medical students was 19.3% and the variable that presented a statistical association with the positive tuberculin test was male sex.

Incidence, Diagnosis and Treatment of Otorhinolaryngologicl, Head and Neck Tuberculosis: A Prospective Clinical Study

Abstract Introduction Tuberculosis is a disease of diversified presentation. It affects almost all organs in the body, and otorhinolaryngological, head and neck involvement is not an exception. Objective To increase awareness about the different clinical presentations of otorhinolaryngological, head and neck tuberculosis, the techniques employed to diagnose it, and to assess the response to the treatment. Methods We conducted a prospective study of 114 patients who presented primarily with otorhinolaryngological, head and neck tuberculosis. Routine blood investigations, chest radiographs, the tuberculin test, and sputum examination for the presence of acid-fast bacilli were performed in all cases. Site-specific investigations were performed in relevant cases only. The patients were treated according to the antitubercular treatment (ATT) regimen recommended by the Indian Ministry of Health and Family Welfare's National Tuberculosis Elimination Program (NTEP), and they were followed up clinically two and six months after starting the ATT. Results Tubercular cervical lymphadenopathy was the most common clinical presentation (85.96%), followed by deep neck abscess (5.27%). Fine-needle aspiration cytology proved to be a reliable tool for the diagnosis of tubercular lymphadenopathy. Improvement at the end of 2 and 6 months of the ATT was observed in 90.35% and 96.50% of the cases respectively. Conclusion The diagnosis of otorhinolaryngological, head and neck tuberculosis requires a high index of clinical suspicion, and the ATT proved to be very effective in reducing the severity of the disease.

Propuesta de modalidad de catastro de infección tuberculosa en contactos escolares de colegios secundarios / Modality proposal of tuberculosis infection screening in high school contacts

Resumen El catastro sistemático de contactos con el objetivo de identificar y tratar a aquellos con infección tuberculosa es uno de los pilares establecidos por la OMS en su Estrategia de Fin a la Tuberculosis. El riesgo de infección tuberculosa en contactos escolares, aunque menor que en los domiciliarios, es significativo. Sin embargo, es bajo el cumplimiento del tratamiento preventivo y varios puntos se prestan a discusión, como ser el corte de la prueba tuberculínica a utilizar, el beneficio de iniciar un tratamiento quimioprofiláctico en ausencia de infección demostrada o de realizar estudios en contactos de casos índice no bacilíferos. Este escrito aborda dichos temas y propone, con evidencia actualizada, una modalidad de estudio para contactos en instituciones de enseñanza secundaria. Dicho catastro propone identificar a los infectados utilizando el punto de corte de 5 mm en la prueba de tuberculina, ofreciendo tratamiento preventivo y seguimiento activo solamente a aquellos con una prueba positiva.

Abstract The systematic registry of contacts with the objective of identifying and treating those with tuberculosis infection is one of the pillars established by the WHO in the end Tuberculosis Strategy. The risk of tuberculosis infection in school contacts, although lower than in households, is significant. However, compliance with preventive treatment is low and several points are open to discussion, such as the cutoff of the tuberculin test to be used, the usefulness of starting a chemoprophylactic treatment in the absence of confirmed infection or carrying out studies in contacts of non-bacilliferous index cases. This paper ad dresses these issues and proposes, with updated evidence, a screening modality for contacts in higher education institutions. This screening proposes to identify those infected using the cut-off point of 5 mm in the tuberculin test, offering preventive treatment and active follow-up only to those with a positive test.

The clinical utility of tuberculin skin tests: a single-center experience

Background: Tuberculin skin test (TST) has played an essential in the diagnosis of latent tuberculosis infection (LTBI) for nearly a century. Objective: This study aimed to investigate the general characteristics of patients tested with TST in a tertiary hospital within two years. Methods: All patients who were evaluated to screen for tuberculosis and received a TST were included. The Mantoux method was used for TST administration. Results: A total of 661 patients, 345 (52.2%) men and 316 (47.8%) women, with a mean age of 43.0 ±15.9 years, were included in the study. Accordingly, TST was performed prior to anti-TNF biological agent therapy for 50% (331) of the participants, for LTBI screening before solid organ and/or hematological stem cell transplantation for 20.4% (135), for screening following contact with tuberculosis for 25.1% (166), for screening of healthcare professionals for 1.1% (7), and medical report for 3.3% (22). 2.7% of the patients who took TST were diagnosed with active tuberculosis (14 with pulmonary tuberculosis and 4 with extrapulmonary tuberculosis). QuantiFERON-TB Gold (QFT) test was performed in 332 (50.2%) patients with anergic TST results. According to TST and QFT test results, 28.3% (187) of the patients were started on tuberculosis prophylaxis. Conclusion: While TST is most performed for LTBI screening prior to biological agent therapy, almost one-fourth of patients taking TST require tuberculosis prophylaxis. On the other hand, about half of the patients require an additional QFT test.

Antecedentes: La prueba de la tuberculina ha jugado un papel fundamental en el diagnóstico de la infección latente por tuberculosis durante casi un siglo. Objetivo: Investigar las características generales de los pacientes a los que se les realizó la prueba de tuberculina en un hospital de tercer nivel. Métodos: Se incluyeron todos los pacientes que fueron incluidos en un tamizaje de tuberculosis mediante la prueba de tuberculina. Se utilizó el método de Mantoux para la administración de esta prueba. Resultados: Se incluyeron en el estudio un total de 661 pacientes, 345 (52.2%) hombres y 316 (47.8%) mujeres, con una edad media de 43.0 ±15.9 años. La prueba de tuberculina se realizó en el 50% (331) de los participantes, antes de la terapia con agentes biológicos anti-TNF; En el 20.4% (135) se hizo la prueba antes del trasplante de órganos sólidos y/o células madre hematológicas; para el 25.1% (166) se realizó tras contacto con la tuberculosis, el 1.1% (7) para tamizaje de los profesionales sanitarios y con informe médico para el 3.3% (22). El 2.7% de los pacientes que se realizaron la prueba de tuberculina fueron diagnosticados con tuberculosis activa (14 pulmonar y 4 extrapulmonar). La prueba QuantiFERON-TB Gold (QFT) se realizó en 332 (50.2 %) pacientes con resultados anérgicos para tuberculina. Según los resultados de las pruebas de tuberculina y QFT, el 28.3% (187) de los pacientes iniciaron profilaxis antituberculosa. Conclusión: Si bien la prueba de tuberculina se realiza comúnmente para la detección de tuberculosis latente antes de la terapia con agentes biológicos, casi una cuarta parte de los pacientes que se les hizo la prueba de tuberculina requieren profilaxis para tuberculosis. Por otro lado, aproximadamente la mitad de los pacientes requieren una prueba QFT adicional.

A Systematic Review of Prevalence and Risk Factors of Latent Tuberculosis Infection Among Medical and Nursing Students

@#Introduction: Clinical training may expose medical and nursing students to workplace hazards comparable to those encountered by healthcare workers (HCWs). This study was designed to investigate the prevalence of latent tuberculosis infection (LTBI) and associated risk factors among medical and nursing students. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria, a systematic review was conducted utilising four electronic databases to appraise and synthesise the literature on LTBI which used the tuberculin skin test (TST) and the blood interferon-gamma release assay (IGRA). Results: Original articles published in the English language between 2010 and 2020 were included, yielding 14 relevant articles. The average prevalence of LTBI in high-burden countries was 38.2% for TST and 20.6% for the IGRA test. According to TST and IGRA findings, the average prevalence of LTBI in nations with an intermediate burden was 16.7% and 4.7 %, respectively. The average prevalence was 2.8% and 1.1% from the TST and IGRA tests for low-burden countries, respectively. A greater risk of LTBI was shown to be related with an increase in age among postgraduate medical school students, a history of Bacillus Calmette-Guerin (BCG) vaccination, origin from high-risk tuberculosis (TB) countries, increased hours of hospital exposure, a history of contact with TB cases, a high body mass index, older age group students, and a lower TB knowledge score. Conclusion: The available evidence from this review emphasised the importance of developing and implementing efficient and cost-effective TB infection-control programmes, particularly in high-burden countries and amongst students at risk.

Prevalence of latent tuberculosis infection among patients with interstitial lung disease requiring immunosuppression / Prevalência de infecção latente por tuberculose em pacientes com doença pulmonar intersticial com necessidade de imunossupressão

ABSTRACT Objective To characterize the prevalence of latent tuberculosis infection (LTBI) in patients with interstitial lung diseases (ILDs) requiring immunosuppression. Only 5 to 10% of individuals infected with Mycobacterium tuberculosis develop tuberculosis, and certain groups of patients have an increased risk of illness, such as the immunocompromised. Patients with ILDs are frequently treated with immunosuppressants and, therefore, might have a higher risk of developing the disease. Methods Prospective study conducted at the ILD reference center of the Federal University of Paraná from January 2019 to December 2020. The screening of LTBI was performed with the use of the tuberculin skin test (TST). Results The sample consisted of 88 patients, of whom 64.8% were women, with a mean age of 61.4 years. The most frequent diagnoses were autoimmune rheumatic disease ILD (38.6%) and hypersensitivity pneumonitis (35.2%). The most common immunosuppressant in use at the time of the TST was prednisone, either in combination with mycophenolate (19.3%) or alone (17.1%). The majority of participants had fibrotic lung disease, characterized by a reticular interstitial pattern on chest computed tomography (79.5%) and moderate to severe functional impairment (mean FVC 69.2%). A prevalence of LTBI of 9.1% (CI 95%, 2.1%-15.1%) was found, with a TST median of 13. Conclusion Patients with ILD who are treated with immunosuppressants are not commonly screened for LTBI, despite being under a greater risk of progression to active disease. This study suggests the need for a more cautious approach to these patients.

RESUMO Objetivo Caracterizar a prevalência de Infecção Latente por Tuberculose (ILTB) em pacientes com Doenças Pulmonares Intersticiais (DPIs) que necessitam de imunossupressão. Apenas 5 a 10% dos indivíduos infectados pelo Mycobacterium tuberculosis desenvolvem tuberculose, sendo que certos grupos de pacientes apresentam maior risco de doença, tais como os imunocomprometidos. Pacientes com DPIs são frequentemente tratados com imunossupressores, portanto, podem apresentar maior risco de desenvolver a doença. Métodos Estudo prospectivo conduzido no Centro de Referência para DPI da Universidade Federal do Paraná (UFPR), entre Janeiro de 2019 e Dezembro de 2020. O rastreio de ILTB foi realizado por meio da Prova Tuberculínica (PT). Resultados A amostra foi composta por 88 pacientes, dos quais 64,8% eram mulheres, com, em média, 61,4 anos de idade. Os diagnósticos mais frequentes foram DPI associada a doença reumática autoimune (DRAI) (38,6%) e pneumonite de hipersensibilidade (35,2%). Prednisona foi o imunossupressor mais comumente utilizado à época da PT, em combinação com micofenolato (19,3%) ou isoladamente (17,1%). A maioria dos participantes tinha doença pulmonar fibrótica, caracterizada por infiltrado reticular em tomografia computadorizada de tórax (79,5%), bem como comprometimento funcional moderado a grave (Capacidade Vital Forçada (CVF) média de 69,2%). Observou-se uma prevalência de ILTB de 9,1% (Intervalo de Confiança (IC) 95%, 2,1%-15,1%), com mediana da PT de 13. Conclusão Não é comum que pacientes com DPI tratados com imunossupressores sejam avaliados quanto à presença de ILTB, apesar de estarem sob um maior risco de progressão para doença ativa. Este estudo sugeriu a necessidade de uma abordagem mais cuidadosa em relação a esses pacientes.

Analysis of tuberculosis screening for newly enrolled students in Hunan Province from 2018 to 2020 / 中国学校卫生

Objective@#To understand tuberculosis screening for newly enrolled students in Hunan Province and to provide reference for scholl based tuberculosis (TB) prevention and control.@*Methods@#During 2018 to 2020, TB screening was carried out for newly enrolled students in Hunan Province, and the screening results were statistically analyzed by descriptive analysis and χ 2 test.@*Results@#In 2018-2020, the average incidence rate of TB among students in Hunan Province was 20.90/100 000, with a decreasing trend by year ( χ 2 trend =89.45, P <0.01), the screening rate of TB in schools was 87.30%, and the screening rate for newly enrolled students was 86.81%, with downward trend by year ( χ 2 trend =2 843.34, 83 443.77, P <0.01). The proportion of suspicious symptoms, close contact, and active pulmonary TB patients among students were 0.53%, 0.21%, and 1.73/10 000, respectively, with decreasing trends by year( χ 2 trend =8 624.05, 2 215.48, 99.14, P <0.01). The proportion of strong positive PPD/ IGRA positive, changes in imaging examination and culturepositive of mycobacterium tuberculosis were 1.52%,0.20% and 12.40%, with increasing trends by year ( χ 2 trend =529.18, 147.65, 25.89, P <0.01). There were statistically significant differences in the proportion of suspicious symptoms, close contact, strong positive PPD/positive IGRA, changes in imaging examination and the proportion of patients with tuberculosis in the regional classification and school classification ( χ 2=529.18, 8 823.13, 705.63, 2 068.03, 1 299.00, 4 318.73 , 33.12, 2 329.07, 35.80, 1 781.65, P <0.01). There was no statistically significant difference in the proportion of culture positive of mycobacterium tuberculosis in the regional classification and school classification ( P >0.05).@*Conclusion@#The screening rate of newly enrolled student showed an upward trend, and the incidence rate of tuberculosis among students showed downward trend. Newly enrolled students among fresh students in high school have the highest PPD positive/IGRA positive rate and the proportion of pulmonary tuberculosis in the student population. It is necessary to increase the screening among fresh students in high school. In areas with conditions, tuberculosis screening of senior two students can be considered.

Latent tuberculosis screening before kidney transplantation in the South of Brazil / Rastreamento de tuberculose latente antes do transplante renal no Sul do Brasil

Abstract Background: Tuberculosis (TB) is a prevalent infection after kidney transplantation (KT) in high-burden countries. Latent tuberculosis infection (LTBI) screening includes previous TB history, chest radiograph findings, and tuberculin test (TST) and/or interferon-gamma release assays (IGRAs) results. We aimed to compare our routine LTBI screening of KT candidates and living donors (LD) with their IGRA results, and evaluate if this would improve isoniazid (INH) treatment referral. Methods: We evaluated adult KT candidates and LD with complete routine LTBI screening and QuantiFERON-TB® Gold In-Tube (QFT) testing. Blood samples were collected from April 4th, 2014 to October 31st, 2018, with follow-up until October 31st, 2019. Results: There were 116 KT recipients, with 30% QFT-positive results. Positive QFT was associated with past TB history (p=0.007), positive TST (p<0.0001), residual radiographic lesions (p=0.003), and diabetes (p=0.035). There were 25 LD, 40% had positive QFT. Positive QFT was associated with a positive TST (p=0.002). Positive QFT results increased INH referral in 80%. Post-transplant TB incidence was 2.6% in a median follow-up of 2 (1-33) months. No variables were associated with post-transplant TB. TB patients had inferior, although non-significant, 5-year graft survival (66.7% vs. 76.5%) (p = 0.402). Conclusion: In the present study, the association of QFT to our routine LTBI screening incremented INH treatment referral, but there was still a high incidence of post-transplant TB, possibly related to other forms of infection, such as new exposure and donor transmission.

Resumo Histórico: Tuberculose (TB) é uma infecção relativamente comum pós-transplante renal (TR) em países com alta prevalência da doença. O rastreamento de infecção latente por tuberculose (ILTB) inclui histórico prévio de TB, achados de radiografia do tórax, resultados do teste tuberculínico (TT) e/ou de ensaio de liberação de interferon-gama (IGRAs). Nosso objetivo foi comparar nossa avaliação de rotina de candidatos ao TR e doadores vivos (DV) com seus resultados de IGRA, avaliando se aumentaria o encaminhamento para tratamento com isoniazida (INH). Métodos: Avaliamos candidatos adultos ao TR e DV com rastreamento para ILTB de rotina completo e coleta de testes QuantiFERON-TB® Gold In-Tube (QFT). Coletamos amostras sanguíneas de 4 de Abril, 2014 - 31 de Outubro, 2018, com acompanhamento até 31 de Outubro, 2019. Resultados: Avaliamos 116 receptores de TR, 30% sendo QFT-positivo. QFT positivo foi associado ao histórico prévio de TB (p=0,007), TT positivo (p<0,0001), lesões radiográficas residuais (p=0,003), diabetes (p=0,035). Avaliamos 25 DV, 40% apresentaram QFT positivo. QFT positivo foi associado a TT positivo (p=0,002). Resultados positivos do QFT aumentaram o encaminhamento para INH em 80%. A incidência de TB pós-transplante foi 2,6% em uma mediana de acompanhamento de 2 (1-33) meses. Nenhuma variável foi associada à TB pós-transplante. Pacientes com TB tiveram sobrevida do enxerto em 5 anos inferior, embora não-significativa (66,7% vs. 76,5%) (p = 0,402). Conclusão: Neste estudo, a associação do QFT à nossa avaliação de ILTB de rotina aumentou o encaminhamento para tratamento com INH, mas ainda houve alta incidência de TB pós-transplante, possivelmente relacionada a outras formas de infecção, como nova exposição e transmissão pelos doadores.

Prevalence of latent tuberculosis and associated factors in patients with chronic kidney disease on hemodialysis / Prevalência de tuberculose latente e fatores associados em pacientes com doença renal crônica em hemodiálise / Prevalencia de tuberculosis latente y factores asociados en pacientes con enfermedad renal crónica en hemodiálisis

Objective: to identify the prevalence of latent tuberculosis in patients with chronic kidney disease on hemodialysis and associated factors. Method: a cross-sectional study conducted with 176 patients with chronic kidney disease on hemodialysis. The tuberculin test was performed with the standardized antigen, distributed by the Brazilian Ministry of Health, and the reading occurred after 72 to 96 hours of the application. An association test (Chi-square, Fisher's exact), prevalence ratio, and multivariate regression tests were performed. Results: the prevalence of latent tuberculosis diagnosed through Tuberculosis Skin Test was 8.5% (15/176). The "has/has had diabetes" (aOR: 0.117; 95%CI: 0.015-0.92) and "having regular garbage collection (aOR: 0.076; 95%CI: 0.008-0.702) factors were associated with a lower probability of having a Positive skin test. Conclusion: the low prevalence of latent tuberculosis identified and the factors associated with it reinforce the need for screening for latent tuberculosis infection for diabetics combined with an analysis of previous risk factors and comorbidities.

Objetivo: identificar a prevalência de tuberculose latente em pacientes com doença renal crônica em hemodiálise e fatores associados. Método: estudo transversal realizado com 176 pacientes com doença renal crônica em hemodiálise. O teste tuberculínico foi realizado com o antígeno padronizado, distribuído pelo Ministério da Saúde do Brasil, e a leitura ocorreu após 72 a 96 horas da aplicação. Foram realizados teste de associação (Qui-quadrado, exato de Fisher), razão de prevalência e regressão multivariada. Resultados: a prevalência de tuberculose latente (teste tuberculínico positivo) foi de 8,5% (15/176). Os fatores "tem/teve diabetes" (ORa:0,117; IC95% 0,015-0,92) e "ter coleta de lixo regular" (ORa:0,076; IC95% 0,008-0,702) foram associados a menores probabilidades de ter teste tuberculínico positivo. Conclusão: a baixa prevalência de tuberculose latente identificada e os fatores associados à mesma reforçam a necessidade de uma triagem da infecção latente por tuberculose para diabéticos combinada com a análise de fatores de risco e comorbidades prévias.

Objetivo: identificar la prevalencia de tuberculosis latente en pacientes con enfermedad renal crónica en hemodiálisis y factores asociados. Método: estudio transversal realizado con 176 pacientes con enfermedad renal crónica en hemodiálisis. La prueba cutánea de la tuberculina se realizó con el antígeno estandarizado, distribuido por el Ministerio de Salud de Brasil, y la lectura se realizó después de 72 a 96 horas de la aplicación. Se realizaron pruebas de asociación (Chi-cuadrado, exacta de Fisher), razón de prevalencia y regresión multivariante. Resultados: la prevalencia de tuberculosis latente (prueba de tuberculina positiva) fue de 8,5% (15/176). Los factores "tiene/ha tenido diabetes" (ORa: 0,117; IC del 95%: 0,015-0,92) y "tener recolección regular de residuos" (ORa: 0,076; IC del 95%: 0,008-0,702) se asociaron con menores probabilidades de tener una prueba de tuberculina positiva. Conclusión: la baja prevalencia de tuberculosis latente registrada y sus factores asociados refuerzan la necesidad del cribado de la infección tuberculosa latente en diabéticos combinado con el análisis de factores de riesgo y comorbilidades previas.

A simple protocol for tuberculin skin test reading certification / Um protocolo simples para a certificação da leitura da prova tuberculínica / Un protocolo simple para la certificación de la lectura de la prueba cutánea de tuberculina

Although tuberculosis preventive therapy is one of the cornerstones for eliminating the disease, many barriers exist in the cascade of care for latent tuberculosis infection, including the need to certify healthcare professionals for reading tuberculin skin tests (TST). This paper proposes and evaluates a simple protocol for TST reading training. Primary care workers from different backgrounds received a 2-hour theoretical course, followed by a practical course on bleb reading. Blebs were obtained by injecting saline into sausages and then in volunteers. A certified trainer then evaluated the effectiveness of this protocol by analyzing the trainees' ability to read TST induration in clinical routine, blinded to each other's readings. Interobserver agreement was analyzed using the Bland-Altman test. The trainees' reading accuracy was calculated using two cut-off points - 5 and 10mm - and the effect of the number of readings was analyzed using a linear mixed model. Eleven healthcare workers read 53 saline blebs and 88 TST indurations, with high agreement for TST reading (0.07mm average bias). Sensitivity was 100% (94.6; 100.0) at 5mm cut-off and 87.3% (75.5; 94.7) at 10mm cut-off. The regression model found no effect of the number of readings [coefficient: -0.007 (-0.055; 0.040)]. A simple training protocol for reading TST with saline blebs simulations in sausages and volunteers was sufficient to achieve accurate TST induration readings, with no effect observed for the number of readings. Training with saline blebs injected into voluntary individuals is safer and easier than the traditional method.

A terapia preventiva da tuberculose é uma das bases para a eliminação da tuberculose. Entretanto, existem muitas barreiras na cascata de cuidados da infecção latente de tuberculose, incluindo a necessidade de certificação dos profissionais de saúde para a leitura da prova tuberculínica (PPD). Aqui, propomos e avaliamos um protocolo simples para capacitação na leitura do PPD. Profissionais na atenção primária com diferentes formações receberam um curso teórico de duas horas, seguido por um curso prático sobre a leitura da enduração. Nas sessões práticas, as pápulas foram obtidas pela injeção de solução salina em salsichas, e depois em voluntários. Depois, a eficácia do protocolo foi avaliada por um instrutor credenciado, com base na capacidade do aluno de ler a enduração do PPD na rotina clínica (em formato duplo-cego em relação às respectivas leituras). A concordância inter-observador foi analisada com o teste de Bland-Altman. A acurácia das leituras dos alunos foi calculada com dois pontos de corte: 5 e 10mm. O efeito do número de leituras foi analisado com um modelo linear misto. Onze profissionais de saúde leram 53 pápulas de solução salina e 88 endurações de PPD. A concordância na leitura dos PPDs foi alta (média de 0,07mm de viés). A sensibilidade foi 100% (94,6; 100,0) com o ponto de corte de 5mm e 87,3% (75,5; 94,7) com o ponto de corte de 10mm. No modelo de regressão, não houve efeito do número de leituras [coeficiente: -0,007 (-0,055; 0,040)]. Um protocolo simples de treinamento em leitura da prova tuberculínica com simulações usando pápulas criadas com solução salina em salsichas e em voluntários foi suficiente para alcançar leituras acuradas da enduração da prova, sem efeito observado pelo número de leituras. O treinamento com pápulas criadas com solução salina em voluntários é mais seguro e mais fácil, comparado com o treinamento tradicional.

La terapia preventiva de la tuberculosis es una de las piedras angulares para la erradicación de la tuberculosis. No obstante, existen muchas barreras en la cascada de cuidado de una infección latente de tuberculosis, incluyendo la necesidad de certificación, en el caso de los profesionales de atención en salud, para la lectura de la prueba cutánea de tuberculina (TST). Aquí proponemos y evaluamos un protocolo simple para el entrenamiento en la lectura de TST. Trabajadores de salud de atención primaria de diferentes contextos recibieron un curso de 2 horas teórico, seguido de una práctica en la lectura de la ampolla. Las ampollas se obtienen inyectado una solución salina en salchichas y luego en voluntarios. Posteriormente, la eficacia de este protocolo fue evaluada mediante un formador certificado a través de la habilidad del personal en formación para la lectura de induración del TST en la rutina clínica, con lecturas cegadas entre ellos. Se analizó la concordancia entre los observadores usando el test Bland-Altman. La precisión de la lectura por parte del personal en formación se calculó usando dos puntos de corte: 5 y 10mm. El efecto del número de lecturas fue analizado usando un modelo lineal mixto. Once trabajadores de salud leyeron 53 soluciones salinas en ampollas y 88 induraciones TST. La concordancia en la lectura del TST fue alta (0,07mm promedio de sesgo). La sensibilidad fue de un 100% (94,6; 100,0) usando los 5mm de corte y 87,3% (75,5; 94,7) usando los 10mm de corte. En el modelo de regresión, no hubo efecto del número de lecturas [coeficiente: -0,007 (-0,055; 0,040)]. Un simple protocolo de entrenamiento para la lectura TST con simulaciones, usando solución salina en ampollas en salchichas y voluntarios fue suficiente para alcanzar lecturas precisas de induración TST, sin efectos observados por el número de lecturas. El entrenamiento con ampollas salinas en personas voluntarias es más seguro y más fácil que el entrenamiento tradicional.

Tuberculin skin test in close contacts in case of school tuberculosis outbreak / 中国学校卫生

Objective@#To evaluate the role of tuberculin skin test prified protein derivative (PPD) in defining the screening scope of close contacts of tuberculosis cases in disposal of tuberculosis outbreak in schools.@*Methods@#In a senior middle school in August 2019, 1 553 students of the grade two were tested by PPD because of a school tuberculosis outbreak. PPD results were compared to grade one students without any association with this tuberculosis epidemic, who were also tested by PPD when beginning school. Potential association between PPD distribution characteristics and tuberculosis case distribution were analyzed.@*Results@#Twenty nine grade two students were diagnozed as tuberculosis infection, seven of which were PPD positive, and with the same MIRU-VNTR genotype. In grade one, 0.1 % (1/796) student showed strong PPD positive, 34.3% (273/796) student showed positive. For grade two students, significant higher rate of strong PPD positive [5.9% (45/757)], and PPD positive [52.0% (394/757)] were observed ( χ 2=45.71, 49.90, P <0.01). Proportion of strong PPD positive in the first floor of the teaching building ( 19.4 %), where tuberculosis cases clustered, was significantly higher than that in other floors ( χ 2=89.81, P <0.01); Number of strong PPD positive students increased with TB cases in each floor of the teaching building ( r =0.99, P <0.01). Proportion of strong PPD positive and PPD positive in floors of the dormitory, where TB cases lived, was significantly higher than in other floors ( χ 2=49.4, 64.9 , P <0.01). Number of strong PPD positive and PPD positive students increased with TB cases in each floor of the teaching building ( r =0.84, 0.56, P <0.01).@*Conclusion@#Strong PPD positive rate well reflects tuberculosis infection of close contacts, and is recommended for defining the scope of screening.

Comparison of the effect of screening test for different tuberculin dosage forms for close contacts of tuberculosis in colleges and universities in Nanning / 中国学校卫生

Objective@#To understand the similarities and differences in different dosage forms of tuberculin test for college students having close contact with tuberculosis in Nanning colleges and universities in order to provide reference for the prevention and control of tuberculosis.@*Methods@#A total of 7 771 students were screened for symptoms and tuberculin skin test(TST)、X radiographs from 2018 to 2019 in Nanning.The used doses of Purified Protein Derivative of Tuberculin (TB-PPD) in 2018 and 2019 were 2 IU and 5 IU respectively.@*Results@#A total of 916 positive cases were detected in 2 years, with the total positive rate of 11.79%. Total strong positive number was 184 and the strong positive rate was 2.37%. The number of tuberculosis patients was 17. Positive rate of the students from grade one to grade four was 13.88%, 8.57%, 10.59%, 10.29%, respectively. The difference was statistically significant(χ 2=46.30，P＜0.01). The positive rates of male and female in the past two years were 13.24%(500/3 777) and 10.42%(416/3 994), respectively (χ 2=17.84, P<0.01)，and there was no significant difference in the diagnosis of pulmonary tuberculosis among TST positive patients (χ 2=0.29,P=0.59). The positive and strong positive rates of 2 IU dose and 5 IU dose were 7.57%, 15.04%, respectively, the difference in dosage forms were statistically significant (χ 2=114.41,P<0.01). The tuberculosis case detection rate (CDR) of moderate & above positive subjects of 2 IU and 5 IU dose was 6.92% and 2.07%, respectively, the difference was statistically significant(χ 2=6.60，P=0.02).@*Conclusion@#More positive tuberculosis cases (including moderate & strong positive) can be detected by using 5 IU dose, though it is may not have advantage over discovering tuberculosis patients comparing to 2 IU dose. However, it is more critical to minimize the following cases and control the outbreak in university.

Incidence of Latent Tuberculosis Infection in a Study of School Contacts Comparing Two Cut-off Points of the Tuberculin Test / Incidencia de infección tuberculosa latente en un estudio de contactos escolares comparando dos puntos de corte de la prueba de tuberculina

Introduction: The risk of tuberculosis infection is associated with close and prolonged contact. Daily contact, poorly ventilated classrooms or delay in diagnosing the index case in a school setting could contribute to contagion. Objective: To know the incidence of latent tuberculosis infection (LTBI) in school contacts comparing two cut-off points of the tuberculin test (PPD, Purified Protein Derivative): ≥ 10mm and ≥ 5mm. To determine the degree of compliance with the performance of control and chemoprophylaxis (ChP) studies. Materials and Methods: We carried out a retrospective analysis of bacillary TB school contacts in teenagers between 12 and 19 years old of the Programmatic Area of the Hospital Parmenio Piñero between February 2016 and December 2017. The evaluation included chest x-ray, lab tests and PPD. We analyzed 2 cut-off points of the PPD: ≥ 10mm and ≥ 5mm, and repeated the test after 3 months in cases with negative results. Primary ChP with isoniazid was indicated for all the contacts, and secondary ChP for those with basal PPD+ or conversion at the third month. We considered ChP compliance in cases where patients followed > 80% of the indicated regime. Results: 331 (89%) of 373 students to be evaluated participated in the study. TB was diagnosed in 4 students (1.2%) through chest x-ray, and they were excluded. Within the remaining 327, the mean age was 15 ± 1.6 years, and 132 (40%) were male. The basal PPD was ≥ 10mm in 20 cases (6.1%), being more frequent in the group of 16-19 years versus the 12-15 years: 10.7% vs. 3.1%; p = 0.004. There wasn't any significant difference regarding sex. 135 contacts (45%) did the second PPD, and 3 conversions were found (2.2%). Primary ChP was indicated for everyone, and secondary ChP for 23 contacts, with 75% and 26% compliance respectively, and without any significant association with age or sex. 4 adverse events were reported (1.2%): polineuritis (n=2), skin allergy and food intolerance. 63 contacts (19.3%) were positive PPD, with PPD ≥ 5mm, being more frequent in males: 26.5% vs. 14.4%, p = 0.006; and in 16-19 vs. 12-15 years: 28.2% vs. 13.2%; p < 0.001. With the second PPD we observed 3 conversions (2.2%). Conclusion: We found 6.1% of LTBI considering a PPD+ ≥ 10mm and 19.3% with PPD ≥ 5mm. Compliance with the second PPD and the secondary ChP scheme was low.

Comparação do ensaio de inteferon-gamma e teste cutâneo tuberculínico para diagnóstico de tuberculose latente em profissionais de saúde de um centro de referência terciária para tuberculose do Estado da Bahia / Comparation of the interferon gamma release assay and tuberculin skin test for diagnosis of latent tuberculosis in health professionals at a tertiary tuberculosis reference center, State of Bahia

Introdução: o Teste Cutâneo Tuberculínico (TCT) tem sido utilizado como diagnóstico para a Tuberculose Infecção Latente (TBIL). Os profissionais de saúde, principalmente os que trabalham com assistência a pacientes com tuberculose (TB), têm risco elevado de contrair a doença ou a TBIL. Normas de biossegurança e qualificação da equipe de trabalho são fundamentais para o controle da Tb entre os profissionais de saúde. Atualmente testes diagnósticos mais específicos para a TBIL têm sido utilizados como alternativa para o padronizado TCT, dentre eles o QuantiFERON-TB Gold (QTF®). Objetivo: comparar e avaliar os resultados obtidos no QTF® e Teste Cutâneo Tuberculínico dos profissionais de saúde de um centro de referência terciário para Tuberculose. Metodologia: o projeto foi aprovado pelo Comitê de Ética em Pesquisa da Fundação Bahiana Desenvolvimento Científico e pelo Comitê de Ética em Pesquisa da instituição hospitalar. Foi utilizado o banco de dados do setor de medicina ocupacional da Instituição e os 87 voluntários que atenderam aos critérios do estudo foram categorizados e distribuídos em dois grupos: TCT negativo (<5mm) e TCT positivo (>5mm). Foi realizada coleta de sangue para o teste QTF®. Resultados: dos 47 profissionais de saúde TCT negativo 53,2% tiveram resultado QTF negativo. Dos 40 profissionais TCT positivo, 67,5% apresentaram resultado QTF® positivo. O grau de concordância do índice kappa foi de 0,24. Conclusão: O QTF® não mostrou uma especificidade superior quando comparado ao TCT.

Introduction: tuberculin Skin test (TST) is a test used to Latent tuberculosis Infection (LTBI) diagnosis. Health professional, principally those that work with tuberculosis (TB) patients, have a high risk of contract and developing the disease or LTBI. Biosecurity norms and professional qualification are fundamentals to TB control in care centers. Actually some diagnosis tests with higher specificity of LTBI are used as an alternative to the TST, such as QuantiFERON-TB Gold (QTF®). Objective: to compare and evaluate the results obtained in the Quantiferon-TB Gold® and TST, of health professionals from a tertiary referral center for Tuberculosis. Methodology: the project was approved by a Research Ethics Committee of FBDC, and by the CEP of the hospital institution. The data base of the occupational medicine sector and the health professionals were categorized and distributed in two groups: Negative Tuberculin test and Positive Tuberculin test. The 93 volunteers who met the criteria and agreed to participate, signed the consent form, with subsequent data collection. A blood collection was also performed to perform Quantiferon-TB Gold® test. Results: of the 47 PS negative Tuberculin test, 53.2% had negative Quantiferon-TB Gold® results and 46.8% positive. Of the health professional positive Tuberculin test, 32.5% presented negative Quantiferon-TB Gold® result and 67.5% positive. Conclusion: quantiferon-TB Gold® did not show superior specificity when compared to Tuberculin test on this coorte.

Diagnostic performance of a commercial ELISA used as a complementary test for bovine tuberculosis in two bovine herds with different disease status / Desempenho diagnóstico de um ELISA comercial usado como teste complementar para tuberculose bovina em dois rebanhos bovinos com diferentes estágios de controle da doença

Bovine tuberculosis is a worldwide spread zoonotic disease. Intradermal tuberculinizations are the most used diagnostic tests in the world. Serological tests can be an ancillary diagnosis for bovine tuberculosis. The objective of this study was to evaluate the diagnostic performance of the ELISA Mycobacterium Bovis Antibody Test Kit IDEXX ™ in infected herds, which were in different disease control stages. One hundred and twenty animals from two dairy herds of Minas Gerais state, Brazil, were subjected to the ELISA serological test and the comparative cervical tuberculin test (CCT). Diagnostic test parameters were estimated using Bayesian latent class models and concordance between tests estimated by the frequentist approach. The ELISA test presented lower sensitivity than CCT in both herds. Its sensitivity was higher in the herd in sanitation process. Specificity estimates were above 95% in both herds. Kappa index indicated low concordance or even disagreement between tests. According to the results, the ELISA IDEXX should not be used as substitution for CCT. The tests must not be associated in series. Parallel association increased diagnostic sensitivity in the herd which was in the process of sanitation.(AU)

A tuberculose bovina é uma zoonose de distribuição mundial cujos testes mais utilizados para o diagnóstico são as tuberculinizações intradérmicas, simples e compartivas. Contudo, testes sorológicos podem constituir diagnósticos auxiliares. O objetivo deste estudo foi avaliar o desempenho diagnóstico do teste ELISA Mycobacterium Bovis Antibody Test Kit IDEXX ® em rebanhos bovinos infectados, que se encontravam em diferentes estágios de controle da doença. Cento e vinte animais de dois rebanhos leiteiros provenientes do estado de Minas Geais-Brasil foram submetidos ao ELISA e à tuberculinização cervical compartiva (TCC). Avaliou-se o desempenho dos testes por meio de modelos Bayesianos de classe latente e a concordância entre os eles, por meio de estatística frequentista. Uma maior sensibilidade do teste foi observada no rebanho previamente tuberculinizado. Em ambos os rebanhos o TCC foi mais sensível que o ELISA. Especificidade acima de 95% foi encontrada em ambos os rebanhos. Foram observadas baixa concordância ou mesmo discordância entre os testes. De acordo com os resultados obtidos, o teste ELISA-IDEXX não deve ser utilizado em substituição à TCC, tampouco devem ser associados em série. Houve aumento da sensibilidade quando os testes foram associados em paralelo no rebanho que já se encontrava em processo de saneamento.(AU)

Risk of infection and disease progression in children exposed to tuberculosis at home, Colombia / Riesgo de infección y progresión de la enfermedad en niños expuestos a tuberculosis en el hogar, Colombia

Abstract Aim: To assess the risk of tuberculosis (infection and disease) in children less than 15 years' old who are household contacts of pulmonary tuberculosis patients in three Colombian cities (Medellín, Cali, and Popayán). Methods: A cohort of 1,040 children household contacts of 380 adults with smear-positive pulmonary tuberculosis was followed up for 24 months. Study period 2005-2009. Results: Tuberculin skin test was positive (≥10 mm) in 43.7% (95% CI: 39.2-48.2). Tuberculin skin test positivity was associated with age 10-14 years (Prevalence Ratio -PR= 1.43, 95% CI: 1.1-1.9), having a BCG vaccine scar (PR= 1.52, 95% CI: 1.1-2.1), underweight, closer proximity to the index case and exposure time >3 months. The annual risk of infection (tuberculin skin test induration increase of 6 mm or more per year) was 17% (95% CI: 11.8-22.2) and was associated with a bacillary load of the adult index case (Relative Risk -RR= 2.12, 95% CI: 1.0-4.3). The incidence rate of active tuberculosis was 12.4 cases per 1,000 persons-year. Children <5 years without BCG vaccine scar had a greater risk of developing active disease (Hazard Ratio -HR= 6.00, 95% CI: 1.3-28.3) than those with scar (HR= 1.33, 95% CI: 0.5-3.4). The risk of developing active tuberculosis augmented along with the increase from initial tuberculin skin test (tuberculin skin test 5-9 mm HR= 8.55, 95% CI: 2.5-29.2; tuberculin skin test ≥10 mm HR= 8.16, 95% CI: 2.0-32.9). Conclusions: There is a need for prompt interruption of adult-to-children tuberculosis transmission within households. Conducting proper contact investigation and offering chemoprophylaxis to infected children could reduce tuberculosis transmission.

Resumen Objetivo: Evaluar el riesgo de tuberculosis (infección y enfermedad) en niños menores de 15 años de edad convivientes de pacientes con tuberculosis pulmonar en tres ciudades colombianas (Medellín, Cali y Popayán). Métodos: Se siguió durante 24 meses una cohorte de 1,040 niños convivientes de 380 adultos con tuberculosis pulmonar bacilífera. Periodo de estudio 2005-2009. Resultados: La prueba de tuberculina fue positiva (≥10 mm) en el 43.7% (IC 95%: 39.2-48.2), y estuvo asociada con la edad de 10-14 años (Razón de Prevalencia-RP= 1.43, IC 95%: 1.1-1.9), tener cicatriz de la vacuna BCG (RP= 1.52, IC 95%: 1.1-2.1). El riesgo anual de infección (aumento de la induración en la prueba de tuberculina de 6 mm o más al año) fue 17% (IC 95%: 11.8-22.2), y estuvo asociado con mayor carga bacilar en el adulto con tuberculosis pulmonar (Riesgo Relativo-RR= 2.12, IC 95%: 1.0-4.3). La tasa de incidencia de tuberculosis activa fue de 12.4 casos por 1,000 años-persona de seguimiento. Los niños menores de 5 años sin cicatriz de vacuna BCG tuvieron un mayor riesgo de desarrollar tuberculosis activa (Razón de Peligro -HR= 6.00, IC 95%: 1.3-28.3), que quienes tenían cicatriz (HR= 1.33, IC 95%: 0.5-3.4). El riesgo de desarrollar tuberculosis activa aumentó conforme el aumento de la prueba de tuberculina inicial (prueba de tuberculina 5-9 mm HR= 8.55, IC 95%: 2.5-29.2; prueba de tuberculina ≥10 mm HR= 8.16, IC 95%: 2.0-32.9). Conclusión: Es necesario interrumpir rápidamente la transmisión de tuberculosis de adultos a niños en los hogares. Realizar investigaciones de contacto apropiadas y ofrecer quimioprofilaxis a los niños infectados podría reducir la transmisión de la tuberculosis.

Unilateral acute posterior multifocal placoid pigment epitheliopathy in a patient with a strongly positive purified protein derivative test / Epiteliopatia pigmentar placóide multifocal posterior aguda unilateral na presença de reação forte positiva para o teste tuberculínico

ABSTRACT A 27-year-old man presented with a complaint of decreased visual acuity in the right eye. Best-corrected visual acuity was 20/60 in the right eye and 20/20 in the left eye. Right eye fundoscopy revealed mild vitritis, multifocal yellowish lesions, and macular serous retinal detachment. Left eye evaluation was normal. Acute posterior multifocal placoid pigment epitheliopathy was diagnosed in the right eye. Complementary exams revealed a strong reaction to the Mycobacterium tuberculosis purified protein derivative test, thus treatment for tuberculosis was initiated. Baseline fluorescein angiography of the right eye revealed early hypofluorescence and late staining of the lesions. Optical coherence tomography of the right eye demonstrated the accumulation of subretinal and intraretinal fluid associated with cystoid macular edema. During follow-up, the retinal fluid and cysts disappeared, which was followed by disorganization of foveal interdigitation and ellipsoid zones. This is the second described case of unilateral acute posterior multifocal placoid pigment epitheliopathy in a patient with a strong positive result to the M. tuberculosis purified protein derivative test.

RESUMO Um homem de 27 anos apresentou uma queixa de diminuição da acuidade visual no olho direito. A acuidade visual melhor corrigida foi 20/60 no olho direito e 20/20 no olho esquerdo. A fundoscopia do olho direito revelou vitreíte leve, lesões amareladas multifocais e descolamento seroso da retina em região macular. A avaliação do olho esquerdo foi normal. Epiteliopatia pigmentar placóide multifocal posterior aguda foi diagnosticada no olho direito. Os exames complementares revelaram forte reação ao teste do derivado proteico purificado Mycobacterium tuberculosis, iniciando terapia antibiótica contra tuberculose. A angiografia fluoresceínica basal do olho direito revelou hipofluorescência precoce e tardia das lesões. A tomografia de coerência óptica do olho direito demonstrou fluído sub- e intrarretiniano associado a edema macular cistóide. Durante o seguimento, os fluídos e cistos retinianos desapareceram, seguido da desorganização das zonas de interdigitação e elipsóide em região foveal. Este é o segundo caso descrito de epiteliopatia pigmentar placóide multifocal posterior aguda unilateral em um paciente com um forte resultado positivo para o teste tuberculínico.

Diagnosis of Latent Tuberculosis Infection: Comparison between the Tuberculin Test and Quantiferon-TB Gold Plus in Household Contacts from the City of Buenos Aires / Diagnóstico de infección tuberculosa latente: comparación de la prueba de tuberculina y el quantiferon-tb gold plus en contactos domiciliarios de la Ciudad de Buenos Aires

The epidemiological control strategy of tuberculosis (TB) includes both the diagnosis and early treatment of baciliferous patients and the identification of individuals with latent tuberculosis infection (LTBI), who represent the pathogen reservoir within the population. Objective: To compare the results obtained using the tuberculin test (PPD, Purified Protein Derivative) and the QuantiFERON-TB Gold Plus (QTF) in a group of household contacts of patients with bacillary pulmonary TB in the city of Buenos Aires. We used two cutoff points to consider PPD as positive: ≥ 5 mm (PPD-5) and ≥ 10 mm (PPD-10). Materials and Methods: Blood samples for QTF were taken from household contacts of patients with bacillary TB, followed immediately by the application of PPD. The QTF was considered as the reference test from which to compare the PPD by calculating sensitivity (S), specificity (E), positive predictive value (PPV), negative predictive value (NPV) and Kappa correlation coefficient. Results: 48 contacts were included (33 women, 69%), age 38.8 ± 19 years, 27 (56%) Argentinean, 18 (38%) Bolivians and 3 (6%) Peruvians, 37 were cases of TB. Only one contact informed She/she hadn't received the BCG; and 44 subjects showed the BCG scar. The QTF was positive in 23 individuals (47.9%) and undetermined in 2 cases (4.2%). Excluding the indeterminate cases from the analysis, there were no significant differences between positive and negative QTF contacts regarding age (33.8 ± 16 vs. 42.1 ± 20 years), nationality: Argentinean (12 of 26.46%) vs. foreigners (11 of 20.55%) and sex: women (18 of 32, 56%) vs. men (5 of 14, 36%). There were 28 (60.9%) positive cases with PPD-5 and 13 (28.3%) with PPD-10. Comparison between PPD-5 vs. PPD-10: S = 73.9 vs. 34.8%, E = 52.2 vs. 78.3%, PPV = 60.1 vs. 61.5% and NPV = 66.7 vs. 54.5%. The coincident results (positive and negative) between QTF and PPD were 29 (63%) for PPD-5 and 26 (56.5%) for PPD-10. Expressed with the Kappa coefficient, they show weak (0.261) and insignificant (0.130) concordance, respectively. Conclusions: Considering the QTF as the reference method for its higher specificity, PPD-5, although less specific, was more sensitive than PPD-10 for the diagnosis of latent tuberculosis infection in the group of household contacts under study.

​Interpretation And Clinical Correlation Of Tuberculin Skin Test Results Among Clinically Diagnosed Childhood Tuberculosis

Background: Diagnosing tuberculosis (TB) was still a worldwide big challenge in cases with negative reports of Xpert MTB/RIF, smear, and culture test of acid-fast bacilli (AFB). A single, direct Xpert MTB/RIF test identified 98.2% of the sputum smearpositive TB cases and 72.5% of those with sputum smear-negative TB. Such a diagnosis was often made based on the clinicalcriteria and other supportive findings like tuberculin skin test (TST).Objective: Hence, this study was to help in the diagnosis and treatment of clinically diagnosed childhood TB, especially in thelimited resource rural areas and developing countries.Materials and Methods: Based on the WHO revised criteria of TB diagnosis, to include clinically diagnosed TB instead ofsmear-negative TB disease, an operational definition of clinically diagnosed TB for the selection of participants for TST wasestablished for this study. Based on the recommendation of the CDC team at the Saskatchewan Lung Association, 2007-03-21at the Wayback Machine, the TST results of the study were interpreted.Results: Hence, in our study, the sensitivity of TST was 82.35% (≥10 mm) in the age group of 1–4 years and 60.16% (≥15 mm)in the age group of >4–12 years. However, this study shows that the positivity rate of TST was increased from 60.16% (≥15 mm)to 86.15% (≥10 mm), if the TST results≥10 mm were interpreted as positive even in this age group of >4 years–12 years.Conclusion: In such very difficult situations of clinically diagnosed TB, this study observed that empiric anti-TB treatment may bestarted without microbiological confirmation to clinically diagnosed childhood TB patient with negative reports of Xpert MTB/RIF,smear, and culture test of AFB, presented with one or more of the following symptoms and signs of clinically diagnosed childhoodTB: (1) Chronic anorexia, (2) ill health and fatigue, (3) weight loss of >5% during the past 3 months or documented failure to striveduring the preceding 3 months, (4) night sweating and persistent fever >2 weeks, and (5) non-remitting cough >2 weeks but cannot bediagnosed clinically by any possible causes than TB, and positive TST report, in resource-limited rural areas anddeveloping countries.