Prevalencia de infección tuberculosa latente e incidencia de viraje tuberculínico en contactos escolares mayores de 5 años en la Ciudad Autónoma de Buenos Aires / Prevalence of latent tuberculosis infection and incidence of tuberculin conversion among school contacts older than 5 years in the City of Buenos Aires

Introducción. La tuberculosis continúa siendo un problema frecuente en contextos de vulnerabilidad socioeconómica. El objetivo principal fue establecer la prevalencia de infección latente y viraje tuberculínico en contactos escolares de casos de tuberculosis. Población y métodos. En un área programática del sur de la ciudad, se evaluó la prevalencia de infección y viraje tuberculínico de 691 niñas, niños y adolescentes utilizando la prueba cutánea de tuberculina. Se investigó la asociación entre pérdida de seguimiento por parte del equipo de salud y características demográficas, escolares y asistencia inicial, y se describió el grado de adherencia cuando la quimioprofilaxis con isoniacida fue indicada. Resultados. Según las definiciones consideradas, la prevalencia de infección latente fue entre el 3,4 % (IC95 %: 2,3-5,2) y el 11,6 % (IC95 %: 9,3-14,4) de los 610 contactos con al menos una prueba cutánea aplicada. La incidencia de viraje tuberculínico se encontró entre el 0,3 % y el 6,8 % de los 294 evaluados. La edad mayor de 18 años, la mayor prevalencia de necesidades básicas insatisfechas en la comuna escolar, la pertenencia al turno escolar vespertino, la negatividad en la baciloscopia del caso índice y la ausencia de aplicación de la prueba cutánea inicial se asociaron con pérdida de seguimiento del contacto. Conclusiones. La incidencia de viraje tuberculínico en contactos escolares fue baja. La adherencia a isoniacida continúa siendo limitada. Se identificaron factores asociados con la pérdida de seguimiento de contactos que podrían orientar estrategias necesarias para mejorar este proceso.

Introduction. Tuberculosis continues to be a common problem in settings of socioeconomic vulnerability. Our primary objective was to establish the prevalence of latent infection and tuberculin conversion among school contacts of tuberculosis cases. Population and methods. In a programmatic area in the south of the City of Buenos Aires, the prevalence of latent infection and tuberculin conversion was assessed in 691 children and adolescents using the tuberculin skin test. The association between loss to follow-up by the health care team and the demographic, school, and baseline care characteristics was studied, and the level of adherence when isoniazid chemoprophylaxis was indicated was described. Results. According to established definitions, the prevalence of latent infection was between 3.4% (95% confidence interval [CI]: 2.3­5.2) and 11.6% (95% CI: 9.3­14.4) in the 610 contacts with at least one skin test. The incidence of tuberculin conversion was between 0.3% and 6.8% in the 294 assessed participants. Age older than 18 years, a higher prevalence of unmet basic needs in the school district, attending the afternoon school shift, negative sputum smear results in the index case, and absence of baseline skin test were associated with contact lost to follow-up. Conclusions. The incidence of tuberculin conversion among school contacts was low. Adherence to isoniazid treatment remains limited. Factors associated with loss of contact tracing were identified, which may guide strategies necessary to improve this process.

Diagnosis of goat tuberculosis using tuberculinization and molecular techniques

Tuberculosis is an infectious, chronic, and worldwide disease. It has been known since the beginning of humanity and still negatively influences public health and livestock, especially, in Brazil, in the northeast. Etiologic agents are the mycobacteria of the Mycobacterium tuberculosis complex, which is the most important in mammals' involvement. The state of Bahia has 68.7% of its territory located in the semiarid region and holds the largest goat herd in the country. Goat breeding is a social and economic activity that adds value to this region. Up to the present, data on goat tuberculosis is unknown in this state. Thus, this study seeks data on tuberculosis prevalence in goats in a semiarid region of Bahia by using the comparative tuberculin test and multiplex polymerase chain reaction (PCR). A total of 600 adult animals of both sexes were evaluated. A prevalence of 0.33% (2/600) and 33.33% (1/3) properties were found for positive animals. Each assessed property had a questionnaire to analyze the epidemiological data management and relevant aspects for the disease occurrence. To confirm the positive tuberculin test results, PCR was used to detect and identify the pathogenic mycobacteria involved in the infection. It is concluded that most of the properties performing goat breeding in the region show low technification levels and promote farming between different species. Low prevalence of the disease alerts preventive measures to avoid major proportion situations that could influence the goat breeding in the state.

Frequency of anergy in a group of patients with rheumatoid arthritis on immunosuppressive therapy / Frecuencia de anergia en un grupo de pacientes con artritis reumatoide y terapia inmunosupresora

ABSTRACT Background: Tuberculin is the globally accepted delayed cutaneous hypersensitivity test for the diagnosis of latent tuberculosis. The alteration of cellular immunity induced by disease-modifying drugs used in rheumatoid arthritis may give a false negative result, also known as cutaneous anergy. There are no studies that determine the frequency of anergy in patients with rheumatoid arthritis and on immunosuppressive therapy. Objective: To determine the frequency and possible factors associated with cutaneous anergy in a group of patients with rheumatoid arthritis and on immunosuppressive therapy. Methods: Cross-sectional analytical observational study including 100 patients with rheumatoid arthritis on immunosuppressive therapy. They were tested for delayed cutaneous hypersensitivity with tuberculin, and a control test with tetanus toxoid. The non-reactivity of both tests was defined as anergy. Results: The overall frequency of cutaneous anergy was 9% (n = 11). It occurred in 33% of men versus 6% of women. The mean age was 57 years, and 89% were over 50 years-old. Being female behaved as a protective variable for the generation of anergy, OR 0.795 [95% CI, 0.658 - 0.959, P<.05]. All patients with anergy were being treated with corticosteroids, 44% with methotrexate, and 33% with biological therapy. Treatment with moderate to high dose prednisone and biological therapy were independently associated as risk factors for presenting with anergy, OR 1.044 [95% CI, 1.008-1.080 P<.05] and OR 1.096 [95% CI, 1.016-1.182, P<.05], respectively. The overall positivity for tuberculin was 13%. Symptoms associated with disease activation were present in 38% of these. All cases (n= 1) of confirmed active tuberculosis were excluded. Conclusions: The high prevalence of cutaneous anergy in patients with RA in the present study, and the evidence presented here, supports the recommendation of a second diagnostic test (tuberculin booster or Interferon-Gamma Release Assays) for the diagnosis of latent TB in patients with RA on immunosuppressive therapy.

RESUMEN Antecedentes: La tuberculina es la prueba de hipersensibilidad cutánea tardía mundialmente aceptada para el diagnóstico de tuberculosis latente. La alteración de la inmunidad celular inducida por los fármacos modificadores de la enfermedad utilizados en la artritis reumatoide puede dar un resultado falso negativo, también conocido como anergia cutánea. No hay estudios que determinen la frecuencia de anergia en pacientes con artritis reumatoide y terapia inmunosupresora. Objetivo: Determinar la frecuencia y los posibles factores asociados con la anergia cutánea en un grupo de pacientes con artritis reumatoide y terapia inmunosupresora. Métodos: Estudio observacional analítico transversal que incluyó a 100 pacientes con artritis reumatoide con terapia inmunosupresora. Se les realizó una prueba de hipersensibilidad cutánea tardía con tuberculina y una prueba de control con toxoide tetánico. La no reactividad de ambas pruebas se definió como anergia. Resultados: La frecuencia general de anergia cutánea fue del 9% (n = 11). Ocurrió en el 33% de los hombres versus el 6% de las mujeres, la edad promedio fue de 57 anos y el 89% tenía más de 50 anos. El sexo femenino se comportó como una variable protectora para la generación de anergia (OR 0,795; IC 95%: 0,658-0,959; p < 0,05). Todos los pacientes con anergia usaron corticosteroides, el 44% fue tratado con metotrexato y el 33% con terapia biológica. El tratamiento con dosis de moderadas a altas de prednisona y terapia biológica se asoció de manera independiente como factor de riesgo para la presentación de anergia: OR 1,044 (IC 95%: 1,008-1,080; p < 0,05) y OR 1,096 (IC 95%: 1,016-1,182; p < 0,05), respectivamente. La positividad general para la tuberculina fue del 13%. Los síntomas asociados con la activación de la enfermedad estaban presentes en el 38% de ellos. Se excluyeron todos los casos de tuberculosis activa confirmada (n = 1). Conclusiones: La alta prevalencia de anergia cutánea en pacientes con artritis reumatoide en el presente estudio y la evidencia presentada respaldan la recomendación de una segunda prueba de diagnóstico (refuerzo de tuberculina o IGRA) para el diagnóstico de tuberculosis latente en pacientes con artritis reumatoide y terapia inmunosupresora.

A double-blind, randomized controlled trial on the efficacy and safety of intralesional 2% zinc sulfate in the treatment of verruca vulgaris in a tertiary hospital

Background@#Verruca vulgaris ranked 10th in the top 10 diseases in 2019 seen among the Philippine Dermatological Society training institutions. The efficacy of immunotherapy, such as intralesional zinc sulfate (ZS), for warts were reported. Considering the limited studies with promising results on verruca, a study on the efficacy and safety of intralesional zinc in the treatment of verruca was considered.@*Objective@#This study aims to determine the efficacy and safety of intralesional 2% ZS in comparison to intralesional purified protein derivative (PPD) among adult patients with verruca vulgaris.@*Methods@#This is a double-blind, randomized, controlled trial involving 44 patients allocated to group ZS (n=22) and PPD (n=22). Intralesional injections of ZS or PPD to the largest wart were done at weeks 0, 2, 4, 6, 8, 10. Clearance and size reduction of the target and distant wart at 12th week and recurrence at 14th week were assessed. Adverse effects were checked.@*Results@#At the 12th week of treatment, higher proportion in group ZS patients achieved total resolution of the target lesion compared to PPD, but results were not statistically significant (29% vs. 19%). Both groups showed decline in the target lesion size. The median size reduction between the two groups showed no significant differences. Three patients from group ZS showed clearance of distant warts while none in group PPD. There was no recurrence of all previously resolved warts. Adverse reactions were pain, edema, and erythema.@*Conclusion@#Intralesional 2% zinc sulfate (29%) was efficacious and safe compared to Intralesional PPD (19%) but the difference was not statistically significant. There was clearance of distant warts in 5% of group ZS patients. The mild adverse events did not warrant discontinuation of treatment.

La lectura de la reacción tuberculínica: un tema controversial / Reading the Tuberculin Reaction: A Controversial Issue

Roberto Koch, en 1882 demuestra la etiología de la TB y años después (1890) propone en el 10° Congreso Internacional de Medicina de Berlín la tuberculina como un "remedio" para la enfermedad. No funcionó, pero nos legó la denominada posteriormente tuberculina bruta o antigua (OT, old tuberculin) que se usó durante años como diagnóstico de infección por Mycobacterium tuberculosis y fue reemplazada por el Derivado Proteico Purificado (PPD) desarrollado por Florencia Seibert en 1934. La técnica de aplicación intradérmica de Mantoux (1908), sigue aún vigente

Tubercúlide papulonecrótica: um relato de caso / Papulonecrotic tuberculids: a case report / Tubercúlide papulonecrótica: un informe de caso

As tubercúlides são reações de hipersensibilidade cutânea aos antígenos do Mycobacterium tuberculosis. Este é o caso de uma mulher de 45 anos que procurou a Unidade Básica de Saúde (UBS) com um quadro de eritema nodoso com mais de 10 anos de evolução, de etiologia desconhecida, e que evoluía como nódulos em pescoço e membros, que se tornavam úlceras necróticas, cicatrizavam e recidivavam periodicamente. Biópsias das lesões evidenciavam um processo inflamatório granulomatoso com extensa necrose, sugestivo de tuberculose, mas sem a presença do bacilo. Após anos sem tratamento adequado, finalmente levantou-se a hipótese de tubercúlide papulonecrótica. A paciente iniciou tratamento com o esquema básico (2RHZE/4RH) e dessensibilização vacinal, recebendo alta por cura.

Las tubercúlides son reacciones de hipersensibilidad cutánea a los antígenos del Mycobacterium tuberculosis. Este es el caso de una mujer de 45 años que buscó la Unidad Básica de Salud (UBS) con un cuadro de eritema nodoso con más de 10 años de evolución, de etiología desconocida, y que evolucionaba como nódulos en cuello y miembros, que se tornaban úlceras necróticas, cicatrizaban y recidivaban periódicamente. Las biopsias de las lesiones evidenciaban un proceso inflamatorio granulomatoso con una extensa necrosis, sugestiva de tuberculosis, pero sin la presencia del bacilo. Después de años sin tratamiento adecuado, finalmente se levantó la hipótesis de tubercúlide papulonecrótica. La paciente inició tratamiento con el esquema básico (2RHZE / 4RH) y desensibilización vacunal, recibiendo alta por curación

The tuberculids are cutaneous hypersensitivity reactions to Mycobacterium tuberculosis antigens. This is the case of a 45-year-old woman who sought the Basic Health Unit (BHU) with erythema nodosum with a 10-year evolution, of unknown etiology, that evolved as nodules in the neck and limbs, which became necrotic ulcers, cicatrized and recurred periodically. Biopsies of the lesions revealed a granulomatous inflammatory process with extensive necrosis, suggestive of tuberculosis, but without the presence of the bacillus. After years without adequate treatment, the hypothesis of papulonecrotic tuberculids finally arose. The patient started treatment with the basic regimen (2RHZE/4RH) and vaccine desensitization, receiving discharge by cure.

Characteristic profile of antibody responses to PPD, ESAT-6, and CFP-10 of Mycobacterium tuberculosis in pulmonary tuberculosis suspected cases in Surabaya, Indonesia

Abstract Accurate and rapid diagnostic tools are important aspects of managing tuberculosis (TB) cases appropriately. However, the sensitivity and specificity of diagnostic kits based on immune response such as the tuberculin skin test (TST) and interferon gamma release assay (IGRA) are still debated. Thus, the exploration and assessment of specific biomarker-targeted antibodies are needed for the development of an accurate and rapid diagnostic tool. The present study was conducted in patients with a respiratory problem suspected to be TB at Dr. Soetomo Hospital, Surabaya, Indonesia. Among 102 patients tested by GeneXpert and AFB, 59 serum samples were from cases retrospectively determined to have active TB. A total of 102 serum of healthy controls (HC) was also collected. The PPD antigen and the recombinant CFP-10 and ESAT-6 proteins were prepared. Antibody responses against these proteins were evaluated by ELISA. All samples were also screened for the possibility of Mycobacterium avium-intracellulare complex (MAC) infection using Capilla MaC kit. The results showed that TB patients had a significantly higher concentration of IgG antibody in response to PPD than the HC. In addition, the receiver operating characteristic (ROC) curve analysis showed that PPD was acceptable for diagnostic purposes with an AUC value of 0.835 (95% CI 0.770-0.900, p < 0.0001). However, ESAT-6 and CFP-10 had low AUCs, and 32 samples from both groups showed a low concentration of IgA antibody against all antigens. The MAC detection results also showed that the concentration of IgA in the HC group was the highest. The current results indicate that PPD is a better antigen for antibody-based detection of TB than ESAT-6 and CFP-10. Based on the MAC detection assay, 53 people in the HC group were probably infected with rapidly growing nontuberculous mycobacteria (NTM), although antibody response to PPD was low.

Potencial do teste IGRA (Interferon Gama Release Assay) para o diagnóstico de tuberculose ocular. Revisão e análise comparativa com o teste tuberculínico cutâneo (PPD) / The potential of the IGRA (Interferon Gamma Release Assay) test for the diagnosis of ocular tuberculosis. Review and comparative analysis with the tuberculosis skin test

Resumo A detecção precisa da infecção latente por tuberculose está se tornando cada vez mais importante devido ao aumento do uso de medicamentos imunossupressores e da epidemia do vírus da imunodeficiência humana, o que aumentou o risco de reativação à tuberculose ativa (TB). O Teste IGRA QuantiFERON® TB Gold apresenta vantagens frente ao teste de PPD como por exemplo, requer somente uma coleta de amostra sanguínea ; não há necessidade que o paciente retorne ao laboratório para leitura e interpretação dos resultados; Os resultados são objetivos, não requerem interpretação do leitor ou interferência de critérios subjetivos; trata-se de um teste in vitro, portanto não há "efeito booster" (potenciação da reação tuberculínica); o teste não é afetado por vacinação prévia por BCG ou infecção por outras espécies de micobactérias. Limitações são descritas, apesar de raras, como reações cruzadas deste método com infecções por algumas espécies de micobactérias não-tuberculosis (incluindo Mycobacterium kansasii, Mycobacterium szulgai e Mycobacterium marinum). Ainda há poucos dados sobre o teste IGRA em certas populações, como por exemplo, em crianças, pacientes imunocomprometidos e mulheres grávidas. Nestes grupos, a interpretação do teste pode ser difícil e mais estudos se fazem necessários.

Abstract Precise detection of latent tuberculosis infection is becoming increasingly important due to increased use of immunosuppressive drugs and the human immunodeficiency virus epidemic , which increased the risk of reactivation to active tuberculosis (TB).The QuantiFERON® TB Gold IGRA Test has advantages over the skin test for TB, otherwise known as a Mantoux tuberculin test, for example, requires only a blood sample collection; there is no need for the patient to return to the laboratory for reading and interpretation of the results; The results are objective, do not require interpretation of the reader or interference of subjective criteria; it is an in vitro test, so there is no "booster effect" (potentiation of the tuberculin reaction); the test is not affected by prior BCG vaccination or infection with other species of mycobacteria. Limitations are described, although rare, as cross-reactions of this method with infections by some species of non-tuberculosis mycobacteria (including Mycobacterium kansasii, Mycobacterium szulgai and Mycobacterium marinum). There is still little data on the IGRA test in certain populations, such as in children, immunocompromised patients and pregnant women. In these groups, the interpretation of the test can be difficult and more studies are needed.

Diagnosis and treatment of latent tuberculosis infection

In order to eliminate tuberculosis worldwide by 2050, effective management of latent tuberculosis infection is essential, and policy-makers have begun to recognize the importance of scaling up preventive therapy. The current guideline recommends targeted latent tuberculosis infection testing that identifies high-risk groups based on risk stratification for progression from latent infection to active disease. Both the tuberculin skin test and interferon-gamma releasing assay have a similar diagnostic efficacy for predicting progression to active tuberculosis. The Korean guideline recommends 9-month isoniazid monotherapy as the standard treatment; however, more evidence supports that short course rifampicin-based regimen is both more effective and tolerable than isoniazid monotherapy.

Proposal to Revise the Screening Test for Latent Tuberculosis Infection in Close Contacts at Elementary Schools in Korea / 예방의학회지

The 2018 National Guideline for Tuberculosis Control, which was published by the Korea Centers for Diseases Prevention and Control (KCDC), mandates conducting an epidemiological survey among close contacts of active tuberculosis patients at public institutions such as schools. In the procedure for these surveys, the tuberculin skin test (TST) is mandated as the screening test for latent tuberculosis infection in elementary school students. However, several guidelines recommend using the interferon-gamma releasing assay (IGRA) for contacts aged over 5 years with a Bacillus Calmette–Guérin vaccination history. The main reason for this is that IGRA has a higher specificity and lower false positive rate than TST. In addition, IGRA requires only a single visit to draw blood and the results are available within 24 hours. These advantages could promote cooperation from both parents and students in conducting these surveys. Thus, these findings regarding the benefits of IGRA for surveys of close contacts at elementary schools should be incorporated into the KCDC guideline.

The Infectivity of Pulmonary Tuberculosis in Korean Army Units: Evidence from Outbreak Investigations / 결핵

BACKGROUND: Tuberculosis (TB) causes substantial health burden to the Korean military. This study aims to assess the impact of infectious TB cases on close and casual contacts in the Korean Army settings based on contact investigation data. METHODS: Six Army units with infectious TB cases from September 2012 to May 2013 were enrolled in the study. We analyzed the clinical data from close and casual contacts screened using the tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube to identify latent tuberculosis infection (LTBI) cases. For the control group, 286 military conscripts with no reported TB exposure were tested by TST only. RESULTS: Of the 667 contacts of index cases, LTBI cases identified were as follows: 21.8% of close contacts of smear-positive cases (71/326), 8.5% of casual contacts of smear-positive cases (26/305), and 2.8% of close contacts of smear-negative cases (1/36). In the control group, 16.8% showed positivity in TST. In a multivariate analysis, having stayed in the same room or next room with TB patients was identified as a risk factor of LTBI. CONCLUSION: Using the data from TB contact investigations in the Korean Army units, we found an overall LTBI rate of 14.7% among the contacts screened. This study demonstrates that contacts living in the same building, especially the same room or next room, with TB patients are at a high risk of acquiring LTBI, serving as additional evidence for defining close and casual contacts of a TB patient with regard to Army barrack settings.

Experiences of Latent Tuberculosis Infection Treatment for the North Korean Refugees / 결핵

BACKGROUND: Tuberculosis (TB) is increasing in immigrants. We aimed to investigate the current status of latent tuberculosis infection (LTBI) treatment for North Korean Refugees (NKR) compared to South Koreans Contacts (SKC). METHODS: TB close contacts in a closed facility of SKC and NKR who underwent LTBI screening in a settlement support center for NKR were analyzed retrospectively. RESULTS: Among tuberculin skin test (TST) ≥10 mm (n=298) reactors, the males accounted for 72.2% in SKC (n=126) and 19.5% in NKR (n=172) (p<0.01). The mean age was higher in South Korea (42.8±9.9 years vs. 35.4±10.0 years, p<0.01). Additionally, the mean TST size was significantly bigger in NKR (17.39±3.9 mm vs. 16.57±4.2 mm, p=0.03). The LTBI treatments were initiated for all screened NKR, and LTBI completion rate was only 68.0%. However, in NKR, LTBI treatment completion rate was significantly increased by shorter 4R regimen (odds ratio [OR], 9.296; 95% confidence interval [CI], 4.159–20.774; p<0.01) and male (OR, 3.447; 95% CI, 1.191–9.974; p=0.02). CONCLUSION: LTBI treatment compliance must be improved in NKR with a shorter regimen. In addition, a larger study regarding a focus on LTBI with easy access to related data for NKR should be conducted.

Good Agreement between an Interferon Gamma Release Assay and Tuberculin Skin Tests in Testing for Latent Tuberculosis Infection among HIV-Infected Patients in Indonesia

BACKGROUND: Latent tuberculosis infection is a condition where there is a persistent immune response to Mycobacterium tuberculosis without clinical manifestations of tuberculosis. Currently, there is no gold standard to diagnose latent tuberculosis infection. The tuberculin skin test and interferon-gamma release assay are currently used to diagnose latent tuberculosis infection. However, studies have shown inconsistencies regarding the level of agreement between these tests in different settings. In this study, we aimed to evaluate the agreement between these two tests for diagnosing latent tuberculosis infection in human immunodeficiency virus (HIV)-infected individuals. METHODS: We screened HIV patients with no clinical symptoms of tuberculosis, a normal chest X-ray, and no history of tuberculosis or use of antituberculous drugs. Participants were tested with tuberculin skin test (TST) and T-SPOT.TB (an interferon gamma release assay) simultaneously. Participants' HIV stage was determined by measuring the level of CD4+ T-lymphocytes. Tuberculosis status was confirmed by sputum examination using GeneXpert. The level of agreement between the TST and T-SPOT.TB results was measured using Cohen's κ coefficient. RESULTS: Of the 112 participants, 20 had a positive T-SPOT.TB test result, and 21 had a positive TST result. The TST and T-SPOT.TB test results showed a high level of agreement (κ = 0.648, P < 0.001). Performance of the tests did not vary with CD4+ level. However, in participants with CD4+ < 200 cells/mm³, T-SPOT.TB detected more latent tuberculosis infections than the TST. CONCLUSION: There was good agreement between the TST and T-SPOT.TB results of latent tuberculosis infection in participants. TST is the preferred test for diagnosing latent tuberculosis infection in HIV-infected patients, especially in resource-limited settings, because it is simple and cost-effective. However, T-SPOT.TB may be useful to rule out latent tuberculosis infection in patients with severe immunodeficiency.

Early diagnosis and treatment of latent tuberculosis infection / Diagnóstico y tratamiento temprano de la infección de tuberculosis latente

Latent tuberculosis infection is a major health problem worldwide. People with latent tuberculosis infection have a lifetime risk of developing active tuberculosis approximately 5 % to 10%. Patients with latent tuberculosis infection were infected with Mycobacterium tuberculosis. Therefore, early diagnosis and treatment of a latent tuberculosis infection are very important. Patients with latent tuberculosis infection do not have the symptoms, signs, radiographic, and bacteriological evidence of active tuberculosis. Consequently, these patients are not contagious to others. Patients with latent tuberculosis infection usually have a positive tuberculin skin test or interferon-gamma release assays test. Systematic testing is recommended for all patients that are at risk for latent tuberculosis infection. The treatment of latent tuberculosis is recommended for patients that are at increased risk for developing active tuberculosis. The medications recommended to treat latent tuberculosis infection are isoniazid, rifampin, and a combination of isoniazidand rifapentine, and isoniazid and rifampin combination regimens. The most common side effect of these medications is hepatotoxicity. Therefore, patient monitoring during treatment should occur every month to evaluate medications side effects and adherence to medications. Post-treatment patient follow-up is very important, but serial or repeats chest radiography is not recommended.

La infección de tuberculosis latente es un gran problema de salud a nivel mundial. Las personas con infección de tuberculosis latente tienen un riesgo de desarrollar tuberculosis activa en aproximadamente 5 % a 10 % en toda su vida. Pacientes con infección de tuberculosis latente fueron infectados con Mycobacterium tuberculosis, por lo tanto, diagnóstico y tratamiento temprano de la infección de tuberculosis latente es muy importante. Pacientes con infección de tuberculosis latente son asintomáticos, no tienen signos físicos o radiográficos anormales, y no tienen evidencia bacteriológica de tuberculosis activa. Consecuentemente, estos pacientes no son contagiosos a otras personas. Pacientes con infección de tuberculosis latente usualmente son positivos para las pruebas de la tuberculina o Interferon-Gamma Release Assays. Pruebas sistemáticas son recomendadas para todos los pacientes que están en riesgo de presentar infección de tuberculosis latente. El tratamiento de tuberculosis latente es recomendado para los pacientes que tienen un elevado riesgo de desarrollar tuberculosis activa. Los medicamentos recomendados para el tratamiento de la infección de tuberculosis latente son isoniacida, rifampicina, y una combinación de isoniacida y rifapentin, y la combinación de isoniacida y rifampicina. El efecto secundario más común de estos medicamentos es hepatotoxicidad. Por lo tanto, la monitorización de estos pacientes durante el tratamiento debería ser cada mes, para evaluar efectos secundarios de los medicamentos y la adherencia al tratamiento. Es muy importante dar seguimiento después del tratamiento, pero hacer radiografías repetidas de pulmones no es recomendado.

Investigation of bovine tuberculosis outbreaks by using a trace-back system and molecular typing in Korean Hanwoo beef cattle

Bovine tuberculosis is a chronic contagious disease responsible for major agricultural economic losses. Abattoir monitoring and trace-back systems are an appropriate method to control bovine tuberculosis, particularly in beef cattle. In the present study, a trace-back system was applied to bovine tuberculosis cases in Korean native Hanwoo beef cattle. Bovine tuberculosis was detected in three index beef cattle during abattoir monitoring in Jeonbuk Province, Korea, and the original herds were traced back from each index cow. All cattle in each original herd were subjected to tuberculin skin test. The positive rates in the tuberculin skin test were 64.6% (62 of 96), 4.8% (2 of 42), and 8.1% (3 of 37) at farms A, B, and C, respectively. On post-mortem examination of 56 tuberculin-positive cattle, 62% had granulomatous lesions, and Mycobacterium bovis was cultured from 40 (71.4%) of the cattle. Molecular typing by spoligotyping and the mycobacterial interspersed repetitive unit-variable-number tandem repeat assay revealed the genotype of the M. bovis strains from the index cattle were same as the M. bovis genotype in each original herd. The results suggest that tracing back from index cattle to the original herd is an effective method to control bovine tuberculosis in beef cattle.

Comparison of Interferon-γ Release Assays and the Tuberculin Skin Test for Diagnosis of Tuberculosis in Human Immunodeficiency Virus: A Systematic Review / 결핵

BACKGROUND: It remains uncertain if interferon-γ release assays (IGRAs) are superior to the tuberculin skin test (TST) for the diagnosis of active tuberculosis (TB) or latent tuberculosis infection (LTBI) in immunosuppressed populations including people with human immunodeficiency virus (HIV) infection. The purpose of this study was to systematically review the performance of IGRAs and the TST in people with HIV with active TB or LTBI in low and high prevalence TB countries. METHODS: We searched the MEDLINE database from 1966 through to January 2017 for studies that compared results of the TST with either the commercial QuantiFERON-TB Gold in Tube (QFTGT) assay or previous assay versions, the T-SPOT.TB assay or in-house IGRAs. Data were summarized by TB prevalence. Tests for concordance and differences in proportions were undertaken as appropriate. The variation in study methodology was appraised. RESULTS: Thirty-two studies including 4,856 HIV subjects met the search criteria. Fourteen studies compared the tests in subjects with LTBI in low TB prevalence settings. The QFTGT had a similar rate of reactivity to the TST, although the first-generation version of that assay was reactive more commonly. IGRAs were more frequently positive than the TST in HIV infected subjects with active TB. There was considerable study methodology and population heterogeneity, and generally low concordance between tests. Both the TST and IGRAs were affected by CD4 T-cell immunodeficiency. CONCLUSION: Our review of comparative data does not provide robust evidence to support the assertion that the IGRAs are superior to the TST when used in HIV infected subjects to diagnose either active TB or LTBI.

Diagnosis and Treatment of Latent Tuberculosis Infection: The Updated 2017 Korean Guidelines / 대한내과학회지

A small number of viable tuberculosis bacilli can reside in an individual with latent tuberculosis infection (LTBI) without obvious clinical symptoms or abnormal chest radiographs. Diagnosis and treatment of LTBI are important for tuberculosis (TB) control in public and private healthcare facilities, particularly in high-risk populations. The updated 2017 Korean guidelines for TB recommend that tuberculin skin tests, interferon-gamma release assays, or a combination of them can be used for the diagnosis of LTBI, depending on the age and immune status of the patient as well as their TB contact history. For diagnosis of LTBI, exclusion of active TB is essential, and the possibility of healed TB in those without a history of treatment for TB but at risk of its development must be considered. The treatment options for LTBI include isoniazid, rifampicin, isoniazid/rifampicin, and isoniazid/rifapentine. The benefits and risks of these agents based on the age of the patient and their hepatotoxicity must be considered when selecting the appropriate drug. Standardized diagnosis and treatment of LTBI based on the updated 2017 guidelines will contribute to the control of TB in Korea as well as to further revisions of the guidelines.

A contact investigation after exposure to a child with disseminated tuberculosis mimicking inflammatory bowel disease / 소아과

PURPOSE: Tuberculosis (TB) is one of the most important diseases that cause significant mortality and morbidity in young children. Data on TB transmission from an infected child are limited. Herein, we report a case of disseminated TB in a child and conducted a contact investigation among exposed individuals. METHODS: A 4-year-old child without Bacille Calmette-Guérin vaccination was diagnosed as having culture-proven disseminated TB. The child initially presented with symptoms of inflammatory bowel disease, and nosocomial and kindergarten exposures were reported. The exposed individuals to the index case were divided into 3 groups, namely household, nosocomial, or kindergarten contacts. Evaluation was performed following the Korean guidelines for TB. Kindergarten contacts were further divided into close or casual contacts. Chest radiography and tuberculin skin test or interferon-gamma-releasing assay were performed for the contacts. RESULTS: We examined 327 individuals (3 household, 10 nosocomial, and 314 kindergarten contacts), of whom 18 (5.5%), the brother of the index patient, and 17 kindergarten children were diagnosed as having latent TB infection (LTBI). LTBI diagnosis was more frequent in the children who had close kindergarten contact with the index case (17.1% vs. 4.4%, P=0.007). None of the cases had active TB. CONCLUSION: This is the first reported case of TB transmission among young children from a pediatric patient with disseminated TB in Korea. TB should be emphasized as a possible cause of chronic diarrhea and failure to thrive in children. A national TB control policy has been actively applied to identify Korean children with LTBI.

Incidence of Active Tuberculosis within One Year after Tumor Necrosis Factor Inhibitor Treatment according to Latent Tuberculosis Infection Status in Patients with Inflammatory Bowel Disease

BACKGROUND: We investigated the incidence of active tuberculosis among patients with inflammatory bowel disease (IBD) treated with tumor necrosis factor (TNF) inhibitors, with or without latent tuberculosis infection (LTBI). METHODS: The study was performed at a Korean tertiary referral center between January 2011 and June 2017. In total, 740 patients with IBD who underwent LTBI screening tests and were followed-up for ≥ 1 year after TNF inhibitor treatment initiation were enrolled. LTBI was detected on the basis of tuberculin skin test results, interferon-gamma release assay results, chest X-ray findings, and previous tuberculosis treatment history. The patients were classified into LTBI (n = 84) or non-LTBI (n = 656) group. The risk of developing tuberculosis in each group was assessed on the basis of standardized incidence ratio (SIR) and 95% confidence interval (CI) for active tuberculosis. RESULTS: Mean patient age was 33.1 years, and patients with Crohn's disease were predominant (80.7%). Within 1 year after the initiation of TNF inhibitor treatment, 1 patient in the LTBI group (1/84; 1.2%) and 7 patients in the non-LTBI group (7/656; 1.1%) developed active tuberculosis. The overall 1-year incidence of tuberculosis among the patients was significantly higher than that among the general population (SIR, 14.0; 95% CI, 7.0–28.0), and SIR was not affected by LTBI status (LTBI group: 14.5, 95% CI, 2.0–102.6; non-LTBI group: 14.0, 95% CI, 6.7–29.4). CONCLUSION: Patients with IBD undergoing TNF inhibitor treatment showed a higher 1-year incidence of tuberculosis than the general population irrespective of LTBI status.

Systemic review: agreement between the latent tuberculosis screening tests among patients with rheumatic diseases

BACKGROUND/AIMS: To estimate the level of agreement and positivity rates of latent tuberculosis infection (LTBI) tests prior to the use of tumor necrosis factor (TNF) inhibitors in relation to underlying rheumatic diseases and endemic tuberculosis levels. METHODS: The Ovid-Medline, Embase, and Cochrane Libraries were searched for articles before October 2013 involving LTBI screening in rheumatic patients, including rheumatoid arthritis (RA), ankylosing spondylitis (AS), juvenile idiopathic arthritis (JIA), and psoriatic arthritis. RESULTS: In pooled analyses, 5,224 rheumatic patients had undergone both a tuberculin skin test (TST) and an interferon-gamma release assay (IGRA) before TNF inhibitors use. The positivity of TST, QuantiFERON-TB Gold In Tube (QFT-GIT), and T-SPOT.TB (T-SPOT) tests were estimated to be 29%, 17%, and 18%, respectively. The agreement percentage between the TST and QFT-GIT, and between the TST and T-SPOT were 73% and 75%. Populations from low-to-moderate endemic TB presented with slightly less agreement (71% between TST and QFT-GIT, and 74% between TST and T-SPOT) than patients from high endemic countries (73% between TST and QFT-GIT, and 81% between TST and T-SPOT). By underlying disease stratification, a lower level of agreement between TST and QFT-GIT was found among AS (64%) than among JIA (77%) and RA patients (73%). CONCLUSIONS: We reaffirm the current evidence for accuracy of LTBI test done by TST and IGRA among rheumatic patients is inconsistent. Our stratified analysis suggests different screening strategies might be needed in clinical settings considering the endemic status in the patient’s country of origin and the precise nature of underlying diseases.