scholarly journals Long-term efficacy of BCG vaccination in goat herds with a high prevalence of tuberculosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Claudia Arrieta-Villegas ◽  
Alberto Allepuz ◽  
Miriam Grasa ◽  
Maite Martín ◽  
Zoraida Cervera ◽  
...  

AbstractVaccination of goats against tuberculosis (TB) has been promoted as an ancillary tool for controlling the disease in infected livestock herds. A three-year trial to assess the efficacy of BCG vaccine was carried out in five goat herds. At the beginning of the trial (month 0), all animals were tested for TB using thee different diagnostic tests. Animals negative to all tests were vaccinated with BCG and all replacement goat kids were also systematically vaccinated throughout the trial. All animals were tested by Interferon-gamma release assay (IGRA) using vaccine compatible reagents at months 6, 12, 24, and 36. The risk factors for TB infection were also evaluated. At the end of the study, four out of five farms showed variable reductions of the initial prevalence (93.5%, 28.5%, 23.2%, and 14.3% respectively), and an overall incidence reduction of 50% was observed in BCG vaccinated goats, although adult vaccinated goats showed higher incidences than vaccinated goat kids. The unvaccinated positive animals remaining in herds and adult BCG vaccinated goats significantly enhanced the risk of infection in vaccinated animals. A systematic vaccination of goats with BCG, together with the removal of positive unvaccinated animals, may contribute to reducing the TB prevalence in goat herds.

2020 ◽  
Author(s):  
Francisca Srioetami Tanoerahar ◽  
Indri Rooslamiati ◽  
Natalie Kipuw ◽  
Hadiyanto ◽  
Soegianto Ali ◽  
...  

Abstract IntroductionActive tuberculosis (TB) patient is a potential source of Mycobacterium tuberculosis transmission in an overcrowded and poor area. Family members living in the same house may have been infected or latent tuberculosis infection (LTBI) may develop. The aim of the study was to explore LTBI among newborns and their family members living in an overcrowded area in Jakarta, Indonesia. MethodsA prospective analytical study was conducted among newborns from October 2016 to March 2017. Interferon gamma release assay (IGRA) was examined before BCG vaccination and after 12 weeks. In parallel, TB active case finding was performed among family members of the newborns.ResultsOf 135 newborns, only 117 (86.7%) came for BCG vaccination. Of 346 family members screened, 8 (2.3%) were detected as untreated active pulmonary TB, confirmed by positive sputum and/or MTB culture. Family members living in the same house with active TB individuals (p=0.011, OR 2.69) as well as being males (p = 0.025; OR 1.68) had a significant higher risk of having a positive IGRA. ConclusionsUntreated pulmonary TB infection in overcrowded areas infects the surrounding neighbors, resulting in latent TB infection. An active program for detecting pulmonary TB cases and preventive measures need to be taken seriously to contain the potential spreading of the infection.


2020 ◽  
Vol 83 (6) ◽  
pp. AB82
Author(s):  
Urmi Khanna ◽  
Ariana Ellis ◽  
Anokhi Saklecha ◽  
Joshua Gallop ◽  
Abdulaziz Galadari ◽  
...  

2018 ◽  
Vol 5 (8) ◽  
Author(s):  
Jody C Sharninghausen ◽  
Adrienne E Shapiro ◽  
David M Koelle ◽  
H Nina Kim

Abstract Background Non-US-born individuals account for the majority of active tuberculosis (TB) in the United States. Interferon gamma release assay (IGRA) is the preferred diagnostic test for latent TB but can produce an indeterminate result. We investigated the prevalence and predictors of an indeterminate IGRA (IND-IGRA) in a diverse cohort of non-US-born individuals and evaluated outcomes after IND-IGRA. Methods We identified patient age ≥18 years who had an outpatient IGRA between 2010 and 2017 in our health system and whose primary language was not English. We used univariate and multivariable logistic regression to examine the association of IND-IGRA with a variety of clinical factors. Results Of 3128 outpatients with ≥1 IGRA done, 33% were Asian, 30% Hispanic, and 29% black; 44% were men, and the median age was 50 years. An initial IND-IGRA occurred in 118 (3.8%; 95% confidence interval [CI], 3.1%–4.5%); notably, Asian race (55%) and rheumatologic conditions (25%) were prevalent in this group. In multivariable analysis, Asian race was independently associated with IND-IGRA (adjusted odds ratio [aOR], 2.9; 95% CI, 1.9–4.3), in addition to the presence of anemia and hypoalbuminemia (aOR for interaction, 4.3; 95% CI, 1.3–14.3). Only 55% of patients with an initial IND-IGRA underwent repeat testing; of those who did, 66% had a determinate result. Conclusions Asian race and anemia/hypoalbuminemia were independent risk factors for an indeterminate IGRA outcome in foreign-born patients screened in the United States. Our study underscores the importance of following through on indeterminate results in these key subgroups.


Author(s):  
A. N. Umo ◽  
O. J. Akinjogunla ◽  
N. O. Umoh ◽  
G. E. Uzono

This study established the diagnosis and risk factors of latent tuberculosis infection (LTBI) among health-care workers in an endemic population using Tuberculin skin test (TST) and Quantiferon TB-gold. A total of 609 Healthcare workers from tuberculosis treatment facilities in Akwa Ibom State, Nigeria were studied. The Interferon-gamma release assay was performed using 3ml of whole blood by ELISA according to the manufacturer’s instruction (Cellestis Ltd., Carnegie, Australia) after which 0.1 ml of 5 tuberculin units of Purified Protein Derivative (PPD) was administered intra-dermally to each subject. TST results were read after 72 hours by measuring the size of indurations in millimetres. Data were analysed using SPSS version 17 (SPSS Inc., Chicago, Illinois). At the threshold of 10 mm, the prevalence of LTBI by TST was 45.8% and 24.8% at the IGRA diagnostic value of ≥ 0.351 IU. Laboratory staff and ward orderlies as well as being in service for >10 years, were more significantly associated with LTBI. A moderate agreement of 76.7%, k = 0.51 was obtained between TST at 10 mm, and QFT. Neither previous exposure to TST nor BCG vaccination affected the prevalence of LTBI in the study population. The difference of 54% prevalence of LTBI between TST and QFT may be due to non-tuberculous mycobacterium (NTM) since TST is non-specific. This may have grave implications of drug toxicity and development of resistance to anti-TB drug among individuals harbouring NTM, but receiving anti-TB medication. The 76.7% agreement between the two tests is an indication that the 10 mm cut-off induration for TST is still relevant in the diagnosis of LTBI.


2018 ◽  
Vol 57 (6) ◽  
pp. 724-732 ◽  
Author(s):  
Marcela Rubio-Carrasquilla ◽  
Cristian David Santa ◽  
Juan Pablo Rendón ◽  
Jorge Botero-Garcés ◽  
Allan J Guimarães ◽  
...  

AbstractHistoplasmosis is the most common endemic mycosis in the Americas. Currently, there is no laboratory test capable to detect subclinical or latent infections by Histoplasma capsulatum (Hc), which might develop as severe infections in immunocompromised individuals. For the first time to our knowledge, we explore the suitability of an interferon gamma release assay (IGRA) to detect latent Hc infection in asymptomatic individuals. A cohort of 126 volunteers was enrolled in the study, 13 of which underwent a Hc infection in the past, and 93 of them showing risk factors for this infection. The remaining 20 participants did not refer any risk factors of Hc infection, but eight of them showed evidences of infection with Mycobacterium tuberculosis. All participants were recruited in Medellin, Colombia, between January 2014 and December 2017. Whole blood samples were cultured with four different Hc crude antigens and phytohemaglutinin as positive control. The interferon (IFN)-γ released by T lymphocytes upon antigen stimulation was quantified by ELISA. A defined cutoff value of 20 pg/ml for the IFN-γ concentration allowed us to distinguish between the group with documented past infections and the group of noninfected individuals with high sensitivity (70–92%) and specificity (85–95%), for the four tested antigens. Positive 82–95% and negative 77–92% predictive values were also very high, comparable to those reported for commercially available IGRAs. The new test constitutes a promising screening method to detect individuals with latent Hc infection, even decades after the primary infection, as evidenced in this study.


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