Strengthening Tuberculosis Services for Children and Adolescents in Low Endemic Settings

In low tuberculosis-burden countries, children and adolescents with the highest incidence of tuberculosis (TB) infection or disease are usually those who have immigrated from high-burden countries. It is, therefore, essential that low-burden countries provide healthcare services to immigrant and refugee families, to assure that their children can receive proper testing, evaluation, and treatment for TB. Active case-finding through contact tracing is a critical element of TB prevention in children and in finding TB disease at an early, easily treated stage. Passive case-finding by evaluating an ill child is often delayed, as other, more common infections and conditions are suspected initially. While high-quality laboratory services to detect Mycobacterium tuberculosis are generally available, they are often underutilized in the diagnosis of childhood TB, further delaying diagnosis in some cases. Performing research on TB disease is difficult because of the low number of cases that are spread over many locales, but critical research on the evaluation and treatment of TB infection has been an important legacy of low-burden countries. The continued education of medical providers and the involvement of educational, professional, and non-governmental organizations is a key element of maintaining awareness of the presence of TB. This article provides the perspective from North America and Western Europe but is relevant to many low-endemic settings. TB in children and adolescents will persist in low-burden countries as long as it persists throughout the rest of the world, and these wealthy countries must increase their financial commitment to end TB everywhere

Quantiferon Gold-in-tube assay for TB screening in HIV infected children: influence of quantitative values

Abstract Background HIV infected children are at increased risk of TB disease and require annual TB screening. Data on use of IGRA for TB screening in them are limited. We retrospectively evaluated the usefulness of Quantiferon Gold-in-tube test (QFT), an IGRA in screening for LTBI in relatively healthy, immunologically stable HIV infected children. Methods HIV infected children with no prior history of TB were screened for latent TB as part of routine care. They underwent risk of TB assessment, TST and QFT. QFT was repeated twice or three times depending on the quantitative values. Independent test validation was also performed. Results Eighty one children had 109 QFT tests. All had adequate mitogen responses. The initial QFT was positive in 15 (18.5%) children; quantitative IGRA responses were 0.35-1.0 IU/mL in 9 (60%), 1.0-10 IU/mL in5 (33.3%) and >10 IU/mL in 1 (6.7%). None that tested positive had documented TB exposure or TB disease. Baseline characteristics in the QFT positive and negative groups were similar. Repeat testing within 17 weeks demonstrated reversion to negative in 79% of cases. Repeat blinded independent testing of all QFT positive results and a random selection of initial negative tests demonstrated concordance in 96% of cases. Seven children (QFT > 1.0 IU/mL or positive TST) were offered INH preventive therapy. In no case has TB disease developed in 2 years of close follow-up. Conclusions QFT is a valid method for LTBI screening relatively healthy, immunologically stable HIV infected children. However, reversion to negative on repeat testing and lack of correlation with TST results and risk of TB exposure makes interpretation difficult

Long-term stability of the inversion process for sugar and ethanol production in an existing Japanese sugar mill

In order to utilize sugarcane with a high reducing-sugar content as the raw material for sugar production, a new technology called the ‘inversion process’ has been developed. This new technology aims to enhance raw sugar yield via removal of reducing sugars through selective ethanol fermentation using an invertase-defective yeast, prior to sugar crystallization. To assess the feasibility of the inversion process technology in an existing sugar mill, a test of continuous and repeated-batch fermentation using clear juice was undertaken at a pilot-scale facility at the Shinko Sugar Mill in Japan. Batch fermentation trials were performed at 35°C for 1.5-3 h and repeated 70 times in a 2000 L fermenter using the same culture of invertase-defective yeast strain GYK-10. To confirm the long-term stability of the selective fermentation, the concentrations of saccharides and ethanol in the fermenter were measured every hour and the residual sucrose ratio and the reducing sugars removal ratio were calculated. Each batch was checked for the presence of contaminating bacteria. The results showed that 88.4% of reducing sugars were converted to ethanol and 99.5% of sucrose remained throughout the 70 consecutive batch fermentations. This indicates that the saccharometabolism selectivity of GYK-10 is stable. Although contamination by some microorganisms, such as Clostridium beijerinckii, Bacillus simplex, and Bacillus brevis, was observed, this had little influence on the fermentation outcomes. This paper reports on the feasibility of using the inversion process in an existing sugar mill

Pilot-scale demonstration and economics of the inversion process for sugar and ethanol production

A novel process for producing sugar and ethanol from high-yielding sugarcane called the Inversion Process has been developed previously. The process incorporates the use of an invertase-defective yeast to selectively ferment reducing sugars in sugarcane juice prior to crystallization to both produce ethanol and enhance the recovery of sugar from the process. To evaluate the technical and economic potential of the technology, the impacts of the Inversion Process on juice and syrup quality, crystal sugar production and recovery were evaluated using a three massecuite boiling scheme at pilot scale and techno-economic modelling was undertaken based on the results obtained. The Inversion Process decreased reducing sugar concentrations by >90%, which resulted in significant purity increases in clarified juice, syrup and A and B massecuites. These outcomes resulted in improved crystallization performance and reduced recycling of impurities. Lower C massecuite and C molasses purities were also achieved resulting in a significant impact on processability and recovery of sugar from C massecuite. Preliminary economic modelling showed the potential for very significant industry benefits with financial benefits accruing from increased sugar production and the production of ethanol from reducing sugars with the benefits of most significance for factories processing low-purity or high-yielding sugarcane. This paper reports on the demonstration of the Inversion Process in Australia and potential technical and financial impacts of the Inversion Process on the operation of sugar factories are discussed