Rapid diagnosis of TB using Aptamer-based assays for Mycobacterium tuberculosis antigens in children and adolescents

Background

Despite advances establishing microbiological evidence of tuberculosis (TB) is still a concern in children due to the limitation of availability of sample and predominance of extrapulmonary TB, there is unmet need for diagnostic tests which are low cost, rapid and sensitive and specific.

Methods

This study evaluated the utility of aptamer-based assay for detecting mycobacterium tuberculosis antigens HspX and MPT 64 in rapid diagnosis of TB in children up to 18 years of age in a tertiary medical college. A total of 100 children were sequentially enrolled with presumptive pulmonary (n = 52 and extrapulmonary n = 48) TB based on clinico-radiological characteristics. The samples were evaluated with ALISA technique for TB antigens and compared with the results of ZN microscopy, GeneXpert and mycobacterial culture MGIT.

Results

The enrolled children had mean age (11.7 + 4.4 years) with both pulmonary (n = 52) and extrapulmonary TB (n = 48). Our study results concluded poor results of smears (11% positivity, sensitivity: 17.7%, NPV: 42.7%) and better of GeneXpert (positivity: 42%, sensitivity of 67.4%, NPV: 65.5%) and culture (positivity 57%, sensitivity 91.9%, NPV 88.3%). HspX antigen by ALISA had comparable results (positivity: 49%, sensitivity: 62.9%; NPV: 54.9%). MPT 64 antigen by ALISA also had similar results (positivity: 45%, sensitivity: 58% and NPV 52, 3%). Sensitivity and specificity were higher in pulmonary TB compared to EPTB for both antigens. HspX antigen assay by ALISA and MPT 64 ALISA over existing microbiological diagnostic methods had additional of 13%.

Conclusion

ALISA technique for mycobacterium antigens HspX and MPT 64 was rapid, low-cost test (1-3$/test) high sensitivity and specificity and comparable to currently available methods.

Indian Academy of Pediatrics Guidelines on the Fast and Junk Foods, Sugar Sweetened Beverages, Fruit Juices, and Energy Drinks

JUSTIFICATION

In view of easy availability and increasing trend of consumption of fast foods and sugar sweetened beverages (fruit juices and drinks, carbonated drinks, energy drinks) in Indian children, and their association with increasing obesity and related non-communicable diseases, there is a need to develop guidelines related to consumption of foods and drinks that have the potential to increase this problem in children and adolescents.

OBJECTIVES

To review the evidence and formulate consensus statements related to terminology, magnitude of problem and possible ill effects of junk foods, fast foods, sugar-sweetened beverages and carbonated drinks; and to formulate recommendations for limiting consumption of these foods and beverages in Indian children and adolescents.

PROCESS

A National Consultative group constituted by the Nutrition Chapter of the Indian Academy of Pediatrics (IAP), consisting of various stakeholders in private and public sector, reviewed the literature and existing guidelines and policy regulations. Detailed review of literature was circulated to the members, and the Group met on 11th March 2019 at New Delhi for a day-long deliberation on framing the guidelines. The consensus statements and recommendations formulated by the Group were circulated to the participants and a consensus document was finalized.

CONCLUSIONS

The Group suggests a new acronym 'JUNCS' foods, to cover a wide variety of concepts related to unhealthy foods (Junk foods, Ultra-processed foods, Nutritionally inappropriate foods, Caffeinated/colored/carbonated foods/beverages, and Sugar-sweetened beverages). The Group concludes that consumption of these foods and beverages is associated with higher free sugar and energy intake; and is associated with higher body mass index (and possibly with adverse cardiometabolic consequences) in children and adolescents. Intake of caffeinated drinks may be associated with cardiac and sleep disturbances. The Group recommends avoiding consumption of the JUNCS by all children and adolescents as far as possible and limit their consumption to not more than one serving per week. The Group recommends intake of regional and seasonal whole fruits over fruit juices in children and adolescents, and advises no fruit juices/drinks to infants and young children (age <2y), whereas for children aged 2-5 y and >5-18 y, their intake should be limited to 125 mL/day and 250mL/day, respectively. The Group recommends that caffeinated energy drinks should not be consumed by children and adolescents. The Group supports recommendations of ban on sale of JUNCS foods in school canteens and in near vicinity, and suggests efforts to ensure availability and affordability of healthy snacks and foods. The Group supports traffic light coding of food available in school canteens and recommends legal ban of screen/print/digital advertisements of all the JUNCS foods for channels/magazines/websites/social media catering to children and adolescents. The Group further suggests communication, marketing and policy/taxation strategies to promote consumption of healthy foods, and limit availability and consumption of the JUNCS foods.

Vancomycin-induced thrombocytopenia in a newborn

Neonatal thrombocytopenia is common and is frequently seen in neonatal sepsis. Drug-induced thrombocytopenia is likely to be missed unless a high index of suspicion is present. Changing of antibiotics for assumed nonresolution of sepsis may lead to persistent thrombocytopenia in a neonate if drug-induced thrombocytopenia is missed. Vancomycin-induced neonatal thrombocytopenia is rarely described in scientific literature. We describe a newborn who was diagnosed with early onset sepsis and vancomycin-induced thrombocytopenia. Other causes of thrombocytopenia such as sepsis, alloimmune thrombocytopenia, thrombosis etc. were excluded. The platelet counts normalized within 72 h of stopping vancomycin. Vancomycin-induced IgM platelet antibodies could not be done in our case (due to financial constraints), but their absence does not exclude the diagnosis of vancomycin-induced thrombocytopenia.