Tuberculosis in Children in a Pediatric Hospital in Mexico

Tuberculosis (TB) remains a global problem and a diagnostic challenge, especially in pediatrics. The aim of this study was to describe the clinical, microbiological, radiological, and histopathological data of TB in children. A 7-year retrospective and descriptive cohort study that included 127 patients under 18 years of age with diagnosis of active TB was conducted from 2011 to 2018 in a pediatric hospital. Tuberculosis was microbiologically confirmed using Ziehl–Neelsen (ZN) staining, culture or polymerase chain reaction (PCR) in a total of 94 (74%) cases. Thirty-three cases were defined as probable TB based on tuberculin skin test result and epidemiological evaluation. The TB forms found were lymph node (39.3%), bone (15.7%), lung (13.6%), and meningeal TB (8.6%). The most common symptoms were fever (48.8%) and adenopathy (45.6%). History of contact was established in 34.6%. Positive ZN staining (sensitivity 30%) and culture (sensitivity 37%) were found in 29% and 37.7% of subjects, respectively. About 64.5% depicted abnormal chest X-ray. Xpert MTB/RIF® (PCR) was positive in 9.4% and biopsy was compatible in 52.7% of these samples. It is fundamental to have laboratory and epidemiological evaluation that support the diagnosis of the disease in children and thus, define its management; since, in most cases, early microbiologic confirmation is lacking.

Production of specific brucellin to diagnose Brucellosis

act : A soluble cytoplasmic antigen (Brucellin) was prepared from Brucella melitensis Rev1 and used to diagnose brucellosis in experimentally infected mice with virulent strains of Brucella melitensis and Brucella abortus two weeks after infection. The best result was obtained with the third peak of the four peaks. All four peaks were used as antigen for skin test in a group of mice two weeks after vaccinated with S19 vaccine and the best result was obtained with third peak. All four peaks were also used as antigen for skin test in a group of mice previously vaccinated with Listeria monocytogenes live attenuated vaccine. All four fractions of the extracted brucellin antigens exhibited a negative skin test result in Listeria monocytogenes experimentally vaccinated mice.