Accuracy of Nasopharyngeal Aspirate GeneXpert Compared to Gastric Aspirate TB Culture and GeneXpert in Diagnosing Pulmonary Tuberculosis in Pediatric Patients

Background@#Pulmonary TB in children remains to be a burden in the Philippines. Diagnosis remains to be a challenge for pediatricians due to its paucibacillary nature, difficulty in obtaining specimens, cost of test as well as the varied sensitivity of the different tests available. Gastric aspirate (GA), commonly used for bacteriological diagnosis of pulmonary tuberculosis (PTB) in children, involves an invasive procedure that may cause discomfort and sometimes require admission. Nasopharyngeal aspirate (NPA), on the other hand, can be easily and non-invasively obtained but is currently not a recommended specimen for testing for PTB. @*Objectives@#This study aims to determine the accuracy of NPA GeneXpert in diagnosing PTB among pediatric patients 0-18 years old with presumptive TB using GA GeneXpert as the initial screening test and GA TB culture as gold standard. @*Methodology@#This prospective, cross-sectional diagnostic study involved collection of single NPA and GA specimens for GeneXpert and TB culture in 100 patients with presumptive PTB seen at a tertiary government hospital in the Philippines. @*Results@#Of the one hundred pediatric patients (mean age 6 ± 5.63 years) enrolled, 50 were clinically diagnosed PTB, 16 bacteriologically-confirmed and 34 were not PTB disease. Sensitivity, specificity and predictive values with 95% confidence intervals of the NPA GeneXpert were determined compared to GA GeneXpert and GA culture. Sensitivity, specificity, positive and negative predictive values of the NPA GeneXpert compared to GA GeneXpert were 70%, 96.67%, 70% and 96.67%, respectively. While NPA GeneXpert compared to GA TB culture were 40%,91.58%, 20% and 96.67%, respectively. @*Conclusion@#GeneXpert testing on a single NPA specimen is a highly specific and rapid test that can be used to diagnose PTB in pediatric patients, particularly where gastric aspiration or mycobacterial culture is not feasible.

Study on cartridge based nucleic acid amplification test in children with Neurotuberculosis at RNT Medical College, Udaipur, Rajasthan, India

Background: The aim was to determine utility of Cartridge based nucleic acid amplification test (CBNAAT) in diagnosis of mycobacterium tuberculosis in children with neurotuberculosis diagnosed on the basis of clinical evaluation, CSF findings and neuroimaging.Methods: A prospective randomized controlled trial was conducted in Pediatric Department of RNT Medical College, Udaipur, Rajasthan, India from July 2017 to June 2018. Total 110 children of age group of 6 months to 18 years with the diagnosis of tubercular meningoencephalitis (TBME) on the basis of clinical evaluation, CSF examination and neuroimaging were included in the study.Results: A total 110 children were enrolled. Maximum number of cases admitted with TBME were among 1-5 years of age group (60.91%). CSF and gastric aspirate were examined by CBNAAT for MTB. 5 (4.55%) children had CBNAAT positivity in CSF. Gastric aspirate was positive among 16 (14.55%) children. None of the patient had CBNAAT positive result both in CSF and gastric aspirate.Conclusions: TBME is a major health problem in children below 5 years. Gene Xpert assay has the potential to significantly improve and escalate the diagnosis of smear-negative body fluid specimens. CBNAAT for mycobacterium tuberculosis was positive in 5 (4.55%) children from CSF and 16 (14.55%) from gastric aspirate. Negative CBNAAT should not prevent any patient with suspected features of TBME from starting anti tubercular treatment (ATT) as sensitivity of this test remains low. Final judgement to start ATT should be based on clinical, biochemical and radiological profile especially in CNS tuberculosis.

Detection of Helicobacter pylori in Gastric Aspirates Using a Monoclonal Antibody-Based Test

BACKGROUND/AIMS: The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans. METHODS: Sixty-one volunteers were enrolled in the study. All of the subjects underwent a 13C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation. RESULTS: Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77+/-1.77 vs 3.49+/-1.30, p<0.05) and ammonia level (1,130.9+/-767.4 vs 184.2+/-126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively. CONCLUSIONS: The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates.

A Case of Congenital Tuberculosis in a Tertiary Care Hospital.

Congenital tuberculosis is an unusual and severe clinical presentation of Mycobacterium tuberculosis (MTB) infection. It is usually difficult to diagnose and treat. We report a tenweek- old male infant who had presented with fever, difficulty in breathing, abdominal distension, convulsion, low weight gain since one month of his age. The diagnosis was made by demonstration of MTB bacilli in the gastric aspirate of baby and chest radiography. Treatment with the four drug regimen including streptomycin was initiated, but the baby died on the third day of ATT. This case gives an account of difficulties in diagnosis and therapeutic management of congenital tuberculosis and alerts for development of protocols that foresee these difficulties.

The prediction of neonatal respiratory distress syndrome by stable microbubble test and surfactant protein A level in gastric aspirate / 中华检验医学杂志

Objective To investigate the application of stable microbubble test ( SMT) and surfactant protein A ( SP-A) level in gastric aspirate in predicting neonatal respiratory distress syndrome ( RDS). Methods One hundred and ten high-risk preterm infants within 1 hour after birth, with gestational age between 24 and 36 weeks, birth weight between 1 160 g and 2 010 g were admitted in the study. The gastric secretion of 1-2 ml was collected during routine aspiration for SMT. At the same time SP-A level was measured by enzyme linked immuno sorbent assay. Results The SMT count and SP-A level in preterm infants with RDS were lower than those of infants without RDS [SMT: (5. 7?2. 4) microbubbleg/mm2( mb/ mm2) vs. (12.4?6.0) mb/mm2, t = 8. 355,P

Gastric Aspirate Examination as an Index for Detection of Early Onset Neonatal Sepsis

PURPOSE: Our study was undertaken to evaluate the efficacy of gastric aspirate examination (GAE) in the early identification of early onset sepsis. METHODS: A retrospective chart review was done for a total 291 neonates who were admitted with high risk for early onset sepsis to Nowon Eulji Hospital neonatal intensive care unit between Jan. 1999 and Jan. 2003. Contents of gastric aspirate via nasogastric tube were analyzed with wet smear, gram stain and culture. Positive blood culuture was our definitive criterion for sepsis. GAE was considered positive when five or more leukocytes per high power field were counted on wet smear or when any bacteria were present on gram stain or when any organism grew on culture. RESULTS: Positive results in gastric aspirate examination are 57 patients (19.6%) in wet smear, 28 patients (9.6%) in gram stain, 30 patients (10.3%) in culture and positive result in blood is 27 patients (9.3%). There are no statistically correlation between gastric aspirate examinations and early onset sepsis. CONCLUSION: We concluded that gastric aspirate examinations are of limited value in predicting the diagnosis of early onset sepsis in neonate.

Tuberculosis infantil en Valdivia: Experiencia clínica en 16 años / Tuberculosis in infancy: sixteen year experience

A clinical experience of tuberculosis (TB) in 104 pediatric patients observed at the Hospital Regional de Valdivia (southern Chile), along a sixteen year period (1986 - 2001) is presented. Pulmonary TB was diagnosed in 88 cases, extrapulmonary TB in 19 cases and both localizations in three cases. Pulmonary TB was bacteriologically confirmed in 62.5% of cases, through either gastric aspirate or sputum samples. Gastric aspirate yielded 42.8% of positive cultures; two infants who presented central nervous system involvement, died. A case of congenital TB was observed in a 30 day old infant. There were no cases of AIDS in this experience. Pediatric TB has progressively decreased its incidence in our region, particularly the extrapulmonary localization, but still represents a challenging disease to clinicians.

Foam test on gastric aspirates in the prediction of respiratory distress syndrome

Philippine statistics show that 66 percent of babies are delivered outside the hospital. Thus, the need for a simple and rapid screening test done immediately after birth to identify those babies who will develop Respiratory Distress Syndrome (RDS) and may subsequently require referral to a tertiary care unit, is evident. Foam test was done on samples of amniotic fluid and gastic aspirate within one hour after collection on 61 deliveries, 35 term and 26 premature. Results of the foan test were correlated with the incidence of RDS. Of the 61 subjects, 39 gave a positive foan test, none of whom developed RDS. Six had an intermediate foam test, also none of whom developed RDS. Results of the foam test on gastric aspirate showed a parallelism with those done on amniotic fluid in 60 out of 61 subjects. Statistical analysis showed that the foam test has a 100 if positive. These data showed that the foam test on gastric aspirate has a high predictive accuracy in the assessment of fetal lung maturity.