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Interpreting the 13C-urea breath test among a large population of young children from a developing country
J E Thomas1, A Dale, M Harding
1Department of Child Health, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom.
Insights
The 13C-urea breath test accurately diagnoses Helicobacter pylori in young children from developing nations. This noninvasive method establishes a reliable cut-off value for infection detection without endoscopy.
Area of Science:
- Pediatric Infectious Diseases
- Gastroenterology
- Diagnostic Technology
Background:
- Helicobacter pylori infection is prevalent in developing countries.
- The 13C-urea breath test (UBT) is a noninvasive diagnostic tool for H. pylori.
- UBT validation in young children in developing regions is lacking.
Purpose of the Study:
- To validate the 13C-urea breath test for diagnosing H. pylori infection in young Gambian children.
- To establish an appropriate cut-off value for UBT in this specific population.
- To assess the UBT's utility as a diagnostic tool in resource-limited settings.
Main Methods:
- 1532 UBTs were performed on 247 Gambian children aged 3-48 months.
- The Expectation-Maximization (EM) algorithm was used to identify distinct positive and negative subpopulations.
- A subset of 14 children underwent UBT alongside upper endoscopy and gastric biopsies for H. pylori confirmation.
Main Results:
- Two subpopulations were identified in the UBT results.
- A cut-off value of 5.47 delta per thousand (‰) at 30 minutes correctly classified 95% of negative and 99.4% of positive cases.
- Comparison with biopsy results showed high concordance, with 7/7 H. pylori-negative children testing negative and 6/7 H. pylori-positive children testing positive.
Conclusions:
- The 13C-urea breath test is a valuable and validated diagnostic tool for H. pylori in young children in developing countries.
- The study provides a method for calculating population-specific UBT cut-off values.
- UBT offers a reliable, noninvasive alternative to endoscopy for H. pylori diagnosis in pediatric populations.
Abstract:
The 13C-urea breath test is a noninvasive tool for the diagnosis of gastric Helicobacter pylori infection. However, it has not been validated in young children from the developing world, where infection is very common. 13C urea breath tests were performed on 1532 occasions on 247 Gambian infants and children aged from 3 to 48 mo. The means and variances of the separate sub-populations of 13C enrichment results contained within the overall dataset were estimated by a Genstat procedure using the EM algorithm, thereby identifying a cut-off value to discriminate positive from negative results. To illustrate the appropriateness of this calculated cut-off value, 13C urea breath tests were performed upon a small group of 14 patients aged 6 to 28 mo undergoing diagnostic upper endoscopy. Fixed gastric antral biopsies were examined to identify H. pylori. Two subpopulations were identified within the large dataset. A cut-off value of 5.47 delta per thousand relative to Pee Dee Belemnite limestone above baseline at 30 min identified 95% of the normally distributed negative sub-population and 99.4% of the log normal distributed positive sub-population. Comparison with endoscopic data confirmed that this cut-off value was appropriate for this population, as 7/7 children without H. pylori on their gastric biopsies had negative urea breath tests, and 6/7 children with gastric H. pylori colonization had positive urea breath tests. These findings confirm the value of the urea breath test as a diagnostic tool in young children from developing countries. They also offer a way to calculate the most appropriate cut-off value for use in different populations and the likelihood that it will correctly assign any value into the appropriate sub-population, without the need for endoscopy.