Related Experiment Video
Updated: Feb 6, 2026
Separation and Fractionation of Culture Filtrate Proteins (CFPs) from Mycobacterium tuberculosis
Published on: July 11, 2025
Risk factors for gastric aspirate culture contamination in children evaluated for tuberculosis in Botswana
A Ho-Foster1, M W Tenforde2, T Arscott-Mills3
1Botswana-UPenn Partnership, Gaborone, Botswana, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Insights
High contamination rates in pediatric gastric aspirate cultures for tuberculosis (TB) impact diagnosis. Hospital collection reduced contamination, while liquid media increased it, suggesting improvements are needed for TB testing in children.
Area of Science:
- Pediatric Infectious Diseases
- Microbiology
- Public Health
Background:
- Gastric aspirate (GA) culture is crucial for diagnosing tuberculosis (TB) in children unable to produce sputum.
- Sample contamination significantly reduces the yield of TB cultures and hinders effective patient management.
Purpose of the Study:
- To determine the prevalence of GA sample contamination in children undergoing TB evaluation.
- To identify factors associated with GA contamination at a central TB reference laboratory in Botswana.
Main Methods:
- A 5-year cross-sectional study analyzed 3642 GA samples from untreated children under 12 years old.
- Descriptive statistics and multivariable logistic regression were used to assess contamination risks.
- Factors examined included patient age, sex, transport time/distance, culture medium, and facility type.
Main Results:
- Overall contamination rate was 35.6%, with only 1.6% TB culture positivity.
- Hospital collection was linked to a lower risk of contamination (aOR 0.53).
- Liquid culture media (MGIT) showed a higher contamination risk compared to solid media (LJ) (aOR 1.88).
Conclusions:
- High contamination rates and low TB detection highlight issues with sample collection and storage in routine settings.
- Findings suggest potential improvements in collection techniques at lower-level facilities.
- The increased risk associated with liquid culture media warrants further investigation.
Setting:
Gastric aspirate (GA) sample culture is commonly performed in children evaluated for tuberculosis (TB) who cannot expectorate sputum. Contamination limits culture yield and negatively impacts care.
Objective:
To evaluate the proportion of and factors associated with GA contamination at a central TB reference laboratory in Botswana.
Design:
This was a 5-year cross-sectional study of untreated children aged 12 years evaluated for TB with the first GA sample registered at the National Tuberculosis Reference Laboratory. We performed descriptive statistics to assess the risk of contamination with patient age, sex, transport time and distance, culture medium, and facility type. We generated multivariable logistic regression models using generalized estimating equation extension.
Results:
We analyzed 3642 samples. The median age was 2 years (interquartile range [IQR] 1-4), median transport time was 4 days (IQR 2-7), and 64.1% of samples were from clinics or health posts. TB culture positivity was 1.6% (60/3642), and contamination was observed in 35.6% (1298/3642). Hospital collection was associated with lower contamination risk (adjusted OR [aOR] 0.53, 95%CI 0.40-0.69) and Mycobacteria Growth Indicator Tube vs. Löwenstein-Jensen medium with higher risk (aOR 1.88, 95%CI 1.51-2.34).
Conclusion:
In routine care settings, high sample contamination and low TB culture yield were observed. This raises questions about the collection technique and storage in lower-level facilities and affirms higher risk with a liquid culture medium.
Related Concept Videos
01:26Factors Affecting the Risk of Infection
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...
01:16Contaminants and Errors
Another key consideration is determining the appropriate number of samples required to...
01:16Gastric Emptying
01:12Relative Risk
01:16Gastric Motility
Peristaltic Waves and Chyme Formation
Upon food entry, the stomach initiates...
01:29Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...