| METHODS OF H PYLORI TESTING |
| MODALITY |
ADVANTAGES |
DISADVANTAGES |
| Noninvasive |
| Urea breath test (UBT) |
- Highly specific and sensitive
- Reliable, inexpensive, rapid, quantitative
- Gold standard test for asymptomatic patients
- Most valuable for assessing response to therapy after 4-8 weeks
- Useful for eradication confirmation
|
- Rarely with false-positive results due to urease-positive organisms
- Provides no information about antibiotic resistance
- Requires withholding of some medications prior to testing
|
| Stool antigen test |
- Highly specific and sensitive
- Rapid, simple and can be modified
- Enzyme-linked immunosorbent assay (ELISA) is the most accurate
|
- Requires withholding of some medications prior to testing
|
| Serology |
- Rapid, quantitative, inexpensive
- May be used to rule out H pylori infection
- Not affected by gastrointestinal bleeding
- Not affected by antibiotic or PPI use
|
- Low sensitivity and specificity
- Not for successful eradication confirmation
- Does not distinguish between active and past infection
|
| Invasive |
| Endoscopy with biopsy and rapid urease test (RUT) |
Endoscopy:
- Permits inspection of pathology
- Allows detection of ulcers, neoplasm
- Allows detection of bleeding
RUT:
- Highly sensitive and specific
- Rapid
- Inexpensive
- Easy-to-use test in a clinical setting
|
Endoscopy:
- Invasive, expensive
- Unable to visualize H pylori
RUT:
- Requires withholding of some medications prior to testing
|
| Culture |
- Highly specific
- Permits determination of antimicrobial susceptibility
|
- Low sensitivity
- Expensive
- Time-consuming
- Expert personnel and care during transport required
- Requires withholding of some medications prior to testing
|
| Histology |
- Highly specific, simple and inexpensive
- More sensitive than RUT and culture
- Allows direct visualization of organism and provides information on associated pathology (eg atrophic gastritis, intestinal metaplasia, gastric cancer)
|
- Several days for result
- Nature of tissue involvement
- With high rate of false-negative results
- Requires withholding of some medications prior to testing
|
| Polymerase chain reaction (PCR) |
- Very good specificity sensitivity
- Liquid phase (DNA-enzyme immunoassay) and reverse dot blot probe assay (LiPA) increase PCR's specificity and sensitivity
- Rapid and accurate results
- Permits determination of antimicrobial susceptibility and virulence typing
|
- Expensive
- Expert personnel and longer time to process required
- Not widely available
|
Helicobacter pylori Infection_Diagnostics