How is H.pylori infection diagnosed?
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Dear Doctor, An endoscopy was performed for my wife, and a biopsy was taken to test the presence of H Pylori. We were told that the bacteria is said to be present if the slide turned pink or red from yellow. The slide was yellowish for about 2 hours until we left the hospital. So, the doctor advised that the bacteria is absent. When we took a look at it after about 24 hours, it looks pink. Does this mean that there's an infection? Note: She was treated for the same bacteria about 6 months ago using HP kit.
Posted Wed, 19 Feb 2014 in Digestion and Bowels
Answered by Dr. Ratnakar Kini 17 hours later
Brief Answer: Answer given below Detailed Answer: Hi, Thanks for posting your query. I am Dr.Ratnakar Kini and I am pleased to assist you. The test that was done is called Rapid Urease Test. As the name suggests, the test is for a rapid diagnosis and is done within a few minutes. Since it did not change color for nearly two hours, the test can be regarded as negative for H.pylori. Whatever you saw after 24 hours should not be taken in to consideration and so she is negative for H.pylori infection. To help you understand the test better - H.pylori produces an enzyme called urease which is what is detected in this test. The biopsy bit is placed in the test kit which contains urea and phenol red. If the tissue has the bacteria, then urease should be present. This urease splits the urea in the test kit in to ammonia and carbon dioxide. This increases the pH. The increase in pH changes the color from yellow to pink due to the presence of phenol red. This is a rapid reaction. So your wife is negative for H.pylori infection. I hope that answers your question. Let me know if I can assist you further. Regards, Dr.Ratnakar Kini
Follow-up: How is H.pylori infection diagnosed? 2 minutes later
Dear Dr XXXXXXX Thank you for your help. I am relieved that there's no need for another antibiotic kit. Just out of curiosity, why did the slide turn pink after a day? Thanks, XXXX
Answered by Dr. Ratnakar Kini 5 minutes later
Brief Answer: Answer given below Detailed Answer: Hi, It is difficult to say why it changed color after 24 hours. As mentioned earlier, the slide just detects a change in pH. Let me know if I can assist you further. Regards, Dr.Ratnakar Kini