How accurately does Combur 9 test detect blood in the urine?

Hello,

Welcome to icliniq.com.

I have read your query and sorry for the discomfort. I saw the files you have attached (attachment removed to protect the patient's identity). In the strip of RBC (red blood cells) that is erythrocytes, there is a color change roughly corresponding to 1+ in the color chart of the Combur 9 test. Can you attach the previous lab test result?

Hematuria can be positive and reported as 1+, 2+, etc., in the normal routine examination or strip test, but hematuria is confirmed by microscopic examination of RBC in the urine. It means a lab technician or doctor, with the help of a microscope, looks for the presence of RBC in the urine to confirm the dipstick test whether the dipstick test is truly positive or false positive. According to the Comber, the strip of RBC is positive with 1+, so now you should take a lab test, both routine and microscopic examination, to confirm the hematuria. Let me explain to you a little about the definition of hematuria. A single urinalysis with hematuria is common and can result from menstruation (in females), viral illness, allergy, exercise, or mild trauma. Hematuria is called significant or persistent if

1) Greater than three RBCs/HPF (red blood cells per high power feild) on three urinalyses.

2) A single urinalysis with greater than100 RBCs, or gross hematuria.

In your case, you had traces of blood in the lab test done three months back. Here I want to ask you whether you had done a microscopic examination of urine in the last test done three months back to confirm the hematuria? Ideally, you should do a repeat microscopic examination of urine to ensure the presence of RBC in the urine. Please attach the previous lab test report and any history associated with the urinary tract to guide you better.

Thanks.

Hi,

Welcome back to icliniq.com.

Thanks for the reply, sir. I saw the files you have attached (attachment removed to protect patient's identity). I remember I have seen the reports earlier too. The microscopic examination says 1 to 2 RBC/HPF (red blood cells per high power field), which is normal, but the routine test mentions the presence of blood traces in the urine. It means a positive urine dipstick test but negative confirmation on urine microscopy examination. It does not confirm hematuria. First, you should remove the fear of cancer or related illness. You do not have such a thing. Since the test is positive in your girlfriend's urine, too, it is likely a false positive, and do not worry about it in the recent Combur test done at home.

I would suggest you take a routine and microscopic examination of urine from the lab, as three months have already elapsed, and then compare the results to know various parameters of the urine sample. (Same suggestion I gave you last time as I remember repeating the test after 2 to 3 weeks). After doing the test, please send me reports to give you a complete explanation and help you to allay your fear. You can also consult me through phone or video consultation as it becomes easier to conversate than the chat query if you are worried.

Thanks.

Hi,

Welcome to icliniq.com.

It is not about trusting one test over another. It is about confirming positive dipstick test results with microscopic examination to look for RBC (red blood cells), the confirmatory test for hematuria. To confirm hematuria microscopic examination of urine is done. So if the dipstick test is reported as 1+ or 2+ that is positive by the lab, then it is confirmed with microscopic examination to assign the diagnosis of hematuria. On the other hand, suppose the dipstick result is positive for blood, but no RBCs are found in the urinary sediment when analyzed on urine microscopy. In that case, that indicates myoglobinuria or hemoglobinuria due to infection, etc. That is why the clinician advises a repeat test to see whether the RBC is still coming in the routine and urine microscopy and if the repeat lab results give similar findings, then further investigation is done to find out the etiology, but if the repeat lab test is normal then nothing further testing is needed. I hope you are getting my point.

I would again suggest you repeat the lab test, and then the attending clinician would be in a better position to guide you. You can also send me the reports of a repeat lab test. I hope I can convey my message and guidance to you properly. If you have any further queries, you can consult me through phone or video consultation as it becomes easier for both of us to discuss the question.

Thanks.

Hi,

Welcome back to icliniq.com.

Myoglobinuria or hemoglobinuria is an entirely different thing. It needs further workup tests to confirm the above and differentiate between them and further tests and medical history to identify the etiology causing such findings. In simple words, you need and should do a repeat lab urinalysis to assess the present condition and compare it with the earlier result. After the repeat test result, I can comment and suggest whether it is worrying or no worry. Your earlier test needs to be followed up with another lab test, and you should take the test. Do not worry about cancer or the related illness you asked about above in the query. Keep yourself positive and try to follow the suggested opinion as your primary attending doctor also guided you to repeat the lab test.

Take care. Thanks.

Hello,

Welcome back to icliniq.com.

I have read your query, and thanks for the follow-up. Let me explain to you. The urine specific gravity test compares the concentration of the solute particles present in the urine. The specific gravity of the urine range from 1.003 to 1030. You have mentioned the present value as 1.010, and it is normal and nothing to worry about. The last value was 1.020, which is still in the range. So both values are in the range. If the value is high above the upper limit or low below the lower limit, it requires further interpretation and other urine results. A high specific gravity value means either the solvent is low, e.g., dehydration, diarrhea, vomiting, or the solute is high, e.g., glucose, proteins. A low specific gravity value means more of the solvent in the urine, e.g., diabetes insipidus, excess water consumption, polydipsia, etc.

The microscopic examination of urine shows the presence of 3 RBCs/HPF (red blood cells per high-power field). This does not signify hematuria, as the 0 to 3 range is normal in the urinalysis result. The American Urological Association defines clinically significant microscopic hematuria as three or more red blood cells per high-power field on microscopic evaluation of urinary sediment from two of three properly collected urinalysis specimens. You mentioned all other reports are normal or negative. This is a good indicator of health status, sir, as the specific gravity is normal, and there is no hematuria present in the urine. What is mentioned in the chemical examination of the urine? Can you attach the report, sir?

Please reply to guide you further.

Thanks.

Hi,

Welcome back to icliniq.com.

I saw the reports you have attached (attachment removed to protect the patient's identity). The erythrocytes are negative and microscopic examination for RBC is between 0 to 3 per HPF (high power field). It is normal to report, sir. There is no microscopic hematuria present in the urine. Last time in your report, you had positive erythrocytes in the biochemical examination. So I suggested you do a repeat test that really worried your last report, and here it is, and the report is normal in terms of microscopic hematuria. Normally no bacteria should be seen in the urinary sediment. But sometimes, it can be found in the urine. It should be correlated with other urinalysis reports to diagnose symptomatic or asymptomatic bacteriuria. If there are no symptoms of urinary tract infection, then it is termed asymptomatic bacteriuria and is generally not treated. A urinalysis with positive tests for nitrites, leukocyte esterase, and bacteria highly suggests a urinary tract infection.

In your test, the nitrites are harmful, and there are normal WBC and pus cells in your report, so it is asymptomatic bacteriuria. Urine culture with sensitivities is recommended if bacteriuria is found and a UTI (urinary tract infection) is suspected. Do you have any symptoms of UTI like

1) Frequent and urgency in the micturition.

2) Burning micturition.

3) Low-grade fever.

It is asymptomatic bacteriuria if you do not have symptoms consistent with UTI. I would suggest you maintain adequate hydration and watch for any symptoms of UTI if they occur in the upcoming time. I hope you find my reply helpful. Please follow up if you have a further related query. Take care

Thanks.

Hi,

Welcome to icliniq.com.

Microscopic urine examination says 0 to 3 means it could be anything between 0 to 3 RBC/HPF (red blood cells per high power field). It is normal to occur in the urinalysis microscopic examination for RBC. You asked which one is the worst? The earlier or recent one, right? Both are normal reports and within the range, and nothing to worry about. Also, a urine dipstick test is done in the morning and 30 minutes before is negative, and it is also confirmed with the normal microscopic examination of urine for RBC. Hence there is no microscopic hematuria in your case with the above report of urinalysis regarding the answers to my UTIs (urinary tract infection) questions. You do not have symptoms of UTI, and urine biochemical examination for UTI is normal; that is, nitrite, WBC, and pus cells in a microscopic exam are normal except few bacteria in the urine sample. It could be due to contamination as well. Hence according to the medical history and lab report of urine, it is asymptomatic bacteriuria, and no treatment is required. You may do a quantitative culture and sensitivity test to know whether the bacteria is present in a significant no. If it is less than 100000 CFU (colony forming unit) per ml, then definitely no treatment is needed. Also, please have an opinion from your treating physician over the presence of bacteria in the urine and whether to do culture and sensitivity testing or not. Drink plenty of water and maintain adequate hydration all the time. I hope I have sorted out your confusion regarding the hematuria in the urine report. Please follow up if you have a further related query. Take care. Thanks.

Hi,

Welcome back to icliniq.com. Please do have an opinion from your treating physician regarding the report, and you will have better guidance and care. Thanks.