Some time ago a friend of mine came to me at her whits end..”Amina, I don’t understand what is going on! I’ve had a UTI (urinary tract infection) that’s just not going away and I don’t know what else to do! I’ve taken 3 rounds of antibiotics and the doctor told me today it’s still there and gave me another prescription! What do you think?”
My first question was “do you have any symptoms? Any burning when you pass urine, blood in the urine, pain in the pelvis, urgency – as in… do you have to rush to go and just a little urine comes out each time?” She said no to everything, so I was like, “well you don’t have a UTI!”
The next question was “how did you give the sample?” She said “I just pee’d into the cup they gave me”.
So a couple things wrong here, first of all, the urine should not be tested for UTI in the absence of symptoms. My friend was having a routine medical I think for life insurance. Or it may have been her yearly physical. In those cases the reasons for looking at the urine include making sure there is no blood or protein in it, things that may signify some sort of kidney disease. Additionally, the doctor may be screening for STIs (sexually transmitted infections), particularly gonorrhea and chlamydia, which may be asymptomatic in women (more on that in a future post).
The other thing is, when giving the sample for a urine test, especially if you are checking for infection, there is a special way to provide the sample. After wiping from front to back with a moist towelette, the first bit of urine is to be passed into the toilet, to flush away the germs that would be at the entrance of the urine tube (the urethra, which leads from the bladder to outside); these germs will contaminate the sample making it test positive when they are not actually causing infection, they are just the normal germs which hang out at various parts of the body. After passing out the first bit of urine, then the container is put in place to catch some urine, then after there is enough in the container, the last bit of urine from the bladder goes into the toilet. The sample is called a “mid-stream” or “clean catch” urine sample.
My friend had urine samples that were falsely positive for infection. The cultures were positive for bacteria because the samples were collected incorrectly, but she did not have an infection. She was never told how to give the samples so all the subsequent samples were positive and she took round after round of antibiotics to no avail. Poor girl. Anyway I explained everything to her, told her to stop the antibiotics and she was quite relieved.
Now I will admit that there are times that patients give the appropriate “clean catch” urine specimen but the culture still comes back positive. In those cases, it is important to look at the analysis of the urine which shows if there are pus cells in the urine. In the absence of a significant amount of pus cells, the positive culture represents “colonization” rather than infections. Colonization just means that the germs are “hanging out” but not causing actual infection with irritation from inflammation. (One of the few cases where bacteria in the urine without symptoms is to be treated is in pregnant women.)
Many people get a little scared if they hear that there is a positive culture, as if they think the germs are going to eat them alive, but the thing is we have germs all over our body (well except some places like the blood stream and the brain which are sterile, i.e. no germs present at all). We became unsterile the moment we emerged from the womb. Cultures of many areas of the body will be positive for that reason and all positive cultures must be interpreted in the context of symptoms present, and the patients overall medical/health condition.
In terms of UTIs, elderly patients may be a bit different sometimes and some of those issues will be covered in future posts. As always, see your personal doctor for evaluation and advice.