Does Trichomoniasis ("trich") exist without sexual transmission in the vagina? I am asking this due to an ongoing investigation into a misdiagnosis and wrong medication given.

I have been told by 2 UK GP's at the same surgery that Trichomoniasis ("trich") is in the vagina and therefore a suspected infection of a female did not have to be a specifically sexually transmitted infection. Everything I have read online contradicts them. I believe they are saying this because one of their doctors prescribed Metronidazole for "suspected Trichomoniasis" and then told the patient a week later after they had taken the whole course that the wrong antibiotic had been given. The real problem was found to be E.coli when the urine was actually tested and the only symptom they had originally was very smelly urine. I am honestly confused by what they are saying but I do cynically think this is their way of getting around it being mis prescribed as a suspected STI - they can blur the lines of it by saying it actually just exists in the vagina so the Doctor is not at fault for suspecting it. They keep telling us they often prescribe Metronidazole without any tests beforehand if they believe the patient has it. The patient is 72 years of age and use of the antibiotic has harmed them greatly and no urine or swab was taken beforehand. I would also like to point out there is no chance of it being dormant in the female patient who has had checks before, no new partner or anything sexual going on and the Metronidazole was shown to have no affect on the urine sample. There were no parasites. Thank you anyone who answers.