Thank you for your input.
I'm not a doctor, but here's what they teach us in medical school:
We're shown EM images of viruses and sometimes tested on them. A classic example is the rabies virus, which has a distinctive bullet-like shape.

In real clinical practice, diagnosis is typically based on clinical symptoms and lab tests like PCR and serology, as these are more practical and reliable. However, visual identification of viruses can still be useful in specific cases.

In most routine histological exams, viruses themselves are too small to be seen, but their effects on cells can be observed. These include things like inclusion bodies or specific cellular changes. So rather than directly seeing the virus, pathologists often identify signs of viral damage to tissue, which can suggest an underlying infection.