Urine test strips show 125+ leucocytes and 0.3+ protein. no traces os blood or nitrite. no pain, fever or other symptoms. can it still be an infection what is the most likely cause?

Possible: Small amounts of protein normal in the urine. Larger amounts may indicate kidney problem. How did you collect the urine? This will have an impact on the amount of leucocytes in the sample. What was the indication for the collection? This will guide interpretation as well. If you are pregnant, even if a symptomatic , your OB will discuss treatment options with you.

Possible UTI: With those findings this could certainly be a uti. If you have symptoms of urine burning sensation, urgency, frequency, little urine production, bladder fullness it is the most likely problem. However, if you have no specific symptoms it might be necessary to order a urine culture for confirmation. It could also be contamination, a culture can definitely confirm that.