Is strep a bacterial infection ? can strep affect the nose and throat and respiratory system ?

Yes: Strep is streptococcus, which is a small round bacterium. Strep pyogenes can cause a throat infection, which can affect swallowing. Strep pneumoniae is a different strain that can cause pneumonia, ear infections and sinus infections. Other forms of strep can affect different areas. Generally, and especially for contagion purposes, it should be treated.