My 2yr old grandson was diagnosed with bronchiolitis and pnemonia. is the pnemonia contagious?

Yes if untreated: Pneumonia and bronchitis are both contagious respiratory infections. However, once an antibiotic is started, bacterial infections are no longer contagious (but viral infections remain contagious since they don't respond to antibiotics.).

Yes: His bronchiolitis is probably due to rsv, which is very contagious. The "pneumonia" may be bacterial, but it may also be something called atelectasis. Atelectasis is when part of the lung "closes down" due to the congestion (not really due to an infection).

Yes: Infections of the respiratory tract are contagious, but take different forms in different people depending upon age, immunity and a multitude of factors. Thus one person ahs pneumonia, the next a sinus infection and the last cold symptoms only. Good handwashing and avoidance are the best prevention.

The infection is: Infections such as RSV may cause lower respiratory tract infections. But another child with the same virus won’t necessarily develop a lower respiratory tract infection. They may have an upper respiratory tract infection.