Passage: Pneumonia is typically diagnosed based on a combination of physical signs and a chest X-ray. In adults with normal vital signs and a normal lung examination the diagnosis is unlikely. However, the underlying cause can be difficult to confirm, as there is no definitive test able to distinguish between bacterial and non-bacterial origin.The World Health Organization has defined pneumonia in children clinically based on either a cough or difficulty breathing and a rapid respiratory rate, chest indrawing, or a decreased level of consciousness. A rapid respiratory rate is defined as greater than 60 breaths per minute in children under 2 months old, greater than 50 breaths per minute in children 2 months to 1 year old, or greater than 40 breaths per minute in children 1 to 5 years old. In children, low oxygen levels and lower chest indrawing are more sensitive than hearing chest crackles with a stethoscope or increased respiratory rate. Grunting and nasal flaring may be other useful signs in children less than five years old. Lack of wheezing is an indicator of Mycoplasma pneumoniae in children with pneumonia, but as an indicator it is not accurate enough to decide whether or not macrolide treatment should be used. The presence of chest pain in children with pneumonia doubles the probability of Mycoplasma pneumoniae.In general, in adults, investigations are not needed in mild cases. There is a very low risk of pneumonia if all vital signs and auscultation are normal. In persons requiring hospitalization, pulse oximetry, chest radiography and blood tests – including a complete blood count, serum electrolytes, C-reactive protein level, and possibly liver function tests – are recommended. Procalcitonin may help determine the cause and support who should receive antibiotics. Antibiotics is encouraged if procalcitonin level reaches 0.25 μg/L, strongly encouraged if it reaches 0.5 μg/L, and strongly discouraged if the level is below 0.10 μg/L. For those with CRP less than 20 mg/L without convincing evidence of pneumonia,...

Question: What is the treatment based on?
the presence of influenza in the community or a rapid influenza test