To determine whether a baby has a fever that is viral or bacterial, tests related to routine blood work, C-reactive protein, calcitoninogen, sputum culture, and mycoplasma antibodies can be perfected. In bacterial infections, white blood cells are higher than normal, neutrophils and neutrophil percentage are higher than normal, C-reactive protein and calcitoninogen will show corresponding increases, and sputum culture can be cultured for bacteria. In viral infections, leukocytes are normal or below normal, lymphocytes can be above or below normal, monocytes are usually increased, and viral antibodies can be positive; C-reactive protein and calcitoninogen are usually normal. The treatment of different infections varies, for example, for bacterial infections, antibiotics such as cefixime, amoxicillin, azithromycin, etc. For viral infections, antipyretic, detoxifying or antiviral drugs such as busulfan, oseltamivir, etc. are needed.