Expert Opinion :
The common organisms causing pneumonia in this age group are:
• Streptococcus pneumoniae
• Hemophilus influenza b (Hib)
• Staphylococcus aureus
• Atypical organisms such as Chlamydia pneumoniae
• Viral pneumonia.
This child has high counts and has bronchopneumonia with effusion. Hence viral pneumonia seems unlikely. The atypical organisms usually cause cough and breathlessness and have crepitations. Also in infants, chlamydia pneumonia is usually seen following neonatal conjunctivitis due to Chlamydia infection. Mycoplasma and ureaplasma are usually seen in school going children. Thus, atypical pneumonias cause more signs of interstitial lung disease rather than lobar pneumonia and also seem unlikely in this child. Among the bacterial infections, Hib is the commonest organisms in this age group and can lead to effusions. Streptococcus pneumoniae leads commonly to lobar pneumonia whereas staphylococcus aureus leads to a rapidly progressive necrotizing pneumonia with deterioration in a matter of hours. Thus most likely cause of pneumonia in this child is a Hib infection. This child’s respiratory PCR panel grew H influenza b and he responded to ceftriaxone.