Pneumonia by Age
Negative-stranded RNA virus that is the most common cause of atypical pneumonia in infants.
What is Respiratory syncytial virus (RSV)?
Opportunistic infection in compromised hosts, especially in post-transplant patients. Found in the Mississippi and Ohio River Valley. Transmitted by inhalation of bird or bat droppings. Calcified lung lesions may become cavitary in chronic progressive form.
What is Histoplasma capsulatum?
Most common cause is community acquired pneumonia. Gram-positive cocci in pairs or short chains.
What is Streptococcus pneumoniae?
Common cause of nosocomial pneumonia, especially in the elderly following infection with influenza. Often complicated by abscess or empyema. Catalase-positive and coagulase-positive.
What is Staphylococcus aureus?
Most likely pathogen in neonates (0-6wks). Catalase-negative, Beta-hemolytic and Bacitracin disc resistant
What is Streptococcus agalactiae (group B)?
Frequently affects AIDS patients. Appears as dark ovoid sporozoites within cysts on silver stain.
What is Pneumocystis jirovecii?
Intracellular organism that is best visualized on silver stain and requires special media to grow--charcoal yeast extract agar. Transmitted from water sources.
What is Legionella pneumophila?
Common cause of pneumonia in Cystic fibrosis patients. Gram-negative bacilli. Oxidase-positive.
What is Pseudomonas aeruginosa?
Common cause of community acquired pneumonia in middle-aged adults and elderly. Catalase negative, alpha-hemolytic and optochin disc senstive.
What is Streptococcus pneumoniae?
Opportunistic infection that characteristically has a thick polysaccharide capsule. Appears as budding yeast in India ink stain. Found in bird droppings, especially pigeon droppings
What is Cryptococcus neoformans?
Most common cause of atypical pneumonia, usually affects young adults. Classically military recruits or college students living in a dormitory
What is Mycoplasma pneumoniae?
Alcoholics are at greater risk of infection from this pathogen. Its thick mucoid capsule results in gelatinous sputum. Causes lobar pneumonia.
What is Klebsiella pneumoniae?
Second most common cause of atypical pneumonia in young adults. Obligate intracellular organism. Does not show up on Gram stain.
What is Chlamydia pneumoniae?
Opportunistic infection that has septate hyphae branching at a 45-degree angle in tissue. Primarily affects neutropenic patients.
What is Aspergillus fumigatus?
Will not grow on sheep agar alone, but will grow on sheep agar with S. aureus. Common cause of pneumonia superimposed on COPD and can lead to COPD exacerbation.
What is Haemophilus influenzae?
Causes aspiration pneumonia, especially in patients at risk for aspiration like comatose patients. Classically results in a right lower lobe abscess.
What are anaerobic bacteria?
Atypical pneumonia in the elderly. Increases the risk for superimposed S. aureus or H. influenzae bacterial pneumonia. Negative stranded RNA virus.
What is the influenza virus?
Causes atypical pneumonia with posttransplant immunosuppressive therapy. Double-stranded DNA, enveloped virus.
What is Cytomegalovirus (CMV)?
Atypical pneumonia with high fever (Q fever) that is commonly seen in farmers and veterinarians
What is Coxiella burnetti?