Table 2.
Rare microorganisms causing pediatric community-acquired pneumonia or occurring in specialized populations
| Microorganism | Comment |
|---|---|
| Viruses | |
| Varicella zoster virus | Potential complication after primary varicella infection. Often severe and associated with secondary bacterial infection. |
| Measles virus | Rubeola. Pneumonia is a frequent complication. |
| Hantavirus | Hantavirus pulmonary syndrome. Rodent exposure. |
| Bacteria | |
| Bordatella pertussis | Pneumonia uncommon manifestation. Bacterial coinfection may be severe, especially in infants. |
| Group B streptococci | Neonatal pneumonia and sepsis. |
| Listeria monocytogenes | Neonatal pneumonia and sepsis. |
| Gram-negative enterics | Neonatal pneumonia and sepsis. Potential pathogens in aspiration pneumonia. |
| Chlamydia trachomatis | Cause of afebrile pneumonia in young infants <3 mo of age. |
| Anaerobes (oral flora) | Potential pathogens in aspiration pneumonia. |
| Legionella pneumophila | Legionnaires’ disease. Rare in children but associated with community outbreaks. Exposure to contaminated artificial freshwater systems. |
| Coxiella burnetti | Q fever. Exposure to wild and domesticated herbivores or unpasteurized dairy (eg, cattle, sheep, and goats). Also potential bioterrorism agent. |
| Chlamydia psittaci | Psittacosis. Bird (eg, pet birds and pigeons) exposure. |
| Francisella tularensis | Tularemia. Rabbit exposure. |
| Yersinia pestis | Pneummonic plague. Rodent flea exposure. |
| Bacillus anthracis | Anthrax. Woolsorter’s disease. Wild and domesticated herbivore (eg, cattle, sheep, goats) exposure. Also potential bioterrorism agent. |
| Leptospira interrogans | Leptospirosis. Exposure to urine of wild and domestic animals carrying the bacterium. |
| Mycobacterium tuberculosis | Rare in US children. Usually associated with high-risk exposures. |
| Brucella abortus | Brucellosis. Exposure to wild and domesticated animals or unpasteurized dairy (eg, cattle, sheep, pigs, goats, deer, and dogs). |
| Fungi | |
| Histoplasma capsulatum | Histoplasmosis. Exposure to bird or bat droppings (eg, poultry/bird roosts and caves). Endemic to eastern and central United States. |
| Blastomyces dermaitidis | Blastomycosis. Environmental exposure to fungal spores (wooded areas). Endemic to Southeastern and Midwestern United States. |
| Cryptococcus neoformans | Cryptococcosis. Exposure to soil contaminated with bird droppings. Significant pathogen nearly exclusively among immunocompromised. |
| Coccidioides immitis | Coccidiomycosis. Valley fever. Environmental exposure to fungal spores (dry, dusty environments). Endemic to Southwestern United States. |
Adapted from Williams DJ, Shah SS. Community-acquired pneumonia in the conjugate vaccine era. J Pediatric Infect Dis Soc 2012;1(4):320. Table 2; with permission.