References:
- Global Infectious Diseases and Epidemiology Online Network: Infectious Diseases of the Philippines, 2013 eBook Edition, ISBN 978-1-61755-582-4, by Stephen Berger. Accessed here.
Bacterial Pneumonia
| Agent | BACTERIUM. Streptococcus pneumoniae, Klebsiella pneumoniae ssp pneumoniae, other aerobic and facultative gram negative bacilli, etc. |
| Reservoir | Human |
| Vector | None |
| Vehicle | Droplet Endogenous infection |
| Incubation Period | 1 to 3 days |
| Diagnostic Tests | Culture of sputum, blood Analyze (“grade”) sputum cytology to assess significance of culture |
| Typical Adult Therapy | Antimicrobial agent(s) appropriate to known or suspected pathogen |
| Typical Pediatric Therapy | As for adult |
| Vaccine | Pneumococcal |
| Clinical Hints | Rigors (“shaking chills”), pleuritic pain, hemoptysis, lobar infiltrate and leukocytosis; empyema and lung abscess suggest etiology other than pneumococcus; foul sputum with mixed flora may herald anaerobic (aspiration) pneumonia. |
| Synonyms | Bacterial pneumonia, Empiema, Empyeem, Empyem, Empyema, Empyeme, Lung abscess, Neumonia, Pleurisy, Pneumococcal infection - invasive, Pneumococcal pneumonia, Polmonite batterica, Streptococcus pneumoniae, Streptococcus pneumoniae - invasive |
The designation “bacterial pneumonia” is generic, and includes a large variety of etiological agents and anatomical presentations (i.e., empyema, lung abscess, lobar vs. broncho-pneumonia, etc.)
- The clinical features of bacterial pneumonia are largely determined by the infecting species and clinical setting.
- All forms are characterized by fever, chest pain, productive cough, and physical or roentgenographic evidence for pulmonary consolidation.
Etiological associations:
- AIDS: Pneumocystis jiroveci, Mycobacteria (non-tuberculous), Tuberculosis, Nocardiosis, Cryptococcosis, Cytomegalovirus
- Animal contact: Q-fever, Ornithosis
- Aspiration: Oral Anaerobes; if nosocomial, Enterobacteriaceae, Acinetobacter, Pseudomonas
- Cystic fibrosis (Fibrocystic disease) • Burkholderia cepacia
- Drowning (“near-drowning”): Pseudoallescheria boydii
- Endocarditis: Staphylococcus aureus
- Immunosuppression: Aspergillosis, Cryptococcosis, Nocardiosis, Pneumocystis jiroveci, Cytomegalovirus
- Infant: see Respiratory syncytial virus, Parainfluenza virus, Respiratory viruses • misc.
- Influenza: Influenza virus, Streptococcus pneumoniae, Staphylococcus aureus
- Myeloma: Streptococcus pneumoniae
- Nosocomial pneumonia: Enterobacteriaceae, Acinetobacter, Pseudomonas, Staphylococcus aureus
- Pulmonary alveolar proteinosis: Nocardia
- Traveler or tourist: Histoplasmosis, Legionellosis, Melioidosis
Pneumocystis Jirovecii Pneumonia
| Agent | FUNGUS. Ascomycota ?, Archiascomycetes, Pneumocystidales: Pneumocystis jiroveci (now separate from Pneumocystis carinii) |
| Reservoir | Human |
| Vector | None |
| Vehicle | Air (questionable) |
| Incubation Period | 4 days to 8 weeks |
| Diagnostic Tests | Identification of organisms in induced sputum, bronchial washings, tissue Serology Nucleic acid amplification |
| Typical Adult Therapy | Therapy: Sulfamethoxazole/trimethoprim 25 mg/5 mg/kg QID X 14d. OR Pentamidine 4 mg/kg/d X 14d. OR Dapsone + Trimethoprim. OR Atovaquone OR Primaquine + Clindamycin Prophylaxis - similar, but at altered dosage. Dapsone also used. |
| Typical Pediatric Therapy | Therapy: Sulfamethoxazole/trimethoprim 25 mg/5 mg/kg QID X 14d. OR Pentamidine 4 mg/kg/d X 14d. OR Dapsone + Trimethoprim. OR Atovaquone OR Primaquine + Clindamycin Prophylaxis - similar, but at altered dosage. |
| Clinical Hints | Dyspnea, hypoxia and interstitial pneumonia; usually encountered in the setting of severe immune suppression (AIDS, leukemia, etc); roentgenographic findings (typically bilateral alveolar pattern) may follow symptoms only after several days. |
| Synonyms | PCP, Pneumocystis carinii, Pneumocystis jirovecio |
P. jiroveci infection often presents as a self-limiting upper respiratory tract infection in infants, predominantly in the age group 1.5 to 4 months of age.
The major presenting symptoms are shortness of breath, fever, and a nonproductive cough.
- Sputum production, hemoptysis and chest pain are rarely encountered.
- Tachypnea and tachycardia are usually prominent
- Children may demonstrate cyanosis, flaring of the nasal alae, and intercostal retractions.
Lung auscultation is usually not helpful, with rales present in only 1/3 of adults with this disease.
- The x-ray usually shows bilateral diffuse infiltrates extending from the perihilar region.
- Other findings can unilateral infiltrates, nodules, cavities, pneumatoceles, hilar lymphadenopathy and pleural effusion.
- Patients receiving aerosolized pentamidine as prophylaxis have an increased incidence of apical infiltrates and pneumothorax.
- Impaired oxygenation is common.
Extrapulmonary infection by P. jiroveci may occur in as many as 3% of infected patients and is reported as an unexpected finding at autopsy.
- The main sites of involvement are lymph nodes, spleen, liver, bone marrow, gastrointestinal tract, eyes, thyroid, adrenal glands, and kidneys.
- The clinical correlate of these findings is rapidly progressive multisystem disease, an enlarging thyroid mass, pancytopenia, retinal infiltrates, pleural effusion, splenic lesions, and calcifications in the spleen, liver, adrenal, or kidney.
- Rare instances of intestinal pseudotumor and cutaneous infection have been reported.