a. Military bases
b. College dormitories
c. Day care centers – infants are the most susceptible
d. Prisons – correctional institutions
e. Other closed environments
Mortality – is about 85% if untreated & 1% with the best treatment
Mode of Transmission: Spread by aerosol, cough, fomites
gram – pleomorphic bacilli, requires chocolate agar, aerobic
After vaccine development, replaced by meningococcal meningitis on the #1 spot.
Hib meningitis occurs mostly in children under age 4.
30 – 50% of children are carriers of this organism. Hib is a common NF in the throat.
3% of adults are carriers; have acquired immunity
Gram +, encapsulated, diplococci
Alpha hemolytic on BAP, greenish, thick gelatinous colonies
A common inhabitant of the nasopharyngeal region
70% of the general population are carriers.
Is called pneumococcal because the organism is famous for causing pneumonia
Sometimes Group C (Streptococcus dysgalactiae) or Group G
Dogs & family pets can be carriers.
Can be picked up from contaminated food, milk, & water.
Adenoids & lymph nodes in the neck swell
Tonsils become quite tender, will see white pus-filled lesions
Chills, headache, acute throat soreness when swallowing, nausea, vomiting
Absence of cough and nasal discharge – will differentiate strep throat from the common cold
Pneumococcal pneumonia – pneumonia caused by Streptococcus pneumoniae; most dangerous; can be fatal; involves the bronchi & alveoli; endogenous; infiltrates blood and pleura
Causes 95% of all bacterial pneumonias
Gram + in pairs, lancet shaped, encapsulated
Its capsules make the bacteria resistant to phagocytosis
Treatment: Penicillin and fluoroquinolones are the drugs of choice
Diagnosis: + blood culture
Short generation time of organism
This type of pneumonia infiltrates blood and pleura; involves the bronchi and alveoli
Most cases are endogenous – coming from the person’s own organisms in the body
Note: 75% of humans have Streptococcus pneumoniae growing in their mouths and pharynges but the organism does not cause harm. Although this organism is extensively studied, it remains as a medical mystery because researchers have not been able to fully explain how it turns into a pathogen.
Pneumococcal pneumonia is very dangerous; can be fatal
Most cases of pneumonia caused by this organism is endogenous because Haemophilus influenzae is NF in the nose.
Will see this type of pneumonia in individuals with other conditions e.g., alcoholism, poor nutrition, cancer, diabetes
Common in COPD patients and smokers, emphysema
Many H. influenzae strains produced Beta lactamase
Drug of choice: Second generation cephalosporins
Requires special media to grow
Similar to Pseudomonas, it likes water
Natural habitat of organism: tap water, cooling towers, shower heads, spas, supermarket produce sprayers, air conditioners, ornamental fountains, humidifiers and vaporizers in patient’s rooms, also in symbiosis with amoebas, free living in soil.
Legionnaire’s disease – most common in males over 50 years of age. Not communicable from person to person.
Mode of transmission: organism enters the patient’s lungs as an aerosol, organism gets airborne
Symptoms: rising fever up to 41°C, chills, headache, vomiting, cough, diarrhea, abdominal pain, fluid in the lungs, chest pain, profuse sweating, mental disorders
Incubation period: 2 – 10 days
Treatment: Erythromycin is the drug of choice or in combination with Rifampin.
Colonies of M. pneumoniae has a distinctive fried-egg appearance.
Causes primary atypical pneumonia or Mycoplasma pneumonia, a mild pneumonia with insidious onset.
b. Some patients have no signs or symptoms related to their respiratory tract – only low-grade fever & malaise.
c. Patients are able to walk around
d. Size of alveoli is decrease – do not fill up with fluid
This type of pneumonia gets confused with viral pneumonia. Usually prevalent in winter and early spring. Common in young adults and children (5 – 19 yrs old)
Symptoms: Low-grade fever, cough, headache
Drug of Choice: Tetracycline (can’t use with children) or erythromycin is alternative