respimicro [recovered]
TRANSCRIPT
24Microbial Diseases of the Respiratory System
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
upper respiratory system
The consists of the nose, pharynx, and associated structures, such as the middle ear and auditory tubes.
Coarse hairs in the nose ciliated mucous membranes ( nose and
throat ) Lymphoid tissue, tonsils, and adenoids
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
lower respiratory system
consists of the larynx, trachea, bronchial tubes, and alveoli.
ciliary escalator alveolar macrophages. Respiratory mucus contains IgA antibodies.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
NORMAL MICROBIOTA OF THE RESPIRATORY SYSTEM
The normal microbiota of the nasal cavity and throat can include pathogenic microorganisms.
The lower respiratory system is usually sterile because of the action of the ciliary escalator.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Upper Respiratory System Upper respiratory normal microbiota may
include pathogens
Figure 24.1MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Microbial Diseases of the Upper Respiratory System
Laryngitis: S. pneumoniae, S. pyogenes, viruses
Tonsillitis: S. pneumoniae, S. pyogenes, viruses
Sinusitis: Bacteria Epiglottitis: H. influenzae Hib vaccine
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROBIAL DISEASES OF THE UPPER RESPIRATORY SYSTEM
These infections may be caused by several bacteria and viruses, often in combination.
Most respiratory tract infections are self-limiting.
H. influenzae type b can cause epiglottitis.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Streptococcal Pharyngitis (Strep Throat) GAS- Streptococcus
pyogenes Resistant to
phagocytosis Streptokinases lyse
clots Streptolysins are
cytotoxic Diagnosis by indirect
agglutination/ EIA
Figure 24.3MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Streptococcal Pharyngitis (Strep Throat) group A beta-hemolytic streptococci-
Streptococcus pyogenes.
Symptoms of this infection are inflammation of the mucous membrane and fever; tonsillitis and otitis media may also occur.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Streptococcal Pharyngitis (Strep Throat) Rapid diagnosis is made by enzyme
immunoassays.
Penicillin is used to treat streptococcal pharyngitis.
Immunity to streptococcal infections is type-specific.
Strep throat is usually transmitted by droplets.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Scarlet Fever Streptococcus
pyogenes Pharyngitis Erythrogenic toxin
produced by lysogenized S. pyogenes by a phage.
Figure 24.4MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Scarlet Fever
Strep throat, caused by an erythrogenic toxin-producing S. pyogenes, results in scarlet fever.
starts general malaise and swelling of neck
Symptoms include a red rash, high fever, and a SPOTTED STRABERRY like red, enlarged tongue.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Diphtheria Corynebacterium diphtheriae: Gram-
positive rod pleomorphic club shape
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Diphtheria Clinical
Start as sore throat and fever followed by general malaise and swelling of neck
Diphtheria (leather) tough grayish membrane of fibrin, dead tissue, and bacteria
Diphtheria toxin produced by lysogenized C. diphtheriae (highly virulent toxin)
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Diphtheria
Figure 24.6MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Diphtheria
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Vao day nghe bai nay di ban http://nhattruongquang.0catch.com
Diphtheria A membrane can block the passage of air. Exotoxin inhibits protein synthesis, and
heart, kidney, or nerve damage may result (fatal)
minimal dissemination of the exotoxin in the bloodstream.
Antitoxin - neutralize the toxin
Antibiotics- Penicillin and Erythromycin can stop growth of the bacteria.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Diphtheria Prevented by DTaP and Td vaccine
(Diphtheria toxoid) Cutaneous diphtheria: Infected skin
wound leads to slow healing ulcer
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
A 15 y/o male patient have chief complaint of difficulty of breathing with associated throat pain, difficulty of swallowing and fever. Physical exam reveals inflamed pharyngeal area covered by grayish thick mucus that is adherent. Patient was noted to have an incomplete set of vaccination. Grams staining reveals gram positive bacilli with endospore.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Corynebacteria (Genus Corynebacterium)• Aerobic or facultatively anaerobic
• Small, pleomorphic (club-shaped), gram-positive bacilli short chains (“V” or “Y” configurations) or in clumps resembling “Chinese letters”
• Cells contain metachromatic granules
• Lipid-rich cell wall contains meso -diaminopimelic acid
OTITIS MEDIA
infection of the middle ear, primarily in infants and young children
three manifestations• acute otitis media• chronic otitis media• otitis media with effusion
A. Symptoms - fever, pain in the ear, dulled hearing.
Otitis Media S. pneumoniae (35%) H. influenzae (20-30%) M. catarrhalis (10-15%) S. pyogenes (8-10%) S. aureus (1-2%)
RSV Affects 85% of children before age 3, and
estimated 8 million cases/ year
Figure 24.7MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Otitis Media
Treated with broad-spectrum antibiotics Amoxicillin
Incidence of S. pneumoniae reduced by vaccine
Figure 24.7MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Otitis Media
Earache, or otitis media, can occur as a complication of nose and throat infections.
Pus accumulation causes pressure on the eardrum causes inflammation and pain.
Often in children because of shorter and more horizontal eustachian tube
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
B. DIAGNOSIS –
1. clinical presentation of fever and pain, especially following an URT infection such as a cold
2. otoscopic examination to see inflammation and/or fluid (pus); also loss of mobility with air pressure
6.
• swelling and blockage • cyclic pattern of damage• discomfort - pressure and blocked nasal passages
Common cold Rhinoviruses (50%) Coronaviruses (15-20%)
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
The Common Cold
Any one of approximately 200 different viruses can cause the common cold; rhinoviruses cause about 50% of all colds.
Immunity is based on the ration of Ig A antibodies
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
The Common Cold
Symptoms Sneezing nasal secretions congestion.
Sinus infections, lower respiratory tract infections, laryngitis, and otitis media can occur as complications of a cold.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
The Common Cold
Colds are most often transmitted by indirect contact.
Rhinoviruses grow best slightly below body temperature.
The incidence of colds increases during cold weather
Antibodies are produced against the specific viruses.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Microbial Diseases of the Lower Respiratory System
Bacteria, viruses, and fungi cause
Bronchitis Bronchiolitis Pneumonia
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Lower Respiratory System The ciliary escalator keeps the lower
respiratory system sterile.
Figure 24.2MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pertussis (Whooping Cough) Bordetella pertussis:
Gram-negative coccobacillus
Capsule Tracheal cytotoxin of cell
wall damaged ciliated cells
Pertussis toxin produces systemic disease
Prevented by DTaP vaccine (acellular Pertussis cell fragments)
Figure 24.8MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Man is only natural host; obligate parasites of man
Disease is highly communicable (highly infectious)
Children under one year at highest risk, but prevalence increasing in older children and adults
Epidemiology of Bordetella pertussis Infection
Whooping cough
Inhalation of aerosols
Adhere to ciliated epithelial cells (FHA, Pili)
Toxin production
Damage to mucosal cells(TCT, Ptx, Acase, LPS?)
Act on neurons(Ptx, Acase, LPS)
Paroxysmal cough
Whooping cough
Symptoms Severe coughing, spasms, inspiratory
whoop Lymphocytosis
Stages of disease Catarrhal -> Paroxysmal -> Convalescent
Spread--highly contagious Inhalation or direct contact with secretion
Usually self-limiting Neurological sequelae Secondary respiratory infections Secondary aspiration pneumoniae
leading cause of death
Pertussis (Whooping Cough)
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pertussis (Whooping Cough)
.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Initial stage of pertussis
resembles a cold and is called the catarrhal
stage.
Paroxysmal (second)
stage
accumulation of mucus
in the trachea and
bronchi causes deep
coughs
Convalescence (third)
stage
can last for months
Clinical Progression of Pertussis
Most infectious, but generally not yet diagnosed
Inflammation of respiratory mucosal memb.
,or death
Laboratory Culture, Prevention & Treatment of Bordetella
Treatment with erythromycin
Nonmotile Fastidious and slow-growing
· Requires nicotinamide and charcoal, starch, blood, or albumin
· Requires prolonged growth · Isolated on modified Bordet-Gengou agar
Pertussis (Whooping Cough)
Laboratory diagnosis is based on isolation of the bacteria on enrichment and selective media, followed by serological tests.
Regular immunization for children has decreased the incidence of pertussis.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
TUBERCULOSIS
Situationer
Leading causes of death world wide Up to a half of world’s population
infected, 95% in developing countries 8 million people get TB every year
(WHO fact sheet 2007)
Philippines ranks 4th for # of TB cases worldwide, highest # per head in SEA
2/3 of Filipinos with TB
(DOH, 2007)
Rex Karl S. Teoxon, R.N, M.D 46
PTB
Mycobacterium tubercle, acid fast bacilli
Airborne/droplets Pott’s disease – thoracolumbar Milliary TB – kidney, liver, lungs
Rex Karl S. Teoxon, R.N, M.D 47
Rex Karl S. Teoxon, R.N, M.D 48
Morphology
Mycobacterium tuberculosis Thin straight rods, 0.4 x 3 µm Acid-fast organisms
Mycobacterial cell wall components Lipids (mycolic acids) Proteins Polysaccharides
TB symptoms
1. Cough with two weeks or more2. Sputum expectoration3. Fever4. Significant weight loss5. Hemoptysis6. Chest and/or back pains
Rex Karl S. Teoxon, R.N, M.D 52
SIGNS AND SYMPTOMS
Wt loss, night sweats, low fever, non productive to productive cough, anorexia, Pleural effusion and hypoxemia, cervical lymphadenopathy
Tuberculosis Mycobacterium
tuberculosis: Acid-fast rod; transmitted from human to human.
M. bovis: <1% U.S. cases, not transmitted from human to human.
M. avium-intracellulare complex infects people with late stage HIV infection.
Figure 24.9MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis Mycobacterium tuberculosis
Acid fast-lipid, wax Slow growth (nutrient permeability) Resist to detergent and common antibiotics
A leading cause of death by infectious disease 50% population infected, 3m death/yr Reemergence in 1980 (AIDS, homeless, immigrants)
Diagnose PPD test Chest X-ray Sputum smear (for acid-fast bacilli) Sputum culture
Diagnosis
Sputum culture Slow, 13 hour generation time, takes weeks
Acid-fast stainingSkin test (PPD)DNA hybridization PCR (16s rRNA)Bacteriophage
Rex Karl S. Teoxon, R.N, M.D 56
PPD – ID
macrophages in skin take up Ag and deliver it to T cells
T cells move to skin site, release lymphokines
activate macrophages and in 48-72 hrs, skin becomes indurated
- > 10 mm is (+)
Rex Karl S. Teoxon, R.N, M.D 57
DIAGNOSIS
Chest x ray - cavitary lesion
Sputum exam Sputum culture
Stages of disease Primary infection
Asymptomatic to flu-like 3-5% develop TB Tubercle (granulomatous response)
Reactivation (active TB) Years later, 10% experience
LRT disease (pneumonia) Disseminated miliary TB
Almost everywhere AIDS and antibiotic resistance
Stages of pathogenesis
Encounter - respiratory droplet Entry - direct inhalation into LRT
(ID=10) SPREAD - alveoli, but can spread
throughout body seeding many tissues Multiplication
Grows in phagosome of macrophage Strict aerobe Very slow in culture (24 hr doubling time)
Evade defenses Inhibits phagolysosomal fusion
Tuberculosis
Tuberculosis is caused by Mycobacterium tuberculosis.
Large amounts of lipids in the cell wall account for the bacterium’s acid-fast characteristic as well as its resistance to dryingnd disinfectants.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis
M. tuberculosis may be ingested by alveolar macrophages; if not killed, the bacteria reproduce in the macrophages.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis
Lesions formed by M. tuberculosis are called tubercles
Dead macrophages and bacteria form the caseous lesion that might calcify and appear in an X ray as a Ghon’s complex.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis Liquefaction of the
caseous lesion results in a tuberculous cavity in which M. tuberculosis can grow.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis New foci of
infection can develop when a caseous lesion ruptures and releases bacteria into blood or lymph vessels; this is called miliary tuberculosis.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
M. tuberculosis Damage
Host response to bacteria (cell-mediated immunity) Glycolipids (Freund adjuvant)
Spread to new hosts Contagious by droplet, resistant to drying
Vaccine - BCG Causes people to become PPD+, not very effective Infect AIDS
Treatment Unusual set of antibiotics (isoniazid, ethambutol,
rifampin) High mutation rate
Tuberculosis
Miliary tuberculosis is characterized by weight loss, coughing, and loss of vigor.
Chemotherapy usually involves 3 or 4 drugs taken for at least 6 months; multidrug-resistant M. tuberculosis is becoming prevalent.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis
Positive tuberculin skin test an active case of TB prior infection vaccination immunity to the disease
Induration and reddening at inoculation site within 48hours.
Most accurate- Mantoux test
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis Laboratory diagnosis is based on the
presence of acid-fast bacilli and isolation of the bacteria, which requires incubation (3-6weeks) of up to 8 weeks (Lowenstein-Jensen Agar)
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
PPD Tuberculosis Skin Test Criteria
PPD = Purified Protein Derivative from M. tuberculosis
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Chest X-Ray of Patient with Active Pulmonary
Tuberculosis
Tuberculosis
Mycobacterium bovis causes bovine tuberculosis transmitted to humans by unpasteurized
milk. affect the bones or lymphatic system. BCG vaccine -a live, avirulent culture of M.
bovis
M. avium-intracellulare complex infects patients in the late stages of HIV
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis Treatment of tuberculosis: Prolonged
treatment with multiple antibiotics. Vaccines: BCG, live, avirulent M. bovis;
not widely used in United States.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Tuberculosis
Figure 24.12MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Rex Karl S. Teoxon, R.N, M.D 78
MANAGEMENT
short course – 6-9 months long course – 9-12 months DOTS- direct observe treatment short
course Case finding Home meds (members of the family) Referrals Follow-up short course – 6-9 months long course – 9-12 months
Rex Karl S. Teoxon, R.N, M.D 79
MANAGEMENT
Follow-up * 2 wks after medications – non
communicable 3 successive (-) sputum - non communicable rifampicin - prophylactic
Rex Karl S. Teoxon, R.N, M.D 80
CATEGORIES OF TB
category I (new PTB) - (+) sputum
category II (relapse)
category III (PTB case) - (-) sputum
Rex Karl S. Teoxon, R.N, M.D 81
TREATMENT: CATEGORY 1 - NEW PTB, (+) SPUTUM
GIVE RIPE 2 MONTHS, MAINTENANCE OF RI 4 MONTHS
CATEGORY 2 - PREVIOUSLY TREATED WITH RELAPSESGIVE RIPES 1ST 2 MONTHS, REPS 1 MONTH, MAINTENANCE RIE 5 MONTHS
CATEGORY 3 - NEW PTB (-) SPUTUM FOR 3XGIVE RIP 2 MONTHS, MAINTENACE RI 2 MONTHS
* IF RESISTANT TO DRUGS GIVE ADDITIONAL MONTH/S AS PRESCRIBED
Rex Karl S. Teoxon, R.N, M.D 82
MDT side effects
r-orange urine i-neuritis and hepatitis p-hyperuricemia e-impairment of vision s-8th cranial nerve damage
AFB SMEAR REPORTING GUIDELINE, DOH
NATIONAL TUBERCULOSIS CONTROL PROGRAM (2001)
Emilio M. Ramirez, MD
National Tuberculosis Control Program (2001) prevent transmission of tubercle bacilli
to a healthy person
Goal: Reduce TB mortality and prevalence through early case detection and treatment
Target: identify at least 70% of new smear (+) cases, cure at least 85% TB patients discovered
Strategy: DOTS (directly observed treatment short course chemotheapy)
Sputum Collection Schedule forDIAGNOSIS
SPOT EARLY MORNING
SPOT
Day 1
First specimen -
collected at the time of consultation or as soon as TB symptomatic is identified.
Day 2
Second specimen
Collected in the morning by the TB symptomatic when he/she is due to submit the specimen to the health center.
Third specimen
Collected at the time the TB symptomatic comes back to the health facility to submit the second specimen.
Ideal sputum specimen?
MACROSCOPIC- Yellowish- Mucopurulent- Cheesy material
When to collect another set of 3 sputum specimens?
When the diagnosis for the sputum microscopy examination is doubtful.
When the patient fails to complete his sputum collection within two weeks from the time of the previous collection.
Ideal sputum specimen?
MICROSCOPIC- greater than 25
wbc/LPO, 5 wbc/OIO
- Presence of alveolar macrophage, dust cells
AFB STAINING
DIRECT SMEAR EXAMINATION(Flow Chart)
SMEARINGSPREADING
DRYING
FIXATION
STAININGINITIAL STAINING
HEATING
WASHING
DECOLORIZATION
WASHING
COUNTER-STAINING
WASHING
DRYING
MICROSCOPIC OBSERVATION
RECORDING & REPORTING
DIRECT SMEAR PREPARATION
LABELING THE SLIDES
Write down the identification number of the sputum specimen on the end of a clean glass slide.
SMEARING
SPREADING
With a coconut midrib, fish out one (1) loopful of purulent, solid particles of the sputum.
Spread the sputum evenly on the slide, approximately 2 x 3 cm
in size.
A Good Smear
Poor/too thick Good Poor/too thin
SMEARING
DRYING
Allow the smear to dry completely at room temperature. Do not dry it under the sun or over the flame.
Place used midribs in a bottle with alcohol and sand mixture or Lysol, or in a plastic containers and burn them later.
SMEARING
FIXATION
Fix the smear by passing it through the flame of an alcohol lamp 2 to 3 times, about 2-3 seconds each.
Heat the back of smeared surface of the slide. Never scorch the smear.
STAINING
FIXATION
Fix the smear by passing it through the flame of an alcohol lamp 2 to 3 times, about 2-3 seconds each.
Heat the back of smeared surface of the slide. Never scorch the smear.
STAINING
INITIAL STAINING
Arrange the slides on the staining bridge consecutively.
Pour carbol fuchsin solution covering the whole surface of the slide.
STAINING
HEATING OF THE SLIDE
Heat the slide using an alcohol lamp or spirit cotton in a stick ‘till steam comes off from the stain.
Do not boil and do not allow the stain to dry. Leave it for five minutes.
STAINING
WASHING OF THE SLIDE Tilt the slide to drain off excess stain.
Wash the staining solution off with a gentle stream of running water.
STAINING
DECOLOURIZATION
Tilt the slide to drain off excess rinse water.
Cover the whole slide with 3% hydrochloric acid-ethanol and leave it until solution runs clear.
Staining
WASHING OF THE SLIDE
Wash the slide with a gentle stream of running water.
Tilt the slide to drain off excess rinse water.
Staining
COUNTERSTAINING
Pour 0.1% methylene blue to cover the whole surface of the smear and leave for 5-10 seconds.
Tilt the slide to drain off excess methylene blue.
Staining
WASHING AND DRYING
Wash the slide with a gentle stream of running water.
Tilt and place the slide on the slide rack to dry in the air.
Don’t place under the sun to dry.
SMEAR READING PROPER SCANNING
Horizontal Scanning
Vertical Scanning
IMPROPER SCANNING
Zigzag Scanning
3 cm
AFB OBSERVATION
Single/parallel form
Clump form
Coccoid form
Scratches on the slide
MICROSCOPIC OBSERVATION OF AFB IN PROPERLY AND IMPROPERLY STAINED SMEAR
PROPER STAINING INSUFFICIENT HEATING
UNDERDECOLORIZED INTENSELY COUNTERSTAINED
National Standard Reporting Scale (2001)
No AFB seen in 300 visual fields 0
1-9 AFB/ 100 visual fields (x1000) +n
10-99 AFB/ 100 visual fields (x1000) 1+
1-10 AFB/ OIF in at least 50 visual fields 2+
>10 AFB/ OIF in at least 20 visual fields 3+
INTERPRETATION OF LAB RESULTS
POSITIVE - if all or at least two of the three
specimens are positive
NEGATIVE - if all (3) specimens are negative
DOUBTFUL - if one of the three specimens is positive (sputum examination should be repeated)
Bacterial Pneumonias
Typical pneumonia is caused by S. pneumoniae.
Atypical pneumonias are caused by other microorganisms.
Lobar pneumonia
bronchopneumoniaMICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pneumonias
Sign/ symptoms
High fever DOB Chest pain Productive cough
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MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Calculation of PSI score*Factor Result PSI score
Patient age 66 years + 66
Specified coexisting illness No 0
Signs on examination
Confusion Yes + 20
Respiratory rate 28 per min 0
Systolic blood pressure 140 mmHg 0
Temperature 38°C 0
Pulse rate 120 bpm 0
Results of investigations
Serum urea level 17 mmol/L + 20
Serum sodium level 136 mmol/L 0
Serum glucose level 19.6 mmol/L + 10
Haematocrit 40% 0
O2 saturation 86% + 10
pH 7.36 0
Pleural effusion No 0
Total 126
* If results of blood tests cannot be obtained rapidly (eg, in remote areas), risk can be determined without the PSI score (see Box 3). In this case, presence of diabetes, respiratory rate > 20 per minute, confusion and multilobar disease on x-ray would have suggested that the patient was at significantly increased risk of death.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Mortality within 30 days according to PSI risk class19
Pneumomoccal Pneumonia Streptococcus
pneumoniae: Gram-positive encapsulated diplococci
Diagnosis is by culturing bacteria.
Penicillin
Fluoroquinolones is drug of
choice.Figure 24.13MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pneumococcal pneumonia(Streptococcus pneumoniae)
Gram-positive diplococcus Encapsulated (>80 serotypes)
Susceptible population Elderly Previously ill Phagocytic dysfunction (e.g., asplenic, sickle
cell)
Also cause meningitis, otitis media Sensitive to optichin; autolysis by bile
Pneumococcal Pneumonia
The bacteria can be identified
alpha-hemolysins, inhibition by
optochin, bile solubility serological tests.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
120
Not optochin sensitive
optochin sensitive
Identification
Pneumococcal Pneumonia
Symptoms Fever breathing difficulty chest pain rust-colored sputum.
A vaccine consists of purified capsular material from 23 serotypes of S. pneumoniae.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Stages of pathogenesis Encounter - humans only, by respiratory
droplet
Entry - colonization of the oropharynx, aspiration into lung (pneumonia)
Spread (extracellular) Pneumonia - blood culture can be positive Meningitis - penetration of mucous membrane Otitis media- eustachian tube to middle ear
Multiplication Grows well in serous fluid in alveoli space
Evade defenses Capsule--antiphagocytic sIgA protease
Haemophilus Influenzae Pneumonia
Gram-negative coccobacillus Alcoholism, poor nutrition, cancer, or
diabetes are predisposing factors. Second-generation cephalosporins
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Mycoplasmal Pneumonia
Mycoplasma pneumoniae causes mycoplasmal pneumonia; it is an endemic disease.
Young adults and children Symptoms persist for 3 weeks and
longer (low fever, cough and headaches)
PRIMARY ATYPICAL/ WALKING PNEUMONIA
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Mycoplasmal Pneumonia
M. pneumoniae produces small “fried-egg” colonies after two weeks’ incubation on enriched media containing horse serum and yeast extract.
Diagnosis is by PCR or serological tests.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Atypical (walking) pneumonia Mycoplasma pneumonia
Lacks peptidoglycan --lactam resistant
Disease primarily in young adults Encounter - inhalation from human Entry - restricted to mucosal surface
Terminal adhesin protein (P1)
Multiplication - require sterols Damage
Inflammation Damage and desquamation of ciliated epithelium
Treatments Erythromycin, doxycycline, tetracyline
Model for mycoplasma pathogenesis in the lungs
Legionellosis
The disease is caused by the aerobic gram-negative rod Legionella pneumophila.
High fever 40.5C, cough and general pneumonia symptoms
The bacterium can grow in water, such as air-conditioning cooling towers, and then be disseminated in the air.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Legionnaire's disease/Pontiac Fever Legionella pneumophila
Gram-negative rod Stains irregularly Silver stain
Disease Pontiac Fever - flu-like in anyone (1968)
Fever muscular ache and cough(self limiting) Legionnaire's disease - pneumonia
Primarily in middle aged to older men who heavy smoker and drinker or chronically ill
1976 American Legion Convention in Philadelphia ( toll 182 cases/29 death)
L. pneumophila
Legionellosis
This pneumonia does not appear to be transmitted from person to person.
Bacterial culture, FA tests, and DNA probes are used for laboratory diagnosis.
Prevention : Copper Ionizing procedure Treatment : Erythromycin, some
macrolides like Azithromycin
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Psittacosis (Ornithosis)
Chlamydophila psittaci – gram negative intracellular bacteria and is transmitted by contact with contaminated droppings and exudates of fowl.
Elementary bodies allow the bacteria to survive outside a host.
s/sx: fever, headache , chills, some with delirium and disorientation
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Psittacosis (Ornithosis)
Commercial bird handlers are most susceptible to this disease.
The bacteria are isolated in embryonated eggs, mice, or cell culture; identification is based on FA staining.
Tx: Tetracycline
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Chlamydial Pneumonia
Chlamydophila pneumoniae causes pneumonia; it is transmitted from person to person.
Atherosclerosis-deposition of fats on arteries
s/sx resemble mycoplasma pneumonia Tetracycline is used for treatment.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Q Fever
Obligately parasitic, intracellular Coxiella burnetii causes Q fever or X fever
The disease is usually transmitted to humans through unpasteurized milk or inhalation of aerosols in dairy barns, cattle tick bites
Laboratory diagnosis is made with the culture of bacteria in embryonated eggs or cell culture.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Q Fever
Wide range of clinical symptoms 60% asymptomatic s/sx: High fever, muscle ache, headache
and coughing Hepatitis and endocarditis (persist for
months) Tx: Doxycycline , Chloroquine
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Melioidosis
Melioidosis, glanders disease (horses) caused by Burkholderia pseudomallei
transmitted by inhalation, ingestion, or through puncture wounds.
Symptoms include pneumonia, sepsis, and encephalitis.
Tx: Ceftazidime
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Disease Symptoms
Streptococcal pharyngitis Pharyngitis and tonsillitis
Scarlet fever Rash and fever
Diphtheria Membrane across throat
Whooping cough Paroxysmal coughing
Tuberculosis Tubercles, weight loss, and coughing
Pneumococcal pneumonia Reddish lungs, fever
H. influenzae pneumonia Similar to pneumococcal pneumonia
Chamydial pneumonia Low fever, cough, and headache
Legionellosis Fever and cough
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Disease Symptoms
Psittacosis Fever and headache
Q fever Chills and chest pain
Epiglottitis Inflamed, abscessed epiglottis
Melioidosis Delayed-onset pneumonia
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Diagnostic
Gram-positive cocci
Catalase-positive Staphylococcus aureusBeta-hemolytic Streptococcus pyogenesAlpha-hemolytic S. pneumoniae
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Gram-positive rods Not acid-fast Corynebacterium
diphtheriaeAcid-fast Mycobacterium
tuberculosis
Gram-negative cocci Moraxella catarrhalis
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
a. Streptococcus pneumoniae
b. Haemophilus influenzae -
c. Moraxella catarrhalis -
Gram-negative rodsAerobes
Coccobacilli Bordetella pertussisRods
Grow on nutrient agar Burkholderia pseudomalleiRequire special media Legionella pneumophila
Facultative anaerobesCoccobacilli Haemophilus influenzae
IntracellularElementary bodies Chlamydophila psittaciNo elementary bodies Coxiella burnetii
Wall-less Mycoplasma pneumoniae
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Viral Pneumonia
A number of viruses can cause pneumonia as a complication of infections such as influenza.
The etiologies are not usually identified in a clinical laboratory because of the difficulty in isolating and identifying viruses.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Respiratory Syncytial Virus (RSV) RSV is the most common cause of
pneumonia in infants 2-6months Life threatening- tx Ribavirin and
Palizumab Coughing, wheezing last more than a
week, fever by bacterial infection
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Influenza Hemagglutinin (H)
spikes used for attachment to host cells.
Neuraminidase (N) spikes used to release virus from cell.
Figure 24.16MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Influenza Antigenic shift
Changes in H and N spikes Probably due to genetic recombination
between different strains infecting the same cell
Antigenic drift Mutations in genes encoding H or N spikes May involve only 1 amino acid. Allows virus to avoid mucosal IgA antibodies.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Influenza Serotypes A: Causes most epidemics, H3N2, H1N1,
H2N2
B: Moderate, local outbreaks C: Mild disease
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Influenza
Deaths during epidemic - secondary bacterial infections.
Multivalent vaccines for the elderly and other high-risk groups.
Amantadine and rimantadine are effective prophylactic and curative drugs
Zanamivir and oseltamivir
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
152
SARS
Coronavirus Severe acute respiratory syndrome
IP: 2-7 days
MOT: respiratory droplet/person to person contact
153
RISK FACTORS
history of recent travel to China, Hong Kong, or Taiwan or close contact w/ ill persons with a hx of recent travel to such areas, OR
Is employed in an occupation at particular risk for SARS exposure, i.e. healthcare worker with direct patient contact or a worker in a laboratory that contains live SARS, OR
Is part of a cluster of cases of atypical pneumonia without an alternative diagnosis
154
SIGNS AND SYMPTOMS
fever, chills, rigors, myalgia, headache, diarrhea, sore throat, rhinorrhea
2-7 days after onset of illness - shortness of breath and/or dry cough
155
DIAGNOSIS
viral culture PCR serologic testing
Mgmt: supportive
Rex Karl S. Teoxon, R.N, M.D 156
Rex Karl S. Teoxon, R.N, M.D 157
Rex Karl S. Teoxon, R.N, M.D 158
Upper Respiratory System
Common cold Coronaviruses Sneezing, excessive nasal secretions, congestion
Lower Respiratory System
Viral pneumonia Several viruses Fever, shortness of breath, chest pains
Influenza Influenzavirus Chills, fever, headache, muscular pains
RSV Respiratorysyncytial virus
Coughing, wheezing
Amantadine is used to treat influenza. Palivizumab, for life-threatening RSV.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
FUNGAL DISEASES OF THE LOWER RESPIRATORY SYSTEM Fungal spores are easily inhaled; they
may germinate in the lower respiratory tract.
The incidence of fungal diseases has been increasing in recent years.
The mycoses in the sections below can be treated with amphotericin B.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Histoplasmosis Histoplasma capsulatum, dimorphic
fungus
Figure 24.17MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Histoplasmosis
Resembles Tuberculosis Histoplasma capsulatum causes a
subclinical respiratory infection that only occasionally progresses to a severe, generalized disease.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Histoplasmosis Transmitted by airborne conidia from soil and
thru bird droppings Diagnosis by culturing fungus Treatment: Amphotericin B or Itraconizole
Figure 24.18MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Coccidioidomycosis Coccidioides immitis- dimorphic fungi
Figure 24.19MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Coccidioidomycosis
Valley Fever or San Joaquin Fever s/sx- fever, coughing and weigth loss Most cases are subclinical, but when
there are predisposing factors such as fatigue and poor nutrition, a progressive disease resembling tuberculosis can result.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Coccidioidomycosis Transmitted by
airborne arthrospores
Diagnosis by serological tests or DNA probe
Treatment: Amphotericin B
Also Ketoconazole, Itraconazole
Figure 24.20MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pneumocystis Pneumonia Pneumocystis
jiroveci (P. carinii) is found in healthy human lungs.
Pneumonia occurs in newly infected infants and immunosuppressed individuals.
Treatment: Timethoprim-sulfamethoxazole Figure
24.22aMICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pneumocystis Pneumonia
P. jiroveci causes disease in immunosuppressed patients.
Site - lining of alveoli DOC Trimetophrim -Sulfamethoxazole
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Pneumocystis
Figure 24.21MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Blastomycosis Blastomyces dermatitidis, dimorphic fungus Found in soil Can cause extensive tissue destruction,
cutaneous lesions Treatment: Amphotericin B
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Blastomycosis (North American Blastomycosis) The infection begins in the lungs and can
spread to cause extensive abscesses.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Other Fungi Involved in Respiratory Disease Opportunistic fungi can cause
respiratory disease in immunosuppressed hosts, especially when large numbers of spores are inhaled.
MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera
Mucor indicus
Opportunistic Fungi Involved in Respiratory Disease
Aspergillus Rhizopus Mucor
Figures 12.2b, 12.4MICROPARA- RESPIRATORY INFECTIONby Dr Sonnie Talavera