Transcript Continues

CHAPTER 9
Respiratory-Related Microbiological
Diseases
9-2
Introduction
• Respiratory system
─Serves as host for infectious diseases,
although contains many layers of defense
─Warm, moist atmosphere facilitating
microbacterial growth
─Site for constant inhalation of environmental
particles
9-3
Upper Respiratory Infections
• Includes
– Sinusitis
– Pharyngitis
– Epiglottitis
– Croup
9-4
Sinusitis
• Description
– Inflammation of hollow sinuses in nasal cavity
– Viral or bacterial
– Signs/Symptoms (S/S) (not limited to): nasal
stuffiness and discharge; pain/pressure in
face; if bacterial, yellow or green nasal
discharge
• Diagnostic
– Observe for ten days to determine if selflimiting or if treatment required
(Continues)
9-5
Sinusitis
• Treatment
– Oral decongestants
– Topical decongestants
– Nasal steroids
– Analgesics
– Antibiotics
9-6
Pharyngitis
• Description
– Inflammation of pharynx and surrounding
lymphatic tissue
– Viral or bacterial
– S/S (not limited to): sore throat; dysphagia;
fever; white, mucosal patches
– Treatment: usually self-limiting; if bacterial,
antibiotics
– Severe complications, if untreated
9-7
Epiglottitis
• Description
─Acute airway obstruction (airway emergency)
─Prevalent in children 2–6 years of age
─Abrupt onset (usually due to haemophilis
influenzae Type B)
─Symptoms (4 Ds): distress (respiratory),
drooling, dysphasia, dysphonia
─Treatment
• Maintain airway
• Antibiotic therapy
9-8
Croup
• Description
– Infection of laryngeal area, prevalent in
children younger than 3 years of age
– Usually viral
– S/S: barking cough, stridor, may be afebrile
– Treatment: air humidification, administration of
oxygen, nebulized epinephrine or
corticosteroids
9-9
Lower Respiratory Infections
• Includes
– Acute bronchitis
– Acute bronchiolitis
– Pneumonia
– Tuberculosis
9-10
Acute Bronchitis
• Description
– Affects bronchi; common in winter months
– Usually viral and may be self-limiting
– S/S: may progress from nonspecific
symptoms (e.g., headache, sore throat) to
thick bronchial secretions with productive
cough; bilateral rhonchi and coarse crackles
– Treatment: symptomatic treatment, antibiotics
(if bronchitis due to pertussis)
9-11
Bronchiolitis
• Description
– Affects bronchioles, especially in infants 2–10
months of age; often in winter–spring months
– S/S (not limited to): restlessness, mild fever,
noisy upper airway breathing, tachypnea
– Most common cause: RSV
– Treatment: antivirals, aerosolized drug
using special nebulizer equipment (hood or
mist tent)
9-12
Pneumonia
• Many types
– Community-acquired pneumonia
– Atypical pneumonia
– Viral pneumonia
– Tracheobronchitis
– HCAP, VAP, HAP
– Aspiration pneumonia
– Pneumocystis jiroveci
(Continues)
9-13
Pneumonia
• Description
– Causes: virus, bacteria, fungus, drugs or
chemicals
– S/S (not limited to): leukocytosis, fever,
rhonchi, dullness of percussion at site
– Diagnostic: chest x-ray and cultures of
sputum and blood
– Assess respiratory function to determine need
for hospitalization
9-14
Community-Acquired Pneumonia
• CAP
– Description of infection is determined by
prevalent pathogens, not geographical
location
– Usual cause: Streptococcus pneumoniae
– Treatment
• Determined by such guidelines as local resistance
patterns, clinical condition, chest x-ray results
• Recommended treatments are frequently updated
9-15
Atypical Pneumonia
• Description
– Cause: organisms not detectable by gram
stain, nor growth on standard cultural media
– Organisms do not respond to antibiotics used
to treat pneumonia
– Often due to Mycoplasma pneumoniae,
Legionella, Chlamydophila pneumoniae
– Treatment
• Empiric therapy
9-16
Viral Pneumonia
• Description
– Determined by molecular diagnostic methods,
such as polymerase chain reaction (PCR) test
– Must rule out bacterial cause
– Bacteria and virus can coinfect
– If bacterial, treat with antibiotics
9-17
Tracheobronchitis
• Pneumonia-like infection caused by
mechanical ventilation
– S/S: fever, new/increased sputum production
– Diagnostic: sputum sample from endotracheal
tube for gram stain and culture
– Treatment
• Antibiotics (determined by local antibiotic
susceptibility patterns)
9-18
HCAP, VAP, HAP
• Health care–associated (HCAP),
ventilator- associated (VAP),
hospital-acquired (HAP)
– Pneumonia related to exposure to/frequent
contact with health care settings
– Preventive measures: decrease aspiration by
patients; prevent cross-contamination;
disinfection/sterilization of respiratory devices;
vaccines against certain infections; education
of hospital staff and patients
9-19
Aspiration Pneumonia
• Two types
– Chemical
• Exposure to stomach acid
• Treatment: symptomatic therapy allowing lungs to
heal
– Bacterial
• Due to aspiration of oropharyngeal organisms, or
aerosol inhalation
• Treatment: empiric antibiotic therapy
9-20
Pneumocystis jiroveci (Carinii)
• Description
– Due to defects in cell-mediated immunity
(e.g., complications of HIV; organ or bone
marrow transplantation; medications)
– S/S (not limited to): asymptomatic (or) fever,
cough, tachypnea, dyspnea
– Diagnostic: ABGs
– Treatment: specific IV or parenteral
medications
9-21
Tuberculosis
• Airborne, chronic disease due to
Mycobacterium tuberculosis
• Latent: inhaled droplet is encapsulated
• Active: inhaled droplet (bacilli) escapes
• S/S: asymptomatic (or) weight loss, fever,
night sweats, bloody sputum
• Diagnostic: Mantoux or PPD, testing of
sputum specimen, chest x-ray
(Continues)
9-22
Tuberculosis
• Treatment
– If latent
• Preventive treatment (isoniazid 6–12 months)
– If active
• Medication regimen 6–24 months
• Directly observed treatment (DOT) may be
required due to noncompliance
9-23
Bioterrorism
• Pulmonary irritants
– Chlorine, phosgene
– Biochemical reactions of irritants cause
laryngospasm and pulmonary edema
• Anthrax
– Transmission: skin contact, inhalation
– If inhaled, spores are transported to lymph
system, germinate and produce toxins
– Treatment: antibiotics
(Continues)
9-24
Bioterrorism
• Plague
– Potential bioweapon, contagious
– Transmission: close contact, aerosol
– Treatment
• If systemic: parenteral antibiotic therapy
• Prophylaxis (post-exposure): oral antibiotics
– Vaccine no longer available; discontinued in
1999
9-25
Avian Influenza (H5N1)
• Carried in intestines of wild birds;
transmitted to domestic birds, including
poultry (cause of human exposure)
• May be transmitted through touching
contaminated surfaces
• S/S noted after a 2- to 5-day incubation
period include (not limited to) fever, cough,
rhinorrhea, diarrhea, abdominal pain
(Continues)
9-26
Avian Influenza (H5N1)
• Symptoms may progress to acute
respiratory distress syndrome
• Treatment
– Prophylaxis and supportive treatment
– Antiviral medications
– Includes treatment of anyone living with
infected patient
9-27
Summary
• Clinical presentation, diagnosis, treatment
of respiratory system infections
– Upper respiratory infections
– Lower respiratory infections
– Bioterrorism
– Avian influenza
(Continues)
9-28
Summary
• Many upper respiratory tract infections due
to viruses
• Treating viral infections with antibiotics
promotes bacterial resistance
• Refer to text/tables for in-depth information
9-29