2. CHAPTER 9 Respiratory-Related Microbiological Diseases 9-2

3. 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

4. Upper Respiratory Infections Includes –Sinusitis –Pharyngitis –Epiglottitis –Croup 9-4

5. 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 self- limiting or if treatment required (Continues) Sinusitis 9-5

6. Treatment –Oral decongestants –Topical decongestants –Nasal steroids –Analgesics –Antibiotics Sinusitis 9-6

7. 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 Pharyngitis 9-7

8. 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 Epiglottitis 9-8

9. 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 Croup 9-9

10. Lower Respiratory Infections Includes –Acute bronchitis –Acute bronchiolitis –Pneumonia –Tuberculosis 9-10

11. 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) Acute Bronchitis 9-11

12. 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

13. Pneumonia Many types –Community-acquired pneumonia –Atypical pneumonia –Viral pneumonia –Tracheobronchitis –HCAP, VAP, HAP –Aspiration pneumonia –Pneumocystis jiroveci (Continues) 9-13

14. 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

15. 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 Community-Acquired Pneumonia 9-15

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

28. Summary Clinical presentation, diagnosis, treatment of respiratory system infections –Upper respiratory infections –Lower respiratory infections –Bioterrorism –Avian influenza (Continues) 9-28

29. 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