© 2004 Wadsworth – Thomson Learning Chapter 22 Infections of the Respiratory System

© 2004 Wadsworth – Thomson Learning Clinical Science Diagnosis –Anatomical –Etiological Prognosis and Treatment Types of infections –Acute –Chronic –Persistent –Symptomatic –Asymptomatic –Local –Systemic –Primary –Secondary –mixed

© 2004 Wadsworth – Thomson Learning Clinical Science Progress of Infections –Incubation –Prodromal –Active –convalescent Figure 22.1

© 2004 Wadsworth – Thomson Learning Respiratory System Figure 22.2

© 2004 Wadsworth – Thomson Learning Epiglottitis Haemophilus influenzae –require components of blood –capsule pathogenic strains resistant to phagocytosis resistant to complement lysis –children most vulnerable –vaccine Hib

© 2004 Wadsworth – Thomson Learning Streptococcal pharyngitis Streptococcus pyogenes –group A beta-hemolytic streptococcus group A--type of polysaccharide antigen beta-hemolytic--type of hemolysis of blood agar –clinical syndrome whitish exudate covering tonsils inflammation of pharynx fever –identification of bacteria throat culture latex agglutination detect antigens

© 2004 Wadsworth – Thomson Learning Complications of S. pyogenes scarlet fever –toxin kills cells septicemia –spread in the bloodstream Rheumatic fever –inflammation in organs/joints –heart valve damage –prevention if Strep throat is treated Acute poststreptococcal glomerulonephritis –inflammation in glomeruli

© 2004 Wadsworth – Thomson Learning Diphtheria Diphtheria-- Corynebacterium diptheriae –Protein toxin –Symptoms localized inflammatory response membranous pharyngitis difficulty in swallowing swelling of lymph glands –Vaccine acellular portion of DTP

© 2004 Wadsworth – Thomson Learning Anthrax Bacillus anthracis Toxins –Edema factor (EF) –Lethal factor (LF) –Protective antigen (PA) macrophages Receptor

© 2004 Wadsworth – Thomson Learning The Common Cold –Rhinoviruses 25-50% of the colds 100+ serotypes transmission by respiratory droplets pathogenesis –replication in epithelial cells –stimulate kinins-secretions –immune response clears virus restoration of epithelium--months treatment: symptoms only –other viruses Coronaviruses (SARS)

© 2004 Wadsworth – Thomson Learning Pneumococcal pneumonia Streptococcus pneumoniae –pneumococcus pathogenic strains--capsule 80 serotypes –clinical syndrome difficult to recover from clinical samples inhaling respiratory droplets intense inflammation –pneumonia –treatment antibiotics –prevention vaccine (Pneumovax)

© 2004 Wadsworth – Thomson Learning Other pneumonias Various bacteria S. aureus, H. influenzae, Klebsiella spp, E. coli, Proteus spp. –secondary infection after other disease –Pathogenesis replication/inflammation in alveoli inflammation leading to fluid in lungs need healthy breathing to facilitate normal cleansing –Treatment--antibiotic

© 2004 Wadsworth – Thomson Learning Atypical pneumonias Primary atypical pneumonia –Mycoplasma pneumoniae –no cell wall Chlamydial Pneumonia –Chlamydia psitacci –exposure to sick birds Q Fever –Coxiella burnetii –Rare, almost never causes death Legionellosis –Legionella pneumophila –natural and artificial water supplies –multiplies intracellularly

© 2004 Wadsworth – Thomson Learning Pertussis Whooping cough Bordatella pertussis –Pathogenesis replication of bacteria production of toxins –Symptoms characteristic cough (whooping) cold symptoms vomiting (intense cough) –vaccine acellular vaccine (DPT)

© 2004 Wadsworth – Thomson Learning Tuberculosis Mycobacterium tuberculosis –pathogenesis inflammation and lesions of lung tissue cellular immune (TC) response slow growth rate –Symptoms varies primary lesions can spread to various tissues –Treatment prolonged multiple antibiotics (6 months) –Increase incidence (drug resistance) Figure 22.9

© 2004 Wadsworth – Thomson Learning Influenza (flu) Influenza virus types A, B, C –Epidemiology annual epidemics and occasional pandemics –antigenic drift and antigenic shift –Symptoms virus inhaled 1-3 days after exposure sudden onset of fever o F malaise, headache, muscle ache, cough –Treatment uncomplicated recovery in few weeks prevent secondary infections--pneumonia, immunization

© 2004 Wadsworth – Thomson Learning Bronchitis Croup –Parainfluenza virus –Symptoms loud, barking cough Bronchiolitis –Respiratory syncytial virus –Paramyxovirus Subtype B: asymptomatic strains Subtype A: predominate in most outbreaks

© 2004 Wadsworth – Thomson Learning Hantavirus Pulmonary Syndrome May 1993 outbreak –Four corners area of Southwest US –70% victims died many healthy lung failure –capillaries leaked-filling air space –Identified virus Sin Nombre virus new strain of Hantavirus –reservoir deer mice and other rodents –isolates worldwide Figure 22.12

© 2004 Wadsworth – Thomson Learning Fungal Infections Histoplasmosis –Histoplasma capsulatum –dimorphic –distribution worldwide certain areas –1% infected become ill Figure 22.13

© 2004 Wadsworth – Thomson Learning Fungal Infections Coccidioidomycosis –semiarid climates –spores inhaled into alveoli Figure 22.14

© 2004 Wadsworth – Thomson Learning Fungal infections Blastomycosis –humans and animals –clinical syndrome resembles tuberculosis distant organs--skin, bone, testes Pneumocystic pneumonia (PCP) –AIDS associated rarely seen before 1980’s most common cause of death with AIDS –cysts in lung