Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anna Faculty Hospital, Brno Miroslav Votava Vladana Woznicová Ondřej Zahradníček Clinical Microbiology Institute for Microbiology, Faculty of Medicine, Masaryk University and St. Anna Faculty Hospital, Brno Agents of respiratory diseases Part One Importance of respiratory diseases • They are the most important infections in general practitioner‘s office (respiratory tract = an ideal incubator) • They have a big economic effect on the economics in general and on health care in particular • They tend to be seen in collectives and often produce outbreaks and epidemics • ¾ of respiratory infections (and even more in children) are caused by viruses Localization of infection in the respiratory tract • Localization of infection – influences the clinical symptomatology – enables to suspect specific agents • Therefore, it is necessary to distinguish: – upper respiratory tract (URT) infections (and adjacent organs infections) – lower respiratory tract (LRT) infections (infections of lower respiratory ways and pneumonias) URT infections and infections of adjacent organs Classification: – infections of nose a nasopharynx – infections of oropharynx incl. tonsillae – infections of paranasal sinuses – otitis media – conjunctivitis LRT infections and lung infections Classification: • Infections of LRT – infection of epiglottis – infection of larynx and trachea – infection of bronchi – infection of bronchioli • infections of lungs Common flora in respiratory ways • To differenciate between the pathologic or normal finding it is necessary to know which bacteria are typically found in respiratory tract of a healthy person • Nasal cavity: usually Staph. epidermidis, less often sterile, coryneform rods, Staph. aureus, pneumococci • Pharynx: always neisseriae and streptococci (viridans group), usually haemophili, rarely pneumococci, meningococci, enterobacteriae, yeasts • LRW: rather sterile; nevertheless, materials from these sites are often contaminated by URW flora Etiology of rhinitis and nasopharyngitis • Viruses – the most common („common cold“): – more than 50 % rhinoviruses – coronaviruses (2nd position) – other respiratory viruses (but not flu!) • Bacteria: – Acute infections: usually secondary • Staph. aureus, Haem. influenzae, Strep. pneumoniae, Moraxella catarrhalis – Chronic infections: • Klebsiella ozaenae, Kl. rhinoscleromatis Treatment recommendation • Because of viral etiology, the majority of rhinitis and nasopharyngitis does not need antibiotic treatment and even does not need bacteriological examination • If necessary (pus full of polymorphonuclears, high CRP levels à markers of bacterial infection) treatment should fit with the result of bacteriological examination • Sometimes we treat (but rather locally only) even without symptoms – treatment of carriers of some epidemiologically important pathogens (e. g. MRSA) Infectious rhinitis also should be differenciated from allergic/vasomotoric rhihitis Etiology of sinusitis and otitis media – I • Acute sinusitis and otitis is usually started by respiratory viruses, M. pneumoniae (myringitis) • Secondary pyogenic inflammations are due to: • S. pneumoniae, H. influenzae type b, Moraxella catarrhalis, Staph. aureus, Str. pyogenes • even anaerobes: genus Bacteroides, Prevotella, Porphyromonas, Peptostreptococcus • Complications: mastoiditis, meningitis purulenta Etiology of sinusitis and otitis media – II • Sinusitis maxillaris chronica, sinusitis frontalis chronica: Staph. aureus, genus Peptostreptococcus • Otitis media chronica: Pseudomonas aeruginosa, Proteus mirabilis Examination and treatment • Today, it is not recommended to perform bacteriological examination in otitis media and sinusitis, except when a relevant specimen is available • Relevant specimen – only a punctate from middle ear or paranasal sinus; NOT nasal swab and NOT ear swab (contamination is present, but no pathogen) • Treatment is usually started by an aminopenicillin or a 1st gen. cephalosporin Inflamation of paranasal cavities (sinusitis acuta) • Temporary finding in cavities is normal at classical rhinitis and there is no reason for treatment • Treatment should be started in case of painful sinusitis, with teathache, headache, fever, lasting at least a weak, eventually neuralgia of N. trigeminus Sinusitis acuta Otitis media Examination and treatment of otitis media • Atb treatment is recommended, when inflammation (pain, red colour, fever) is presented and anti-inflammatory treatment is not sufficient • Drug of choice is amoxicillin (e. g. AMOCLEN), alternative possibly co-trimoxazol • Ear swab examination is useless, except after paracentesis, or natural tympanon perforation • Pyogene fluid, taken during paracentesis, can be examined Etiology of conjunctivitis – I • Conjunctivitis is usually of viral origin • It usually accompanies acute URT infections In adenovirus infections typically: follicular conjunctivitis, faryngoconjunctival fever (adenoviruses 3, 7), epidemic keratoconjunctivitis (adeno 8,19) • Other viral conjunctivitides: hemorrhagic conjunctivitis (enterovirus 70) herpetic keratoconjunctivitis (HSV) Treatment is usually local only Etiology of conjunctivitis – II • Bacterial conjunctivitis • Acute: – suppurative conjunctivitis: S. pneumoniae, S. aureus, in children also other bacteria – inclusion conjunct.: C. trachomatis D – K • Chronic: – S. aureus, C. trachomatis A – C (trachoma) • Allergic, mechanic (allien body) Oropharyngeal infections • Acute tonsillitis and pharyngitis: usually viral (rhinoviruses, coronaviruses, adenoviruses, EBV – inf. mononucleosis, coxsackieviruses – herpangina) • Among bacterial, the most important: ac. tonsillitis or tonsillopharyngitis due to S. pyogenes (= β-haemolytic streptococcus, group A according to Lancefield) • More bacterial agents: streptococci group C, F, G, pneumococci, Arcanobacterium haemolyticum, H. influenzae?, N. meningitidis?, anaerobes? • Rare, but important: Corynebacterium diphtheriae, Neisseria gonorrhoeae Treatment of oropharyngeal infections • Bacteriological examination recommended in all cases, incl. a „typical tonsilitis“ • When Streptococcus pyogenes is found, the „old good“ Fleming‘s penicillin is the best • Modern drugs like azithromycin, clarithromycin etc. have worse effect and should be used in allergic persons only • Besides bacteriological examination, a determination of CRP level (marker of a bacterial infection) is recommended Viral tonsilopharyngitis Tonsilopharyngitis Purulent bacterial tonsilitis A note on respiratory viruses and other „virologically examined“ microoorganisms • Respiratory viruses are related to many types of respiratory infections, therefore it is useful to know them • Virological laboratories examine patients´ sera labelled „examination of antibodies against respiratory viruses“ – usually, they perform tests for the most common agents • Such examinations often include non-viral agents – atypical bacteria, that are not keen to be caught by bacteriological cultivation Respiratory viruses – I • The most important and most common: – influenzavirus A a B – adenoviruses – RSV and metapneumoviruses – parainfluenzaviruses (type 1+3 = Respirovirus, type 2+4 = Rubulavirus) – rhinoviruses – coronaviruses (incl. SARS causing virus) Respiratory viruses – II • Less common viral agents • HSV • coxsackieviruses • echoviruses • EBV • Ťahyňa virus Respiratory agents – III • Bacterial agents causing atypical pneumoniae (but diagnosed in virological laboratories): • Mycoplasma pneumoniae – the most common • Coxiella burnetii – Q-fever • Chlamydia psittaci – ornithosis • Chlamydophila pneumoniae Epiglottitis Etiology of epiglottitis • Epiglottitis acuta: Serious disease – medical emergency The child may suffocate! • Practically one and only important agent: Haemophilus influenzae type b („Hib“) George Washington died of epiglottitis Etiology of laryngitis and tracheitis • Respiratory viruses (other than agents of nasopharyngitis): parainfluenza and influenza A viruses & RSV • Bacterial: Chlamydophila pneumoniae, possibly Mycoplasma pneumoniae, secondarily: S. aureus and Haemophilus influenzae laryngotracheitis pseudomembranosa (croup): Corynebacterium diphtheriae Lagyngitis acuta Examination and treatment of laryngitis and tracheitis • To perform throat swab is useless (different bacteria in pharynx than in larynx). Except for chronical situations, microbiological examination is not indicated. • Treatment symptomatic - antibiotics are not recommended Etiology of bronchitis • Acute bronchitis: influenza, parainfluenza, adenoviruses, RSV Bacterial, secondarily after viruses: pneumococci, haemofili, stafylococci, moraxellae Bacterial, primarily: Mycoplasma pneumoniae, Chlamydophila pneumoniae, Bordetella pertussis • Chronic bronchitis (cystic fibrosis): Pseudomonas aeruginosa, Burholderia cepacia Bronchitis acuta Etiology of bronchiolitis • Isolated bronchiolitis in newborns and infants only: Pneumovirus (= RSV) Metapneumovirus Pneumonia Different types of pneumoniae • Acute – community-acquired pneumoniae – in originally healthy • adults • children – in debilitated persons – after a contact with animals • Acute – nosocomial pneumoniae • ventilator-associated – early – late • others • Subacute and chronic pneumoniae Etiology of pneumoniae – I Acute, community-acquired, in healthy adults • bronchopneumonia and lobar pneumonia: – Streptococcus pneumoniae – Staphylococcus aureus – Haemophilus influenzae type b • atypical pneumonia: – Mycoplasma pneumoniae – Chlamydophila pneumoniae – Influenza A virus (during an epidemic only) Etiology of pneumoniae – II Acute, community-acquired, in healthy children • Bronchopneumonia: – Haemophilus influenzae – Streptococcus pneumoniae – Moraxella catarrhalis – In newborns: Streptococcus agalactiae enterobacteriae • atypical pneumonia: – respiratory viruses (RSV, infl. A, adenoviruses) – Mycoplasma pneumoniae – Chlamydophila pneumoniae – in newborns: Chlamydia trachomatis D-K Etiology of pneumoniae – III • Acute, community-acquired, in debilitated individuals: – pneumococci, staphylococci, haemofili – Klebsiella pneumoniae (alcoholics) – Legionella pneumophila • In more serious immunodeficiency: – Pneumocystis jirovecii – CMV – atypical mycobacteria – Nocardia asteroides – aspergilli, candidae Etiology of pneumoniae – IV Acute, community-acquired, after a contact with animals: • Bronchopneumonia – Pasteurella multocida – Francisella tularensis (tularemia) • Atypical pneumonia – Chlamydia psittaci (ornithosis) – Coxiella burnetii (Q-fever) Etiology of pneumoniae – V Acute, nosocomial: • VAP (ventilator-associated pneumonia) – early (up to the 4th day of hospitalization): sensitive community strains of respiratory agents – late (from the 5th day of hospitalization): resistant hospital strains • Others – viruses (RSV, CMV) – legionellae Etiology of pneumoniae – VI • Subacute and chronic: – aspiration pneumonia and lung abscesses • Prevotella melaninogenica • Bacteroides fragilis • peptococci and peptostreptococci – lung tuberculosis and mycobacterioses • Mycobacterium tuberculosis • Mycobacterium bovis • atypical mycobacteria Pneumonia Bronchopneumonia Lobar and lobular pneumonia Examination in lung infections • Clinical examination and X-ray, important is differentiation classic × atypical pneumonia • Classical pneumoniae - properly taken sputum is useful, eventually (in septic course) blood for blood culture • Atypical pneumoniae - serology -mycoplasma and chlamydophila (eventually in complex of „respiratory viruses serology“). • Hospital pneumoniae also legionella examination Treatment in LRW and lung infections • In classic community pneumoniae amoxicilin, eventually according to causative agent and its antibiotic susceptibility • In atypical pneumoniae tetracyclins or (especially in children < 8) macrolids. • In hospital infections treatment according to in vitro susceptibility test necessary – pseudomonads and burkholderiae resistant! • In TB usually combination of three of four drugs necessary