RESP TRACT INFECTIONS Flashcards

Question

Diagnosis of Sinusitis

Answer 1

The diagnosis is made from clinical findings.  Bacterial culture of the nasal discharge can be taken but is not very helpful as the recovered organisms are generally contaminated by the resident flora from the nasal passage. In chronic sinusitis, a careful dental examination, with sinus x x-rays may be required. An antral puncture to obtain sinusal specimens for bacterial culture is needed to establish a specific microbiologic diagnosis.

Answer 2

Antimicrobial therapy, a beta beta-lactamase resistant antibiotic such as amoxicillinamoxicillin-clavulanateclavulanate or cephalosporin may be used.

Answer 3

Acute inflammation of the middle ear caused by infection.

Answer 4

Otitis media indicates inflammation of the middle ear. * Risk Factors: 3 3-7 years old, chronic sinusitis, chest disease…etc * About 50% are caused by respiratory viruses. * Bacterial: S. Pneumonia (40%) H. Influenza (30%), Moraxella Catarrhalis (

Answer 5

Ear pain * Headache * Neck pain with fluid drainage from the ear * Fever * Irritability * Lack of balance Hearing loss

Answer 6

Commonly follows an upper respiratory infection extending from the nasopharynx to the middle ear.  The presence of purulent exudate in the middle ear may lead to meninges.

Answer 7

Choice for first first-line therapy is amoxicillin amoxicillin-clavulanate. In most adults, the dose is amoxicillin 875 mg with clavulanate 125 mg.

Answer 8

Pharyngitis is an inflammation of the pharynx. * The aetiology can be bacterial, viral and fungal infections as well as non-infectious aetiologies such as smoking. * Most cases of acute pharyngitis are caused by viruses. * Many of the viruses associated with the common cold syndrome may also result in pharyngitis and include rhinoviruses, coronaviruses, enteroviruses, adenoviruses, influenza. * Group A beta-haemolytic streptococcus or Streptococcus pyogenes is the most important bacterial agent associated with acute pharyngitis

Answer 9

As with common cold, viral pathogens in pharyngitis appear to invade the mucosal cells of the nasopharynx and oral cavity, resulting in oedema of the mucous membranes.

Answer 10

There are no clinical features that reliably distinguish viral and bacterial causes:  Red, sore, or “scratchy” throat.  Vesicles or ulcers may also be seen on the pharyngeal walls.

Answer 11

For viral pharyngitis: symptomatic treatment only.  Bacterial pathogens require antimicrobial therapy.  Penicillin, or erythromycin for penicillin penicillin-allergic patients.

Answer 12

Acute inflammation of the epiglottis, larynx, trachea caused by infection. * Haemophilus influenzae type b is the most common cause of epiglottitis. * Epiglottitis is less common in adults. Some cases of epiglottitis in adults may be of viral origin. * Most cases of laryngotracheitis are due to viruses including: parainfluenza, influenza, adenovirus…

Answer 13

Serious obstructive inflammatory process that occurs principally in children between 2-5 but can occur outside of this. Obstruction is supraglottic as opposed to the subglottic obstruction of laryngitis

Answer 14

A viral infection may precede infection with H. influenzae in episodes of epiglottitis. However, viral laryngotracheitis commonly begins in the nasopharynx and eventually moves into the larynx and trachea. Inflammation and oedema involve the epithelium, mucosa and submucosa of the subglottis which can lead to airway obstruction.

Answer 15

Epiglottitis begins with fever * Sore throat * Hoarseness * Drooling * Dysphagia and progresses to severe respiratory distress * Noisy breathing * Barking cough

Answer 16

Pharyngeal swabs may be used to isolate pathogens in patients with laryngotracheitis, Virus isolation, antigen detection Elisa, or PCR on nasopharyngeal aspirates. * Epiglottic swabs for culture should be taken under direct vision by specialists, because swabbing can precipitate acute airway obstruction. Blood cultures should also be sent. Lateral radiographs of the neck may show the enlarged epiglottis. * ImmunofluorescentImmunofluorescent-antibody staining to detect virus in sputum, pharyngeal swabs, or nasal washings.

Answer 17

Haemophilus influenzae type b conjugated vaccine is recommended for all pediatric patients. * Intubation and ventilation may be necessary. * Intravenous antibiotic therapy should be instituted immediately. Epiglottitis and Group Laryngotracheitis

Answer 18

An acute upper respiratory tract or skin infection, caused by toxin toxin-producing strains of Corynebacterium diphtheriae with central nervous system and cardiac complications. * After the introduction of immunisation, diphtheria became rare in the developed world, but still common in developing countries. * The microorganism is transmitted by aerosol spread, but infected skin lesions can also act as reservoirs for infection. * Diphtheria can be treated, but in advanced stages, diphtheria can damage the heart, kidneys and nervous system. Even with treatment diphtheria can be deadly, especially in children.

Answer 19

The microorganism colonises the pharynx, multiplies and produces a toxin. * The toxin produced by pathogenic strains of C. diphtheriae inhibits protein synthesis. * It acts locally to destroy epithelial cells and phagocytes, resulting in the formation of a prominent exudate, sometimes termed a ‘false membrane’. * Cervical lymph nodes become grossly enlarged (‘bull bull-neck’ appearance). * The membrane and swelling can cause airway obstruction and death. * The toxin also spreads via the lymphatics and blood, resulting in myocarditis and polyneuritis.

Answer 20

Fever and pharyngitis with a false membrane that may cause airway obstruction; enlarged cervical lymph nodes; myocarditis with cardiac failure; and polyneuritis. * In skin infections, chronic ulcers with a membrane form and toxicity is mild.

Answer 21

a | Characteristic bull neck caused by enlarged lymph nodes. b | Thick pseudomembrane in the posterior pharynx. The pseudomembrane is a layer of bacteria and debris from necrosis of the surrounding tissues due to diphtheria toxin. c | Cutaneous lesion caused by Corynebacterium diphtheriae.

Answer 22

Diphtheria is confirmed by isolation of Corynebacterium spp. * Throat swabs, detection of toxins by ELISA and/or PCR. * Demonstrating toxin is essential, because non non-toxin producing strains of C. diphtheriae do not cause diphtheria.

Answer 23

Treatment should be commenced before laboratory confirmation and includes antitoxin and antibiotics (penicillin or erythromycin). * The main treatment is DAT, which contains antibodies obtained from the serum of horses that have been immunized against DT . * Diphtheria is a notifiable infection in the UK * Diphtheria control is mainly based on immunization of the population through vaccination

Answer 24

The ‘upper respiratory tract’ is separated from the ‘lower respiratory tract’ at the level of the vocal cords. Lower respiratory tract infections therefore include those affecting the trachea, bronchi, bronchioles and lung parenchyma.  These syndromes, especially pneumonia, can be severe or fatal.  Although viruses, and fungi can all cause lower respiratory tract infections, bacteria are the dominant pathogens; accounting for a much higher percentage of lower than of upper respiratory tract infections.

Answer 25

Bronchitis and bronchiolitis involve inflammation of the bronchial tree.  Bronchitis is usually preceded by an upper respiratory tract infection.  Chronic bronchitis with a persistent cough and sputum production is caused by a combination of environmental factors, such as smoking, and bacterial infection H. influenzae influenzaeand S. pneumoniae pneumoniae.  Bronchiolitis is a viral respiratory disease of infants and is caused primarily by respiratory syncytial virus virus, parainfluenza viruses, influenza viruses.  Bronchiolitis occurs mainly in children aged less than 2 years; it is particularly severe in infants aged less than 6 months.

Answer 26

Bronchioles vs bronchi swelling!

Answer 27

When the bronchial tree is infected, the mucosa becomes hyperaemic and oedematous and produces bronchial secretions. * The damage to the mucosa can range from simple loss of mucociliary function to actual destruction of the respiratory epithelium. * Exudate made up of necrotic material and respiratory secretions lead to airway obstruction.

Answer 28

Symptoms of an upper respiratory tract infection with a cough. * Mucopurulent sputum may be present. * Fever is common. * Wheezing or an actual lack of breath sounds may be noted.

Answer 29

Bacteriologic examination and culture of purulent respiratory secretions. * Aspirations of nasopharyngeal secretions or swabs for viral culture in infants with bronchiolitis. * Serologic tests demonstrating a rise in antibody titre to specific viruses. * fluorescentfluorescent-antibody staining, ELISA and/or PCR.

Answer 30

Treat symptoms * Antimicrobials usually not helpful. * Corticosteroids, bronchodilators, or prophylactic antibiotics.

Answer 31

Pneumonia is common, with a significant morbidity and mortality * This is an important infection worldwide. It is most common in the winter months * >2 million cases in UK in 2018 * 2nd leading cause of hospitalization in UK * Leading cause of death (~20,000 deaths) ~10% of patients with pneumonia die * Pneumonia is an inflammation of the lung parenchyma * Numerous factors, including environmental contaminants and autoimmune diseases, as well as infection, may cause pneumonia * Streptococcus pneumoniae is the most common agent of community community-acquired acute bacterial pneumonia

Answer 32

Microbes constantly enter airways but many factors prevent colonisation

Answer 33

Disrupting or overwhelming these defense mechanisms can allow microbes to colonise the lungs resulting in pneumonia

Answer 34

Community-acquired pneumonia pneumonia. * Hospital -acquired pneumonia ; HAP is a pneumonia presenting two or more days after admission to hospital. One of the most common nosocomial infections * Pneumonia in immuno immuno-compromised individuals individuals; * Aspiration pneumonia ; Patients may aspirate oropharyngeal or gastric contents into their upper and lower airways. The initial insult is a chemical pneumonitis, but infection may develop later

Answer 35

Malaise  Fever  Shortness of breath  Productive cough  Pleuritic chest pain  Tachypnoea  Tachycardia  Focal chest signs e.g. crackles, cyanosis, hypoxia and confusion.  Severe cases lead to bloodstream infection and severe sepsis with circulatory collapse and multiorgan failure.

Answer 36

Infectious agents gain access to the lower respiratory tract by the inhalation of aerosolised material or by aspiration of upper airway flora. * Pneumonia occurs when lung defence mechanisms are overwhelmed.

Answer 37

1. arrival of pathogens in alveolar space 2. Uncontrolled multiplication of pathogens 3. local production of cytokines primarily by alveolar macrophages 4. Recruitment of neutrophils into the alveolar space and introduction of cytokines into systemic circulation

Answer 38

Sputum specimens for culture and microscopy (Gram stain) – only occasionally useful, not routinely recommended. * Blood cultures (positive in 15% of cases cases). * Urine antigen detection for pneumococcal infectioninfection. * Polymerase chain reaction (PCR) now commonly replacing serology for viruses, Mycoplasma, Chlamydophila and Coxiella infectionsinfections. * Serology (viruses and Mycoplasma, Chlamydia, Coxiella and Legionella species species). * Bronchoalveolar lavage (BAL) specimens obtained by bronchoscopy for microscopy, culture and direct immunofluorescence tests . * Chest radiograph: lobar, patchy or diffuse shadowing . Radiological changes often lag behind clinical course and are not predictive of the microbiological cause.

Answer 39

Once a diagnosis is made, t herapy is directed at the specific organism responsible. * Management of gas exchange and fluid balance are important. * The pneumococcal vaccine should be given to patients at high risk . * In AIDS patients, trimethoprim/sulfamethoxazole, aerosolized pentamidine or other antimicrobials can be given for prophylaxis.

RESP TRACT INFECTIONS Flashcards

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