Respiratory Tract Infections Flashcards
What viruses can be picked up on a viral throat swab?
- Influenza A+B
- RSV
- Rhinovirus
- Adenovirus
- Enterovirus
- Coronavirus
- Parainfluenza
What symptoms are experienced by a patient with a streptococcal tonsillitis?
Exudate Pus Pain Dysphagia Dysphonia Swollen red tonsils tender lymph nodes
Scoring high on what two types of criteria make a streptococcal sore throat more likely?
FeverPAIN Score: Fever (during last 24 hrs) Pus on tonsils Attended rapidly (<3 days of symptom onset) Inflamed tonsils No cough
Or Centor Criteria: Fever Pus Inflamed cervical lymph nodes No cough
Quincy is a potential complication of tonsillitis. What is this?
- Peri-tonsillar abscess
- Can be drained to treat
Epiglottitis is a critical emergency. TRUE/FALSE?
TRUE - bacterial infection can cause difficulty breathing
- previously was mostly caused by HiB in children until vaccine was created
- now mainly caused by strep pneumoniae/ strep pyogenes/ staph aureus
How is epiglottitis treated in an emergency?
- Endotracheal tube
- IV antibiotics (ceftriaxone, vancomycin, clindamycin)
What viruses are known to cause the common cold (coryza)?
Adenovirus
Rhinovirus
Respiratory Syncytial Virus (RSV)
What are common complications of the cold?
Acute bronchitis
Sinusitis
How does sinusitis present?
Frontal headache Retro-orbital pain Maxillary sinus pain Tooth ache Purulent Discharge
Most sinusitis is self-limiting. TRUE/FALSE?
TRUE
- resolves in around 10 days
What can be used to treat sinusitis symptoms whilst it is clearing?
Nasal decongestant
- Oxymetazoline
- Pseudoephedrine
Nasal Steroid sprays
- beclometasone
- fluticasone
How does Diptheria usually present in the throat?
- white coloured pseudomembrane seen over back of the throat
Why is diptheria considered a life-threatening condition?
The toxin produced by the bacteria causes life-threatening effects
How long is the incubation period for flu and other common viruses?
Influenza and parainfluenza viruses: 1-4 days
Rhinoviruses: 1-5 days
RSV: 7 days
(=> up to 1 week)
How long is the incubation period for streptococcal tonsillitis?
Group A streptococci: 1-5 days
Which virus that can cause throat symptoms has a long incubation period?
Epstein-Barr virus: 4-6 weeks
causes glandular fever
What infectious conditions can affect the lower respiratory tract?
Acute bronchitis Acute exacerbation of COPD Pneumonia Influenza Fungal Infection
What is acute bronchitis?
- cold which "goes to the chest" => preceeded by cold - Productive cough - fever in some cases - Normal chest examination
What symptom of acute bronchitis can be the most debilitating for patients?
If they experience tracheitis (trachea inflammation) then this can be very painful when they cough
Patients with pre-existing lung disease (e.g. COPD) already experience a lot of symptoms that would be consistent with infection. What are these?
- Chronic sputum production
- Bronchoconstriction
- Inflammation of the airways
- Breathlessness
- Chest pains
What symptoms and signs would prompt you to consider infection in a patient with pre-existing lung disease?
- Increased sputum production +/- change in colour
- More wheezy/ SOB
O/E
- Respiratory Distress
- Wheeze
- Coarse crackles
- Cyanosed
- advanced disease – ankle oedema
How are acute exacerbations of COPD managed in the community?
- Antibiotic. e.g. amoxicillin or doxycycline
- Bronchodilator inhalers
- Short course of steroids (sometimes)
When would you refer a COPD exacerbation to the hospital?
Evidence of respiratory failure
Not coping at home
How would a COPD exacerbation be treated in hospital?
- IV antibiotics
- Measure ABGs
- CXR to look for other diseases
- Give oxygen if hypoxaemic
- Rest, initially, then mobilise
What are the main symptoms of pneumonia?
CHEST: Cough Haemoptysis SOB Preceding URTI
GENERAL SYMP: Malaise Sweats/Rigors Myalgia/Arthralgia Abdominal pain Diarrhoea
How do older people present with pneumonia?
confusion
diarrhoea
reduced mobility
rarely cough
What are the main signs of pneumonia?
- Fever/Rigors
- Herpes labialis
- Tachypnoea
- Crackles/Rub
- Cyanosis
- Hypotension
What markers can be used to grade the severity of pneumonia?
- Temperature <35 or >40
- Cyanosis PaO2 < 8 kPa
- WBC <4 or >30
- Multi-lobar involvement
GI disturbance is common in Legionella pneumonia. TRUE/FALSE?
TRUE
How does Influenza typically present?
Fever (high, abrupt onset) Malaise Myalgia Headache Cough (dry + painful, then productive + painless)
Give an example of a “Flu-like” virus?
Parainfluenza
Haemophilus influenzae is a strain of flu. TRUE/FALSE?
- FALSE it is a bacterium (not a virus)
=> not a primary cause of ‘flu
=> may be a secondary invader
How is flu transmitted?
- droplets
OR direct contact with respiratory secretions of someone with the infection
=> need aerosol protection (PPE)
What are the potential complications of flu?
- Primary influenzal pneumonia
- Secondary bacterial pneumonia
- Bronchitis
- Otitis media
- Influenza during pregnancy may cause perinatal mortality, prematurity and lower birth weight
A secondary bacterial pneumonia which develops after the flu is most common in what vulnerable groups?
- infants
- elderly
- pre-existing disease
- pregnant women
What treatment is usually given for the flu?
Symptomatic Tx:
- bed rest
- fluids
- paracetamol
When are antivirals used in the treatment of flu and what antivirals can be given?
Antivirals:
- oseltamivir
- Zanamivir
NICE states only to be given if:
- early in disease when flu is still “circulating”
- patient is at risk of complications
When do flu epidemics usually occur? When do pandemics occur?
Epidemics
- each winter
- small changes in surface proteins of the virus
=> can reinfect patients already vaccinated
Pandemics
- rare, unpredictable
- influenza A only
How does the lab confirm a case of influenza?
PCR of viral swab taken from patient
- Nasopharyngeal swabs
- Throat swabs
How is flu “prevented”?
Killed vaccine:
- Contains 2 FluA viruses and 1/2 FluB viruses
- given annually to:
=> adult patients at risk
=> health care workers
=> children 6 months to 2 years at risk of complications
Live attenuated vaccine:
- More effective than killed vaccine in children aged 2-17
- Administered intra-nasally
At what time of the year is parainfluenza virus most prevalent?
Summer
=> contrasts Influlenza which is prevalent in winter
What organisms may cause an atypical pneumonia?
Mycoplasma (only common one in UK today)
Coxiella (from sheep/goats)
Chlamydophila (from pet birds - parrots, budgies)
How are atypical pnuemonias such as Mycoplasma, coxiella and Chlamydophila treated?
Respond to tetracyclines/macrolides
i.e. clarithromycin
How are atypical pneumoniae species confirmed by the lab?
- serology (gold top vacutainer)
- virus detection
PCR on respiratory swabs / secretions
How does bronchiolitis usually present?
1st or 2nd year of life Fever Coryza Cough Wheeze
If bronchiolitis is severe what symptoms may patients experience?
- grunting
- decreased PaO2
- Intercostal / sternal indrawing
What virus most commonly causes bronchiolitis?
Respiratory Syncytial Virus (RSV)
How is RSV confirmed by the lab?
PCR
- nasopharyngeal swab
- throat swab
How is Bronchiolitis caused by RSV treated?
- supportive
Bronchiolitis epidemics usually happen at what time of the year?
Winter
Which other virus has been newly recognised to cause bronchiolitis similar to RSV in various patient groups?
Metapneumovirus
What areas can be swabbed or tested to do a virus panel in Tayside?
nasopharyngeal swab
throat swab
bronchoalveolar lavage (BAL)
endotracheal aspirate etc
What viruses are looked for on a virus panel in Tayside?
Flu A/Flu B parainfluenza 1-4, coronaviruses (4 species) metapneumovirus adenovirus RSV rhinovirus enterovirus Mycoplasma pneumoniae
Chlamydia Trichomatis can cause infantile pneumonia if present in the mother before birth. TRUE/FALSE?
TRUE
- diagnosed by PCR on urine of mother or pernasal / throat swabs of child
Describe the pathological appearance of pneumonia in the lung tissue
- acute inflammatory response
- Exudate = fibrin-rich fluid (found in the alveoli)
- Neutrophil + Macrophage infiltration
- Thickened alveolar walls
What complications can pneumonia cause for the lung tissue?
Fibrous scarring
Abscess
Bronchiectasis
Empyema
What is a lung abscess and what symptoms does it cause in the patient?
- Localised collection of pus (Tumour-like)
- usually due to patient aspirating
Symptoms: - Chronic malaise and fever
Describe the type of reaction TB causes in the lung
- Type IV (delayed) hypersensitivity
- granulomas with necrosis
Describe the pathology of Acute TB in the lung
- inhaled organism phagocytosed
- carried to hilar lymph nodes
Immune activation causes granuloma to form (this can kill organism) - In a few cases, infection is overwhelming and spreads
How long does the acute phase of TB last?
1st exposure and up to 5 years afterwards
How does the lung tissue change in Primary vs Secondary TB?
Primary:
- Small focus in periphery of mid zone
- Large hilar nodes (granulomas)
- granulomas have a centre of “caseous necrosis”
Secondary:
- cavitating apical lesion
What stain is used to identify TB?
Acid fast stain
- organism appears red
- if patient has decreased immunity, more organisms appear on staining
What is it called when TB spreads throughout the lung tissue?
Miliary disease
- haematogenous spread to lower lobe causes miliary white foci to appear
Why does TB disease reactivate?
Decreased T-cell function due to:
- age
- coincident disease (HIV)
- immunosuppression
Reinfection at high dose OR more virulent organism
What organisms are more likely to infect an immunocompromised host?
- Virulent TB infection
- Opportunistic pathogen
virus (cytomegalovirus - CMV)
bacteria (Mycobacterium)
fungi (aspergillus, candida, pneumocystis)
protozoa (cryptosporidia, toxoplasma)
