5, 6, 7 - URI + LRI + Cases

Droplet vs aerosol

Droplets are large and heavy, spreading directly or via fomites, while aerosols are small and light and can travel via the air

Most common causes of URIs

Virus

Storing a viral specimen

Viral transport media in 4 degrees celcius

What is a VTM made of?

Isotonic salt solution + antibiotics

What collection if a viral infection requires a VTM, and what doesn’t?

Nasopharyngeal swabs/aspirate etc but a bronchoalveolar lavage doesn’t, since it’s already full of liquid

3 ways to test for respiratory viruses and what do they use?

1. Immunofluoresence(Viral antigen)

2. Immunochromatography(Viral antigen)

3. PCR(Viral nucleic acid)

Which one of the tests, and of what specimen is most vulnerable to wrong results?

Nasopharyngeal swab tested via immunochromatography

Common cold vs influenza Thai names

หวัด vs ไข้หวัดใหญ่

Common cold vs influenza

• Onset

• Fever

• Aches

• Chills

• Fatigue

• Sneezing

• Cough

• Stuffy nose

• Sore throat

• Headache

Common cold vs influenza

• Onset: Gradual vs abrupt

• Fever: Rare vs usual

• Aches: Slightly vs usual

• Chills: Rare vs usual

• Fatigue: Sometimes vs usual

• Sneezing: Common vs sometimes

• Cough: Mild vs common

• Stuffy nose: Common vs sometimes

• Sore throat: Common vs sometimes

• Headache: Rare vs common

The flu is concerning for which groups of people?

• Children younger than 5, pregnant women, elderly, ppl w conditions like asthma

What is a condition that can be similar to the flu?

Dengue

What treatment must we avoid in a common cold?

Antibiotics

What is a centor criteria, and how does it work?

• It’s a criteria used to identify how likely a group A streptococcus is to be the cause of a sore throat rather than bacteria

• If the score is high, it’s a higher chance of a GAS infection

Croup

• Full name

• Cause

• Demographic

• Symptoms

• Treatment

• Laryngotracheobronchitis

• Viruses, typically parainfluenza

• 6M to 5Y children

• Barking cough, stridor, chest wall retractions, hoarse voice

• Supportive

Steeple(pencil) sign

Pneumonia definition

Inflammation lung parenchyma(Alveoli + interstitium)

A good quality sample of sputum has

• How many squamous epithelial cells

• How many PMNs

1. 25 or less squamous epithelial cells → rules out contamination

2. 25 or more PMNs

Most common cause of community acquired pneumonia

S. pneumoniae

Most common cause of hospital acquired pneumonia

• MRSA

• E. Coli

• Enterobacter

• Klebsiella

• Pseudomonas aeruginosa

• Acinetobacter baumannii

Bronchi vs bronchiole thai names

Bronchi: หลอดลม

Bronchiole: หลอดลมฝอย

Bronchiolitis main differences from bronchitis

• Bronchiolitis is more common and potentially dangerous in children under 2

• Bronchiolitis may have wheezing, while bronchitis doesn’t

• Bronchitis usually has a normal CXR

Viral pneumonia difference from bronchitis and bronchiolitis

• Groups at risk include younger children, elderly, and immunocompromised, although all ages can get it

• Patients will have a fever, and a CXR will show infiltrations/consolidations

Lobar pneumonia and interstitial infiltration are typically found in what kinds of pneumonia

• Bacterial vs viral/atypical bacterial

Viral bronchitis, bronchiolitis, and pneumonia treatments

• Supportive for all three

  • Maybe antiviral or antibiotic for pneumonia depending on the cause

Most common types of influenza in humans

A and B

Antigenic drift vs shift

• Drift is slowly gaining mutations while shift is usually involving swapping segments with another virus strain and making a totally new strain

Most common viral respiratory cause in children under 4

RSV

Who should get vaccinated for RSV?

1. Adults over 75 or 50-74 with risk of severe RSV

2. Pregnant women of weeks 32-36 to protect the baby(Abrysvo)

3. Infants(Nirsevimab)

Antiviral option for severe RSV

Ribavirin

RSV + HPIV causes what in most people

Mild common cold symptoms but can cause acute bronchitis, bronchiolitis, and pneumonia in young children/immunocompromised(+ Croup for HPIV)

Parainfluenza types and meaning

• Type 1 and 2: Cold, CROUP

• Type 3: Bronchitis, bronchiolitis, pneumonia

• Type 4: Least common, causes mild URI symptoms

Centor Criteria Criterion

1. Tonsillar exudates

2. Tender/swollen anterior cervical adenopathy

3. Fever by history

4. Abscence of cough

5. Age: +1 if 3-14 years, 0 if 15-44, -1 if 45 or more

What do we do if the Centor criteria is at the max score

• Consider GAS testing

• May have to give antibiotics depending on the case

• Note how even with the full score, we aren’t fully sure if it’s bacterial or not

COVID-19 most common treatment for non-severe cases

• Supportive, no antiviral

Most common causes of respiratory virus infection in children

• 3 weeks to 4 years old

• Over 5 years old

• 3wks → 4y: RSV

• Over 5: Influenza

Which flu cases may not receive oseltamivir?

• Cases that have had symptoms for a while, like 4-5 days, since Oselta prevents spread from infected cells but doesn’t kill ones already infected, so it works best when the virus hasn’t really spread much yet