Influenza, COVID-19 Flashcards
What is influenza?
Viral respiratory tract infection
What are the clinical presentation for influenza that is different from common cold?
Influenza: onset is abrupt; fever, body aches, chills, fatigue, body weakness, Chest discomfort, Cough, HA are usual. Sneezing, stuffy nose, sore throat are sometimes.
Common cold: Onset is gradual. Sneezing, stuffy nose, sore throat usual.
The other S&S are slight/rare
How is influenza tracked in SG?
Bimodal distribution
Dec-Feb
May-July
Which influenza types are clinically significant?
Influenza A - humans, swine, equine, avian, multiple other species
Clinical presentation: most severe illness, sig mortality in young persons; Epidemics and pandemics
Influenza B: Humans only
Clinical Presentation: Severe illness in older adults or high risk persons; Less severe epidemics
Influenza C (not clinically sig but exists): human, swine Clinical presentation: mild respiratory illness wo seasonality; No epidemics
What are the complications of influenza?
- Viral pneumonia (normally URTI first, but then go to LRTI –> becomes viral)
- Post-influenza bacterial pneumonia (particularly those caused by S. aureus) - mortality >30%
- respiratory failure
- exacerbate underlying pulmonary or cardiac comorbidities
- febrile seizures
- myocarditis or pericarditis
Who are at high-risk for influenza-related complications?
- children <5yo
- elderly >= 65yo
- preg women or within 2 wks post-partum
- residents of nursing homes or long-term care facilities
- obese ind with BMI >= 40kg/m2
- ind w chronic medical conditions (e.g. asthma, COPD, HF, DM, CKD, immunocompromised, etc.) - very specific conditions only, does not include HTN, HLD
How to prevent influenza? (3 prevention strategies)
1) Good personal hygiene
- wash your hands
- minimise touching of eyes, nose or mouth
- cover nose and mouth when coughing/ sneezing
- use a serving spoon when sharing food
2) Healthy lifestyle
- balanced diet
- exercise regularly
- adequate sleep
- dont smoke
3) Vaccination
- best prevention
- inactivated trivalent or quadrivalent vaccine
- adm IM once per yr
- indicated for all ind >= 6mths of age and above
~ Chemoprophylaxis (use drug to prevent influenza): not routinely recommended; to avoid sub-therapeutic dosing
How to diagnose influenza?
- Viral cultures not recommended
- Molecular tests available for use of practice
~ limited use in outpatient: mostly treated empirically
~ used inpatient: RT-PCR
When to treat influenza?
- for documented/ suspected influenza:
~ initiate asap within 48h of smx onset for ind who fulfill any ONE of the following:
– hospitalised
– high-risk for complications
– severe, complicated, or progressive illness
~ May be considered for others (outpatients) presenting within 48h of smx onset
When is antiviral given?
When antiviral med is started within this time window - greatest benefit in preventing influenza related complications
Short time interval - acceptable for med to be started empirically
Upon -ve PCR to conclude no influenza / alternative diagnosis hat explain pts smx, antiviral can be stopped
Still doubtful conflicting - whether benefit to start antiviral when pt present smx beyond 48hours
What are the treatment options for influenza?
Antiviral - Oseltamivir
1ST LINE: active against Influenza type A and B
- 75mg PO BD for 5d
- Renally dose adjusted
Duration may be prolonged in pts who are immunocompromised/ critically ill - up to total of 10d
MOA: neuraminidase inhibitor
- interferes w protein cleavage
- inhibits release of new virus
Well-tolerated: HA; Mild GI effects
What are the common S&S for both influenza and COVID-19?
Both COVID-19 and flu have varying degrees of S&S, from asymptomatic to severe smx. Common smx:
- Fever or feeling feverish/having chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue (tiredness)
- Sore throat
- Runny or stuffy nose
- Muscle pain or body aches
- Headache
- Vomiting and diarrhea
- Change in or loss of taste or smell, although this is more frequent with COVID-19.
How Long Symptoms Appear After Exposure and Infection for influenza and COVID?
Similarities: 1 or more days can pass between when a person becomes infected and when he or she starts to experience illness smx.
Differences:
COVID-19 take longer to experience symptoms than if they had flu.
Flu: experiences smx anywhere from 1 - 4d after infection.
COVID-19: experiences smx about 5d after being infected, but smx can appear 2 - 14d after infection.
How Long Someone Can Spread the Virus for Influenza VS COVID?
Similarities: possible to spread the virus for at least 1 day before experiencing any smx.
Differences:
COVID-19 could be contagious for a longer time than if they had flu.
Flu: contagious for about 1 day before they show symptoms.
Older children and adults with flu appear to be most contagious during the initial 3-4 days of their illness but many people remain contagious for about 7 days.
Infants and people with weakened immune systems can be contagious for even longer.
COVID-19: still under investigation.
possible for people to spread the virus for about 2 days before experiencing signs or symptoms (or possibly earlier) and remain contagious for at least 10 days after signs or symptoms first appeared. If someone is asymptomatic or their symptoms go away, it’s possible to remain contagious for at least 10 days after testing positive for COVID-19. People who are hospitalized with severe disease and people with weakened immune systems can be contagious for 20 days or longer.
How does influenza and COVID spreads?
spread from person-to-person between people who are in close contact with one another –> cough/ sneeze –> inhaled into lungs
spread by inhalation or even touching
Differences:
COVID-19 is generally more contagious than flu viruses. Also, COVID-19 has been observed to have more superspreading events than flu. This means the virus that causes COVID-19 can quickly and easily spread to a lot of people and result in continual spreading among people as time progresses.
