Stage 1: asymptomatic incubation period, proportion unknown but thought maybe as high as 50%; variable incubation period but usual is 5 to 6 days with range from 1 to 14 days; asymptomatic transmission possible for 1 to 2 days prior to symptoms
Stage 2: non-severe symptomatic period, generally lasts about a week (but highly variable) and then recovery, approx 80% of symptomatic patients
Stage 3: a severe stage with complications; 15% severely unwell, 5% critically unwell, mortality rate 1% to 3% and as high as 20% in patients aged over 80
Severe complications typically occur from day 5 (median times to hospital admission are 7 days and to ITU 10 days)
Main severe complications
Acute respiratory distress syndrome, leading to respiratory failure
Sepsis can occur secondary to bacterial or viral pneumonia
Cytokine release syndrome ('cytokine storm'), a systemic later hyper immune response leading to a flood of inflammatory proteins and cells into the lungs and other organs leading to respiratory and multi-organ failure
Rapid deterioration may occur at any time with increasing breathlessness and a sepsis-like picture, and this needs appropriate safety netting
Risk factors for severe complications
Older age, especially aged over 80
Co-morbidities, especially asthma, COPD, hypertension, heart disease and diabetes
Note elderly and those with immune suppression may have atypical presentations
Men are twice as likely to get a severe illness or to die
However, anyone can get a severe disease and people with risk factors can deteriorate rapidly
Fever 80% and cough 80% are the most common symptoms, but may be absent
Focus questions on breathing in context of (for further detail see CEBM 23.3.20
'How is your breathing today?' Then listen for the ability to complete sentences.
A change in symptoms, a clear story of deterioration is likely to be more important than whether the patient feels short of breath.
Have a low threshold for measuring sats and respiratory rate in unwell patients with dyspnoea (which may mean a limited face-to-face consultation) to exclude hypoxaemia and respiratory failure
An oxygen saturation of < 92% on air is predictive of adverse outcomes in patients with pneumonia
CRB65 not validated in people with coronavirus and requires BP measurement 'which may be difficult or undesirable during the COVID‑19 pandemic and risks cross-contamination NICE'.
NEWS2 score may be useful to help decisions on hospital admission but has not been validated for COVID-19 in primary care and 'a face to face assessment should not be arranged solely to calculate a NEWS2 score NICE'
Cough: avoid lying on back; a teaspoon of honey; consider codeine linctus or tablets 15mg to 30mg every 4 hours if cough distressing; second choice morphine sulphate oral solution if severe and distressing
Fever: do not use antipyretics with the sole aim of reducing fever; paracetamol preferred to NSAID
Dyspnoea: keep the room cool and open windows; encourage relaxation and breathing techniques
If pneumonia is clinically suspected, is it viral or pneumonia?
Viral pneumonia is more likely if previous typical coronavirus symptoms for ~1 week, severe myalgia, anosmia, breathless with no pleuritic pain.
Bacterial more likely if secondary deterioration after a few days of symptoms, pleuritic pain, purulent sputum.
Antibiotics? Not routinely, but consider if likely bacterial cause or unclear if viral or bacterial, or patient at high risk of complications (NB we do not want to miss possible treatable disease in these groups)
1st line doxycycline 5 days (200mg stat day 1 then 100mg daily remainder) or amoxicillin 5 days (500mg TDS); do not routinely use dual antibiotics
Who should we admit to hospital?
NICE give no clear guidance on who should be admitted, so follow local guidance
This will be very patient-specific depending on frailty, co-morbidities and personal wishes/care plans.
Features associated with a severe illness which should prompt consideration of urgent admission unless advance directive to the contrary include
SOB with minimal exertion, unable to complete full sentences or get out of bed, no urine output, cyanosis or mottled skin
RR ≥ 25, HR 125, O2 SAT ≤ 94%
RCGP suggests we tell patients to seek urgent medical advice if they become significantly breathless, develop chest pains, become pale and clammy ('like someone who is about to vomit') or seem more muddled or confused.
Warn patients there is a small risk of rapid deterioration, usually day 5-8
Conclusion: We can reassure that whilst for most people COVID-19 will be a mild and self-limiting illness, serious complications and rapid deterioration may occur at any age or stage and this needs appropriate safety netting