Although the majority of those affected will only experience mild symptoms, 14% will develop severe disease that requires hospitalisation and oxygen support, and 5% will require admission to an intensive care unit. Of those critically ill, most will require mechanical ventilation.

Older people may present with mild symptoms but have high risk of deterioration and should be admitted to a designated unit for close monitoring [Image: Freepik]

Vulnerable populations

Early Covid-19 case reports suggest that patients with underlying conditions are at higher risk for complications or mortality. Up to 50% of hospitalised patients have a chronic medical condition. The World Health Organization (WHO), lists cardiovascular disease (CVD) and diabetes, as conditions that make older people ‘more vulnerable to becoming severely ill with the virus’.

Concerns have also been raised about the susceptibility of patients with asthma and chronic obstructive pulmonary disease (COPD). Data from the Chinese Center for Disease Control and Prevention show that the fatality rate was highest in Covid-19 patients with:

  • CVD (10.5%)
  • Diabetes (7.3%)
  • Chronic respiratory disease (6.3%),
  • Hypertension (6%)
  • Cancer (5.6%).

Older people may present with mild symptoms but have high risk of deterioration and should be admitted to a designated unit for close monitoring. For those with mild illness, hospitalisation may not be required unless there is concern about rapid deterioration or an inability to promptly return to hospital, but isolation to contain/mitigate virus transmission should be prioritised.

All patients cared for outside hospital (e.g. at home or non-traditional settings) should be instructed to manage themselves appropriately according to local/regional public health protocols for home isolation and return to a designated Covid-19 hospital if they get worse.

What is considered mild disease?

The WHO defines patients with mild disease as those with uncomplicated upper respiratory tract viral infection and non-specific symptoms such as fever, fatigue, cough (with or without sputum production), malaise, muscle pain, sore throat, dyspnoea, severe nasal congestion, or headache. In some cases, patients present with diarrhoea, nausea, and vomiting.

The elderly and immunosuppressed may present with atypical symptoms. Symptoms due to physiologic adaptations of pregnancy or adverse pregnancy events, such as dyspnoea, fever, gastrointestinal-symptoms or fatigue, may overlap with Covid-19 symptoms.

When is it severe disease?

In severe cases, Covid-19 can be complicated by acute respiratory distress syndrome (ARDS), sepsis and septic shock, multi-organ failure, including acute kidney injury and cardiac injury. The most common diagnosis in severe Covid-19 patients is severe pneumonia. Adolescent and adult patients with severe pneumonia present with fever or suspected respiratory infection, plus one of the following:

  • Respiratory rate >30 breaths/min
  • Severe respiratory distress or SpO2 ≤93% on room air.

In children, symptoms include a cough or difficulty in breathing, plus at least one of the following:

  • Central cyanosis or SpO2 <90%
  • Severe respiratory distress (eg grunting, very severe chest indrawing)
  • Signs of pneumonia with a general danger sign: Inability to breastfeed or drink, lethargy or unconsciousness, or convulsions.

Other signs of pneumonia may be present:

  • Chest indrawing
  • Fast breathing (in breaths/min): <2 months: ≥60; 2–11 months: ≥50; 1–5 years: ≥ 40.

While the diagnosis is made on clinical grounds, chest imaging may identify or exclude some pulmonary complications.

Covid-19 and CVD

Up to 40% of patients who required hospitalisation had CVD or cerebrovascular disease. Wang et al found that acute cardiac injury, shock, and arrhythmia were present in 7.2%, 8.7%, and 16.7% of patients, respectively, with higher prevalence amongst patients requiring intensive care.

The American College of Cardiology recommends the following approach to patients with CVD and Covid-19:

  • Make plans for quickly identifying and isolating CV patients with Covid-19 symptoms from other patients, including in the ambulatory setting
  • It is reasonable to advise all CV patients of the potential increased risk and to encourage additional, reasonable precautions
  • It is important for patients with CVD to remain current with vaccinations, including the pneumococcal vaccine given the increased risk of secondary bacterial infection with Covid-19
  • CVD patients should be vaccinated against influenza in accordance
  • In geographies with active Covid-19 outbreaks, it may be reasonable to substitute telephonic or telehealth visits for in-person routine visits for stable CVD patients to avoid possible nosocomial Covid-19 infection; planning for emergency telehealth protocols should begin now
  • It is reasonable to triage Covid-19 patients according to underlying CV, diabetic, respiratory, renal, oncological, or other comorbid conditions for prioritised treatment
  • Providers are cautioned that classic symptoms and presentation of acute myocardial infarction (AMI) may be overshadowed in the context of Covid-19, resulting in underdiagnosis.
  • Specific protocols should be developed for the management of AMI in the context of a Covid-19 outbreak, both for patients with and without a Covid-19 diagnosis:
  • Particular emphasis should be placed on acute percutaneous coronary intervention and coronary artery bypass surgery, including protocols to limit catheterisation lab and operating theatre personnel to a required minimum
  • Pre-determining requirements for enhanced personal protection and assessing postprocedural sterilisation sufficiency
  • In extreme circumstances, clinical leadership may need to assess the risk/ benefit ratio of acute MI intervention against nosocomial infection risk.
  • For patients with heart failure or volume overload conditions, copious fluid administration for viral infection should be used cautiously and carefully monitored S General immunological health remains important for both providers and patients, including eating well, sleeping and managing stress

Covid-19 and diabetes

According to the American Diabetes Association, people with diabetes have a higher risk of ‘worse outcomes’, but do not have a greater chance of contracting the virus than the general population. In general, people with diabetes are more likely to experience severe symptoms and complications when infected with a virus. If diabetes is well-managed, the risk of getting severely sick from Covid-19 is about the same as the general population.

When people with diabetes do not manage their diabetes well and experience fluctuating blood sugars, they are generally at risk for a number of diabetes-related complications. Having heart disease or other complications in addition to diabetes could worsen the chance of getting seriously ill from Covid-19 , like other viral infections, because the body’s ability to fight off an infection is compromised.

Viral infections can also increase inflammation, or internal swelling, in people with diabetes. This is also caused by abovetarget blood sugars, and both could contribute to more severe complications. When sick with a viral infection, people with diabetes do face an increased risk of diabetic ketoacidosis (DKA), commonly experienced by people with type 1 diabetes.

DKA can make it challenging to manage fluid intake and electrolyte levels, which is important in managing sepsis. Sepsis and septic shock are some of the more serious complications that some people with Covid-19 have experienced. The key to preventing any form of infection in patients with diabetes, agree the experts, is glucose control.

Are people with asthma and COPD at greater risk?

Respiratory experts say that people with asthma do not seem to have a higher risk of infection than their non-asthmatic counterparts. In general, people with asthma have a higher risk of respiratory diseases, but it is not higher with Covid-19. The American Centres for Disease Control and Prevention (CDC), however, disagrees and states that: ‘People with asthma may be at higher risk of getting very sick from Covid-19. Covid-19 can affect your respiratory tract (nose, throat, lungs), cause an asthma attack, and possibly lead to pneumonia and acute respiratory disease’.

The CDC say the best way to prevent illness is to avoid being exposed to this virus. Asthma UK cautions that patients with severe or difficult to treat asthma should take extra care. They recommend that asthma patients should:

  • Use their inhaler medication daily as prescribed. This will help reduce the risk of an asthma attack being triggered by Covid-19 or any other respiratory virus. Although most bodies caution that corticosteroids should be avoided in treating Covid-19 , patients with well-controlled asthma who stop regular use of low-dose ICSs have an increased risk of an asthma exacerbation compared with those who continue treatment as prescribed
  • Take their inhalers where-ever the patient goes, and if they feel their asthma symptoms flare up, they should use it immediately
  • Patients should be advised to get a peak flow meter and to start a peak flow diary. This is a good way to track asthma attacks and can help tell the difference between asthma and Covid-19 symptoms
  • Patients who develop flu-like symptoms, a cold or any other respiratory infections, should be advised to stay in bed
  • If a patient comes down with flu, a cold, or any other respiratory infection, advise them to stay in bed and take paracetamol for aches and pains and drink lots of water and other drinks;
  • Keep medicines close to bed so they don’t have to get up unnecessarily;
  • Keep on using their inhalers;
  • Not ignore symptoms – especially if they feel breathless or wheezy
  • Seek medical attention if symptoms return within four hours
  • Flu especially can really wipe you out, so don’t try to do too much too soon.

The American COPD Foundation and the Respiratory Health Association say people with COPD and other lung conditions are at an increased risk for serious outcomes if they become infected, which is also true for seasonal influenza and pneumonia. A study by the University College London indicates that COPD is a risk factor for severe cases of Covid-19.

The team showed that patients who experienced dyspnoea, or difficulty in breathing (67.2%), after being infected with the virus were 3.7 times more likely to have severe disease and 6.6 times more likely be admitted to an intensive care unit, compared to those who did not show this symptom. Patients with COPD should take extra precautions to avoid getting infected, advice most bodies. Please see our infographic on page XX for information on how to avoid getting infected.

What about smokers?

There is still no robust evidence to suggest an increased risk of infection amongst smokers. However, data from China show that people who have respiratory conditions caused by tobacco use are at higher risk of developing severe Covid-19 symptoms. Among Chinese patients diagnosed with Covid-19 associated pneumonia, the odds of disease progression (including mortality) were 14 times higher among people with a history of smoking compared to those who did not smoke.

Other studies have shown that smokers incur a 2- to 4-fold increased risk of invasive pneumococcal lung disease, a disease associated with high mortality. Influenza risk is twofold higher and more severe in smokers compared with non-smokers. In the case of tuberculosis smokers also have a twofold increased risk of contracting the infection and a 4-fold increased mortality. The bottom-line… now might be a good time to quit!