KUALA LUMPUR, April 22 – Smokers and those who vape could have higher chances of contracting Covid-19, contributing to the spread of the virus, and developing severe illness, lung experts said.
Cardiothoracic surgeon Dr Anand Sachithanandan and respiratory physician Dr Helmy Haja Mydin highlighted frequent hand-to-mouth movements from smoking and vaping, as well as the impact of smoking on lung function and the immune system.
Below is CodeBlue’s Q&A with Lung Cancer Network Malaysia co-founder Dr Anand and Asthma Malaysia co-founder Dr Helmy about the risks of smoking on falling seriously ill from respiratory disease Covid-19, how people can quit smoking or vaping, and recommendations to the government to ring-fence some revenue from tobacco taxation for public health programmes.
Is there any evidence for the perception that smokers are more likely to contract the coronavirus and more likely to die from Covid-19?
A curious observation of this ongoing global pandemic is the remarkably low proportion of smokers among hospitalised Covid-19 patients.
Data from both China and the USA shows that smokers account for only a small fraction of these patients despite the high smoking prevalence within their general population.
In China for example, 26.6% of the population smoke, yet only 6.5% of hospitalized Covid-19 patients were smokers. In the USA, data from the CDC showed only 1.3% of hospitalized Covid-19 patients were smokers despite a national smoking prevalence of 14%.
One might wonder if nicotine (smoking) could paradoxically have a protective effect against Covid-19? On balance, this is unlikely.
Amid an emerging and overwhelming epidemic, it is quite possible that reporting of smoking status may not be accurate. The disproportionately low figures recorded might be due to varying definitions of who is a smoker.
A person who becomes unwell and stops smoking just days prior to hospital admission may declare himself a non-smoker. Others might be genuinely too sick or fearful to provide an honest or coherent report of their tobacco use. Doctors perhaps are too busy or overwhelmed to take a thorough detailed history.
Smoking is also generally more prevalent in lower socioeconomic classes where affordable access to hospital care might be limited.
Finally, the prevalence of smoking is lower in the elderly, who are more likely to require hospital admission. For all these reasons, the smoking data is probably an underestimate. Hopefully we will soon have our own local data to analyse.
Several recent studies from China suggest smokers are at risk of severe Covid-19 illness that may require admission to the intensive care unit, mechanical ventilation or even higher odds of dying. However, it is important to bear in mind these are retrospective observational studies, hence the medical researchers could not adjust for possible confounding risk factors.
For example, whilst smokers may be over-represented in this high-risk group, it is possible that there were more elderly people or more people with underlying co-morbidities like ischaemic heart disease, diabetes or hypertension; risk factors that may also contribute towards a poor outcome.
It can be difficult to tease out which risk factor is most responsible. It will be important to see more data from other centres involving more patients but for now it seems reasonable to conclude that smokers are at risk.”
Why are smokers thought to be at greater risk?
There are three important considerations. First, the act of smoking involves repetitive and frequent hand-to-mouth movements. Our hands are constantly in contact with easily contaminated high-touch surfaces like door handles and lift buttons.
Our ‘dirty’ hands may easily transfer the virus to our eyes, face or mouth with a higher risk of viral entry and infection. Frequent smoking may also make the wearing of a face mask less practical and less effective.
A recent study from Hong Kong showed that people are most infectious one to two days prior to developing symptoms when viral shedding is highest. Hence the rationale for face masks even if one is asymptomatic.
Secondly, smoking is known to impair our lung function and immune system. The coronavirus seems to have a predilection for our respiratory system (airways and lungs) and chronic smokers may be more susceptible to a severe infection due to ‘weaker’ lungs from long term smoking damage and a depressed immune response.
Many smokers develop emphysema or chronic obstructive pulmonary disease, which reduces their lung reserve and capacity to fight the virus.
Thirdly, the SARS-CoV-2 coronavirus requires a living host (human) to replicate and cause harm. The critical entry point is the angiotensin converting enzyme II (ACE-2) receptor which is found in the lining of our airways (respiratory epithelium) and lungs (type II alveolar pneumocytes) in addition to the small intestine, kidneys and lining of blood vessels (endothelium).
This ACE-2 receptor is responsible for the initial entry of the virus into the host cell and facilitates fusion between the host (human) cell and virus membrane, a prerequisite for cellular infiltration. Scientists have shown that there is increased expression of this ACE-2 gene in the lungs of smokers compared to non-smokers.
In short, smoking can cause a significant increased expression and upregulation of ACE-2 receptors in the smaller airways and lungs. Hence the virus has more opportunity to invade the body and smokers have a higher odds of a severe Covid-19 infection due to a higher viral load.
Can smoking increase the spread of the SARS-CoV-2 coronavirus?
Smoking is a well-known risk factor for many respiratory infections. This includes viruses, bacteria and tuberculosis. Smoking increases inflammation in the airways and lungs, and also reduces the ability of the lungs to clear itself of these microorganisms.
As a consequence, it is more likely that smokers contract diseases such as the SARS-CoV-2 coronavirus and inadvertently contribute to its spread.
For the smoker himself (prevalence amongst adult males in Malaysia is approximately 43%, and 1% for women), the physical hand-to-mouth movement means that the risk is higher, given the increased frequency of touching the face and mouth. This is applicable to both conventional and electronic cigarettes.
Of course, there are other forms of smoking – shisha being one. Shisha is usually smoked in a group, with a single mouthpiece and hose shared between users. The equipment used, the lack of hygiene and the small physical space between users all increase the risk of transmission of infections.
What can / should smokers do?
In an ideal world, this is an opportunity to quit smoking. Being away from social settings and work might actually provide the perfect opportunity to not be swayed by societal pressure to smoke. However, the MCO is a very stressful period for most of us. If there is a high level of anxiety and stress, then it may not be the best time to quit.
If one does decide to quit, it should be planned ahead and done with the support of all at home.
Willpower is important, but efforts to quit tend to be more successful when it is combined with medication and psychological support. Medication such as nicotine replacement therapy can help reduce physical cravings and withdrawal symptoms (visit www.jomquit.com).
Psychological support and cognitive behavioural therapy are also important as although smokers are addicted to nicotine, there are many social and psychological factors that nudge them towards continued smoking.
Ideally, one should set a date and quit. However, some may find this too challenging and would opt to cut down on the number of cigarettes first. There is no one right answer for all.
Either way, efforts must be made to protect those who are exposed to secondary and tertiary smoke – with the Movement Control Order (MCO), it is likely that non-smokers will suffer more. Smokers must do what is necessary to protect their loved ones from the consequences of their actions.”
What can the government /society-at-large do to mitigate this risk?
The illicit cigarette trade here is rampant. Six out of every 10 cigarettes sold in Malaysia last year evaded taxes. This cost the treasury an estimated RM5 billion in lost revenue. Simply increasing the minimum cigarette price (MCP) won’t work.
Our customs and border controls must be more vigilant and meticulous to curb smuggling.
Otherwise any further increase in the MCP will be counterproductive and merely fuel the sale of contraband cigarettes. These black-market cigarettes are potentially more damaging as the ‘labeled’ nicotine and tar content is very dubious.
The government must also diligently monitor and strictly enforce the smoking ban at eateries nationwide especially once the MCO is lifted to protect children and non-smokers. Any attempt to set up designated public smoking shelters must be strongly resisted. It will normalise smoking and runs counter to the goal of creating a smoke-free culture here.
The WHO Framework Convention on Tobacco Control advocates against such shelters due to insufficient credible evidence regarding their safety and effectiveness. It is worth remembering that Malaysia previously ratified the WHO framework in 2005 and we must uphold it.
We are very much focused on Covid-19 at the moment, but the other challenges that we face as a nation have not suddenly disappeared. This includes the impact of tobacco on non-communicable diseases (NCDs) and diseases such as lung cancer.
There is sufficient evidence that tobacco smoking worsens the outcome of Covid-19.
In fact it also worsens the outcomes of patients with co-morbidities such as diabetes and hypertension, which are also known poor prognostic factors for Covid-19.
As people are anxious regarding the pandemic, I would urge the government to capitalise on this opportunity to educate the public on the dangers of smoking and the need to protect both themselves and their loved ones.
This can be done in combination with the various public service announcements on hand-washing and social distancing.
Work can also be done with the Ministry of Health (KKM) and the National Security Council (MKN) on utilising telcos in sending appropriate SMSs that can serve as both a reminder and warning for those who smoke. As always, all forms of warning must be coupled with information on the availability of quit-smoking services.
What would you like to see going forward?
Some revenue from tobacco taxation should be ring-fenced to directly fund a screening programme (with low dose computed tomography) for early detection of lung cancer in high-risk chronic smokers and former smokers.
Lung cancer remains a leading cause of cancer mortality here with very poor outcomes as the vast majority of cases are detected too late. It is a curable disease if detected early.
Smoking remains the most identifiable and modifiable risk factor. Screening and smoking cessation are complementary and should go hand-in-hand. Funds should also be set aside for a national database to collect relevant data to drive future clinical research of tobacco-related diseases.
The government should continue to place public health as a key focus of its legislative agenda. From a tobacco control point of view, this would include continuing with plans to ban smoking in public areas and introducing new initiatives such as plain packaging.
The pandemic has also highlighted the need to invest in public health. This should take the form of ring-fencing a budget for joint efforts by government, professional organisations and civil society to educate and empower patients.