A question of escalation

With the spread of the coronavirus (Covid-19) to 36 countries, as at 24 February, the prospect of the World Health Organization (WHO) declaring a pandemic gets more likely. While the morbidity rate for the outbreak is less than that with SARS or MERS, the infection rate appears high and containment is clearly proving a problem for some countries. With the virus now affecting countries and regions well beyond China then the declaration of a pandemic can be expected.

Medical professionals in the US think that ‘it is likely we will see a global pandemic. If a pandemic happens, 40% to 70% of people world-wide are likely to be infected in the coming year’. (Professor Marc Lipsitch, Harvard School of Public Health).

Dr Robert Redfield at US Centers for Disease Control and Prevention (CDC) believes ‘the virus is probably with us beyond this season, beyond this year, and I think eventually the virus will find a foothold and we'll get community-based transmission and you can start to think about it like seasonal flu.’ This means it is residual and could have peaks and troughs.

It could quite possibly settle down into a respiratory illness that comes back seasonally (winter/spring). It could also mutate and acquire different characteristics’, stated Dr Redfield. The virus has yet to create clusters of infection in the southern hemisphere where summer temperatures may be keeping it at bay. Disturbingly, the temperatures in Singapore have recently been in the mid-to-high 80s. That suggests higher temperatures may slow but probably won’t stop transmission of the new virus, Lipsitch said.

In 2009, during the last flu pandemic, the fact that there was a new flu virus circulating was only realised in late April — around the time when flu typically subsides in this part of the world. Transmission abated somewhat over the summer but the big wave of infections in North America began early in the fall. By the time a vaccine started to become available in November, the outbreak had peaked.

To mask or unmask

The general advice is that face masks do not provide protection against the virus but they can reduce the chance of an infected person spreading the disease and reduce the chances of a non-infected person becoming infected. (See protocols offered in previous new item here.)

The WHO website states clearly that: ‘People with no respiratory symptoms, such as cough, do not need to wear a medical mask.’

This notwithstanding, many people feel that the act of wearing a mask is something that gives reassurance and there can be a strong cultural affinity based on previous disease outbreaks or for anti-pollution reasons. Masks seen to be worn by health workers – and other professions – strengthen the belief in some benefit. This will be hard to alter.

Hence, it is important to point out correct actions to follow when wearing and disposing of masks.

First, wearing of face masks for prolonged periods is not recommended as a mask becomes less effective when moist. The WHO does offer this advice on wearing a mask. It makes the point that masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.

Second, the WHO states that if a mask is worn then the user must know how to wear it and dispose of it properly. A non-reusable fabric mask lasts around 8 hours. To continue wearing a dirty mask may be worse than wearing nothing. Higher grade masks or respirators like the N95 mask are uncomfortable and make breathing an effort and talking unintelligible.

According to David Carrington, a consultant in clinical virology at St George’s Hospital, London, ‘Scientific data does not support surgical masks in public, largely because people are confused about how to wear them but it’s not stupid to wear a mask if its tight-fitting, replaced fast and you wash your hands.’