(and other infectious diseases)



It is worrying to hear Professor Roy Anderson, the man who masterminded the disastrous contiguous cull as a means of stamping out Foot and Mouth in 2001, saying that we should all relax and stop worrying as the SARS virus is quite hard to transmit. Although SARS is less infective than influenza, the central fact is that it is possible to catch SARS by sharing a hotel with an infected case, as happened with "Patient Zero" Dr Liu Jianlun, in the Metropole hotel in Hong Kong in February. It is thought that he passed the disease in a lift. The fact that sharing a public building with a case can result in infection should be enough to ring alarm bells for an infectious disease with a mortality of 5 - 10%.

Although, fortunately, the firstoutbreak has died out, it is very likely that there will be further outbreaks, and we need to make changes to limit the global spread of this and other infectious diseases.

Some comment has pointed out the relatively higher mortality resulting from established health problems such as malaria and car crashes. This argument misses the point about infectious diseases which, unlike car crashes, undergo exponential growth if each case passes the virus on to more than one person.

SARS is a real global health threat, and deserves a precautionary approach, not patronising reassurances. The establishment is in the denial phase of this crisis, as it was in February 2001 with FMD, and as it was in the first few years of the spongiform encephalopathy crisis. It is depressing that at this stage the debate in Parliament is around whether it should be made a notifiable disease. Of course it should be made a notifiable disease. The decision is a no-brainer. How sad that the DoH should be struggling with it.

What weapons do we have to fight SARS? It may take five or ten years to produce an effective vaccine, more if the virus displays advanced mutation abilities. No effective anti-viral drugs are available, and even if they were, the cost would be prohibitive to all except a tiny minority of rich patients. Therefore the only defence that we have is containment of spread, which means quarantine of infected cases and potentially infected cases.

Airline measures

One measure that could control spread of the virus through airlines would be to change the cabin air filter after each step of a journey, and sending the used filter for virological examination for the SARS coronavirus.

Dr Poon, the originator of the quick (3-4 hour) PCR test for HCV has confirmed to me that this is feasible.

Airline toilet facilities should also be monitored by a virology swab at least once on a journey from a region with a high risk of SARS, and microbiological contamination of touchable surfaces should be brought as low as practicably achievable.

These measures would be cost effective, practicable, and could be extended to cover other communicable diseases, for instance TB.

Quarantine that virus

We have seen in the case of Toronto the problems associated with putting whole communities in quarantine. It is inconvenient, and it reduces income from passing trade. It is bad for the economy. Why bother to do it when only a few dozen have died? The answer is that a swift, localised and effective quarantine policy applied today may save us from a protracted, globalised and ineffective quarantine policy applied in six months' time.

How should quarantine work in practice? It should be the default position that anyone who has been in contact in a known case - and contact here means sharing any enclosed space, such as a hotel, with them, not just sharing a bedroom or nursing them - should take 10 days in as much isolation as is practicable - minimising the number of people that they see face to face. Potential cases should wear masks to reduce the range of travel of their breath, coughs and sneezes. Touch should be minimised, and after any touch contact, hands should be washed.

High-risk contacts who fall in to defined categories (for instance, someone who has been in a hotel at the same time as a case) should be formally obliged to go into quarantine - perhaps with some kind of financial compensation.

More importantly, we need to change the prevalent assumptions about going to work when ill. Anyone who has a flu like illness of any kind, even if they have not been in contact with the SARS virus, ought to take the same measures. There are two reasons for this: first, because some cases of SARS will arise because transmission will occur without knowledge of the infectious case, for instance, if an infected person sits beside you in the train. The other reason is that we should be doing this in any case, SARS or no SARS. It is always advisable to take yourself out of circulation if you have a flu-like illness (meaning fever, hot and cold feelings, aching head and muscles, weakness and cold, sore throat and cough) because if you insist on being a hero and going to work, three thing happen. First, you spread it to your colleagues. Second, you will not work efficiently. And third, you will take longer - sometimes much longer - to recover.

In this way, the positive opportunity offered by the SARS crisis is that it may change the way we manage viral infections. Instead of being expected to come in to work when sick, we will be expected to stay away: and that will in a fairly short time reduce the levels of many viruses which are circulating in the community, and hence the burdens that they impose on the NHS and the economy.

Although effective and desirable, quarantine measures as sketched out above require a lot of a public that is used to getting a pill to cure any illness, as opposed to having to change individual behaviour. It is no wonder that official scientists like Roy Anderson, who has a track record of telling Government what it wants to hear, will steer their advice away from quarantine until it is blindingly obvious that it is the only logical and practical response to this new and serious public health threat.

Richard Lawson MB BS MRCPsych

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© 2001 R. Lawson This page was last updated on 27.4.03