Friday, April 25, 2003

21st century superbug

I wrote this for publication on spiked on 24 April 2003.

Severe Acute Respiratory Syndrome (SARS) is the 'killer bug' that has now affected 3947 people in 27 countries. Of these, 229 have died. There is no cure or vaccine for the disease, which appears to spread by close contact with an infected person. Many of the early victims were hospital workers, and many cases require ventilation to survive: both of which factors put a strain on health services. Death rates from the disease seem to be rising, leading to suggestions that a more virulent form of the disease may have developed. People have been advised not to visit Hong Kong, mainland China or Toronto, Canada. Sales of face masks have risen in many of the countries affected.

The number of reported cases remains a tiny fraction of the populations of the countries affected. Even in Hong Kong, the most disproportionately affected area, the 1434 reported cases represent just 0.02 percent of the people living there. As a comparison, in the year 2000 there were 7578 cases of tuberculosis in Hong Kong. So while SARS in Hong Kong is a significant new strain on health services, it not out of proportion to other, existing infections.

There is even less reason for general alarm elsewhere in the world. Eighty-seven percent of all cases have been in mainland China and Hong Kong, and many cases in other countries have been among travellers who contracted the disease while in China and Hong Kong. There is panic over the apparent rise in the number of cases: but these are cumulative figures, not new cases. Of the 3947 cases reported, 1935 patients have already recovered. Moreover, there has been a big leap in cases reported simply because China is now providing more accurate figures. An examination of the level of new cases reported each day by the World Health Organisation (WHO) shows that the number has been surprisingly static throughout April.

As for reports of an increasing death rate, or a 'virulent new strain', it is simply too early to come to any conclusions. For example, in contradiction to these gloomy suggestions, Taiwan has had 29 cases to date, but not a single death. It will be some time before the differences in outcomes can be explained.

What is clear is that SARS is a powerful demonstration of the ability of medical services to respond to novel disease. WHO is now convinced that the virus responsible has been identified, as have the likely modes of transmission. Treatment methods have been adapted to minimise the risk to hospital staff. While there is no cure, a reasonably successful form of care has been devised. The death rate appears to be quite low, although there is variation between countries. All this for a disease that was only identified as something new and important in February 2003.

SARS does, however, appear to have damaged economies. Travellers face quarantine procedures at airports, as do many private school children returning from the worst affected areas. Governments have taken draconian steps to deal with anyone who refuses to cooperate with containment measures. While the health risk of SARS appears largely under control, the consequences of the panic could run and run.

Don't panic

SARS: Hong Kong cases still falling

outstanding HK cases
SARS is more and more a mainland Chinese problem.

I've updated the Excel file with the latest WHO figures.

Thursday, April 24, 2003

SARS figures: 23 April 2003

I've updated the figures in the spreadsheet to include 23 April 2003. There were 341 new cases reported in the latest figures, with 22 extra deaths and 97 cases reported as recovered or discharged from hospital. The figures are again skewed by a big jump in mainland China figures. Are these new cases or catching up on inaccurate reports in the past?

To get a sense of where things are going, I've isolated the Hong Kong figures on the spreadsheet.

Here is the Excel file with all the data.

One billion could die! Worse than AIDS!

It hardly seems that way if Hong Kong is anything to go by:
Hong Kong SARS by onset
Outstanding cases are falling as more people are now recovering than being infected.

Wednesday, April 23, 2003

Square-eyes and big bones

Watching TV too much makes you fat, according to a report from the Harvard School of Public Health. A group studied fifty thousand women over a six-year period and compared their risk of becoming obese or developing type II diabetes with changes in their eating habits. The study found that watching TV for an extra two hours per day increased the risk of obesity by 25 percent and the risk of diabetes by 14 percent. The research leader, Dr Frank Hu, is quoted as saying, 'Compared with other sedentary behaviours, TV watching is associated with lower resting metabolic rate...Also, people tend to eat junk foods while watching TV, due to constant exposure to food commercials.'

The first statement may well be true, but the second one is slightly bizarre. People may very well eat crap in front of the TV, but that's because they like to eat crap when they relax. It is not because the commercials tell them to.

How useful is this piece of research? On the face of it, fifty thousand women sounds impressive. But how much inaccuracy does there have to be in terms of calorie count, other exercise taken, actual TV watched and in the weighting of other factors, in order to make the percentages mentioned utterly meaningless. The results seem to be common sense, but it would be difficult to draw conclusions from this work safely.

In any event, Dr Hu lives the dream: 'We should not only promote increasing physical activity levels but also target a decrease in sedentary behaviours, especially prolonged TV watching. Personally, I have a treadmill in front of a TV so that I can do some exercise while watching the news.'

Chill out, Doc!

TV watching 'makes you obese', BBC News, 23 April 2003

SARS figures: 22 April 2003

I've updated the figures in the spreadsheet to include 22 April 2003. There were 86 new cases reported in the latest figures, with 12 extra deaths and 62 cases reported as recovered or discharged from hospital.

Here is the Excel file with all the data.

Tuesday, April 22, 2003

SARS data: cumulative vs. new cases

Here's a graph I've created which simply logs the number of cases newly reported by the WHO each day. To keep it consistent, where there is a gap between days, I've averaged out the data.

Presenting a graph like this is not without problems. This is not an accurate reflection of the number of actual new cases to arise each day. The WHO graph on cases by date of onset is better (see my note on Monday 21 April 2003 about this). However, that graph does not reflect all the cases, especially the revised Chinese figures. What is interesting about the graph above is that it reflects the data that the media have been reporting on. And, one or two spikes aside as chunks of cases have been added at one time, the figures are remarkably static, hovering around 100 cases per day throughout most of April. Hardly a deepening crisis.

Here is the Excel file with all the data, which I will endeavour to keep updated.

Monday, April 21, 2003

Economic impact of SARS

The New York Times reports the further fallout from the SARS epidemic on the economy. Some parts of East Asia's economy are now shrinking, it would appear, because of the disease, but the effects are felt thousands of miles away. In Australia, fishermen whose main customers are Hong Kong restaurants are seeing their trade dry up.

Economies Sickened by a Virus, and Fear, New York Times, 21 April 2003

SARS update

A very interesting graph to be found on the WHO site shows the number of cases against the date of onset. This is a useful antidote to the alarm caused by constantly quoting a cumulative figure:
SARS cases by onset
It would seem that the number of new cases is no longer rising and may well be falling, although it is too soon perhaps to draw very firm conclusions, and this data does not include the revised figures from China.

Sunday, April 20, 2003

New York smoking ban

There are mixed feelings in New York, according to Emma Simpson of the BBC, at the new law introduced by the patrician mayor Michael Bloomberg against smoking in bars and restaurants. While it means a cleaner atmosphere for everyone, it also means lower takings in bars, which is hitting the pockets of the very people the law is supposed to be protecting.