Wednesday, 27 July 2011

Them foreign germs? Comin’ over here?

This post first appeared on the 21st Floor site

So, the Olympics are one year away, running from 27 July to 12 August 2012 . The Paralympics (29 August to 9 September) run soon afterwards.
That’s a lot of people coming to London. Many of them foreign, so cue the Daily Mail getting into a froth about nasty foreigners and their nastier germs.
Anyway, I digress. Lots of people in one place (otherwise known as a mass gathering) means there is potential for outbreaks of infectious diseases. The authorities have to be as prepared as possible, and this would include liaison between dozens of institutions and offices, including local and national government, healthcare bosses, the police, the Mayor’s office, and also the Health Protection Agency (HPA).
The HPA (soon to be reformed into a Department of Health entity called Public Health England) are the body responsible for disease surveillance in England (Health Protection Scotland, and Public Health Wales seeing to the rest of Great Britain). They are key to the monitoring and confirmation of potential outbreaks, and providing advice and support for the containment of the outbreaks. They have reference laboratories all over the country, with the main site being in Colindale, in north-west London.
According to the specific pages on the HPA website, during the period of the Olympics, they will be ‘producing a daily public health report’ that will be disseminated to appropriate partners and collaborators. They have also carried out training exercises (codenamed Exercise Bucephalu), identifying best practice in situations of mass casualties and evacuations. As well as infectious disease outbreaks, they will also monitor other public health concerns, such as bioterrorism, fires, radiation, chemical attacks etc.
But back to infection – what does happen during mass gatherings? The risk of an outbreak does of course increase. More people around in crowded areas, perhaps with unusual strains and serotypes of interesting bacteria and viruses. But this does not mean that half the Olympic stadium will be charging towards some overcrowded toilets immediately after the opening ceremony, nor does it mean the equestrian events will be tarnished with a hefty bout of equine flu. Let’s look at what happens in previous mass gatherings.
The Hajj is perhaps the world’s largest mass gathering. Somewhere near 2 million pilgrims attend this 5-day Muslim festival in Mecca every year, which poses significant crowd-control and public health issues. This festival has experienced outbreaks of meningitis, and pilgrims are considered at high risk of tuberculosis and other respiratory infections. The World Health Organisation now publish guidance on vaccination requirements before visas to Saudi Arabia are issued.
With sporting events, and in relation to the dynamics of infection, they tend to play out a little differently. People are in close proximity to each other for maybe a couple of hours, then disperse. The 1998 football world cup was held in France, and the network of surveillance systems set up to capture health-related data suggested that there was no significant increase in cases of communicable diseases. Fast forward to Portugal and the 2004 European Championships – during the tournament, there were ten foodborne outbreaks, seven cases of meningococcal disease and one case of legionnaires disease. Visitors were not affected, and cases numbers among residents were not unduly affected by the presence of thousands of extra tourists. During the 2006 world cup in Germany, a norovirus outbreak was picked up through the enhanced surveillance systems, but nothing of great impact beyond that.
A further paper also suggests that, on the whole, there is no great increase in incidence of infectious diseases during large sporting events. But preparation and surveillance, as described above, here for the Beijing Olympics, and here for the Vancouver Winter Olympics, is absolutely key.  Because despite the risks rarely playing out into a worst-case scenario, we certainly don’t want them foreign germs (or the good old-fashioned British ones with union jack-themed flagellae) spreading freely about the capital...

Michael Head

Wednesday, 29 June 2011

Elephants on a trapeze – is a ban on circus animals backed up by the evidence?

Right, now the inspiration for this post came from a thread on the Bad Science forum. It's not an area in which I have the slightest expertise; however, like some of the posters in that thread, and perhaps like many people generally, I have an in-built moral compass that assumed that keeping performing animals in circuses is wrong. I couldn't really suggest a valid reason - the best I could come up with would be something along the lines of "well, it's cruel and inhumane, it's obvious". If asked to justify why this was my opinion, I'd run out of steam very quickly.

The Independent newspaper has been running a campaign against the use of wild circus animals, and recently reported on the House of Commons voting to ban their use (24 June 2011). It's arguably a popular move, as it aligns them with the press (unless other newspapers have been running a campaign to increase the number of circus animals; if they have, then I've missed that one), and it'll ring some nice bells with the electorate (always a good thing). And the vocal animal rights lobby will be very pleased indeed with this. 

But are the reasons for a ban actually backed up by the evidence?

We have a report from DEFRA (Department for Environment, Food and Rural Affairs) from 2007, entitled 'Wild Animals in Travelling Circuses'. They report the number of wild animals being used in British circuses as 'less than 50' (the Independent report above quotes a number of 39). Amongst their conclusions are - 

  • The Academic Panel concluded that there appears to be little evidence to demonstrate that the welfare of animals kept in travelling circuses is any better or worse than that of animals kept in other captive environments
  • It is concluded that in relation to England, Wales, and Scotland, the consequence of the Academic Panel’s Report is that Ministers do not have before them scientific evidence sufficient to demonstrate that travelling circuses are not compatible with meeting the welfare needs of any type of non-domesticated animal presently being used in the United Kingdom.  
So, they state quite clearly that circuses do not typically fall foul of current animal legislation. We do of course hear of ill-treatment of wild circus animals every so often. These cases do tend to stick in the mind, and can induce the perception that this sort of cruelty is routine in circuses. Presumably it is not. I can't quite grasp that circuses would amble about their daily business whilst beating their performing elephant with a stick, as not only would this risk bad publicity and the close attention of the not-always-so-liberal activists, but they would be at risk of losing their licenses and their livelihood. 

The DEFRA report also concludes that - 

  • The  overriding conclusion of this exercise is that our present state of knowledge about the  welfare of non-domesticated animals used in circuses is such that we cannot look to scientific evidence for a steer in the development of policy; it is, ultimately, an entirely  political decision.  Once the relevant policy is decided  upon, its implementation is essentially a question of politics and law; science, on this occasion, provides no relevant guidance as to the appropriate principle to be adopted.  
So, it's not purely a scientific decision; the politics are important too. Of course they are - but should they be? A brief search of pubmed produces some interesting papers. 

One Veterinary Journal publication (June 2011) suggests that 'Animal welfare issues cannot simply be addressed by means of objective biological measurements of an animal's welfare status under certain circumstances.' The Bad Science thread discusses the use of cortisol as a biological measure of stress levels in animals - can we use this as a gauge of how relaxed an animal is? The points were made that a captive environment is a low-stress place to be, as there is no threat of predators, poachers and there is 24-hour veterinary care available nearby. Regardless of whether cortisol is a good biological marker, the authors of this VJ paper conclude ' In assessing whether or not a given welfare status is morally acceptable, animal welfare scientists must be aware that scientifically based, operational definitions of animal welfare will necessarily be influenced strongly by a given society's moral understanding.' 

A 2011 paper by Fabregas et al suggests that in zoos, a 'naturalistic enclosure' tended to provide a more suitable environment for that species than a non-naturalistic one. On this basis, a circus is less likely to be providing a decent living quarters for their lions than a good zoo. However, the point still stands that the animals are theoretically 'safer' in their captive environment than they are knocking about the African plains. 

How is the behaviour of captive wild animals? Again, dipping into the world of zoos, there is this paper from Birkett and Newton-Fisher on primate behaviour, and they concluded that 'while most behaviour of zoo-living chimpanzees is 'normal' in that it is typical of their wild counterparts, abnormal behaviour is endemic in this 
population despite enrichment efforts'. Can this sort of finding be extrapolated to circus wild animals? Can we also clearly suggest that their behaviour is abnormal enough to be concerning? 

So, a few points raised, with arguments for and against the motion. Clearly politics and public opinion hold great sway here. Perhaps circus animals are mostly unstressed, they do see a good vet now and again, and there are not that many of them anyway. However, there are high profile examples of animal cruelty and they may behave undesirably abnormally. Plus, who actually needs a circus with animals when we have some excellent zoos in the UK? 

I started this blog post ill-informed on the facts, yet with a clear opinion that the keeping of circus wild animals  is cruel. I now consider myself far better informed of some of the key issues, and am more confused than I ever was before. I'm off for a fag and a beer - (Camel in the coat pocket and Tiger in the fridge, in case you were wondering). 

This has not been based on an exhaustive literature search, and it's an area of which I know little. Do send me corrections of inaccuracies or good links to further reports or an evidence base. I'm keen to be educated here! 

Monday, 13 June 2011

The Economist suggests the end of AIDS? Really?

Article first published on blogging site the 21st Floor 

So, it’s 2011, and it’s the 30th birthday of AIDS. Not much to cheer about there, although it is a convenient point to reflect on the impact of this devastating infection, to scan the horizons to see what might happen in the future,  and to push for even greater investment and collaboration in the future.

The Economist has run a leading article entitled “The end of AIDS?” with the sub-heading “Thirty years on, it looks as though the plague can now be beaten, if the world has the will to do so”
Now, let me be so bold as to suggest this is massively over-stating the case of our progress in the battle against this most ingenious of retroviruses.  Yes, we have seen huge improvements in the standard of care, the provision of better and better drugs (one-a-day pills trumping the previous cocktail of drugs sufferers used to have to take daily), greater understanding of the virus genome and immunological response. But to head the article with as grand a statement as “the end of AIDS” is nowhere near the truth.

The Economist says that “the war on AIDS is going far better than anyone dared hope”. I would say that 30 years ago, knowing that  30.8 million adults and 2.5 million children were living with HIV at the end of 2009 would not have featured in too many experts’ best-case scenarios. The Economist gives one reason for their optimistic approach is as “the death rate is dropping”. This is true, and cause for good cheer – but limit yourself to half a pint, as there is work and thinking to be done. A dropping death-rate, whilst of course A Very Good Thing, also means there are more people alive with the virus (especially with around five million new infections each year). More people to look after in stretched or non-existent healthcare facilities, and more money needed to spend on life-saving drugs. The burden transfers from how we can keep these people alive, to how we can look after them now we’ve kept them alive in the first instance. The latter is preferable to the former, but it’s one heck of a challenge. Especially given so many of those infected are living in low-income countries, which are not remotely prepared or able to deal with it.

So, what to do? Well, a vaccine would be nice. The finalisation and approval of this Holy Grail of medicine would go a long way to justifying a headline such as “The end of AIDS?”. But any vaccine is many years away, and certainly not on the horizon. It is over the horizon, and much further along a maze of winding roads – we do not yet know quite which is the road that leads us to the Emerald City, or how far it is. There have been promising initial studies on vaccine research previously, and they have ended up a disappointment; work continues around the world to build on these failures and try to generate a genuine, and massive, positive angle to this.

What else is there? Antiretroviral drugs are improving all the time, but whilst they suppress the viral load, thus reducing risk of transmission, they are not designed with prevention in mind. Microbicides are an interesting approach – they are essentially topical drugs that can be smeared inside the vagina or rectum, and act there as anti-infectives. Trouble is, we are still at the ‘promising study reveals hope’ stage for these too, such as the CAPRISA study or another candidate (also reported in the Economist, June 2011). And once we have a reliable microbicide in however many years from now that would be, it needs to be provided to every country around the world, it needs to be accepted by the public and not treated with suspicion, and women need to learn to how apply it and how to be empowered by it.

Which brings us onto another huge segment of the problem - behavioural.

Yes, the typical behaviour of mankind is not ideal for stopping a global pandemic of epic proportions, no matter how clever the medicine, what with our propensity for promiscuity, lack of safe sex and a lack of promotion of safe sex (are you reading this, Benedict?*), rape, poor education, attitudes to HIV itself, attitudes to associated stigmas such as homosexuality, and so on. Entire behavioural and cultural shifts are phenomenally difficult to introduce, and take a long time.

The Economist article is mostly very well written, being both interesting and thought provoking.  But winning the war on HIV and AIDS? At best, we’re in a stalemate at the moment. A very long stalemate. It should get better – but it will take a long old time and at huge cost (mortality, morbidity and economically) to mankind.

Michael Head

* I reckon probably not