Sixty years ago smallpox was endemic across much of the world, killing two million people each year. In 1959 an international programme to eliminate the virus was started, not least because it was a disease amenable to large-scale vaccination. In 1977, the last case was diagnosed and recorded. It had taken just eighteen years to achieve the elimination of the entire disease in the wild.
This was the first-ever case of a major disease organism being destroyed in the wild, and there has only been one other - far less well-known, but in its own way quite significant. This is rinderpest, a dangerous viral infection most common in cattle but infecting some other species of livestock. It took several decades to exterminate, but success finally came in 2001.
A third disease has been the target of atempts at total elimination. This is poliomyelitis, which in the 1980s still infected hundreds of thousands of people. Polio, if not a killer on the same scale as smallpox, is particularly prone to attack children and can leave them with severe impairments that can last a lifetime.
A faltering retreat
Poliomyelitis has been subject to an intensive programme of vaccination, with attenuated live virus forming the basis of the process. By 2012, substantial success had been achieved, with only 223 cases diagnosed and the virus remaining endemic in three countries: Pakistan, Nigeria, and Afghanistan. The programme had been coordinated by the World Health Organisation (WHO) and backed by Unicef, though much of the funding - more than $850 million over two decades - came from the Rotary Foundation, the charitable arm of Rotary International.
Much of the success was achieved in the first few years through to 2001, but the dozen years since then have proved far more difficult. A contributing factor is that effective vaccination requires a basic but well-distributed health service that may be beyond the capabilities of some countries, particularly in their remote rural areas. This can be compensated for by well-staffed and well-organised short-term endeavours, but even these have to cope with elements such as the need to keep cool supplies of the attenuated vaccine under field conditions.
But a more important obstacle in the way of final elimination is that the regions where infection remains (and indeed is increasing) are conflict-zones facing endemic disruptions and severe disturbances of everyday security. Polio is now identified as being present in ten countries; it has risen in Afghanistan, spread to Syria and Iraq, and moved fom Cameroon to Equatorial Guinea (see Dan Bifelsky & Rick Gladstone, “Rapid spread of polio sets off a health emergency”, New York Times, 6 May 2014).
Even more worrying is that the virus is present in several countries (in human sewage, for example) that have yet to produce any actual cases. Israel is one such, while new cases are being recorded in Somalia and Ethiopia. Worldwide, the trend of decline is now reversing and thus putting at risk the impressive progress of the previous three decades: a historic low point of 223 new cases was reached in 2012, but this near doubled to 417 new cases in 2013. The sparseness of records in remote or conflict-ridden areas means the latter could underplay the true picture.
The WHO is now calling for a huge new effort to curb the spread of polio through much tighter controls on travelling from endemic areas and a renewed emphasis on childhood vaccination. It will be hard to secure funding for this, and government assistance will be crucial; charitable sources have proved vital, with Rotary’s commitment particularly impressive, but the nature of the current emergency requires intervention on a governmental level too (see Brian Cathcart, "Polio: a war not yet won", 13 May 2005)..
A silent catastrophe
More generally, what is happening with polio is a stark reminder of one of the less recognised impacts of warfare, namely the way it can multiply susceptibility to disease among populations already damaged by poverty and insecurity.
2014 is the beginning of a long commemoration of the first world war that in most accounts lasted from 1914-18 and is estimated to have killed 11 million people. The appalling aftermath of the war is less remembered: an influenza epidemic, often termed “Spanish flu”, which started in 1918, was spread partly by troop movements and took hold among the weakened populations of an impoverished Europe. The human cost is not certain even now but may have have been far in excess of 25 million people worldwide, perhaps as many as 50 million - that is, twice or even four times more than were killed in the war itself.
The uncertainty is largely owed to the severe censorship imposed by governments over the epidemic, ostensibly to limit any outbursts of panic. Indeed it is likely that the use of the term “Spanish flu” in common parlance arose not because Spain was particularly affected but because it was neutral in the war and had far lighter censorship.
Whatever the truth in this aspect, the disease was made worse by the war itself - and in human terms was even more of a killer. It is a stark reminded of this "side-effect" or "by-product" that the epidemic is so far being almost largely ignored in the 1914-18 war's extensive media commemorations.
Polio will not reach the same extent as Spanish flu. But the risk of a pandemic is growing and needs urgent action to contain it. With luck that may happen, given the attention the problem is now getting. But it would be of even more greater value if the impact of war and conflict on the spread of disease was more generally realised. Where polio is concerned, a decade or more of determined action may yet be needed before the end is in sight.