Less than four months ago the world was cheered to learn that India had gone a full year with no new cases of polio - a landmark that left only Pakistan, Afghanistan and Nigeria on the World Health Organization's list of countries where the disease is endemic.

But the battle is far from over, judging by the WHO's latest expressions of alarm. It says that in both Nigeria and Afghanistan the number is creeping up, while budget shortfalls are jeopardising the effort to hold polio at bay in 24 other high-risk countries. Right now the numbers of new infections are small.