Spending billions more to eradicate polio would be a better approach than trying to control the disease, given the financial and human health costs of allowing the virus to circulate, a new study suggests.

Poliomyelitis is a highly infectious viral disease that mainly affects children, causing inflammation of motor neurons in the brain stem and spinal cord that can lead to paralysis, deformed limbs and, in the most severe cases, death by asphyxiation.

In Thursday's online issue of the medical journal the Lancet, researchers from the Harvard School of Public Health in Boston analyzed the costs and health outcomes of wiping out polio worldwide compared with trying to control cases in India, Nigeria, Pakistan and Afghanistan.

"We shouldn't just accept on face value the idea that we can have low cases and low costs in perpetuity if we don't eradicate," said the study's lead author, Prof. Kimberly Thompson, of Harvard's Kids Risk Project.

Last spring, Dr. Isao Arita, a former WHO official who is now with the Agency for International Health in Kumanmoto, Japan, suggested dropping the goal of eradicating polio. Instead, the focus could shift to controlling cases, Arita wrote in a letter to the journal Science.

The study by Thompson and Uintjer Tebbens assumed eradication is a realistic goal, and then used mathematical models to show the relative effectiveness of maintaining and increasing immunity among populations where the virus is currently widespread.

"As long as it is technically achievable, eradication offers both lower cumulative costs and cases than control in the long-term, even with the costs of achieving eradication exceeding several billion dollars more," said Thompson.

Wavering commitment

For example, if eradication were dropped in favour of a control policy that relied on routine immunization, about 200,000 expected cases of paralytic polio would be expected in low-income countries over 20 years, the model suggested.

"A wavering commitment to eradication is not a good option," said Tebbens.

In February, Dr. David Heymann, an epidemiologist who leads WHO's polio eradication unit, said the global campaign needs another $1 billion US from donors, which would bring the total for the plan to more than $6 billion US.

The eradication campaign has been set back by donor fatigue, rumours doubting the safety of the oral polio vaccine in Nigeria and Pakistan, and scientists questioning if the campaign is using the appropriate tools.

Dr. Neal Halsey, a vaccine expert at the Johns Hopkins Bloomberg School of Public Health in Baltimore, supports eradication, but prefers a more expensive injectable vaccine such as the one used in developed countries rather than the oral variety.

"Eradication is not only possible, but it must be done. The world will not tolerate the continued problems."

With files from the Canadian Press