Polio in #pakistan Risks Spreading Paralytic Virus, WHO Says

July 8 (Bloomberg) -- Pakistan reported wild poliovirus in a 16-month-old child, the first case of the type-3 strain in six months, the World Health Organization said.

The child from a conflict-affected, inaccessible area of Khyber Agency, developed paralysis on June 9, the United Nations health agency said in a statement on its website yesterday. It's the first case of type-3 polio detected in Asia so far this year.

The strain, one of two in circulation, "is on the verge of elimination" in Asia, WHO said. Its presence in Pakistan means it may spread to other areas of Asia and beyond, particularly given large-scale population movements within the country, between Pakistan and Afghanistan, and travel for Umrah and the Hajj, or pilgrimage to Mecca, in the coming months, the agency said.

"Confirmation of continuation of WPV3 transmission in tribal areas of Pakistan has significant implications for the global effort to eradicate WPV3, particularly as Asia is on the verge of eliminating circulation of this strain," WHO said.

Poliovirus is shed by infected people in feces and can spread as a result of poor sanitation and hygiene. The virus invades the nervous system, causing paralysis in one out of every 200 children infected.

It paralyzed millions of people worldwide in the 20th century before vaccines became widely available from the mid-1950s. At the height of the most extensive polio outbreak ever in 1952, almost 60,000 cases with more than 3,000 deaths were reported in the U.S. alone.

Cases Halve

Worldwide, 252 cases of wild poliovirus have been reported this year, compared with 501 at the same time last year, the Global Polio Eradication Initiative in Geneva said on July 6. Pakistan, Chad and the Democratic Republic of Congo account for 80 percent of this year's total.

The poliovirus consists of an RNA genome enclosed in a protein shell called a capsid. There are three serotypes of wild poliovirus -- types 1, 2 and 3 -- each with a slightly different capsid protein, according to WHO.

Nine out of 10 of this year's polio cases were caused by type-1, which the WHO says is the most pervasive strain of poliovirus. Type-2 has been eliminated in the wild, with the last cases detected in India in 1999. Type-3 is localized in northern India, northern Nigeria, Pakistan and Afghanistan, the UN agency says.

--Editors: Nicholas Wadhams, Jason Gale