Second form of polio virus disappears

The second of three forms of polio virus has disappeared, experts have reported.

There are three types of wild polio virus, which, though scientifically different, cause the same symptoms, including paralysis or even death.

The type 2 of this virus has disappeared four years ago, and now the World Health Organization said the type 3 has disappeared.

But type 1 is still moving to Afghanistan and Pakistan.

Polo usually touches children under five years of age. WHO estimates one in 200 cases leads to irreversible paralysis, transmits periscope.

Death can occur when respiratory muscles are affected by paralysis.