8 September - The United Nations World Health Organization (WHO) reported today that the recent outbreak of polio in Angola is spreading into other, previously polio-free parts of the country and the neighbouring Democratic Republic of the Congo (DRC).

The wild poliovirus 1 (WPV1) outbreak that began in April 2007 has now been recorded in the DRC's Kasai province, which borders Angola.

In addition, a case was detected in Katanga province in the DRC's southeast in June that was genetically linked to a separate virus traced back to Angola.

Polio, sometimes called poliomyelitis, is a highly infectious and potentially lethal disease that spreads from person to person. Wild poliovirus could infect virtually everyone who is not yet immune through vaccination, and there is no cure.

It has been eradicated in most parts of the world, but remains endemic in Afghanistan, Pakistan, India and Nigeria.

WHO said that great strides made towards eliminating polio in Nigeria, which has seen a 99 per cent drop in cases this year compared to 2009. Also recording successes are West Africa, where no new cases have been reported since May, and the Horn of Africa, where there have been no polio cases in the past 12 months.

Central Africa is now seen to be the greatest obstacle to efforts to eradicate the virus on that continent.

WHO noted that there is a high risk of WPV1 spreading to other countries from Angola and the DRC due to the limited success of control measures and the historical cross-border spread from both nations.

As many as 25 per cent of children are regularly missed during supplementary immunization campaigns in Angola, while in the DRC, no response activities have been carried out in the country's volatile east since last November.

Also, due to surveillance gaps, it is possible that there are more cases of WPV1 in the two countries, WHO said.

Last month, the agency and the UN Children's Fund (UNICEF) called on national authorities and communities to get involved with a polio immunization campaign aiming to reach nearly 6 million children in Angola.