Aid workers in war-torn Somalia are struggling to contain a dangerous outbreak of the crippling polio virus, with rampant insecurity hampering efforts, the United Nations said Friday.
Six years after the Horn of Africa nation was declared free of the virus, at least 105 cases have been confirmed in Somalia, the "worst outbreak in the world in a non-endemic country," the UN Office for the Coordination of Humanitarian Affairs said.
Its warning came just two days after medical aid charity Doctors Without Borders (MSF) announced it was pulling out of Somalia after more than two decades, a move that affects hundreds of thousands of needy people.
"The polio outbreak plaguing Somalia has spread despite significant efforts to curb the disease," OCHA added in a statement.
While some four million people have been vaccinated, getting drugs to more than 600,000 children in southern and central Somalia -- areas partly under control of the Al-Qaeda linked Shebab, who block vaccination efforts -- is "extremely challenging", it said.
"The inability to fully access these areas constitutes a major threat to the control of the outbreak," it said, warning that "Somalia remains one of the most difficult and dangerous environments in the world for aid workers."
While over 100 cases of polio have been recorded, "the fact that this number of children show symptoms of paralysis means that there are probably thousands more with the virus, who do not have symptoms, but are capable of spreading it," OCHA added.
Around 10 cases have also been reported in northeastern Kenya, which hosts almost half a million Somali refugees in sprawling camps.
In Somalia, while the bulk of cases are in the southern and central regions, the outbreak has also spread to self-declared independent Somaliland in the northwest.
With only 223 polio cases worldwide recorded last year, according to the World Health Organisation (WHO), the number affected in Somalia is alarming, although cases worldwide have dropped by over 99 percent from some 350,000 in 1988.
Highly infectious polio is spread by person-to-person contact, exacerbated by poor sanitation and a lack of clean water.
Affecting mainly children aged under five, it can cause total paralysis within hours, WHO warns.
Multiple armies are fighting for control of southern Somalia, including rival warlords, Islamist extremists and a rag-tag national army backed by a 17,700-strong African Union force.
Aid workers report growing attacks on their staff.
On Wednesday, MSF closed all its operations in Somalia after 22 years of working in the troublespot, warning of growing insecurity and "extreme attacks".
The pullout by MSF, an aid agency that has earned a reputation for working in the toughest of conditions, will cut health care for hundreds of thousands of Somalis.
MSF blamed "armed groups and civilian leaders" who it said "increasingly support, tolerate, or condone the killing, assaulting, and abducting of humanitarian aid workers".
While many of the areas MSF has left are not under the control of central government, the withdrawal is also a major blow to the reputation of the authorities in Mogadishu.
When Mogadishu's government took power last year, it was hailed by the international community as offering the best chance for peace in Somalia since the collapse of central government in 1991.
Somalia's government said it was "deeply saddened" by MSF's decision, noting that the aid agency had previously remained working even through "the darkest periods" of Somalia.
"We fear that this decision will lead to a catastrophic humanitarian crisis," Development Minister Maryan Qasim said Thursday, pleading for MSF to stay on.