Th number of reported polio cases worldwide rose from 2012 to 2013, even as health organizations step up their effort to fully eradicate the disease. According to the World Health Organization, the annual number of cases rose 70 percent from 223 in 2012, and the number of countries reporting the infections rose from 4 to 8.

The WHO credits the rise due to "spillover" from countries like Pakistan, Nigeria, and Afghanistan—the three countries where polio has never been fully eradicated. While numbers fell in Nigeria and Afghanistan, the polio vaccine is undergoing a large controversy in Pakistan, where vaccination programs are mistrusted  following the United States' fake program used to track down bin Laden. Violence against polio workers in the country, where 20 workers ahve been killed since July 2012, is still a threat.

Elsewhere, the civil war-torn Syria is facing its own polio crisis, reporting 10 cases last month. That makes it the country's first outbreak of the disease since 1999, and getting aid to is a logistical nightmare given the ongoing violence. The UN estimated that half a million children in the country have not been vaccinated against the disease. A couple of weeks ago, the UN airlifted vaccines for 538,000 people into the northern region of the country.