From Afghanistan to Somalia, the struggle to eradicate polio continues to lurch along in fits and starts. The past few days have brought a modicum of good news and some potentially quite bad news.

On May 13, the Taliban issued a statement declaring that it would no longer target polio vaccine workers and is ordering its fighters to help in vaccination campaigns. The group had previously marked vaccine workers for death because of fears that they might be acting as spies for Western countries—fears that were further inflamed by a successful US effort to assassinate Osama bin Laden that included a sham hepatitis vaccine campaign by the CIA.

Just two days earlier, however, the World Health Organization reported that “wild-type” poliovirus was isolated in Somalia from a 32-month-old girl who suddenly became paralyzed, as well as from three other individuals with whom she was in contact. Genetic testing has since indicated that the virus in question is linked to polioviruses circulating in northern Nigeria, according to Nature’s newsblog.  The setback marks the first new case of naturally occurring polio in Somalia since March 2007. Emergency vaccination initiatives—and fund-raising to pay for them—are now underway.

As the accompanying map shows, this development is a concern not just for Somalia, but for a broad swath of Africa, where low vaccination rates leave children particularly vulnerable to infection with polio, most likely from Nigeria (particularly northern Nigeria), where the virus is still endemic. In our increasingly interconnected world, an uncontrolled outbreak in these countries could fuel polio’s return around the globe--which would be particularly tragic considering that there had been only 26 cases of polio (before the Somalia news) reported worldwide so far in 2013, compared with 53 at this point last year.