“South Sudan officials are hopeful the country will soon be declared polio-free,” if the nation can go another four months without recording a polio case, VOA News reports. “Before 2008, the area that is now South Sudan had been considered free of polio,” but “[t]hat year the country was re-infected through an imported strain that originated in Nigeria,” the news service writes. The country has not recorded a new case in more than 32 months, Abdi Aden Mohamed, head of the WHO in South Sudan, said, adding, “We are very cautious in the sense of there are a number of countries surrounding South Sudan that cases might be here and there,” according to VOA. Volunteers working to vaccinate every child under the age of six recently concluded the country’s 24th immunization campaign since polio reappeared in the nation, the news service notes (Green, 3/30).