Gaborone, Botswana -- The discovery of Botswana's first polio case in 13 years is a wake-up call to other African countries believed to be free of the crippling disease, U.N. officials warned Tuesday amid a massive door-to-door immunization campaign.
Botswana is the ninth previously polio-free country on the continent to become re-infected following an outbreak in west and central Africa.
A young boy from the northern town of Maun was reported infected on February 8 with a strain of the disease traced to Nigeria, some 1,550 miles (2,500 kilometers) north of this impoverished southern African nation.
Nigeria's northern state of Kano has been the global epicenter of polio since last October, when authorities there kept children from being inoculated because of persistent rumors the vaccines are unsafe.
Fears that health officials could meet similar resistance in Botswana from a number of small Christian sects led the government to obtain a High Court order last week making it illegal for parents to refuse to have their children vaccinated. The offense is punishable by up to three months in jail or a 500 pula ($103) fine.
The Apostle Church of God, a northern-based sect with an estimated 50,000 followers, is one of the largest groups that urge their members to eschew modern medicine in favor of prayer.
Officials at the U.N. Children's Fund and World Health Organization stress that they represent a tiny percentage of Botswana's 1.7 million people. But they warn the disease spreads rapidly and say just one case can expose up to 100,000 people to infection.
"This is a real wake-up call for the rest of the world to step up surveillance of suspected cases," said Gordon Jonathan Lewis, UNICEF representative to Botswana.
He praised the swift response of the government, which mobilized a huge vaccination drive in May using everything from radio adverts to cellular phone text messages.
Despite initial resistance by some Christian groups, he said, most parents relented when health officials explained the risks to their children.
Vaccinators braved deserts and crocodile-infested rivers to reach 222,000 children under the age of 5, who are being targeted again this week for a second dose of the oral vaccine, he said.
Polio usually infects children under 5 through contaminated drinking water and attacks the central nervous system, causing paralysis, muscular atrophy, deformation and, in some cases, death.
A $3 billion, 16-year global campaign to eradicate polio has reduced cases of the disease from 350,000 in 1988 to fewer than 1,000 last year. But health officials warn fresh outbreaks will continue until the disease is completely eradicated around the world.
Lewis urged other countries to follow Botswana's example.
"Turning the tide against polio is possible," he said. "The people of Botswana have been exemplary in their mobilization against the disease."