More than 20,000 people infected in measles outbreak in Madagascar

Madagascar, the island nation off the coast of East Africa, has been hammered by its worst measles outbreak in decades. The secretary general of the ministry of health told CNN that more than 50,000 people have caught the disease since October 2018 and there have been more than 300 deaths -- mostly children.

Because of its relative rarity in the developed world, measles is sometimes incorrectly regarded as a mild virus with limited impact. But it can take hold rapidly and cause encephalitis, deafness and in extreme cases, death, especially when a patient is malnourished or has a weakened immune system.

That perspective helped him recognize the warning signs of a larger outbreak. "Our one doctor here, who has been practicing physician for 12 years, had never seen a case of measles until a month ago. And then boom, boom, boom, they started walking through the door. And it hasn't stopped," he says.