"For a period of 60 days, students will be required to wear face masks," says Carlos Moreno, the district's director of education, as Ecuadorian students in Santo Domingo de los Tsachilas return to school amid a viral outbreak in the northwestern region. The country has reported 250 cases of whooping cough in its most populous provinces, including Pichincha, while authorities have issued a yellow fever alert for northern regions bordering Colombia. IMAGES AND SOUNDBITES