বিশ্ব থেকে গুটি বসন্ত উচ্ছেদের ঘোষনা প্রদান করে বিশ্ব স্বাস্থ্য সংস্থা কত সালে?
নোট
Smallpox is an acute contagious disease caused by the variola virus, a member of the orthopoxvirus family. It was one of the world's most devastating diseases known to humanity. It was declared eradicated in 1980 following a global immunization campaign led by the World Health Organization.
Source: WHO