Nepal is almost 100% safe for travel. After the massive divesting earthquake at 25 April 2015 many traveler curious about Nepal. Among the 75 districts just 14 districts are affected and two trekking route Langtang and Manaslu was destroyed but both are already constructed and ready to welcome the travelers. If you visit the affected trekking area it will be great support for local to recover their lifestyle. So travel and trekking is safe in Nepal.