The top US health official has declared gun violence in the country a public health crisis. “Firearm violence is a public health crisis in America that poses a serious threat to the health and well-being of our country,” Vivek Murthy said on Tuesday. About 50,000 people in the US die each year from gun-related injuries – self-inflicted or caused by others, according to health authorities. Injuries inflicted with guns are now the most common cause of death among children and young people. Murthy recommends a range of measures to counteract this, including providing more money for research and s…