Sore throats are infections caused by bacteria or viruses. People usually recover quickly (usually after three or four days), although some develop complications. A serious but rare complication is rheumatic fever, which affects the heart and joints. Antibiotics reduce bacterial infections but they can cause diarrhoea, rash and other adverse effects and communities build resistance to them.
This review of 27 trials with 12,835 cases of sore throat found that antibiotics shorten the illness by an average of about one day and can reduce the chance of rheumatic fever by more than two-thirds in communities where this complication is common.