Antibiotics are used to treat or prevent certain types of bacterial infections, but they are not effective against viral infections, such as the common cold or flu. Infections that are not serious but are unlikely to be cured without antibiotics Infections that are not serious but may spread to others if left untreated Recovery can be greatly accelerated with the use of antibiotics Risk of more serious complications if antibiotics are not used People who are at risk for bacterial infections Use of antibiotics may also be recommended for people who are more susceptible to bacterial infections antibiotics. This may include: people over 75 years of age infants younger than 72 hours who have a bacterial infection or are at higher than average risk of developing one heart failure people with diabetes who must take insulin people who are immunocompromised – due to an underlying health condition (such as HIV) or side effects of certain therapies (such as chemotherapy) antibiotics to prevent infection sometimes antibiotics are given to prevent infection, rather than to fight it This includes: If you are having surgery You may get an infection after a bite or wound Experiencing some health problem that causes a significantly increased risk of infection If you are having surgery Certain surgeries have a high risk of infection and antibiotics are often recommended to prevent infection. Certain types of eye surgery Joint replacement surgery Pacemaker surgery Biliary and intestinal surgery Surgical removal of the gallbladder Surgical removal of the appendix Bites or wounds Antibiotics are recommended for wounds that can become infected, such as animal or human bites, or wounds that come in contact with soil or feces. Individual factors Some people are particularly susceptible to infection and therefore must be given antibiotics. They include: people who have had their spleen removed people who have received chemotherapy people who have sickle cell anemia in some cases, antibiotics may be considered for people whose infections keep recurring or increase the risk of complications, for example: cellulitis urinary tract infections genital herpes rheumatic fever, etc.