The duration of fever is related to the type and location of the infecting bacteria, and the specific duration of fever can last for several days or weeks. There are many kinds of bacterial infections in children. If the infection is caused by Streptococcus pneumoniae or Streptococcus haemolyticus, the fever can generally subside after 2-3 days and the body temperature gradually returns to normal after adequate anti-infective treatment. In case of infectious fever caused by E. coli infection, the fever may subside after 3-5 days of medication and the body temperature will slowly return to normal. If the fever is caused by S. typhi, the fever lasts longer and may be around 2-3 weeks. Different types of bacterial infections in children cause fever of different durations, and timely treatment is necessary to reduce fever as early as possible. It is important to note that children should be allowed to eat more fruits and vegetables for comprehensive nutrition and to increase immunity to avoid bacterial infections.