Flaccid fever is also known as septic fever. It is a persistent temperature above 39 degrees, with large fluctuations and temperature fluctuations of more than 2 degrees in a 24-hour period, but all above normal levels. It is commonly seen in sepsis, rheumatic fever, severe tuberculosis and septic inflammatory disease. So, what should be done to prevent persistent flaccid fever caused by rheumatic fever? The following is a brief introduction: To prevent persistent flaccid fever, we must first prevent its primary cause, and persistent flaccid fever is commonly associated with rheumatic fever. Since rheumatic fever has a family tendency to occur frequently and is hereditary, relatives of patients are at high risk for rheumatic fever and should focus on prevention. Treatment is currently recommended in patients with confirmed group A hemolytic streptococcal pharyngitis or in adolescents over 5 years of age at the time of the proposed diagnosis of upper respiratory tract streptococcal infection, and can be given as a single dose of long-acting penicillin intramuscularly in 2-4 doses over 10 days. Prophylaxis is mainly aimed at the young, those with high susceptibility factors, multiple recurrences of rheumatic fever, those who have had cardiac inflammation and those with sequelae of valvular disease, with the primary aim of preventing and reducing heart damage. Long-acting penicillin, administered intramuscularly every 3 to 4 weeks, is used for at least 10 years, or until the age of 40, or even for lifelong prophylaxis.