A 19 y.o. girl admitted to the hospital complained of pain in the knee and fever of 38,6°C. She is ill for 2 weeks after acute tonsillitis. On exam, hyperemia and swelling of both knees, temperature is 37,4°C, HR- 94/min, BP- 120/80 mm Hg, and heart border is displaced to the left; S1 is weak, systolic murmur is present. Total blood count shows the following: Hb- 120 g/L, WBC- 9,8 - 109/l, ESR of 30 mm/L. ECG findings: the rhythm is regular, PQ = 0,24 sec. What is a causative agent of the disease?

Answer options

1. Autoimmune disorder
2. Staphylococci
3. Ricchetsia
4. Viral-bacterial association
5. Beta-hemolytic streptococci

Explanation

A 19 y.o. girl admitted to the hospital complained of pain in the knee and fever of 38,6°C. She is ill for 2 weeks after acute tonsillitis. On exam, hyperemia and swelling of both knees, temperature is 37,4°C, HR- 94/min, BP- 120/80 mm Hg, and heart border is displaced to the left; S1 is weak, systolic murmur is present. Total blood count shows the following: Hb- 120 g/L, WBC- 9,8 - 109/l, ESR of 30 mm/L. ECG findings: the rhythm is regular, PQ = 0,24 sec. What is a causative agent of the disease?Rheumatic fever is caused by group A streptococcus Beta hemolytic. It is an inflammatory disease that can involve the heart, joints (polyarthritis), skin, and brain. Rheumatic fever may occur following an infection of the throat (angina). The underlying mechanism is believed to involve the production of antibodies against a person's own tissues. Treating people who have strep throat with antibiotics, such as penicillin, decreases the risk of developing rheumatic fever. If joints involve then migratory pain occurs.