Question

Case Study #3 Clinical History: A 67-year-old male had rheumatic heart disease for thirty years. Three months prior to death he began to have episodes of fever and chills accompanied by signs of worsening congestive heart failure. Splinter hemorrhages and purpuric skin rashes were noted three weeks before death. Laboratory Findings: Blood cultures grew alpha-hemolytic streptococci. Gram stain shows gram positive cocci in chains. Autopsy revealed thickening of the mitral valve. Many friable calcified pink-gray granular lesions were present on the valve. Splinter hemorrhage Growth on Blood Agar Gram Stain of blood culture Most cases that present with these findings are caused by 1. Chlamydiae 2. Rickettsiae 3. Fungi 4. Bacteria In this particular patient, the MOST LIKELY causative organism was? 1. Group A Streptococci 2. Streptococcus viridans 3. Streptococcus pyogenes 4. Group B Streptococci The heart Valve MOST OFTEN affected by infective endocarditis in IV drug abusers is the: 1. Aortic valve 2. Mitral valve 3. Pulmonic valve 4. Tricuspid valve

Answer 1

• 4. Bacteria

Most cases that present with these findings are caused by bacteria. Blood cultures for the patient reveled the growth of alpha-hemolytic streptococci. This bacteria is responsible for conditions such as endocarditis. Moreover, the splinter hemorrhages represent a bacterial endocarditis. Bacterial infection in the inner lining of the heart can lead to splinter hemorrhages. These types of condition cannot be caused by chlamydia, Rickettsia and fungi. Chlamydia is basically responsible for sexually transmitted diseases, rickettsia is responsible for diseases such as ehrlichiosis and Q fever. Fungi can be responsible for endocarditis in addition to bacteria but an agar test is required to confirm the cause.   

• 2. Streptococcus Viridians

The patient was having an infection of alpha-hemolytic streptococcus which is also known as Streptococcus Viridians. It is considered as the most common cause of heart infection such as endocarditis after medical or dental procedures. The group a streptococcus are responsible conditions such as soft tissue infections such as cellulitis. The group b streptococcus are not fatal and are usually responsible UTIs. Streptococcus pyogenes are among group a streptococcus and they are usually responsible for diseases such as scarlet fever, cellulitis and erysipelas.   

• 4. Tricuspid valve

Infective endocarditis is considered as a serious complication of IV drug abuse. This mainly impacts the Tricuspid valve of the heart although it can also impact the mitral or the aortic valves in the heart.