Infections of the heart and circulatory system

Question 1

Bacteriaemia

Answer 1

Bacteria in the blood stream

Question 2

Septicaemia

Answer 2

Presence of clinical symptoms as a result of bacteraemia
Usually due to gram negative bacilli
Catheters often cause septicaemia

Diagnosed by 3 draws of blood and colormetric detection.

Treated with aminoglycoside and B lactam and metronidazole against obligate anaerobes such as bacteroides

Question 3

Plague

Answer 3

Yersinia pestis = enterobacteriaceae, pleomorphic, gram negatve
Transmitted by fleas

Question 4

New born babies

Answer 4

Susceptible to listeria monocytogenes infection and Group B strep eg S. agalactice

Question 5

Endotoxic shock

Answer 5

• gram negative bacteria
• Lipid A component leads to vasodilation and heat shock as the blood pressure drops
• Body constricts the peripheral nerves leading to cold shock; disseminated intravascular coagulation takes place and clotting factors are used up.
• Toxic shock syndrome toxin 1 - group A streptococcal infection - presents a super antigen and leads to a cytokine storm

Question 6

Which valve does endocarditis usually infect? which does it effect in IV drug users?

Answer 6

Mitril valve usually

Tricuspid valve in IV drug users

Question 7

What leads to the production of a biofilm in endocarditis?

Answer 7

The presence of vegetations, previously damaged valves and fibrinogen

Question 8

When does early prosthetic endocarditis usually take place?

Answer 8

Within a year of replacement and tends to be by viridans strep, enterococci or coagulase negative staph which form biofilms

Question 9

S. aureus and IV drug users

Answer 9

Causes native valve endocarditis

Question 10

Major in diagnosis endocarditis

Answer 10

2 x blood cultures and an endocardiogram

Question 11

Minors in diagnosis endocarditis

Answer 11

• predisposing factors: IV drug use, heart condition
• fever, vascular embolli or janeways lesion
• immunologic phenomena (Osler’s nodes, Roth’s spots)
• Microbiological evidence

Question 12

Diagnosis of endocarditis =

Answer 12

• 2 majors
• 1 major and 3 minors
• 5 minors

Question 13

Mycotic anerysm

Answer 13

inflammatory damage and weakening of the arterial wall and aneurysm

Question 14

Supprative thrombophlebitis

Answer 14

inflammation of the vein wall, clot formation and common with IV catheterisation