Chapter 24 microbiology ( endocarditus)

Question 1

Bacteraemia

Answer 1

bacteria present in blood. It is asymptomatic and can occur simply by brushing of teeth or chewing ( especially when someone has periodontitus)

Question 2

septicaemia

Answer 2

Sepsis of blood. . This is when a large number of organisms enter the blood and multiply and persist in the blood stream. These cause symptoms like fever, hypotension, and rigors.

Question 3

Sepsis syndrome

Answer 3

Is a systematic response to microbial products or constituents circulation in the blood mediated by inflammatory cytokines

Question 4

infections of the heart include

Answer 4

pericarditis, myocarditis, and endocarditis

Question 5

What is infective endocarditis?

Answer 5

inflammation of the endocardium of the heart valves and sometimes the endocardium

Question 6

Microbiology aetiology of endocarditis

Answer 6

more than 80% of the time it is caused by streptococci and staphylococci. Viridans also can cause it and most patients with this have a previous heart lesion and a quarter of the time the patient gives a history of a recent dental procedure

Question 7

Acute form of endocarditus

Answer 7

rapidly progressive and is caused by bacteria like streptococcus, pneumoniae, staphylococcus aureus, and streptococcus pyogenes

Question 8

subacute form of endocarditus

Answer 8

More chronic and progresses rather slowly. This is caused by a less virulent bacteria like Viridans streptococci, staphylococcus epidermis, and enterococcus faecalis

Question 9

Symptoms of endocarditus are…

Answer 9

fever, malaise, loss of weight, anaemia, splinter haemorrhages, petechiae, cardiac murmur, haematuria, and splenomegaly

Question 10

step 1 of pathogenesis

Answer 10

breach of endocardium or an abnormality of endocardial surface is the first event that makes the valvular surface finally sucumb to infection

Question 11

step 2 of pathogenesis

Answer 11

platelet aggregates that form on the breached endocardium detach stabilize and consolidate through fibrin deposition , forming a sterile thrombus. This is a potential trap for circulating microbes. ( with no bacteria yet its called a non bacterial thrombotic endocarditis). These platelets can form on foreign objects as well like prosthetic valves

Question 12

step 3 of pathogenesis

Answer 12

Next step organisms in the circulating blood attach to the trapped thrombotic endocardium or prosthetic device. ( now the clot is called bacterial vegetation)

Question 13

step 4 of pathogenesis

Answer 13

They then multiply and colonize with fibrin deposition happening. This creates a defense for them. This is called a fibrin-platelet barrier and protects the bacteria from phagocytes

Question 14

step 5 of pathogenesis

Answer 14

Now the valve is permanently scarred and thickened.

Question 15

frequency of of bacteraemia with infective endocarditis and dentistry

Answer 15

The frequency of bacteraemia is related to preoperative oral sepsis of the patient and the degree of trauma and tissue injury . ( depending on the degree of oral sepsis a patient can get bacteraemia by simply brushing their teeth)

Question 16

What are good ways to indentify at risk patients

Answer 16

use medical history, use medical cards, be a part of the medical team

Question 17

Antibiotic prophylaxis

Answer 17

According to the American Heart association patients that have a prosthetic cardiac valve, previous infective endocarditis, congenital heart disease, repaired heart defects with prosthetic material, cardiac transplant who develop cardiomyopathy should be given prophylaxis antibiotics

Question 18

patients from the previous heart problems must be given antibiotics if the dental procedure is what?

Answer 18

involve gingival tissue or periapical region of teeth of perforation of oral mucosa

Question 19

what are some antibiotic prophylaxis for miscellaneous conditions

Answer 19

prosthetic heart, hip joint implants, third surgery molar, dental implants

Question 20

name some high risk predisposing facors for endocarditis of people at risk

Answer 20

Aortic valvular disease, prosthetic valves, mitral insufficiency, ventricular septal defect, patent ductus arteriosus, coarctation of aorta, previous infective endocarditis,

Question 21

Intermediate risk predisposing factors of people at risk

Answer 21

mitral valve prolapse and stenosis, pulmonary and tricuspid valve disease, degenerative aortic valve disease, non-valvular intracardiac prosthetic implants

Question 22

Low/ negligible risk predisposing factors of people at risk

Answer 22

atrial septal defect, coronary artery disease, cardiac pacemakers, arteriosclerotic plaques.