Find a Registered Dental Hygienist

GO

Knowledge Network

FACT SHEET: Infective Endocarditis (also known as “IE”, “infectious endocarditis”, and “bacterial endocarditis”; includes “acute bacterial endocarditis” and “subacute bacterial endocarditis”; caused by various bacteria, including viridans group streptococci, Staphylococcus aureus, coagulase-negative staphylococcus, Streptococcus gallolyticus, and enterococci, as well as fungi/yeast, including Candida albicans)

Date of Publication: March 5, 2019
GO TO:

Note: This fact sheet’s emphasis is on the prevention of IE (particularly antibiotic prophylaxis). The initiation questions immediately below are answered primarily in the context of prevention, not from the perspective of a patient/client presenting with active infective endocarditis.

Is the initiation of non-invasive dental hygiene procedures* contra-indicated?

  • No.

Is medical consult advised?  

  • No, unless active infective endocarditis is suspected. [This would be a rare situation in the dental hygiene office setting.]

Is the initiation of invasive dental hygiene procedures contra-indicated?**

  • Yes, pursuant to Ontario Regulation 501/07, for a patient/client with any cardiac condition for which antibiotic prophylaxis is recommended in the current guidelines set by the American Heart Association (AHA), unless the CDHO member has consulted with either the patient/client’s physician, dentist, or registered nurse in the extended class [RN(EC)]1 and determined that it is appropriate to proceed if the patient/client has taken the prescribed medication per the AHA guidelines.
  • No, for a patient/client without cardiac conditions for which antibiotic prophylaxis is recommended in the current guidelines set by the AHA and without other significant risk factors or other prescribed contraindications under Ontario Regulation 501/07.

Is medical consult advised? 

  • Yes, for a patient/client with any cardiac condition for which antibiotic prophylaxis is recommended in the current guidelines set by the AHA. The need for antibiotic prophylaxis for the prevention of IE should be considered on an individual basis in conjunction with the healthcare practitioner most familiar with, and qualified to advise regarding, the patient/client’s specific condition.  
  • Yes, for paediatric patients/clients with congenital heart disease and adult patients/clients with cardiac valve conditions or ventricular assist devices or implantable hearts to ascertain whether antibiotic prophylaxis is required (see below for more detail).
  • Yes, if active infective endocarditis is suspected. [This would be a rare situation in the dental hygiene office setting.]

Is medical clearance required? 

  • Yes, for a patient/client with any cardiac condition for which antibiotic prophylaxis is recommended in the current guidelines set by the AHA, unless the CDHO member has consulted and determined that it is appropriate to proceed in accordance with Ontario Regulation 501/07.

Is antibiotic prophylaxis required?  

  • No, for a patient/client without cardiac conditions for which antibiotic prophylaxis is recommended in the current guidelines set by the AHA and without other significant risk factors for which antibiotic prophylaxis may be required2.
  • For most patients/clients, taking preventive antibiotics before a dental/dental hygiene visit is not indicated3.
  • Yes, unless there is informed medical direction to the contrary, for a patient/client with any cardiac condition for which antibiotic prophylaxis is recommended in the current guidelines set by the AHA4. Antibiotic prophylaxis for IE is recommended before dental/dental hygiene procedures that involve manipulation of either gingival tissue or the periapical region of teeth or perforation of the oral mucosa for patients/clients (“high risk”) with:
    • prosthetic cardiac valve or material, including
      • presence of cardiac prosthetic valve;
      • transcatheter implantation of prosthetic valves;
      • cardiac valve repair with devices, including annuloplasty, rings, or clips; and
      • left ventricular assist devices or implantable heart.
    • previous, relapse, or recurrent infective endocarditis;
    • congenital5 heart disease (CHD)6 that includes:
      • unrepaired cyanotic CHD7, including palliative shunts and conduits;
      • completely repaired congenital heart defect repaired with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure8; and
      • repaired CHD with residual defects9 at the site of or adjacent to the site of a prosthetic patch or prosthetic device; and
      • surgical or transcatheter pulmonary artery valve or conduit placement such as Melody valve and Contegra conduit.
    • cardiac valvulopathy after cardiac transplant10.
  • Those at greatest risk of an adverse outcome from infective endocarditis (i.e., “high risk” patients/clients, as specified above) should receive a single dose of a preventive antibiotic before all dental procedures that involve manipulation of gingival tissue or the periapical regions of teeth or that perforate the oral mucosa. (See Table 1 below.)

Is postponing treatment advised?

  • Yes, if antibiotic prophylaxis qualification (or lack thereof) for a particular patient/client is unclear to the dental hygienist (and therefore medical consultation/clearance is indicated).
  • Yes, if patient/client has not taken or been administered antibiotic prophylaxis recommended by the patient/client’s physician, dentist, or nurse in the extended class [RN(EC)]11. Most prophylaxis regimens entail oral, intramuscular (IM), or intravenous (IV) administration of an antibiotic 30 to 60 minutes pre-procedure12.

Oral management implications

  • The eligibility criteria for antibiotic prophylaxis have been reduced (i.e., relaxed) in recent years. Infective endocarditis is now believed by most authorities to more likely result from transient bacteremias associated with routine activities of daily living (such as tooth-brushing and chewing) rather than from bacteremia resulting from an invasive dental/dental hygiene procedure.
  • While various authorities differ in their recommendations, one area where most guidelines agree is with regard to regular dental surveillance to promote good oral hygiene, thus reducing the need for invasive dental/dental hygiene procedures (and resultant occurrence of transient bacteremia) and subsequently the risk of IE.
  • Antibiotic prophylaxis for the prevention of infective endocarditis is specifically recommended by the current guidelines of the AHA13 for specified “high risk” patients/clients (as per above) undergoing:
    • scaling and root planing of teeth;
    • prophylactic cleaning of teeth or implants where bleeding is anticipated;
    • periodontal procedures (i.e., curetting tissue, periodontal probing, periodontal surgery, and subgingival placement of antibiotic fibres and strips);
    • tooth extraction;
    • oral suture removal;
    • oral biopsies;
    • dental implant placement and replantation of avulsed teeth;
    • endodontic instrumentation or surgery beyond the apex;
    • placement of orthodontic bands; and
    • intraligamentary and intraosseous local anaesthetic injections.
  • In addition to ensuring that a recommended preventive antibiotic is administered 30 to 60 minutes before at-risk procedures, the dental hygienist may consider directing the “high risk” patient/client to use a pre-procedural antimicrobial rinse (e.g., chlorhexidine) before tissue manipulation14. 
  • Specific antibiotics and regimens recommended for antibiotic prophylaxis of IE (based on current AHA guidelines) are described in the CDHO Advisory on Infective Endocarditis, Heart Conditions. (See Table 1: Antibiotic Prophylaxis Regimens for Patients/Clients at Highest Risk of Adverse Outcome from Infective Endocarditis Who Are Undergoing Dental/Dental Hygiene Procedures below.)
  • When a patient/client is taking a prescribed antibiotic prophylaxis regimen, appointment scheduling is affected. It is not in the patient/client’s interest to unnecessarily prolong the course of treatment procedures, nor is it desirable to increase the risk of antibiotic resistance. Appointments should be scheduled for longer periods15 and as close together as possible, with the caveat to ideally separate appointments by 9 to 14 days for antibiotic coverage purposes.
  • To reduce or avoid the need for a “rotational schedule” of antibiotics for a patient/client at risk for IE requiring multiple dental hygiene appointments for at-risk procedures, the dental hygienist should consider scheduling appointments at least 10 to 14 days apart16. If this is not possible or appropriate, then a rotational schedule of antibiotics should be considered in conjunction with the patient/client’s medical practitioner. Such a schedule is further elaborated on in the CDHO Guideline on Recommended Antibiotic Prophylaxis Regimens for the Prevention of Infective Endocarditis and Hematogenous Joint Infection. (See Table 2: Antibiotic Prophylaxis Regimens for Adult Patients/Clients at Highest Risk of Adverse Outcome from Infective Endocarditis Who Require Multiple Dental Hygiene Appointments Within a 9-Day Period [no penicillin allergy] below.)
  • In patients/clients who are receiving a short course (7 to 10 days) of oral antibiotic therapy before an invasive dental/dental hygiene procedure, it is preferable to select a different class of antibiotic listed in Table 1 of this fact sheet. Ideally, one would delay an elective dental/dental hygiene procedure for at least 10 days after completion of a short course of antibiotic therapy.17

Oral manifestations

  • There are no oral manifestations specific to IE. Petechiae may occur in the oral cavity as part of the general presentation.

Related signs and symptoms

  • The incidence of IE ranges from about 2 to 10 cases per 100,000 persons per year, equating to about 700 new cases per year in Ontario.
  • Infective endocarditis is inflammation of the endocardium (the membranous inner lining of the heart) resulting from infected vegetations (growths). It usually involves cardiac valves, which may be damaged or destroyed. Usually fatal if left untreated18, IE typically results from microbes infecting abnormal cardiac valves (including prosthetic valves) or other damaged heart tissue19; it rarely occurs in persons with normal hearts in the absence of intravenous drug misuse (IDU).
  • Bacteremia (i.e., the presence of bacteria in the blood) is the usual precursor of IE. Infection-causing microbes enter the bloodstream and travel to the heart, where they establish infection on damaged heart valves or other damaged heart tissue.   
  • Transient bacteremia is common after invasive dental/dental hygiene procedures, involving bacteria normally resident in the mouth and upper respiratory system. However, infective endocarditis is much more likely to result from frequent exposure to random bacteremias associated with daily activities (such as chewing food, brushing teeth, flossing, using toothpicks, use of water irrigation devices, etc.) than from bacteremia caused by a dental or dental hygiene procedure.
  • IE results from bacterial infection with, amongst a variety of causative organisms, viridans group streptococci (VGS, which are a major component of human oral and intestinal flora and are responsible for about 16% to more than 50% of all IE); Staphylococcus aureus (which may infect normal heart valves, accounts for about 28% of IE, and in an IE context is associated with intravenous drug misuse)20; or enterococci (which are part of the intestinal flora of humans and animals). However, IE also results occasionally from fungal/yeast infection, including Candida albicans (which is more commonly associated with thrush and candidiasis of the genital system).
  • Rheumatic heart disease21 is the primary risk factor for IE in low- and middle-income countries (where affected persons are often young and untreated streptococcal disease is relatively common), whereas intravenous drug misuse is an IE risk factor of increasing concern in developed countries such as Canada.
  • There are two major forms of IE:
    • acute bacterial endocarditis (ABE), which is a severe infection with rapid course of action usually caused by pathogenic organisms capable of producing widespread disease; and 
    • subacute bacterial endocarditis (SBE), which is a more slowly progressing infection with nonspecific clinical features.
  • Risk factors for infective endocarditis are linked with the mouth, because bacteria commonly associated with bacteremia leading to IE are found in the mouth. Risk is associated with invasive dental/dental hygiene procedures and poor oral hygiene.
  • Persons at elevated lifetime risk of IE (not all of whom are recommended to receive antibiotic prophylaxis for dental/dental hygiene procedures) include those with artificial heart valves, congenital heart disease, cardiac valve defects (such as mitral insufficiency), history of rheumatic heart disease, and history of intravenous drug misuse. 
  • For most persons, the risk of antibiotic-associated adverse events exceeds the benefit, if any, from antibiotic prophylaxis for IE.
  • Signs/symptoms of IE may develop slowly or suddenly22. A typical first sign is fever, possibly low grade and intermittent. Heart murmurs are heard in about 85% of patients/clients with IE. Warning signs/symptoms include chest pain, hematuria (blood in urine), and numbness or weakness of muscles. Other associated signs/symptoms include chills; sweating (including night sweats); facial pallor; joint pain; muscle aches; shortness of breath; petechiae; Osler nodes23; splinter hemorrhages24; Janeway lesions25; Roth spots26; splenomegaly (enlarged spleen); cardiac dysrhythmia; pericardial rub27; pleural rub28; and delirium.
  • Infected clots may break off in the heart and be carried by blood circulation to the brain (risking stroke and brain abscesses), lungs (pulmonary embolus), kidneys (risking acute renal failure), and spleen (risking splenic infarction). Other potential complications include heart failure and cardiac dysrhythmias, including atrial fibrillation.

References and sources of more detailed information

Table 1: Antibiotic Prophylaxis Regimens for Patients/Clients at Highest Risk of Adverse Outcome from Infective Endocarditis Who Are Undergoing Dental/Dental Hygiene Procedures (based on 2021 “American Heart Association Scientific Statement: Prevention of Viridans Group Streptococcal Infective Endocarditis”, which updates 2007/2008 AHA Guidelines)

Table 1
i    IM = intramuscular
ii   IV = intravenous
iii  or other first– or second-generation oral cephalosporin in equivalent adult or paediatric dosage
iv  Clindamycin is no longer recommended for antibiotic prophylaxis for dental/dental hygiene procedures. It may cause more frequent and severe reactions than other antibiotics used for antibiotic prophylaxis.
v   Cephalosporins should not be used in an individual with a history of anaphylaxis, angioedema, or urticarial with penicillins (including ampicillin).

Table 2: Antibiotic Prophylaxis Regimens for Adult Patients/Clients at Highest Risk of Adverse Outcome from Infective Endocarditis Who Require Multiple Dental Hygiene Appointments Within a 9-Day Period (no penicillin allergy) [based on Pickett FA and Gurenlian JR. Preventing Medical Emergencies: Use of the Medical History in Dental Practice (3rd edition). Baltimore/Philadelphia: Wolters Kluwer Health; 2015. (Box 8-4, p. 97), with modification based on 2021 “American Heart Association Scientific Statement: Prevention of Viridans Group Streptococcal Infective Endocarditis”i] 

Table 2

The recommendations in Table 2 are for adult patients/clients, with no penicillin allergy, who are at highest risk for infective endocarditis (due to the specified heart conditions and the dental procedures listed in the 2007 AHA protocols, and as augmented by the 2021 AHA Statement).

i  Clindamycin is no longer recommended for antibiotic prophylaxis for dental/dental hygiene procedures.
ii Doxycycline is a consideration ahead of, or after, cephalosporin in a multiple appointments scenario.


Date: April 4, 2018
Revised: August 7, 2019; June 14, 2021; August 7, 2023


FOOTNOTES

1 In Ontario, a registered nurse in the extended class is also known as a nurse practitioner (NP).
2 Antibiotic prophylaxis may also be indicated to prevent surgical site infections for certain dental procedures or based on the patient/client’s medical status (e.g., chemotherapy-induced neutropenia), as distinct from antibiotic prophylaxis directed specifically toward the prevention of infective endocarditis.
3 Prior to 2007, the AHA recommended that patients/clients with nearly every type of congenital heart disease receive antibiotics before dental procedures or operations on the mouth, throat, and gastrointestinal, genital, and urinary tracts. However, in 2007 the AHA simplified its recommendations, and antibiotics were only recommended for patients/clients with the highest risk of adverse outcome from IE. In 2021, the AHA issued a Scientific Statement that examined the 2007 viridans group streptococcal (VGS) IE prevention guidelines based on review of available evidence; the 2021 Statement confirmed the 2007 AHA recommendations to limit VGS IE prophylaxis only for categories of patients/clients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. AHA 2021 provided additional information/changes in two areas; namely, 1/ the underlying conditions for which antibiotic prophylaxis is suggested, and 2/ the antibiotic regimens for dental procedures.
4 According to the “ACC/AHA 2008 Guideline Update on Valvular Heart Disease: Focused Update on Infective Endocarditis” from the American College of Cardiology/American Heart Association (which reflects the 2007 AHA guidelines for infective endocarditis prophylaxis), antibiotic prophylaxis is only recommended for the highest risk groups of patients/clients undergoing the highest risk procedures. These oral healthcare procedures involve manipulation of gingival tissue and/or the periapical region of teeth, as well as perforation of the oral mucosa. Specifically, antibiotic prophylaxis is not recommended for dental radiographs, adjustment of orthodontic appliances, placement of orthodontic brackets, placement or removal of prosthodontic or orthodontic appliances, anaesthetic injections through non-infected tissue, bleeding from trauma to the lips or oral mucosa, and shedding of deciduous teeth. Also of note, patients/clients with bicuspid aortic valve, acquired mitral or aortic valve disease, rheumatic heart disease, and cardiomyopathy do not require antibiotic prophylaxis (because they are no longer designated “high risk” conditions for the purposes of antibiotic prophylaxis for IE) according to the 2007 AHA guidelines. In addition, the 2021 “AHA Scientific Statement: Prevention of Viridans Group Streptococcal Infective Endocarditis” specifically does not suggest antibiotic prophylaxis for dental procedures for: implantable electronic devices (such as pacemakers or similar devices); septal defect closure devices when complete closure is achieved; peripheral vascular grafts and patches (including those used for hemodialysis); coronary stents or other vascular stents; central nervous system (CNS) shunts; vena cava filters; or pledgets.
5 congenital = present from birth
6 Except for the conditions listed here, antibiotic prophylaxis is no longer recommended by the AHA for any other form of CHD.
7 Common types of cyanotic congenital heart disease (i.e., birth defects resulting in oxygen levels lower than normal) include tetralogy of Fallot (TOF, in which there are 4 defects that affect the heart; namely, ventricular septal defect [VSD], pulmonary stenosis, right ventricular hypertrophy, and overriding aorta) and transposition of the great arteries (TGA, in which the pulmonary artery is attached to the left side of the heart, and the aorta is attached to the right side of the heart).
8 Prophylaxis is reasonable during this period, because endothelialization of prosthetic materials requires 6 months.
9 Residual defects include persisting leaks or abnormal flow.
10 in particular, cardiac transplant recipients with valve regurgitation due to a structurally abnormal valve
11 Recent prior antibiotic use should be considered before prophylactic antibiotics are prescribed (in order to reduce risk of antibiotic resistance). For the patient/client at risk for IE who requires multiple dental/dental hygiene for at-risk procedures within a 9-day period, different “rotational” antibiotics should be administered. For more details, refer to the CDHO Guideline on Recommended Antibiotic Prophylaxis Regimens for the Prevention of Infective Endocarditis and Hematogenous Joint Infection.
12 If an antibiotic has inadvertently not been administered prior to the procedure, the antibiotic may usually be administered up to 2 hours after the procedure.
13 The AHA’s 2007 antibiotic prophylaxis guidelines for IE (and subsequent 2021 “Scientific Statement: Prevention of Viridans Group Streptococcal Infective Endocarditis”) differ from those from some other authorities, including the guidelines of the National Institute for Health and Clinical Excellence (NICE), which is affiliated with the British National Health Service. As per Ontario Regulation 501/07, members of the CDHO should abide by the AHA guidelines.
14 Research results are contradictory regarding the efficacy of oral antimicrobial rinses to reduce bacteremia associated with dental/dental hygiene procedures, with the preponderance of evidence suggesting no clear benefit. Guidelines are conflicting.
15 A particularly lengthy dental appointment, however, may be a concern when one considers the half-life of an administered antibiotic. Amoxicillin has a half-life of about 80 minutes, and thus a pre-procedure 2-gram dose of amoxicillin would be expected to have an acceptable minimum inhibitory concentration (MIC) for penicillin-sensitive viridans group streptococci for at least 6 hours. If a procedure lasts longer than 6 hours (which is very unlikely for dental hygiene procedures, as distinct from some dental procedures), then it may be prudent to administer an additional 2 g dose.
16 If appointments for procedures requiring antibiotic prophylaxis are scheduled within a 9-day period or if a patient/client is currently on an antibiotic regimen for other reasons, an alternative antibiotic should be used to reduce the risk of microbial antibiotic resistance.
17 In patients/clients who are receiving parenteral (i.e., non-oral, such as intravenous) antimicrobial therapy for IE or other infections and require a dental procedure, the same parenteral antibiotic may be continued through the dental procedure.
18 Treatment of IE requires hospitalization and intravenous antibiotics (and, controversially, potentially anticoagulants), and ultimately may require surgery to replace damaged cardiac valves. Even with antibiotic therapy, mortality may reach 30%.
19 Valvular and congenital abnormalities, particularly those associated with high velocity jets of blood, can result in endothelial damage, platelet-fibrin deposition, and predisposition to microbial colonization.
20 In the context of IDU-associated infective endocarditis, methicillin-resistant staphylococcus aureus (MRSA) is a particular concern.
21 Rheumatic heart disease (RHD) describes a group of short-term (acute) and long-term (chronic) heart disorders that are caused by rheumatic fever (RF). RHD usually occur 10-20 years after the initial RF illness, but not everyone with rheumatic fever will go on to develop RHD. [Rheumatic fever is an inflammatory disease triggered by Group A streptococcal bacterial infection. It usually begins as strep throat infection or scarlet fever that hasn’t been treated with antibiotics.]
22 Medical investigation of IE may include blood cultures, complete blood count, echocardiogram, chest x-ray, and CT scan of the chest.
23 Osler nodes are painful, red, subcutaneous nodules on the distal pads of the fingers and toes.
24 Splinter hemorrhages are thin, red to reddish-brown lines of blood underneath the nails (“subungual”) in the direction of nail growth. They look like splinters underneath a fingernail. The hemorrhages may be caused by microemboli (tiny clots) that damage capillaries, which can result from infective endocarditis.
25 Janeway lesions are irregular, red, usually flat, painless, hemorrhagic lesions found on the palms, soles, and thenar and hypothenar eminences (i.e., bases of thumb and little fingers respectively).
26 Roth spots are retinal hemorrhages with small, clear centres.
27 Pericardial rub (also known as pericardial friction rub) is an audible medical sign associated with pericarditis (inflammation of the pericardium, which is the fibrous sac surrounding the heart).
28 Pleural rub (also known as pleural friction rub) is an audible medical sign associated with pleuritis (also known as pleurisy, which is inflammation of the tissue that lines the inner chest cavity and surrounds the lungs).


* Includes oral hygiene instruction, fitting a mouth guard, taking an impression, etc.
** Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991. Invasive dental hygiene procedures are scaling teeth and root planing, including curetting surrounding tissue.