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Intravenous Drug Abuse Endocarditis

Last updated Oct. 16, 2018

Approved by: Maulik P. Purohit MD, MPH

Infective endocarditis is an infection of the heart valves or the heart’s inner lining, known as the endocardium. Infective endocarditis is usually caused by a bacteria or a fungus.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Endocarditis caused by Intravenous Drug Abuse
  • Infective Endocarditis in Injection Drug Users
  • Infective Endocarditis in Intravenous Drug Abusers

What is Intravenous Drug Abuse Endocarditis? (Definition/Background Information)

  • Infective endocarditis is an infection of the heart valves or the heart’s inner lining, known as the endocardium. Infective endocarditis is usually caused by a bacteria or a fungus
  • Intravenous Drug Abuse Endocarditis occurs in individuals who share contaminated needles and syringes while using illegal drugs. It is usually caused by the bacteria Staphylococcus. It may be also caused by Streptococcus or Enterococcus bacterium
  • The infection from the site of injection (hand or arm) may enter the bloodstream (usually resulting in bacteremia) and attack the lining of the heart or the heart valves. Intravenous Drug Abuse Endocarditis often goes underdiagnosed
  • Infective Endocarditis in Intravenous Drug Abusers can occur at any age, but it generally affects young adults who are addicted to the usage of injectable drugs. Such individuals may not have any history of heart-related abnormalities or diseases
  • The signs and symptoms of Intravenous Drug Abuse Endocarditis range from low-grade fever, fatigue, and joint pain, to severe features that include stroke (sudden weakness of limbs or face due to disruption of brain’s blood supply), cardiac arrhythmias, and damage to kidney and spleen
  • The treatment of Intravenous Drug Abuse Endocarditis is based on the organism type causing the infection. Bacterial infection is treated through intravenous antibiotics and fungal infection using antifungal medication. Surgery may be required in some cases
  • Untreated Intravenous Drug Abuse Endocarditis can lead to an extremely poor prognosis and is almost always be fatal. With appropriate early diagnosis and treatment, the outcomes are better. However, the prognosis also depends upon a set of factors including the type of organism causing infection, the health status of the individual, and the presence of any heart illnesses, among other factors

Who gets Intravenous Drug Abuse Endocarditis? (Age & Sex Distribution)

  • Intravenous Drug Abuse Endocarditis is more common in younger adults than other age groups due to their risky behavior, such as the use of intravenous (IV) drugs. However, individuals of any age may be at risk
  • The infection is generally more common in males than in females
  • It may affect individuals of all racial and ethnic background and no preference is noted

What are the Risk Factors for Intravenous Drug Abuse Endocarditis? (Predisposing Factors)

The key risk factor for Intravenous Drug Abuse Endocarditis is intravenous drug abuse, with sharing of needles and syringes that are contaminated. However, there may be additional factors that place such individuals at a higher risk for endocarditis. These factors may include:

  • Any cause of bacteremia that may include medical procedures such as:
    • Oral surgery, tooth extraction
    • Abdominal surgery
    • Genitourinary surgery; prostate resection
    • Diagnostic procedures such as upper GI endoscopy, colonoscopy, and barium enema
    • Transesophageal echocardiography
    • Placement of intravascular catheters
    • Poor oral hygiene and aggressive brushing of teeth can also result in bacteremia
  • Heart valve related:
    • Placement of an artificial (prosthetic) valve
    • Heart valve repaired with a prosthetic material
    • Age related degeneration of the heart valves
    • Valvulopathy, or heart valve disease, arising in a transplanted heart
  • Heart related: It has to be noted that 65% of the individuals may not have any history of heart diseases:
    • Previous history of endocarditis
    • Certain congenital heart diseases
    • Rheumatic heart disease: An autoimmune response of the heart to a bacterial infection of the throat (caused by Streptococcus pyogenes)
  • HIV and AIDS patients, because of suppressed immune system
  • Poorly-controlled diabetes
  • Longstanding corticosteroid therapy

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Intravenous Drug Abuse Endocarditis? (Etiology)

In most cases, Intravenous Drug Abuse Endocarditis is caused by bacteria that include the following:

  • Staphylococcus aureus, which is the most common infection agent
  • Streptococcus sp.
  • Enterococcus sp.
  • HACEK (group of gram-negative bacteria), in rare cases: It is seen in intravenous (IV) drug users who regularly contaminate their needles with saliva

Candida albicans is a fungus that is also seen in intravenous drug users.

What are the Signs and Symptoms of Intravenous Drug Abuse Endocarditis?

The signs and symptoms associated with Intravenous Drug Abuse Endocarditis may include:

  • Low-grade fever, which comes and goes in a majority of individuals, and chills
  • Night sweats
  • Fatigue and malaise, which is a feeling of discomfort or uneasiness
  • Anorexia, or the lack of appetite; weight loss
  • Headache
  • Arthralgia or joint pain; stiff neck and backache
  • Chest pain (pleuritic pain), cough
  • Confusion
  • A new or changing heart murmur: It is an abnormal heart sound that can be listened with a stethoscope
  • Electrical abnormalities in the heart (cardiac arrhythmias)
  • Stroke: It is a condition in which blood supply to an area of the brain is disrupted that results in a weakness of certain part of the body such as an arm, leg, or face
  • Formation of septic emboli within the bloodstream (septic emboli are blood clots admixed with bacteria)
  • Abdominal signs and symptoms such as nausea/vomiting and abdominal pain
  • Janeway lesions, which are small, painless, red or hemorrhagic lesions on the palms and sloes
  • Osler’s nodes, which are painful, red, raised lesions mostly on distal fingers
  • Intracranial hemorrhage: Hemorrhage within the brain
  • Conjunctival hemorrhage: Conjunctiva is a membrane that lines the inside of the eyelid and the sclera (the white part of the eye)
  • Splinter hemorrhages: These are tiny blood clots under the finger nails
  • Kidney and spleen infarcts: Interruption of blood supply to the kidney and spleen resulting in permanent damage of some of their portions
  • Enlarged spleen
  • Glomerulonephritis: Damage to the kidneys resulting in the loss of blood and proteins in the urine
  • Roth’s spots: These are retinal hemorrhages and are seen with a fundoscope (an ophthalmoscope to view the inside of the eye)

How is Intravenous Drug Abuse Endocarditis Diagnosed?

Infective Endocarditis in Intravenous Drug Abusers is a condition that is often underdiagnosed. Healthcare providers should be very aware of individuals, who are drug abusers and presenting low-grade fever, that they may have the condition.

In order to diagnose Intravenous Drug Abuse Endocarditis, the physician will initially perform a physical exam with evaluation of medical history. During a physical examination, the physician will look for the presence of the following:

  • Low-grade fever
  • A new or changing heart murmur
  • Janeway lesions
  • Osler’s nodes
  • Roth’s spots
  • Splinter hemorrhages
  • Conjunctival hemorrhages
  • Weakness/paralysis of a part of body (leg arm or face), which may be due to a brain stroke
  • Apart from the above, a history of intravenous drug abuse may be noted

Certain specific tests that may help in the diagnosis of Intravenous Drug Abuse Endocarditis such as:

  • Blood cultures: Blood is drawn from a vein and sent to the laboratory, where it is placed on a special dish to see the growth of the bacteria/fungus responsible for causing endocarditis 
  • Chest X-ray
  • Echocardiography: It is an ultrasound of the heart that is performed to assess cardiac function, size of the heart chambers, and the status of heart valves
  • Electrocardiogram or EKG for detecting conduction abnormalities of the heart

Endocarditis is usually diagnosed using Duke’s diagnostic criteria, which consists of a combination of major criteria and minor criteria. A definitive diagnosis should satisfy any of the following conditions:

  • The presence of any 2 major criteria
  • The presence of 1 major criterion and 3 minor criteria
  • The presence of 5 minor criteria

Major criteria include the following:

  • 2 blood cultures positive for infectious organisms
  • Blood cultures that are positive for microorganisms, which are taken 12 hours apart
  • 3 blood cultures positive on separate occasions that are taken at least 1 hour apart
  • Abnormalities in echocardiogram showing either a mass or abnormal blood flow
  • Abscess of the heart
  • New abnormalities developing in a prosthetic valve (partial dehiscence of the valve)
  • Recent onset of regurgitation of the valve causing abnormal blood flow (valvular regurgitation)

Minor criteria include the following:

  • Previously diagnosed heart condition
  • A positive history of intravenous drug use
  • Fever above 38 deg. C
  • Presence of vascular infarcts, hemorrhage, aneurysm, and emboli occurring in any part of the body
  • Abnormal immune findings such as glomerulonephritis, positive rheumatoid factor, Osler nodes
  • Positive blood cultures that do not meet the criteria described in the ‘major criteria’
  • Abnormal echocardiogram findings not described in the ‘major criteria’

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Intravenous Drug Abuse Endocarditis?

Intravenous Drug Abuse Endocarditis, if not promptly treated can cause major complications. The complications may affect any part of the body and may include:

  • Mitral and aortic valve incompetence: The bacteria/fungi clump together with other cell fragments and form aggregates of bacterial or fungal growth (vegetations) on the heart valves. If not treated promptly, it might result in permanent damage to the valves
  • Congestive heart failure: Due to damaged heart valves, it is difficult for the heart to pump enough blood to meet the requirements of the body. This can eventually result in heart failure and death
  • Formation of myocardial abscesses: An abscess may develop within the heart muscle and cause abnormal heartbeat rhythms (electrical conduction defects)
  • Infections in other parts of the body (metastatic infections): Infected material and vegetations formed on the heart valves dislodge and travel through blood to infect other organs of the body resulting in lung, kidney, spleen, and brain abscesses
  • 40% of the individuals may have neurological complications, which usually results from bleeding in the brain (intracerebral hemorrhage), embolic stroke, multiple sites of brain infection caused by microabscesses
  • Heart failure; permanent heart damage

How is Intravenous Drug Abuse Endocarditis Treated?

Intravenous Drug Abuse Endocarditis is a serious infection and requires an early and effective treatment in a hospital setting.

  • Treatment of bacterial infections:
    • Intravenous antibiotics, wherein antibiotics are given through the vein. Initially an empiric antibiotic is started usually vancomycin or ceftriaxone, which is then later modified depending upon the laboratory results
    • Sometimes surgery is needed to treat persistent infections not responding to antibiotic therapy
  • Treatment of fungal infections:
    • Administration of antifungal medication
    • Surgery is also sometimes needed to treat endocarditis caused by fungal organisms
  • Surgery may be performed to remove the infected area in the heart, or to correct the heart valve abnormalities

How can Intravenous Drug Abuse Endocarditis be Prevented?

  • Intravenous Drug Abuse Endocarditis can be completely prevented by avoiding the use of intravenous drugs through shared needles and syringes
  • Frequent follow-up physician visits for individuals who have been diagnosed with endocarditis in the past

What is the Prognosis of Intravenous Drug Abuse Endocarditis? (Outcomes/Resolutions)

Intravenous Drug Abuse Endocarditis, if left untreated is almost always fatal. The prognosis depends on a set of factors that include:

  • The overall health condition of the individual
  • The type of organism causing infection
  • The presence of any heart disease or heart abnormality
  • The presence of any prosthetic heart device
  • Surgical procedures involving the heart
  • The severity of the signs and symptoms and development of complications (if any)
  • Presence of other underlying conditions

With early and effective treatment, individuals with Intravenous Drug Abuse Endocarditis can have a good prognosis.

The prognosis is known to be worse for the following group of individuals:

  • Older individuals
  • Infection with resistant organism
  • Long delay in treatment
  • Aortic and multiple valve involvement
  • Large vegetations or aggregates of bacterial or fungal growth
  • Prosthetic valve infection
  • Infection with fungal organism
  • Infection with Staphylococcus aureus
  • Major embolic event resulting in large damage to the kidney, spleen, or lungs
  • Left-sided endocarditis as compared to right-sided endocarditis

Additional and Relevant Useful Information for Intravenous Drug Abuse Endocarditis:

Please visit our Heart & Vascular Health Center for more physician-approved health information:


What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: July 22, 2016
Last updated: Oct. 16, 2018