Editing Infective endocarditis (section)

==Diagnosis==
[[Image:Endocarditis ultrasound.gif|thumb|Vegetation on the [[tricuspid valve]] by [[echocardiography]]. Arrow denotes the vegetation.]]

In general, the Duke criteria should be fulfilled in order to establish the diagnosis of endocarditis.<ref name="Hubers2020"/><ref name=Durack>{{cite journal | vauthors = Durack DT, Lukes AS, Bright DK | title = New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke Endocarditis Service | journal = The American Journal of Medicine | volume = 96 | issue = 3 | pages = 200–9 | date = March 1994 | pmid = 8154507 | doi = 10.1016/0002-9343(94)90143-0 }}</ref> Although the Duke criteria are widely used, they have significant limitations.<ref name="Hubers2020"/> For example, the sensitivity of the Duke criteria for detecting infective endocarditis decreases when prosthetic heart valves are present.<ref name="Hubers2020"/>

As the Duke criteria rely heavily on the results of echocardiography, research has addressed when to order an [[echocardiogram]] by using signs and symptoms to predict occult endocarditis among people who inject drugs<ref name=Weisse>{{cite journal | vauthors = Weisse AB, Heller DR, Schimenti RJ, Montgomery RL, Kapila R | title = The febrile parenteral drug user: a prospective study in 121 patients | journal = The American Journal of Medicine | volume = 94 | issue = 3 | pages = 274–80 | date = March 1993 | pmid = 8452151 | doi = 10.1016/0002-9343(93)90059-X }}</ref><ref name=Samet>{{cite journal | vauthors = Samet JH, Shevitz A, Fowle J, Singer DE | title = Hospitalization decision in febrile intravenous drug users | journal = The American Journal of Medicine | volume = 89 | issue = 1 | pages = 53–7 | date = July 1990 | pmid = 2368794 | doi = 10.1016/0002-9343(90)90098-X | doi-access = free }}</ref><ref name=Marantz>{{cite journal | vauthors = Marantz PR, Linzer M, Feiner CJ, Feinstein SA, Kozin AM, Friedland GH | title = Inability to predict diagnosis in febrile intravenous drug abusers | journal = Annals of Internal Medicine | volume = 106 | issue = 6 | pages = 823–8 | date = June 1987 | pmid = 3579068 | doi = 10.7326/0003-4819-106-6-823 }}</ref> and among non drug-abusing patients.<ref name=Leibovici>{{cite journal | vauthors = Leibovici L, Cohen O, Wysenbeek AJ | title = Occult bacterial infection in adults with unexplained fever. Validation of a diagnostic index | journal = Archives of Internal Medicine | volume = 150 | issue = 6 | pages = 1270–2 | date = June 1990 | pmid = 2353860 | doi = 10.1001/archinte.150.6.1270 }}</ref><ref name=Mellors>{{cite journal | vauthors = Mellors JW, Horwitz RI, Harvey MR, Horwitz SM | title = A simple index to identify occult bacterial infection in adults with acute unexplained fever | journal = Archives of Internal Medicine | volume = 147 | issue = 4 | pages = 666–71 | date = April 1987 | pmid = 3827454 | doi = 10.1001/archinte.147.4.666 }}</ref> However, this research is over twenty years old and it is possible that changes in the epidemiology of endocarditis and bacteria such as [[staphylococci]] make the following estimates incorrect.

The blood tests [[C reactive protein]] (CRP) and [[procalcitonin]] have not been found to be particularly useful in helping make or rule out the diagnosis.<ref>{{cite journal | vauthors = Yu CW, Juan LI, Hsu SC, Chen CK, Wu CW, Lee CC, Wu JY | title = Role of procalcitonin in the diagnosis of infective endocarditis: a meta-analysis | journal = The American Journal of Emergency Medicine | volume = 31 | issue = 6 | pages = 935–41 | date = June 2013 | pmid = 23601504 | doi = 10.1016/j.ajem.2013.03.008 }}</ref>

===Ultrasound===
[[Echocardiography]] is the main type of diagnostic imaging used to establish the diagnosis of infective endocarditis.<ref name="Hubers2020"/> There are two main types of echocardiography used to assist with the diagnosis of IE: transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE).<ref name="Hubers2020"/>

The transthoracic echocardiogram has a sensitivity and specificity of approximately 65% and 95% if the echocardiographer believes there is 'probable' or 'almost certain' evidence of endocarditis.<ref name="Shively">{{cite journal | vauthors = Shively BK, Gurule FT, Roldan CA, Leggett JH, Schiller NB | title = Diagnostic value of transesophageal compared with transthoracic echocardiography in infective endocarditis | journal = Journal of the American College of Cardiology | volume = 18 | issue = 2 | pages = 391–7 | date = August 1991 | pmid = 1856406 | doi = 10.1016/0735-1097(91)90591-V | doi-access = free }}</ref><ref name="Erbel">{{cite journal | vauthors = Erbel R, Rohmann S, Drexler M, Mohr-Kahaly S, Gerharz CD, Iversen S, Oelert H, Meyer J | title = Improved diagnostic value of echocardiography in patients with infective endocarditis by transoesophageal approach. A prospective study | journal = European Heart Journal | volume = 9 | issue = 1 | pages = 43–53 | date = January 1988 | pmid = 3345769 | doi=10.1093/oxfordjournals.eurheartj.a062389}}</ref> However, in endocarditis involving a prosthetic valve, TTE has a sensitivity of approximately 50%, whereas TEE has a sensitivity exceeding 90%.<ref name="Hubers2020" /> The TEE also has an important diagnostic role when the TTE does not reveal IE but diagnostic suspicion remains high,  since TEE is more sensitive for infective endocarditis and is better able to characterize infection-related damage to the heart valves and surrounding tissues.<ref name="Hubers2020" />

Guidelines support the initial use of TTE over TEE in people with abnormal blood cultures, a new heart murmur, and suspected infective endocarditis.<ref name="Hubers2020" /> TEE is the preferred initial form of imaging in people with suspected infective endocarditis who have a moderate to high pretest probability of infective endocarditis, including people with prosthetic heart valves, blood cultures growing ''[[Staphylococcus]]'',  or have an intracardiac device (such as a [[pacemaker]]).<ref name="Hubers2020" />

<gallery>
File:UOTW 27 - Ultrasound of the Week 1.webm|Ultrasound showing infectious endocarditis<ref name=UOTW27>{{cite web|title=UOTW #27 – Ultrasound of the Week|url=https://www.ultrasoundoftheweek.com/uotw-27/|website=Ultrasound of the Week|access-date=27 May 2017|date=26 November 2014|url-status=live|archive-url=https://web.archive.org/web/20170509110315/https://www.ultrasoundoftheweek.com/uotw-27/|archive-date=9 May 2017}}</ref>
File:UOTW 27 - Ultrasound of the Week 2.webm|Ultrasound showing infectious endocarditis<ref name=UOTW27/>
File:UOTW 27 - Ultrasound of the Week 3.webm|Ultrasound showing infectious endocarditis<ref name=UOTW27/>
File:UOTW 60 - Ultrasound of the Week 1.webm|Ultrasound showing another case of infectious endocarditis<ref>{{cite web|title=UOTW #60 – Ultrasound of the Week|url=https://www.ultrasoundoftheweek.com/uotw-60/|website=Ultrasound of the Week|access-date=27 May 2017|date=5 October 2015|url-status=live|archive-url=https://web.archive.org/web/20170509150141/https://www.ultrasoundoftheweek.com/uotw-60/|archive-date=9 May 2017}}</ref>
</gallery>

===Modified Duke criteria===
Established in 1994 by the Duke Endocarditis Service and revised in 2000, the Duke criteria are a collection of major and minor criteria used to establish a diagnosis of infective endocarditis.<ref name="Durack"/><ref name="Li2000">{{cite journal | vauthors = Li JS, Sexton DJ, Mick N, Nettles R, Fowler VG, Ryan T, Bashore T, Corey GR | title = Proposed modifications to the Duke criteria for the diagnosis of infective endocarditis | journal = Clinical Infectious Diseases | volume = 30 | issue = 4 | pages = 633–8 | date = April 2000 | pmid = 10770721 | doi = 10.1086/313753 | doi-access = free }}</ref> According to the Duke criteria, diagnosis of infective endocarditis can be definite, possible, or rejected.<ref name="NEJM Review, Hoen" /> A diagnosis of infective endocarditis is definite if either the following pathological ''or'' clinical criteria are met:

One of these pathological criteria:
* Histology or culture of cardiac vegetation, embolized vegetation, or intracardiac abscess from the heart finds microorganisms
* Active endocarditis
One of these combinations of clinical criteria
* Two major clinical criteria
* One major and three minor criteria
* Five minor criteria
Diagnosis of infective endocarditis is possible if one of the following combinations of clinical criteria is met:
* One major and one minor criteria
* Three minor criteria are fulfilled

====Major criteria====
Positive blood culture with typical IE microorganism, defined as one of the following:<ref name="NEJM Review, Hoen" />
* Typical microorganism consistent with IE from two separate blood cultures, as noted below:
** [[Streptococcus viridans|Viridans-group streptococci]], or
** ''[[Streptococcus bovis]]'' including nutritional variant strains, or
** [[HACEK]] group, or
** ''[[Staphylococcus aureus]]'', or
** Community-acquired ''[[enterococci]]'', in the absence of a primary focus
* Microorganisms consistent with IE from persistently positive blood cultures defined as:
** Two positive cultures of blood samples drawn >12 hours apart, or
** Three or a majority of ≥four separate blood cultures (with first and last sample drawn at least one hour apart)
** ''[[Coxiella burnetii]]'' detected by at least one positive blood culture or [[IgG antibody]] titer for [[Q fever]] phase 1 antigen >1:800. This was previously a minor criterion
Evidence of endocardial involvement with positive echocardiogram is defined as
* Oscillating intracardiac mass on valve or supporting structures, in the path of regurgitant jets, or on implanted material in the absence of an alternative anatomic explanation, or
* Abscess, or
* New partial dehiscence of prosthetic valve or new valvular regurgitation (worsening or changing of preexisting murmur not sufficient)

====Minor criteria====
* Predisposing factor: known cardiac lesion, recreational [[drug injection]]
* Fever >38&nbsp;°C
* [[Embolism|Vascular]] phenomena: arterial emboli, [[lung|pulmonary]] [[infarct]]s, [[Janeway lesions]], [[conjunctiva]]l hemorrhage
* Immunological phenomena: [[glomerulonephritis]], [[Osler's nodes]], [[Roth's spots]], [[Rheumatoid factor]]
* Microbiologic evidence: Positive blood culture (that doesn't meet a major criterion) or serologic evidence of infection with organism consistent with IE but not satisfying major criterion
'''Updated (2023) Modified Duke Criteria for Infective Endocarditis:''' Infective endocarditis (IE) is a life-threatening condition and the Duke criteria (established in 1994 and revised in 2000) has been fundamental for the diagnosis of the disease. However, the landscape of micro-biology, diagnostics, epidemiology, and treatment for lE has evolved significantly over the years. The 2023 modified Duke criteria address these changes: [https://medicalstudyhub.com/updated-2023-modified-duke-criteria-for-infective-endocarditis/ Updated (2023) Modified Duke Criteria for Infective Endocarditis]

===Risk===
Among people who do not [[intravenous drug use|use intravenous drugs]] and have a fever in the [[emergency department]], there is a less than 5% chance of occult endocarditis. Mellors in 1987 found no cases of endocarditis nor of staphylococcal bacteremia among 135 febrile patients ''in the emergency room''.<ref name=Mellors/> The upper [[confidence interval]] for 0% of 135 is 5%, so for statistical reasons alone, there is up to a 5% chance of endocarditis among these patients. In contrast, Leibovici found that among 113 non-selected adults ''admitted to the hospital'' because of fever there were two cases (1.8% with 95%CI: 0% to 7%) of endocarditis.<ref name=Leibovici/>

Among people who do use intravenous drugs and have a fever in the emergency department, there is about a 10% to 15% prevalence of endocarditis. This estimate is not substantially changed by whether the doctor believes the patient has a trivial explanation for their fever.<ref name = Marantz/> Weisse found that 13% of 121 patients had endocarditis.<ref name=Weisse/> Marantz also found a prevalence of endocarditis of 13% among such patients in the emergency department with fever.<ref name=Marantz/> Samet found a 6% incidence among 283 such patients, but after excluding patients with initially apparent major illness to explain the fever (including 11 cases of manifest endocarditis), there was a 7% prevalence of endocarditis.<ref name=Samet/> During the [[Opioid epidemic in the United States]], hospitals observed an increase in [[stroke]] associated with infective endocarditis.<ref>{{Cite journal |last1=Salehi Omran |first1=Setareh |last2=Chatterjee |first2=Abhinaba |last3=Chen |first3=Monica L. |last4=Lerario |first4=Michael P. |last5=Merkler |first5=Alexander E. |last6=Kamel |first6=Hooman |date=March 2019 |title=National Trends in Hospitalizations for Stroke Associated With Infective Endocarditis and Opioid Use Between 1993 and 2015 |journal=Stroke |language=en |volume=50 |issue=3 |pages=577–582 |doi=10.1161/STROKEAHA.118.024436 |pmid=30699043 |pmc=6396300 |issn=0039-2499}}</ref>

Among people with staphylococcal bacteremia (SAB), one study found a 29% prevalence of endocarditis in community-acquired SAB versus 5% in nosocomial SAB.<ref name=Kaech>{{cite journal | vauthors = Kaech C, Elzi L, Sendi P, Frei R, Laifer G, Bassetti S, Fluckiger U | title = Course and outcome of Staphylococcus aureus bacteraemia: a retrospective analysis of 308 episodes in a Swiss tertiary-care centre | journal = Clinical Microbiology and Infection | volume = 12 | issue = 4 | pages = 345–52 | date = April 2006 | pmid = 16524411 | doi = 10.1111/j.1469-0691.2005.01359.x | doi-access = free }}</ref> However, only 2% of strains were resistant to methicillin and so these numbers may be low in areas of higher resistance.{{citation needed|date=February 2021}}