Table 2.

Evolution of diagnostic techniques for infective endocarditis

Diagnostic Technique	Introduction Period	Key Advantages	Limitations	Examples of Pathogens Detected	References
Blood Cultures	Early 1900s	Gold standard; can identify a wide range of bacteria in IE; easy to implement.	Fails in 30% of cases, especially post-antibiotics; slow to yield results (days).	Staphylococcus aureus, Streptococcus viridans	[19]
Serology	1950s-1960s	Non-invasive; useful for fastidious organisms like Coxiella burnetii.	Requires specific tests for different organisms; lacks broad applicability.	Coxiella burnetii (Q fever)	[20]
Histopathology	1900s (Routine use began later)	Direct visualization of valvular tissue; provides definitive diagnosis.	Invasive; requires heart valve biopsy; not always feasible.	Any organism causing valve damage (e.g., bacterial, fungal)	[21, 22]
Polymerase Chain Reaction (PCR)	1980s-1990s	High sensitivity; detects DNA directly from clinical samples.	Relatively costly and limited to known pathogens with available primers.	Bartonella, Tropheryma whipplei	[23]
16S rRNA Sequencing	Late 1990s	Broadens bacterial identification range; effective for rare and slow-growing bacteria.	Limited to bacterial pathogens; cannot detect viruses or fungi.	Tropheryma whipplei, Bartonella species	[24]
Metagenomic Next-Generation Sequencing (mNGS)	2010s-Present	Rapid, comprehensive detection of bacteria, fungi, and viruses.	High cost, complex data interpretation, lack of standardized clinical protocols.	Broad range: bacterial, viral, fungal (including rare and fastidious organisms)	[25]