What is an Infectious Diseases Physician?
An infectious diseases (ID) physician is a medical specialist with advanced training in the diagnosis, treatment, and prevention of infections caused by bacteria, viruses, fungi, parasites, and other microorganisms, who serves as both a clinical consultant and a public health expert. 1, 2
Core Clinical Expertise
ID physicians possess in-depth knowledge of medical and laboratory science, epidemiology, antimicrobial pharmacokinetics, and host-pathogen interactions that enables optimal patient outcomes through strong partnerships with other clinicians and laboratory specialists. 3
Primary Clinical Activities
Based on contemporary practice patterns, ID physicians manage a diverse range of conditions: 2
- Skin and soft tissue infections (approximately 16% of consultations) 2
- Respiratory tract infections (approximately 16% of consultations) 2
- Bone and joint infections (approximately 17% of consultations) 2
- Bloodstream infections and bacteremia 3
- Healthcare-associated infections (35% of consultations) 2
- Infections in immunocompromised patients (21% of consultations) 2
- Prosthesis-related infections (13% of consultations) 2
- Multidrug-resistant pathogen infections (13% of consultations) 2
The most commonly encountered pathogen is Staphylococcus aureus, implicated in approximately 24% of episodes—four times more frequently than the next most common organism. 2
Specialized Diagnostic Skills
ID physicians excel at navigating complex diagnostic challenges that require: 3
- Interpretation of culture-negative infections requiring specialized testing 3
- Selection and interpretation of appropriate microbiological specimens, working closely with certified microbiology specialists 3
- Application of molecular diagnostics including nucleic acid amplification tests 3
- Serological testing for difficult-to-culture pathogens 3
- Recognition of travel-related infections requiring detailed exposure histories 3
System-Level Impact
Beyond individual patient care, ID physicians provide substantial value through: 1, 4
Antimicrobial Stewardship
ID physicians direct programs that optimize antibiotic use, combat antimicrobial resistance, and reduce adverse drug effects—activities considered very important by 94% of program directors and hospital epidemiologists. 3, 5, 4
Infection Prevention and Control
ID physicians lead hospital epidemiology efforts including: 5, 4
- Surveillance for resistant bacteria (81% consider very important) 5
- Central line-associated bloodstream infection prevention (90% consider very important) 5
- Hand hygiene programs (90% consider very important) 5
- Isolation precautions (93% consider very important) 5
Public Health Functions
ID physicians play crucial roles in: 1, 6
- Disease surveillance and outbreak response 1, 6
- Communicable disease exposure management (81% consider very important) 5
- Notifiable disease reporting to public health authorities 3
- Population health interventions that improve community outcomes 1, 6
Multidisciplinary Collaboration
ID physicians must interact effectively with a wide range of medical specialties given the diversity of infections and affected organ systems. 2 This requires broad understanding of cardiology (for endocarditis management), surgery (for source control), critical care (for sepsis management), and numerous other disciplines. 3, 2
Training and Certification
ID physicians complete internal medicine or pediatrics residency followed by 2-3 years of fellowship training in infectious diseases, with board certification available through subspecialty examination. 5 Training encompasses clinical microbiology, antimicrobial therapy, infection control, and increasingly, healthcare epidemiology and antimicrobial stewardship. 5
Value Proposition
ID physicians are uniquely positioned to positively impact the Triple Aim of healthcare reform: better health, better care, and lower per capita cost. 4 They improve clinical outcomes, facilitate appropriate transitions of care, and direct system-level improvements through infection prevention and antimicrobial stewardship programs. 4 Despite this substantial value, much of their public health work remains undercompensated, creating workforce challenges for the specialty. 1