Infectious disease (medical specialty)

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Infectious disease (infectiology)
Gram stain 01.jpg
Gram stain of bacteria: a test frequently performed in infectiology to distinguish between different types of bacteria.
SynonymInfectious diseases, infectious medicine, infectious disease medicine
Significant diseases Infections, e.g. osteomyelitis, pneumonia, tuberculosis, covid-19, HIV/AIDS, influenza, also public health issues e.g. epidemics, antimicrobial resistance, bioterrorism
Significant tests Gram staining, microbiological cultures (including blood cultures), serological tests, genotyping, polymerase chain reaction (PCR), [ medical imaging]]
SpecialistInfectious disease specialist, Infectiologist, Infectionist
Glossary Glossary of medicine

Infectious diseases, also known as infectiology, is a medical specialty dealing with the diagnosis and treatment of complex infections. An infectious disease specialist's practice consists of managing nosocomial (healthcare-acquired) infections or community-acquired infections and is historically associated with travel medicine and tropical medicine.



Infectious diseases specialists typically serve as consultants to other physicians in cases of complex infections, and often manage patients with HIV/AIDS and other forms of Immunodeficiency. [1] Although many common infections are treated by physicians without formal expertise in infectious diseases, specialists may be consulted for cases where an infection is difficult to diagnose or manage. They may also be asked to help determine the cause of a fever of unknown origin. [1] [2]

Specialists in infectious diseases can practice both in hospitals (inpatient) and clinics (outpatient). In hospitals, specialists in infectious diseases help ensure the timely diagnosis and treatment of acute infections by recommending the appropriate diagnostic tests to identify the source of the infection and by recommending appropriate management such as prescribing antibiotics to treat bacterial infections. For certain types of infections, involvement of specialists in infectious diseases may improve patient outcomes. [3] In clinics, specialists in infectious diseases can provide long-term care to patients with chronic infections such as HIV/AIDS.


Infectious diseases is historically associated with travel medicine and tropical medicine, as many diseases acquired in tropical and subtropical areas are infectious in nature. [4]


Infectious diseases specialists employ a variety of diagnostic tests to help identify the pathogen that is causing an infection. Common tests include Gram staining, blood cultures, serological tests, genotyping, and polymerase chain reaction.


Infectious diseases specialists employ a variety of antimicrobial agents to help treat infections. The type of antimicrobial depends on the organism that is causing the infection. Antibiotics are used to treat bacterial infections; antiviral agents treat viral infections; and antifungal agents treat fungal infections.


NamesDoctor, Medical Specialist, Infectious diseases Consultant
Occupation type
Activity sectors
Education required
Doctor of Medicine (M.D.) or
Doctor of Osteopathic Medicine (D.O.) or
Bachelor of Medicine, Bachelor of Surgery
Fields of
Hospitals, Clinics

United States

In the United States, infectious diseases is a subspecialty of internal medicine and pediatrics [5] i.e., an internist does at least an additional two years of a fellowship and a pediatrician does at least three years to qualify as an infectious diseases specialist and take the infectious diseases board certification exam of the American Board of Internal Medicine or the American Board of Pediatrics. The exam has been given as a subspecialty of internal medicine since 1972 and as a subspecialty of pediatrics since 1994. [6] [7]

Related Research Articles

Antimicrobial resistance Ability of a microbe to resist the effects of medication

Antimicrobial resistance is the ability of a microbe to resist the effects of medication that once could successfully treat the microbe. The term antibiotic resistance is a subset of AMR, as it applies only to bacteria becoming resistant to antibiotics. Resistant microbes are more difficult to treat, requiring alternative medications or higher doses of antimicrobials. These approaches may be more expensive, more toxic or both. Microbes resistant to multiple antimicrobials are called multidrug resistant (MDR). Those considered extensively drug resistant (XDR) or totally drug-resistant (TDR) are sometimes called "superbugs".

Infection Invasion of an organisms body tissues by disease-causing agents

An infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection.

Methicillin-resistant <i>Staphylococcus aureus</i> Bacterium responsible for difficult-to-treat infections in humans

Methicillin-resistant Staphylococcus aureus (MRSA) refers to a group of Gram-positive bacteria that are genetically distinct from other strains of Staphylococcus aureus. MRSA is responsible for several difficult-to-treat infections in humans. MRSA is any strain of S. aureus that has developed, through horizontal gene transfer and natural selection, multiple drug resistance to beta-lactam antibiotics. Beta-lactam (β-lactam) antibiotics are a broad-spectrum group that include some penams and cephems such as the cephalosporins. Strains unable to resist these antibiotics are classified as methicillin-susceptible S. aureus, or MSSA.

Cervicitis is inflammation of the uterine cervix. Cervicitis in women has many features in common with urethritis in men and many cases are caused by sexually transmitted infections. Non-infectious causes of cervicitis can include intrauterine devices, contraceptive diaphragms, and allergic reactions to spermicides or latex condoms. Cervicitis affects over half of all women during their adult life.

Bacteremia is the presence of bacteria in the blood. Blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal. It is distinct from sepsis, which is the host response to the bacteria.

<i>Klebsiella pneumoniae</i> Species of bacterium

Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultative anaerobic, rod-shaped bacterium. It appears as a mucoid lactose fermenter on MacConkey agar.

Pulmonology Study of respiratory diseases

Pulmonology or pneumology is a medical specialty that deals with diseases involving the respiratory tract. It is also known as respirology, respiratory medicine, or chest medicine in some countries and areas.

An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. Agents that kill microbes are microbicidal, while those that merely inhibit their growth are called biostatic. The use of antimicrobial medicines to treat infection is known as antimicrobial chemotherapy, while the use of antimicrobial medicines to prevent infection is known as antimicrobial prophylaxis.

Tropical medicine medical specialty

Tropical medicine is an interdisciplinary branch of medicine that deals with health issues that occur uniquely, are more widespread, or are more difficult to control in tropical and subtropical regions.

Julie Gerberding American physician, educator, infectious disease specialist

Julie Louise Gerberding is an American infectious disease expert and the former director of the U.S. Centers for Disease Control and Prevention (CDC) and administrator of the Agency for Toxic Substances and Disease Registry (ATSDR).

Subacute bacterial endocarditis Human disease

Subacute bacterial endocarditis is a type of endocarditis. Subacute bacterial endocarditis can be considered a form of type III hypersensitivity.

Infection prevention and control is the discipline concerned with preventing healthcare-associated infections; a practical rather than academic sub-discipline of epidemiology. In Northern Europe, infection prevention and control is expanded from healthcare into a component in public health, known as "infection protection". It is an essential part of the infrastructure of health care. Infection control and hospital epidemiology are akin to public health practice, practiced within the confines of a particular health-care delivery system rather than directed at society as a whole. Anti-infective agents include antibiotics, antibacterials, antifungals, antivirals and antiprotozoals.

Infectious Diseases Society of America Medical association

The Infectious Diseases Society of America (IDSA) is a medical association representing physicians, scientists and other health care professionals who specialize in infectious diseases. It was founded in 1963 and is based in Arlington, Virginia. As of 2018 IDSA had more than 11,000 members from across the United States and nearly 100 other countries on six different continents. IDSA's purpose is to improve the health of individuals, communities, and society by promoting excellence in patient care, education, research, public health, and prevention relating to infectious diseases. It is a 501(c)(6) organization.

Medical microbiology Branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases

Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses, and one type of infectious protein called prion.

Antibiotic misuse misuse or overuse of antibiotics, with potentially serious effects on health

Antibiotic misuse, sometimes called antibiotic abuse or antibiotic overuse, refers to the misuse or overuse of antibiotics, with potentially serious effects on health. It is a contributing factor to the development of antibiotic resistance, including the creation of multidrug-resistant bacteria, informally called "super bugs": relatively harmless bacteria can develop resistance to multiple antibiotics and cause life-threatening infections.

Itzhak Brook is an Adjunct Professor of Pediatrics and Medicine at Georgetown University School of Medicine, Washington DC. He specializes in infectious diseases. He is the past chairman of the Anti-infective Drug Advisory Committee of the Food and Drug Administration (FDA) and chaired the Committee when AZT was approved for the treatment of HIV/AIDS in 1987.

Chronic Lyme disease (CLD) is the name used by some people with "a broad array of illnesses or symptom complexes for which there is no reproducible or convincing scientific evidence of any relationship to Borrelia burgdorferi infection" to describe their condition and their beliefs about its cause. Both the label and the belief that these people's symptoms are caused by this particular infection are generally rejected by medical professionals, and the promotion of chronic lyme disease is an example of health fraud. Chronic Lyme disease in this context should not be confused with genuine Lyme disease, a known medical disorder caused by infection with Borrelia burgdorferi, or with post-treatment Lyme disease syndrome, a set of lingering symptoms which may persist after successful treatment of infection with Lyme bacteria.

Antimicrobial stewardship is the systematic effort to educate and persuade prescribers of antimicrobials to follow evidence-based prescribing, in order to stem antibiotic overuse, and thus antimicrobial resistance. AMS has been an organized effort of specialists in infectious diseases, both in Internal Medicine and Pediatrics with their respective peer-organizations, hospital pharmacists, the public health community and their professional organizations since the late 1990s. It has first been implemented in hospitals. In the U.S., within the context of physicians' prescribing freedom, AMS has largely been voluntary self-regulation in the form of policies and appeals to adhere to a prescribing self-discipline. At hospitals, this may take the form of an antimicrobial stewardship program. As of 2019, California and Missouri have made AMS programs mandatory by law.

The Society of Infectious Diseases Pharmacists (SIDP) is a non-profit professional association of pharmacists and allied health professionals who specialize in infectious diseases and antimicrobial stewardship. According to the Board of Pharmaceutical Specialties, clinical pharmacists specializing in infectious diseases are trained in the use of microbiology and pharmacology to develop, implement, and monitor drug regimens that incorporate the pharmacodynamics and pharmacokinetics of antimicrobials for patients.

Jasmine R. Marcelin is a Caribbean-American infectious disease physician and an Assistant Professor in the Department of Internal Medicine at the University of Nebraska Medical Center (UNMC). Marcelin is also the Associate Medical Director of the Antimicrobial Stewardship Program and as well as the Co-Director of Digital Innovation and Social Media Strategy at UNMC. Marcelin is dedicated to advancing diversity, inclusion, and equity in her communities and is a founding member of the Infectious Diseases Society of America Inclusion, Diversity, Access & Equity Taskforce. Marcelin uses social media to advance medicine, diversity, and patient advocacy and has published articles on how to effectively use social media for these purposes.


  1. 1 2 "IDSA : What is an ID Specialist". Retrieved 2015-10-27.
  2. "ABMS Guide to Medical Specialties" (PDF).
  3. "The Value of an Infectious Diseases Specialist | Safe HealthcareSafe Healthcare | Blogs | CDC". Archived from the original on 2015-11-17. Retrieved 2015-11-14.
  4. Joint Royal Colleges Postgraduate Training Board. "Infectious Diseases". Archived from the original on 2013-12-12. Retrieved 2013-12-12.
  5. "Infectious Disease, Internal Medicine". Association of American Medical Colleges. Archived from the original on 2015-02-06.
  6. "Exam Administration History". American Board of Internal Medicine. Retrieved 25 April 2019.
  7. Douvoyiannis, Miltiadis; Litman, Nathan; Belamarich, Peter; Goldman, David L. (2011). "A survey of current and past Pediatric Infectious Diseases fellows regarding training". BMC Medical Education. 11: 72. doi:10.1186/1472-6920-11-72. PMC   3188472 . PMID   21943353.

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