What is Infectious Arthritis?

Infectious arthritis (IA) is a general term that refers to any arthritic condition caused by microorganisms, in which the capacity of infectious agents to colonize the joint is influenced by host-related factors along with the properties of microbe.

A painful infection in the joint, Infectious arthritis is also known as septic arthritis. It can occur when an infection from another part of the body spreads to joints or the fluid surrounding the joint. Germs that cause infection might enter the body through surgery, open wounds, or injections. Infectious arthritis generally affects only one joint at a time. It affects youngsters more frequently than adults.

The infection usually spreads through the circulation to the joints. These joints can get infected as a result of an injection, surgery, or damage.

Image Credit: Suriyawut Suriya/Shutterstock.com

Causes and causative agents

Bacteria, viruses, and fungus can all cause infectious arthritis. Bacteria are the most common causative agent. Gonococcus, spirochetes, certain Gram-positive bacteria, and certain Gram-negative bacteria can cause the infection. The majority of joint infection processes are caused by bacteria migrating from a distant place, primarily through hematogenous dissemination.

A contiguous center of infection, such as sepsis or adjacent tissue infection, or direct injection by a traumatic or iatrogenic event are two more routes through which microorganisms might penetrate joints.

Gonococcus is most commonly seen in the knee joints, but it can also impact the tendons and bursae, causing tendonitis and bursitis. Infectious arthritis can develop days or weeks after gonorrhea symptoms begin. It affects women more frequently than men. The second most common cause of infectious arthritis is Staphylococcus (a gram-positive bacterium). It's commonly referred to as a "staph infection."

A staph infection can develop as a result of a skin or sinus infection, or following surgery. Rheumatoid arthritis patients and those who take steroids or immunosuppressive drugs (such as Imuran and Cytoxan) are more likely to develop infectious arthritis caused by staphylococcus bacteria.

Does Drinking Alcohol Cause Joint Pain in Arthritis?

Hemophilus is a Gram-negative bacterium that causes meningitis and severe sore throat. It is a common cause of infectious arthritis in children, but it is uncommon in adults. Under a microscope, spirochetes appear to be spiral-shaped bacteria. Spirochetes come in a variety of shapes and sizes.

Lyme disease is infectious arthritis caused by one type of bacteria (Borrelia). People contract this disease after being bitten by a tick. Lyme disease can affect anyone, but it is more frequent in children.

Viruses can also cause infectious arthritis. It is frequently caused by a viral infection that's already in a person's system. Infectious hepatitis, mumps, and infectious mononucleosis are viral illnesses that can cause infectious arthritis for a brief period. The inflammation of the joints usually lasts one to two weeks.

German measles can also cause infectious arthritis, which can continue for up to a year after the rash has disappeared. Infectious arthritis is least commonly caused by fungi. Arthritis caused by a fungus usually takes a long time to develop. Fungi that cause arthritis are commonly found in soil, bird droppings, and some plants (especially roses).

Risk factors and symptoms

Risk factors for infectious arthritis include a systemic (blood-borne) infection, osteoarthritis, history of septic arthritis, use of IV drugs, and rheumatoid arthritis. Other factors that may increase the risk for infectious arthritis are diabetes, alcoholism, HIV, old age, lung or liver disorders, and suppressed immune system.

The knee, hip, shoulder, elbow, wrist, and finger are the most common joints affected by septic arthritis. The majority of the time, only one joint is impacted. Fever, chills, soreness, and swelling in the joint are all frequent symptoms, though they vary from person to person.


Infectious arthritis is a life-threatening condition with a death incidence of 7-15%. More than 50% of those who survive, suffer from long-term repercussions (such as cartilage damage). In regions such as Scandinavia and Australia, the incidence of septic arthritis has been reported to be 5.7–9 per 100 000 person-years.

The incidence in the United Kingdom has increased to 43% between 1998 and 2013, from 5.5 to 7.8 per 100 000 person-years. However, epidemiological data on this disease from low-income areas are scarce.

Diagnosis and treatment

The diagnosis of infectious arthritis begins with an analysis of medical history followed by a physical examination and a series of other tests. X-rays can be used to identify damage in the joints, and various laboratory tests can be performed to detect the presence of an infection. Identification of the specific germ responsible for the infection is crucial for further treatment and management.

Bacteria and fungi are commonly detected in joint fluid, blood, urine, or the diseased area. The symptoms and medical history of a person are frequently used to diagnose a viral infection.

A combination of joint drainage and antibiotic medicines is used to treat the condition. Antibiotics are almost always used to treat bacterial infections. The antibiotic administered will be determined by the bacteria that is causing the ailment. Antibiotics can usually stop an illness in a few days, but they may need to be given over several months in other circumstances.

Infectious arthritis caused by a virus usually resolves without treatment, whereas fungal infections are treated with antifungal medications.

The joint fluid of many people with infectious arthritis needs to be drained to remove infected synovial fluid, relieve pain, reduce inflammation, and protect the joint from further damage. Joint aspiration is the least intrusive treatment, in which a doctor (or another health care practitioner) inserts a needle into the joint and removes fluid. To drain fluid, an arthroscopic operation or, in more severe circumstances, open joint surgery may be employed.

Infectious arthritis requires rapid diagnosis and effective treatment. Rigorous research from low-income countries might aid in a better understanding of the condition, facilitating better therapeutic approaches.


  • Mrinalini, D., Sizheng, S, Z., Nicola, G. (2020). Global public interest in infectious and non-infectious arthritis: an evaluation using Google Trends, Rheumatology, 59(1),245–246. https://doi.org/10.1093/rheumatology/kez283
  • Skármeta, N. P., Espinoza-Mellado, P. A., Elissalt, N., Diez, F. J., & Fumeaux, J. E. (2020). Infectious arthritis and the temporomandibular joint. A review. Cranio : the journal of craniomandibular practice, 1–9. Advance online publication. https://doi.org/10.1080/08869634.2020.1819687
  • Jessica, M, G. (2019). Bacterial Behavior in Synovial Fluid and Development of a Novel Therapeutic to Combat Infectious Arthritis. [Doctoral dissertation, North Carolina State University, Raleigh, North Carolina] Retrieved from https://www.proquest.com/openview/608b73a7cd4922eb1519e0e081d28ea7/1?pq-origsite=gscholar&cbl=18750&diss=y
  • Infectious Arthritis. [online] Arthritis Foundation. Available at: https://www.arthritis.org/diseases/infectious-arthritis
  • Infectious Arthritis. [online] University of Washington (Orthopaedics and Sports Medicine). Available at: https://orthop.washington.edu/patient-care/articles/arthritis/infectious-arthritis.html
  • Septic Arthritis. [online] John Hopkins Medicine (Health). Available at: https://www.hopkinsmedicine.org/health/conditions-and-diseases/arthritis/septic-arthritis

Further Reading

  • All Arthritis Content
  • What is Arthritis?
  • Types of Arthritis
  • Arthritis Treatment
  • Arthritis History

Last Updated: Nov 19, 2021

Source: Read Full Article