Device Related Infection

Over half of the nearly 2 million healthcare-associated infections can be traced back to implanted medical devices—a growing concern as more people rely on these life-saving technologies to manage serious health conditions.

Table of contents

• What Is Device Related Infection?
• Other Names
• How Common Are These Infections?
• What Causes Device Infections?
• Common Microorganisms
• The Role of Biofilms
• Who Is at Higher Risk?
• How Are Device Infections Diagnosed?
• Preventing Device Infections
• Treatment Approaches

What Is Device Related Infection?

A device related infection is a reaction by the body’s immune system to one or more microorganisms that have colonized an implanted medical device. These infections represent a significant complication that can occur after surgical implantation of devices that are increasingly used to improve quality of life and patient survival.^[1][2]

The infection typically begins when microorganisms adhere to the foreign material of the implant. These organisms then undergo a complex transformation, leading to the formation of a biofilm—a structured community of bacterial cells enclosed in a self-produced protective layer that sticks to the device surface. This biofilm structure provides a physical barrier and changes the properties of the bacteria, making them much more resistant to the body’s immune defenses and to antibiotic treatments when used alone.^[2]

As a result, the microorganisms living on the device can multiply and cause damage to nearby tissue. This might include loosening of the implanted device, wound separation, or disruption of device components such as heart valves. Infections can also spread throughout the body, causing symptoms like fever or pieces of infected material traveling through the bloodstream.^[2]

implant-associated infection, medical device-related infection, prosthetic device infection, foreign body-related infection

Other Names

Device related infections are also known by several other terms, including implant-associated infection, medical device-related infection, prosthetic device infection, and foreign body-related infection.^[2]

How Common Are These Infections?

Of the nearly 2 million healthcare-associated infections reported by health authorities, approximately 50 to 70 percent can be attributed to indwelling medical devices.^[1][2] Approximately 25 percent of all healthcare-associated infections are device-associated infections.^[3]

The death rate associated with these infections varies greatly depending on the type of device. It can range from less than 5 percent for devices such as dental implants and urinary catheters to more than 25 percent for mechanical heart valves.^[1] The highest death rates are seen with prosthetic valve infections of the heart.^[3]

Despite efforts to prevent these infections, rates continue to rise. Analysis of hospital records covering 4.2 million device implantations over 16 years showed that the incidence of infection increased by 210 percent. The annual rate rose steadily and then jumped significantly from 1.53 percent in 2004 to 2.41 percent in 2008.^[1]

This increase is happening for several reasons. More devices are being used, the technology is becoming more complex with more components, and patients receiving these devices tend to be older and have other health conditions that weaken their immune systems.^[1][4] The infection rate is also higher for devices that are reimplanted compared to first-time implants.^[3]

It is important to note that diagnosing device infections can be challenging due to the lack of a universally accepted definition for what constitutes an infection and its severity, as well as the shortage of standardized diagnostic criteria. This often leads to an underestimate of the true number of these infections.^[2]

What Causes Device Infections?

Device related infections are most often caused by bacteria, though they can also result from viruses, fungi, or other microorganisms. Infections can develop through several pathways. The device may become contaminated during surgery or due to trauma. Bacteria can also reach the device by traveling through the bloodstream from another infection site in the body, or by spreading from an infection in nearby tissue.^[3]

When a medical device is implanted into the body, it unavoidably creates the potential for microbial colonization and infection. The implanted material provides a surface where microorganisms can attach and grow. Once microorganisms attach to the device, they are difficult to remove because they form protective communities called biofilms.^[1]

The onset of infection symptoms can occur early after implantation—suggesting contamination at the time of surgery—or can be delayed, sometimes appearing months or even years later.^[2]

Common Microorganisms

The types of microorganisms that cause device infections depend on which device is affected and when the infection develops. Gram-positive bacteria are the most common culprits across most device types.^[3]

For cardiac devices such as pacemakers and implantable defibrillators, the most common causes are bacteria from the Staphylococcus group, including Staphylococcus aureus and coagulase-negative staphylococci. Other bacteria that can cause cardiac device infections include Corynebacterium, Propionibacterium, Enterococcus, and Streptococcus species. Gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli, and Klebsiella species are less common. In rare cases, fungi like Candida species, nontuberculous mycobacteria, or Nocardia species can cause infection.^[3]

For orthopedic devices like joint replacements and fracture fixation devices, the timing of infection matters. Early infections occurring within four weeks after surgery are typically caused by S. aureus or coagulase-negative staphylococci. Chronic infections developing four weeks or more after surgery can involve S. aureus, coagulase-negative staphylococci like S. epidermidis, or anaerobic bacteria like Propionibacterium species. Infections that spread through the bloodstream to seed the device, usually two or more years after surgery, tend to involve Streptococcus species or gram-negative bacteria.^[3]

Urinary catheter biofilms may initially be composed of a single species, but longer exposure inevitably leads to biofilms containing multiple species.^[5]

The Role of Biofilms

A key feature of device related infections is the formation of biofilms. Biofilms develop when microorganisms irreversibly attach to the device surface and produce substances—primarily polysaccharides—that help them stick together and to the surface, creating a protective structural framework.^[5]

These polysaccharides can be seen under microscopes either as thin strands connecting cells to the surface and to each other, or as sheets of material covering the surface. Most of the biofilm volume is actually composed of this surrounding material rather than bacterial cells themselves.^[5]

The biofilm matrix can act as a filter, trapping minerals or components from the patient’s blood. Biofilms are both difficult to remove from surfaces and highly resistant to antimicrobial treatment. Research has shown that treatment with levels of antibiotics far exceeding what would normally kill bacteria can reduce biofilm cell counts by only a small amount, while the same dosage would almost completely eliminate freely floating bacteria of the same type.^[5]

This resistance to treatment means that bacteria living in biofilms behave very differently from individual bacteria floating freely. They grow at different rates and are much harder to eliminate with standard antibiotic treatments, which is why device infections pose such a significant public health challenge.^[5]

Who Is at Higher Risk?

Certain conditions and factors can increase a person’s likelihood of developing a device related infection. Understanding these risk factors is important because some can be addressed to reduce infection risk.^[2]

People with underlying medical conditions that weaken the immune system are more susceptible to infection. These conditions include diabetes, cancer, organ transplantation, kidney disease requiring dialysis, chronic obstructive pulmonary disease, and heart failure. Each of these can decrease the body’s ability to fight off infection.^[1][2][16]

People who take certain medications are also at increased risk. These include corticosteroids that suppress the immune system, medications to prevent blood clots, and certain cancer-fighting drugs. Antibiotics themselves can also affect risk by altering the body’s normal bacterial balance.^[2][3]

Procedures and treatments that provide additional ways for germs to enter the body increase susceptibility. This includes surgeries, urinary catheters, breathing tubes, and other invasive procedures. Conditions that require frequent injections, such as diabetes requiring insulin, also increase risk because each needle break in the skin creates a potential entry point for bacteria.^[16]

A history of previous device infection significantly increases the risk for future infections. Patients undergoing device revision or replacement procedures face higher infection rates than those receiving devices for the first time.^[3]

Patient demographics also play a role. In one large study, device infections occurred most frequently in white males over 65 years of age.^[1]

How Are Device Infections Diagnosed?

Diagnosing a device related infection can be challenging, particularly when there are no visible signs at the device site or when symptoms are subtle. Diagnosis generally relies on clinical evaluation supported by laboratory tests, imaging studies, and evidence found during surgery.^[2][3]

A specific definition of device infection might include the presence of clinical signs and symptoms of infection, evidence of infection found during surgery, and positive cultures showing bacterial growth from samples taken from the explanted device.^[2]

The clinical presentation can vary considerably depending on the type of device, which microorganism is causing the infection, and the patient’s immune status. Infections are most common in the first six months after a device is implanted, but they can occur at any time.^[3][19]

Local signs of infection at the device site may include pain, redness, swelling, warmth, drainage, ulceration (a break in the skin), or visible erosion of the device through the skin. Some patients may have no local symptoms at all.^[3][19]

Systemic symptoms suggesting the infection has spread throughout the body include fever, chills, and general illness. Deep-seated infections can cause inflammation of the heart lining and valves—a serious condition called endocarditis—or bone infections called osteomyelitis.^[3][19]

Diagnostic methods commonly include taking samples for microbiological testing to identify which organism is causing the infection. This involves culturing samples taken from or near the device. Imaging tests such as echocardiography may be performed, and in selected cases, specialized imaging like positron emission tomography combined with computed tomography scans can help identify infection.^[2][11]

Non-specific inflammatory markers in blood tests may be elevated but are not definitive for diagnosis.^[2] Diagnosis is ultimately confirmed by finding microorganism growth in cultures or by seeing evidence of infection in tissue samples examined under a microscope.^[3]

Studies have shown that the longer the delay in diagnosing and removing an infected device, the greater the risk of death. Therefore, patients who notice any signs or symptoms of infection should contact their doctor right away. It is important to inform healthcare providers about any implanted devices, as knowing this information can help them diagnose and treat conditions faster.^[19]

Preventing Device Infections

Prevention is critically important because device infections often require complete removal of the device, prolonged antibiotic treatment, and sometimes replacement surgery—all of which generate substantial healthcare costs and can negatively impact quality of life.^[4][12]

Several strategies have been developed to prevent device infections, and these work at different stages of the infection process. Understanding and adhering to published prevention guidelines is essential.^[12]

Antibiotic prophylaxis—giving antibiotics before device implantation—is a standard preventive measure. These antibiotics typically target staphylococcal bacteria, which are the most common cause of device infections. The antibiotics should be administered before the surgical procedure begins.^[7][11][12]

Proper surgical technique and maintaining a sterile environment during implantation are fundamental to preventing contamination of the device at the time of surgery. This includes careful preparation of the skin, proper hand hygiene by healthcare workers, and use of sterile equipment.^[12]

New preventive technologies are being developed and tested. One promising approach involves antibacterial sleeves or envelopes that can be placed around certain cardiac devices during implantation. These sleeves are designed to release antimicrobial substances that prevent bacterial attachment and biofilm formation.^[11][17]

Other preventive strategies under investigation include modifying device surfaces to make them resistant to bacterial attachment, developing coatings that release antibiotics or other antimicrobial substances, and creating materials that interfere with biofilm formation.^[1][8]

Addressing modifiable risk factors before device implantation can also reduce infection risk. This includes optimizing control of conditions like diabetes, addressing malnutrition, and reviewing medications that might increase infection risk.^[12]

For procedures involving device revision or replacement, extra precautions are warranted since infection rates are higher in these situations compared to first-time implants. Primary prevention of infection in the original device is therefore particularly important.^[12]

Treatment Approaches

When a device infection does occur, treatment typically requires a comprehensive, multidisciplinary approach involving surgical teams, infectious disease specialists, and other healthcare providers.^[3][4]

The cornerstone of treatment for most device infections is complete removal of the infected device and all its components. This is necessary because bacteria living within biofilms on the device are highly resistant to antibiotics alone. Studies show that attempting to treat the infection with antibiotics while leaving the device in place is rarely successful for long-term cure.^[7][19]

Antibiotic therapy is an essential part of treatment. This typically begins with antibiotics chosen to cover the most likely organisms—an approach called empirical therapy. For most device infections, this means using antibiotics effective against staphylococcal bacteria. Once culture results identify the specific organism causing the infection, treatment is adjusted to target that organism specifically—this is called targeted antibiotic therapy.^[2][11]

The duration of antibiotic treatment varies depending on the type of device infected, the specific organism involved, and whether the infection has spread beyond the device site. Treatment courses are often prolonged, sometimes lasting several weeks or longer.^[4]

Important questions remain about the best treatment strategies, including the optimal duration and timing of antibiotic therapy and the most effective techniques for device reimplantation when needed.^[11]

For patients who rely on their devices for survival or quality of life, such as those with pacemakers or joint replacements, planning for device replacement after infection clearance is an important part of care. The timing of reimplantation must balance the need for the device against the risk of reinfection.^[7][19]

Given the significant challenges in treating established device infections and the time required to develop and translate new preventive technologies, there is an urgent need for continued development of both preventive and treatment strategies.^[1][8]