Published: 18 Jun 2025

ICD9: 790.7      ICD10: R78.81      ICD11: MA15.0

Bacteremia is the presence of bacteria in the bloodstream.
It's not a disease in itself, but rather a condition that can lead to serious infections. Think of it like this: the bloodstream should ideally be sterile, so bacteria being present is an abnormal situation.

Here's a more detailed breakdown:

Definition: Bacteremia refers to the presence of viable (living) bacteria in the bloodstream.

Causes: Bacteria can enter the bloodstream through various routes, including:
Infections: Existing infections in other parts of the body (e.g., pneumonia, urinary tract infections, skin infections, abscesses) can spread to the bloodstream.
Medical Procedures: Invasive procedures like surgery, catheter insertion (especially central lines), dental work, endoscopy, and even routine procedures like IV insertion can introduce bacteria.
Compromised Barriers: Breaks in the skin (wounds, cuts, burns) or lining of the gut (e.g., due to inflammatory bowel disease) can allow bacteria to enter the bloodstream.
Intravenous Drug Use: Sharing needles can directly inject bacteria into the bloodstream.
Normal Flora: In some cases, bacteria that normally reside on the skin or in the gut can enter the bloodstream, especially in people with weakened immune systems.

Types: Bacteremia can be categorized in different ways:

Transient Bacteremia: A brief, temporary presence of bacteria in the blood, often cleared by the immune system without causing harm. This can happen after minor procedures like brushing your teeth.
Intermittent Bacteremia: Bacteria enter the bloodstream periodically, often associated with an infection in a confined area (e.g., an abscess) that releases bacteria intermittently.
Continuous Bacteremia: Bacteria are constantly present in the bloodstream, often due to an infected intravenous catheter or endocarditis (infection of the heart valves).
Asymptomatic Bacteremia: Bacteria are present in the blood, but the person experiences no symptoms.
Symptomatic Bacteremia: Bacteria are present in the blood, and the person experiences symptoms.

Symptoms: Symptoms of bacteremia can vary widely depending on the severity of the infection and the person's overall health. They may include:

Fever (often high)
Chills
Rapid heart rate
Rapid breathing
Confusion or altered mental status
Low blood pressure (hypotension)
Weakness or fatigue
Nausea and vomiting

Complications: If left untreated, bacteremia can lead to serious complications, including:

Sepsis: A life-threatening condition caused by the body's overwhelming response to an infection. It can lead to organ damage, shock, and death.
Septic Shock: A severe form of sepsis characterized by dangerously low blood pressure and organ failure.
Endocarditis: Infection of the inner lining of the heart and heart valves.
Osteomyelitis: Infection of the bone.
Meningitis: Infection of the membranes surrounding the brain and spinal cord.
Abscesses: Collections of pus in various parts of the body.

Diagnosis: Bacteremia is diagnosed by a blood culture, which involves taking a blood sample and testing it for the presence of bacteria. Multiple blood cultures may be needed to confirm the diagnosis.

Treatment: The treatment for bacteremia typically involves:

Antibiotics: Antibiotics are the mainstay of treatment to kill the bacteria in the bloodstream. The specific antibiotic used will depend on the type of bacteria identified in the blood culture and the person's overall health.
Source Control: Identifying and treating the source of the infection is crucial. This may involve draining an abscess, removing an infected catheter, or treating an underlying infection.
Supportive Care: Supportive care, such as intravenous fluids, oxygen, and medications to support blood pressure, may be needed to manage complications.

Risk Factors: Certain factors can increase the risk of developing bacteremia, including:

Weakened immune system (e.g., due to HIV/AIDS, cancer, chemotherapy, organ transplant)
Chronic illnesses (e.g., diabetes, kidney disease, liver disease)
Recent surgery or invasive procedures
Indwelling medical devices (e.g., catheters, prosthetic joints)
Intravenous drug use
Very young or very old age

In summary, bacteremia is the presence of bacteria in the bloodstream, which can be a serious condition that requires prompt diagnosis and treatment to prevent life-threatening complications. It's crucial to seek medical attention if you suspect you may have bacteremia.