Bloodstream infection

Bloodstream Infection

A bloodstream infection (BSI) occurs when a pathogenic microorganism enters the blood and causes a systemic inflammatory response. Bloodstream infections can result from bacteria, viruses, fungi, or parasites entering the bloodstream, leading to potentially life-threatening conditions such as sepsis and septic shock. These infections are a major concern in healthcare settings due to their association with high morbidity and mortality rates.

Causes and Risk Factors

Bloodstream infections can be primary, with no apparent source, or secondary, resulting from an infection in another part of the body. Common causes include:

• Bacterial infections, with organisms such as Staphylococcus aureus, Escherichia coli, and various species of Streptococcus and Enterococcus.
• Viral infections, including HIV and Hepatitis C.
• Fungal infections, notably by Candida species.
• Parasitic infections, though less common, can also lead to BSIs.

Risk factors for developing a bloodstream infection include:

• Hospitalization, especially in intensive care units (ICU) where central venous catheters are used.
• Immunosuppression, due to conditions like cancer, diabetes, or treatments such as chemotherapy.
• Recent surgery or invasive medical procedures.
• Age, with very young and elderly individuals being at higher risk.

Symptoms

Symptoms of a bloodstream infection can vary but often include:

• Fever and chills
• Rapid breathing and heart rate
• Low blood pressure
• Confusion or altered mental status
• Fatigue and weakness

Diagnosis

Diagnosis of a bloodstream infection involves:

• Blood cultures to identify the causative organism.
• Complete blood count (CBC) and other blood tests to assess the body's response to infection.
• Imaging studies, such as X-rays or CT scans, to locate the source of infection if it is secondary.

Treatment

Treatment of bloodstream infections typically involves:

• Antibiotics, Antivirals, Antifungals, or antiparasitic medications, depending on the type of organism causing the infection.
• Removal or replacement of any infected intravenous lines or medical devices.
• Supportive care, including fluids and medications to maintain blood pressure and organ function.

Prevention

Preventive measures against bloodstream infections include:

• Strict adherence to hand hygiene and aseptic techniques by healthcare providers.
• Careful management and timely removal of intravenous lines and catheters.
• Surveillance and infection control programs in healthcare facilities.

Complications

Complications of bloodstream infections can be severe and include:

• Sepsis and septic shock, leading to multiple organ failure.
• Localized infections, such as endocarditis or osteomyelitis, resulting from the spread of infection.
• Long-term health issues or disability resulting from severe sepsis.

See Also

• Infectious Disease
• Critical Care Medicine
• Microbiology