Hepatitis B surface antigen in environmental samples from hemodialysis units

Area of Science:

• Hepatology
• Infectious Diseases
• Environmental Health

Background:

• Hepatitis B virus (HBV) poses a significant risk in healthcare settings, particularly hemodialysis units.
• Environmental contamination with hepatitis B surface antigen (HBS Ag) is a concern for disease transmission.

Purpose of the Study:

• To assess the extent and sources of environmental contamination with HBS Ag in hemodialysis units.
• To determine the relationship between the presence of blood and HBS Ag on surfaces.

Main Methods:

• Samples from surfaces, saliva, and rectal swabs were collected from two hemodialysis units.
• HBS Ag presence was quantified using radioimmunoassay.
• Samples were categorized based on epidemiological factors and presence of blood.

Main Results:

• HBS Ag was detected in 4.3% of all samples; 1.5% of blood-free samples and 18.5% of blood-contaminated samples were positive.
• Oral samples from HBS Ag-positive patients were consistently positive.
• Contamination was found on surfaces with and without direct patient contact, and not solely linked to visible blood.

Conclusions:

• Environmental contamination with HBS Ag in hemodialysis units extends beyond spilled blood and equipment.
• The presence of HBS Ag on surfaces suggests multiple transmission routes.
• Complete separation of HBS Ag-positive patients from HBS Ag-negative patients is crucial to prevent transmission.