Related Experiment Video
Updated: Aug 10, 2026

A Protocol to Set Up Needle-Free Connector with Positive Displacement on Central Venous Catheter in Intensive Care Unit
Published on: July 13, 2019
Infection risks from electrically operated breast pumps
1Department of Bacteriology, Royal Postgraduate Medical School, Hammersmith Hospital, London.
Abstract:
Using formula milk seeded with Staphylococcus epidermidis as indicator, bacteria were observed to pass beyond the collecting bottles of three electrically operated breast pumps. Bacteria were recovered from sites distal to the level of visible contamination, the incidence increasing with repeated use of the apparatus. Despite use of a sterile collecting bottle, retrograde contamination of freshly collected milk may occur from previously contaminated components of the pumps. The results suggest that a terminal in-line air filter is essential to ensure aerosols containing potentially pathogenic bacteria do not contaminate the suction source or be emitted to the environment with the exhaust air. Where a single pump is used by more than one person adequate sterilization of all removable components is essential.
Insights
Bacteria can contaminate breast milk and the environment through electric breast pumps. Regular sterilization and in-line air filters are crucial for preventing contamination and ensuring infant safety.
Area of Science:
- Microbiology
- Biomedical Engineering
- Public Health
Background:
- Electric breast pumps are widely used for infant feeding.
- Concerns exist regarding the potential for bacterial contamination during milk expression.
- Staphylococcus epidermidis is a common bacterium that can cause opportunistic infections.
Purpose of the Study:
- To investigate the potential for bacterial contamination and aerosolization using electric breast pumps.
- To identify the routes of contamination within the breast pump apparatus.
- To assess the effectiveness of standard cleaning procedures in preventing contamination.
Main Methods:
- Formula milk was seeded with Staphylococcus epidermidis as an indicator organism.
- Three electrically operated breast pumps were used in repeated trials.
- Bacterial presence was assessed at various sites within and beyond the pump apparatus, including collected milk and exhaust air.
Main Results:
- Bacteria were detected beyond the collecting bottles, indicating passage through the pump system.
- Contamination levels increased with repeated use of the breast pump.
- Retrograde contamination of freshly collected milk was observed even with sterile collection bottles.
- Bacteria were recovered from sites distal to visible contamination.
Conclusions:
- Electric breast pumps can aerosolize and disseminate bacteria, posing a risk of contamination.
- Standard sterilization protocols may be insufficient to prevent contamination with repeated use.
- Terminal in-line air filters are essential to prevent contamination of the suction source and environmental emission of bacteria.
- Adequate sterilization of all removable components is critical when a single pump is shared.
More Related Videos
Related Concept Videos
Healthcare Associated Infections II: Preventive Measures
The best practices for preventing healthcare-associated infections include hand hygiene, patient risk...
Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
Standard Precaution
Hand hygiene is the most crucial means to prevent the transmission of disease. Employers are legally required to provide their workers with personal protective equipment (PPE) to minimize exposure or contact with...
Transmission-based Precautions I: Contact, Enteric, and Droplets
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumonia I: Introduction

