Cross-Contamination in Labs: Causes & Avoidance

Cross-contamination is routinely spoken about across labs and can be a massive headache waiting to happen.  To start off, it’s important to define it.  Simply put, cross-contamination is defined as an unintentional transfer of an unwanted impurity from one sample to another.  

Outcomes of Cross-Contamination

Whether it be unintentional or not, cross-contamination can result in a number of adverse outcomes including but not limited to:

• Time being lost
• Exposing staff members to safety hazards
• Invalid results
• Labs actually having to shut down
• Credibility and reputational damage
• Increase in costs 

None of these outcomes are desirable and especially so in light of the fact that clinical labs are responsible for 13 billion tests conducted on an annual basis and support ⅔ of all medical decisions.  Accuracy, precision and non-contaminated outcomes are required.  

Causes of Lab Contamination

There are multiple causes of lab contamination and perhaps too many to even capture here but below are a summary of the main causes:

• Human Error

It’s not that complicated.  “I’m only human” is typically stated when mistakes happen.  To an extent, it is true.  We get tired.  We get frustrated.  We look for short-cuts.  We are pressed for speed.  We make errors subsequently…except that the outcome of these errors can be quite serious as noted. 

• Poor environmental conditions

We all can relate to how environmental changes can impact us personally but too often we are guilty of not thinking about how it can affect our samples.  Air-borne contaminants and changes in temperature, humidity, and even the degree of light can all lead to contamination issues.   

• A non-existent or poor culture of safety in the lab

Many labs will have safety protocols documented and will put their staff through an annual safety training.  That’s great but it doesn’t exactly build a culture of safety where there is complete buy-in right across the board.  When you don’t speak about cross-contamination often enough or when you don’t make it a big enough deal, then the steps outlined to eliminate or mitigate risks start to be sidelined.   

•   Poor hygiene levels

This covers both personal hygiene and unclean tools & equipment.  Let’s start with the former.  Do you wear the appropriate PPE at all times?  Do you change your disposable gloves between samples?  Do you find yourself reusing disposable gloves?  Do you wear closed shoes?  The list can go on and these are fairly obvious questions with common sense answers.  Unfortunately, common sense is not commonly used!  With poor personal hygiene, comes the inevitable issues with the standard of cleanliness of equipment and tools with no lack of scheduled cleaning, no sterilization steps taken or indeed any account of any sorts in regards to a cleaning/sterilization document.  

How to Avoid Cross-Contamination in the Lab

Cross-contamination is not necessarily inevitable in the lab.  There are multiple steps that you can take to significantly mitigate the risk of cross-contamination or eliminate it.

• Automation

One of the main drivers of cross-contamination is simply human-error and that in turn is driven by a number of factors such as tiredness, frustration and cutting corners.  Automation eliminates those factors.  Lab automation also allows for faster processing without the inevitable errors.  Importantly, it also reduces the number of touches by a lab technician.  The less the touches, the lower the risk of cross-contamination.

• Be organized

Know what’s what and know where everything goes.  Think about your workflow and literally how one step moves to the next.  This will eliminate the need to keep moving things around (less touches, lower cross-contamination risks).  It will also allow you to properly document each step and train your staff on what they need to do each and every time.  Organization also covers cleaning & sterilization of equipment.  Staff have to know how to do so, what to use and when to do it.  Moreover, make sure you have the right PPE for your staff and in sufficient quantities.   

• Communication & Training

Communication is key.  If you don’t talk to your staff about this topic, if you don’t talk about the risks or get their input, then how do you expect to get their buy-in?  You can take all the necessary steps but the culture has to be supportive of those steps and it has to be ingrained in your team for it to work.  This also includes supporting your staff with the necessary training to highlight required behaviors and following up accordingly.

The mitigation/elimination steps are not ridiculously out of reach.  As noted, much of the causes of cross-contamination stem from human error.  Behaviors can be changed with consistent communication and training.  Automation is key too.  For more information on how automation can help your lab, contact us today!