For thousands of years, man has been mystified by fireflies—about 1,900 species of nocturnal, glow-in-the-dark beetles. In fact, these bioluminescent insects have inspired poets and delighted children for centuries. It was theorized that their blinking light was used to attract mates and possibly fend off predators. However, how they managed to produce the light in their abdomen and blink it so precisely was a mystery.
Finally, the secret was revealed. In the late 1940s scientists discovered that a dissolved gas lets the firefly’s nervous system switch on its flash of light. In a complex arrangement among nerve cells, light-producing cells, and an enzyme-assisted reaction, the firefly’s lantern emits that greenish glow that is so common in the early summer twilight in many parts of the world.
Interestingly, a similar technology is now being used in medical centers and other types of facilities worldwide to help detect the presence of bacteria, and other potentially dangerous microorganisms on a variety of surfaces and objects by the way these microorganisms “glow” when tested. With this knowledge in hand, these facilities are better able to protect the health of patients and staff alike.
Detecting Adenosine Triphosphate
“All living things have a universal source of energy used to power their cells known as adenosine triphosphate, or ATP,” says Martin Easter, General Manager of Hygiena International Worldwide, which manufactures rapid hygiene-monitoring systems, environmental collection systems, and other devices used to determine the presence of microorganisms on surfaces and instruments. “The ATP molecule is enormously intricate, and we are just now beginning to understand how it works. However, we know that it is present in all living organisms and biological residues.”
According to Easter, if ATP is detected on a surface or instrument, it means that microorganisms and life-supporting residue for these germs is present, which can be potentially harmful to human health. “And since samples are generally taken after cleaning, testing for ATP will provide important feedback on the effectiveness of the cleaning processes and systems used in a medical facility,” he says. “Hospital and facility administrators can then use this information to help improve the hygiene of their facilities where necessary.”
Measuring for ATP
The first ATP machines for industrial applications were introduced in the late 1970s, according to Easter. Before this, the only reliable method to measure the hygienic status of many surfaces was conventional cultures based on agar plate counts. These systems provided information about the number of microbes present; however, they revealed little about the residue left on a surface that can support and promote the survival and growth of microbes.
Over the years, ATP instrumentation has gotten much smaller, less expensive, more exact, and easier to use, which has allowed it to be used in more locations and types of facilities. Although the actual testing procedure may vary depending on the type of ATP machinery used, Easter indicates the following are the key steps in the typical investigation process:
• Samples should preferably be taken from the same location every time for accurate results and testing comparisons.
• A swab, pre-wetted with an enzyme extractant to take ATP from cellular material, is applied to the test area; care must be taken not to touch the swab to any areas other than the area of interest.
• The swab is returned to a shaft housing where it may be stored for up to four hours.
• After proper equipment warm-up, the swab is then inserted into the testing equipment.
• Test results should be available in approximately 15 seconds, which is why these systems are referred to as “rapid” monitoring.
“If ATP is present, it will glow, just like the abdomen of a firefly glows,” says Easter. “The glow from the ATP is analyzed by the monitoring equipment and given in relative light units (RLU). The higher the RLU, the more ATP—and the greater the need for more thorough and effective cleaning of the surface area tested.”
Improving Cleaning with ATP and Other Science
In the United States, it has been estimated that 10 percent of all hospital patients acquire a nosocomial—hospital-acquired—infection as a result of treatment in a medical facility. This is a huge number, amounting to approximately 2 million patients a year, 166,667 per month, 38,461 per week, 5,479 per day, 228 per hour, or 3 per minute. More than 80,000 people die every year because of a hospital-acquired infection, and estimates as to the financial costs of these infections range from $5 billion to more than $11 billion annually. However, what is most striking is that it is believed that at least one-third of nosocomial infections are preventable.
“Using testing equipment to help detect the presence of microorganisms on surfaces that can cause nosocomial infections is the first step in finding where a problem area exists,” says John Richter, the technical director of a leading cleaning equipment maker. “Once discovered, implementing cleaning systems and processes to eradicate the problem not only helps protect patient health but brings more science into cleaning.”
Richter was one of the presenters at the recent Cleaning Industry Research Institute (CIRI) symposium in Las Vegas.
This organization is seeking to help identify, assemble, and establish science-based issues important to the professional cleaning industry. According to Richter, the jansan industry is moving rapidly toward more high-performance, science-based cleaning technologies.
A Systematic Approach
Both Easter and Richter believe that medical facilities must adopt some type of systematic approach to test for cleaning effectiveness. “A list of control points [testing areas] needs to be determined, and a pass/fail system must be established,” says Easter. “Using this approach, contaminated surfaces can be detected before they have a chance to become a health hazard, and a passing retest indicates that the area has been cleaned efficiently to protect building occupant health.”