A Thread tied into a tampon or pad can detect it Candida albicans Overgrowth – also known as yeast infection – within 10 minutes, scientists reported in ACS Omega in May. If the product turns out to work at home, the authors say, it could enable women around the world to self-diagnose yeast infections quickly and cheaply, improving care – especially in environments with limited resources.
Currently, to confirm a diagnosis of yeast infection, a woman must see her doctor, have her vagina swabbed, and then wait 24–72 hours for the results of a PCR test. This is inconvenient for most women and a major challenge for those with limited access to health care.
A diagnosis is not required for women to buy over-the-counter antifungal medicines. So if they experience itching or other symptoms, they can assume they have a yeast infection and are using treatment without a diagnosis. But the symptoms of a yeast infection – itching, burning sensation, and changes in discharge – can be caused by a number of problems, from bacterial infections to allergies.
“Many women with these symptoms do not have yeast infections and unnecessarily use over-the-counter yeast infection medication. This diagnosis could potentially reduce the unnecessary use of yeast drugs in the absence of yeast infections, ”says Christine Metz, who studies molecular medicine at the Feinstein Institutes for Medical Research in New York and was not involved in the study. Improper use of these antifungal drugs can delay proper care, waste time and money, and contribute to antifungal resistance.
The idea for the diagnostic tampon came up a few years ago, says Naresh Kumar Mani, biotechnologist at the Manipal Institute of Technology in India and lead author of the study. “I spoke to my colleague – she is an obstetrician – and also to another colleague, a medical mycologist. Not much emphasis is placed on it Candida albicans, although it is a disaster for the immunocompromised [people], Newborns and women. ”While the most common symptoms aren’t life-threatening, says Mani, if the fungus spreads throughout the body, it can be devastating. “Among the intensive care patients candidate is the leading fungal pathogen that causes severe sepsis or septic shock. . . . It is therefore important to detect it at an early stage. ”The researchers wanted to develop a quick and inexpensive test to self-diagnose the infection.
First, they looked for an assay that showed overgrowth from C. albicans for vaginal discharge. They landed on L-proline-β-naphthylamide (PRO), a substrate that reacts to L-proline aminopeptidase, an enzyme produced by C. albicans and other organisms. PRO is used in laboratory tests and has been around for 30 years, according to Mani, but has rarely been used clinically. It is a known carcinogen.
“These substrates are hydrolyzed the moment they come into contact with the enzyme, resulting in a simple change in color,” explains Mani.
Then the researchers needed a way to make a matrix of thread that could be embedded in a tampon or sanitary napkin and that would support the substrate. The researchers chose tampons and sanitary towels because they wanted to incorporate their threads into products already on the market that could absorb enough of the L-proline aminopeptidase to detect them. Like most threads, the threads the team bought from a local craft store were treated with wax and hydrophobic binders to keep them from absorbing liquids. So they washed the strings three times in a heptane solution to remove their coatings, treated them with the substrate and threaded them into tampons and sanitary towels.
because C. albicans usually lives in small amounts in the vaginal microbiome, says Mani, the team identified the threshold at which infection occurs and designed the assay to only change color when there is a high enough concentration of the enzyme. They exposed the treated products to simulated vaginal discharge, which with C. albicans. If there was enough fungus to indicate a yeast infection, the threads turned pink. The more mushrooms there were, the darker the shade of pink.
The approach needs to be updated before it can be used. For one, the fact that the threads turn deep pink can be an obstacle when diagnosing an infection during menstruation as the indicator color could be obscured by blood. Metz also points out that other pathogens, such as bacteria Clostridium difficile, can produce the enzyme L-proline aminopeptidase.
Mani says the team is also looking for analogues to the current substrate, as PRO is a known carcinogen. Another limitation is that the product has so far only been tested with simulated samples, neither on the actual vaginal discharge nor in a real environment.
Despite these caveats, Metz says the “inexpensive, easy, and quick way to detect vaginal yeast infections at home is an advancement in improving women’s health.” Mani is currently working with staff in the US and UK to find PRO analogs and secure funding to bring the product to market.
“Self-diagnostic tools are important to improve access [to healthcare]”Says Erica Cahill, a gynecologist at Stanford University, in an email to The scientist. “The most important question is what will people do with tools like this? Will they be less likely to take medication if it is negative (or will they use it anyway because of their symptoms)? Will it be more likely that you will be treated with a positive test? “