A new toxic shock syndrome (TSS) study contains not only new data but some recycled misinformation on tampon use, according to a leading US expert who says the incidence of the rare syndrome may be rising in some regions.
In the discussion section of the study, which tracks the role of tampons and menstrual cups in the development of menstrual TSS, a sometimes fatal infection linked to tampon use, the authors recommend, "Long tampon carriage may also alter the structure [of the tampon] in a manner favoring S. aureus growth and TSST-1 production, advocating for short use time and frequent changing."
When Patrick Schlievert, PhD, chair of the Department of Microbiology and Immunology at the University of Iowa, read that line, he called the editor of Applied and Environmental Microbiology and asked that the study be changed immediately (his request was denied).
"The statement is absolutely false," Schlievert told CIDRAP News. "The study was fine except that one sentence, but we've known since the early 1980s that frequent changing of tampons increases, not decreases, the risk of TSS by introducing more oxygen into the vagina."
Revisiting the 1970s outbreak
Schlievert was one of the leading researchers who worked on the Tri-State Study, the most comprehensive look at menstrual TSS in the United States. At the height of TSS epidemic in the 1970s, 10 out of every 100,000 women were infected, some losing fertility or their lives to the bacterial infections cause by Staphylococcus aureus producing toxic shock syndrome toxin 1 (TSST-1).
Schlievert helped identify the key players of TSS.
"For TSS you need a neutral pH, protein, a temperature of 37° Celsius, and oxygen," said Schlievert. "That oxygen comes from the insertion of tampons, because the vagina is an aerobic environment."
In 1983, Schlievert and colleagues successfully convinced the Centers of Disease Control (now known as the Centers for Disease Control and Prevention) to alter its recommendation to change tampons from every 2 hours (its previous advice) to every 4 to 8 hours, and to use the lowest effective absorbency.
"This advice does not eliminate risk, but if women choose to use tampons, which most US women do, then that later advice reduces the risk as low as possible," Schlievert said.
Tampons and menstrual cups
The new study's aim was to reexamine S aureus growth with use of modern tampon and menstrual cups. Lead author Gerard Lina, MD, PhD, a professor of microbiology at the University Claude Bernard in Lyon, France, and his colleagues note in the study that removal of a tampon removes the oxygen required for production of the TSS toxin.
"In our experience, menstrual TSS occurred with extend[ed] use of tampon and cup, not short one especially because S. aureus has not enough time to growth and produce TSST-1," Lina said in an email to CIDRAP News. "For menstrual toxic shock syndrome [there] are arguments that extended carriage of tampon and cup increases the risk of the disease, not for frequent changing."
Schlievert said that this understanding of the TSS toxin only partially explains bacterial growth and doesn't account for the oxygen added when tampons are inserted. The study used a lab setup designed to reproduce conditions inside the vagina and did not involve actual women.
"It is absolutely clear that TSS is associated with oxygen introduction through introduction of air, oxygen is required for TSS toxin production, and too-frequent changing of tampons leads to greater overall oxygen levels vaginally," he said.
Diagnosing the 'mystery illness' again
Schlievert said Lina's study, and the recommendation to frequently change tampons, is dangerous. Though TSS is a rare disease, it's on the rise in some communities, and young clinicians who have never had to diagnose the disease before are failing to spot it.
"Eighty percent of the population has the antibody to TSS, so the maximum incidence we've seen was during the height of the epidemic, at 10 out of 100,000," Schlievert said. "We had that incidence down to 1, but now we see it back up to 3 or 4 per 100,000."
Schlievert said the use of high-absorbency tampons, especially by young teenage athletes, is contributing to TSS incidence, as is the practice of using more than one tampon at a time to reduce leaking.
"Now we have clinicians calling TSS a 'mystery illness' when they see it in young teens," Schlievert said. He has identified thousands of cases of TSS, and is still called to help diagnose cases.
Patients must be followed up diligently, he says, as recurrence can be as high as 60% in tampon users who've had one episode of TSS.
Apr 20 Appl Environ Microbiol study