Written by: Maya Galinsky
TSS may be a rare danger, but menstrual cups still require attention and awareness!
Menstrual cups have gained popularity in recent years as an eco-friendly and cost-effective alternative to traditional sanitary products. However, there have been concerns about the potential risk of developing toxic shock syndrome (TSS) associated with their use. TSS is a rare but serious illness caused by Staphylococcus aureus bacteria that can occur during menstruation. S. aureus produces a toxin, TSS toxin 1 (TSST-1), that is tightly regulated by several systems in the bacteria. Physical and chemical factors such as oxygen, carbon dioxide, and pH can affect the production of TSST-1. TSS is characterized by fever, hypotension, rash, and multiorgan failure with at least 3 organs being involved.
A study by Liao et al. (2019) investigated the impact of currently marketed tampons and menstrual cups on S. aureus growth and TSST-1 production in vitro. In vitro is a medical study or experiment done in a laboratory within the confines of a test tube or laboratory dish. The study found that higher levels of S. aureus growth and toxin production occurred in menstrual cups than in tampons. The difference may be due to the additional air introduced into the bag by cups, with differences based on cup composition and size. Results suggest that aeration, more than the composition of the cup, influences toxin production. The use of a small menstrual cup is recommended as air inserted into the vagina along with the cup may favor S. aureus growth and TSST-1 production in the catamenial products collected in the cup.
Moreover, an additional risk of using menstrual cups can occur when the volume of menstrual fluid overflows in the vaginal canal, reaching contact with the vaginal mucosa, allowing toxins to transport into the blood and the development of menstrual TSS.
In addition to the study by Liao et al. (2019), there have been confirmed cases of menstrual TSS associated with the use of menstrual cups. In a study by Mitchell et al. (2015), a confirmed case of TSS was reported in a woman who used a menstrual cup. Menstruators should be aware of the potential risks associated with menstrual cups and carefully follow instructions for use and cleaning.
It is important to note that significant amounts of biofilm of S. aureus remained after 8 hours and 3 washes with water, regardless of the cup model or composition. Results suggest that menstruators may reinsert a contaminated cup when following the advice of manual instructions for menstrual cups (to remove, empty, and rinse with tap water before reinserting). A protocol including a second cup that allows for cup sterilization by boiling between uses should be recommended.
Carbon dioxide and oxygen concentrations can affect the virulence of pathogenic bacteria such as S. aureus. TSS toxin production has been reported to be higher during menses, possibly due to the altered levels of iron, oxygen, carbon dioxide, pH, hormones, and osmolarity, which could affect the total number of bacteria present, the number of colonizing species and/or gene expression. Findings suggest that menses can provide a source of oxygen to the vaginal environment. These findings may be important for genital diseases that affect women more frequently during menses, such as pelvic inflammatory disease, cervical Chlamydia trachomatis, human immunodeficiency virus, and bacterial vaginosis, as well as menstrual vaginal TSS.
In conclusion, menstrual cups are a viable and environmentally friendly alternative to traditional sanitary products. However, the risk of menstrual TSS should not be overlooked. Menstruators should be aware of the potential risks associated with menstrual cups and carefully follow instructions for use and cleaning. The use of a small menstrual cup and a protocol that allows for cup sterilization by boiling between uses should be recommended to reduce the risk of TSS. Further research is needed to understand the link between menstrual cups and menstrual TSS fully.
El Soufi, H., El Soufi, Y., Al-Nuaimi, S., & Bagheri, F. (2021). Toxic shock syndrome associated with menstrual cup use. IDCases, 25, e01171.
Hill, D. R., Brunner, M. E., Schmitz, D. C., Davis, C. C., Flood, J. A., Schlievert, P. M., … & Osborn, T. W. (2005). In vivo assessment of human vaginal oxygen and carbon dioxide levels during and post menses. Journal of Applied Physiology, 99(4), 1582-1591.
Liao QP, Huang Y, Zhou Y, Chen Y, Zou Y, Liu F, et al. (2019). Impact of currently marketed tampons and menstrual cups on Staphylococcus aureus growth and toxic shock syndrome toxin 1 production in vitro. BMC Microbiology, 19, 1-10.
Mitchell M, Bisch S, Arntfield S, Hosseini-Moghaddam S. (2015). A confirmed case of toxic shock syndrome associated with the use of a menstrual cup. Can J Infect Dis Med Microbiol, 26, 218-220.
Schlievert PM. Role of superantigens in human disease. J Infect Dis 1993;167
(May 1 (5)):997–1002