ENDOMETRIOSIS CAN INCREASE SUSCEPTIBILITY TO INFECTIONS

Rosati M, Conti F, Di Michele S, Bramante S. Endometriosis can increase susceptibility to infections. International Journal of Infection. 2026;10(1):23-26.

M. Rosati^1*, F. Conti¹, S. Di Michele² and S. Bramante¹

¹ Department of Obstetrics and Gynecology, Santo Spirito Hospital, Pescara, Italy;
² Division of Gynecology and Obstetrics, Department of Surgical Sciences, University of Cagliari, Cagliari, Italy.

*Correspondence to:
Maurizio Rosati, MD,
Department of Obstetrics and Gynecology,
Santo Spirito Hospital,
65129 Pescara, Italy.
e-mail: Maurizio.rosati18@outlook.com

Received: 02 February, 2026 Accepted: 31 March, 2026

ISSN 3103-6678 [online] Copyright 2026 © by Biolife-publisher This publication and/or article is for individual use only and may not be further reproduced without written permission from the copyright holder. Unauthorized reproduction may result in financial and other penalties. Disclosure: all authors report no conflicts of interest relevant to this article.

ABSTRACT

Endometriosis occurs when the lining of the uterus grows outside the uterus, causing pain, inflammation, and sometimes infertility. Endometriosis can sometimes be confused with infections due to overlapping symptoms such as infertility, pelvic pain, immune dysfunction, and inflammation. The chronic inflammation that occurs in endometriosis can weaken the immune system and increase susceptibility to infections. Immune dysregulation can cause high levels of pro-inflammatory cytokines which contribute to chronic inflammation and reduce the immune response. Pro-inflammatory cytokines are produced primarily by macrophages activated by microorganisms. Neutrophils are also activated by microbial infections and produce reactive oxygen species (ROS), which decrease the immune response, damage DNA, and mediate inflammation.

KEYWORDS: Endometriosis, gynecology, immunity, infection, disease, inflammation

INTRODUCTION

Endometriosis occurs when the endometrium, the lining of the uterus, grows outside the uterus, causing pain, inflammation, and possible infertility. It is a difficult disease to diagnose, yet its incidence is estimated at approximately 5-7% in women of reproductive age (approximately 14 million affected women) in Europe, and the incidence is 4.2–35 / 10,000 women/year in the USA (1). Endometriosis itself is not an infection, but it can sometimes be associated with or confused with some gynecological infections because of overlapping symptoms such as infertility, pelvic pain and inflammation (2). The causes of endometriosis are completely unknown, but there is no shortage of hypotheses. Some studies suggest that endometriosis is associated with an alteration of the vaginal microbiota, which may increase susceptibility to infections (3).

Endometriosis is a chronic gynecological disease associated with inflammation, immune dysfunction, and potential susceptibility to infections (4). The female reproductive organs are often susceptible to infections, such as human papillomavirus (HPV), chlamydia, gonorrhea, coronavirus disease of 2019 (COVID-19), that cause pain, fever, and vaginal discharge (5). Chronic inflammation weakens the immune system and increases susceptibility to infections. Immune dysregulation in endometriosis is associated with a cytokine imbalance with high levels of IL-1β, IL-6, and TNF, that contributes to chronic inflammation, potentially affecting the immune response to infections (6) (Fig.1).

Fig. 1. In endometriosis, viral infection increases reactive oxygen species (ROS) that causes oxidative stress, leading to an ineffective immune response that facilitates bacterial infection, which can result in chronic infection.

ENDOMETRIOSIS

Immune dysregulation can cause inflammation and cytokine imbalance. High levels of pro-inflammatory cytokines such as IL-1β, IL-6, and TNF contribute to chronic inflammation, reducing the immune response. Additionally, estrogen promotes the growth of endometriotic lesions and suppresses immune responses, making the tissue more susceptible to infections, and altered progesterone signalling in endometriotic tissue leads to dysfunctional immune surveillance (7).

In endometriosis, activated peritoneal macrophages exhibit increased inflammatory activity and a reduced ability to eliminate pathogens (8). Infections are closely linked to oxidative stress, and these two conditions influence each other. During a microbial infection, the immune system activates neutrophils and macrophages, which produce reactive oxygen species (ROS) to destroy pathogens. Excessive production of ROS can damage healthy tissues, creating oxidative stress, and when there is oxidative stress, ROS and decreased antioxidant defenses promote chronic inflammation and DNA damage (9,10). Oxidative stress promotes infections by weakening the immune system and altering the cell membranes that protect cells from pathogens (11). For example, viral infections can significantly increase oxidative stress, while chronic bacterial infections can maintain a continuous inflammatory state (12). Vaginal flora imbalance with vaginosis is often painless, like endometriosis, and can coexist with it. It is likely that the microbiome, bacteria in the reproductive tract, may be different in those with endometriosis, potentially causing a greater vulnerability to infections such as bacterial vaginosis or urinary tract infections (UTIs) (13).

Women with endometriosis may have a higher incidence of recurrent UTIs due to inflammation and chronic inflammation and hormonal imbalances in endometriosis may contribute to recurrent yeast infections (14). Infectious complications after surgery are often related to pelvic inflammatory disease (PID) and can also develop in the presence of endometriosis, resulting in fever and general malaise. Postoperative infections after endometriosis may be associated with a higher risk of infection (15). Following surgery, there is a small risk of infections at the incision site or inside the pelvic cavity (16).

The symptoms of endometriosis, such as chronic pelvic pain, painful periods, and pain during sex, can mimic those of PID. PID is a serious bacterial infection often caused by sexually transmitted diseases such as chlamydia or gonorrhea. Bacterial imbalances in the uterus and fallopian tubes may contribute to the development or worsening of endometriosis (17). Women with endometriosis and inflammatory vaginal diseases may be more susceptible to infections such as Chlamydia trachomatis and Neisseria gonorrhoeae due to a dysregulated immune environment (18).  Moreover, bacterial infections such as Mycoplasma and Ureaplasma have been linked to the progression of endometriosis. Mycoplasma genitalium and other mycoplasmas are bacteria that lack a cell wall, making them difficult to eliminate (19).  Chronic mycoplasma infections can cause inflammation (often not severe) and can alter the vaginal immune response.

In endometriosis, the immune system fails to properly eliminate endometrial cells, creating an environment rich in inflammatory cytokines that promotes immune dysfunction (20). There are strong hypotheses that microbial infections activate innate immune cells, promoting an inflammatory environment that can aggravate endometriosis (20). In endometriotic lesions, bacterial endotoxins, such as lipopolysaccharide (LPS) from Gram-negative bacteria, can fuel the inflammatory process by stimulating Toll-like receptor 4 (TLR4) (21).

In endometriosis, susceptibility to infections can be reduced with anti-inflammatory and immunomodulatory treatments, therapies that reduce oxidative stress, reduce inflammation by lowering cytokine levels, and regulate estrogen activity. The pain and symptoms of endometriosis can be relieved with the use of non-steroidal anti-inflammatory drugs (NSAIDs), hormone therapy, or surgical options.  Antibiotic therapy may be beneficial for patients with endometriosis for bacterial infections with an imbalanced vaginal microbiome (22). The use of probiotics may help maintain a healthy vaginal and gut microbiome and reduce the risk of infection (23).

CONCLUSIONS

In conclusion, endometriosis is not an infection because it is not caused by bacteria, viruses, or other microorganisms, but it can indirectly increase the risk of infection. Endometriosis can alter the immune environment, which can negatively affect the immune system and promote inflammation caused by pathogens.

Conflict of interest

The authors declare that they have no conflict of interest.

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