What is the most common microbiology cause of Pelvic Inflammatory Disease (PID) with intrauterine contraception devices (IUCD)?

Most Common Microbiology Cause of PID with IUDs

PID associated with intrauterine devices is polymicrobial, involving the same sexually transmitted and endogenous organisms as non-IUD-related PID, with Chlamydia trachomatis and Neisseria gonorrhoeae being the most common sexually transmitted pathogens, along with various anaerobic and facultative bacteria from the lower genital tract. 1, 2

Key Microbiologic Agents

The microbiology of IUD-associated PID mirrors that of PID in general and includes:

Sexually Transmitted Pathogens

• Chlamydia trachomatis is recovered from the cervix in 5-39% of women with PID and represents the leading cause of PID in both mild and severe cases 3, 4
• Neisseria gonorrhoeae is isolated from the cervix in 27-80% of PID cases 3
• Both organisms are equally common in IUD-associated PID as they are in non-IUD PID 1, 2

Anaerobic Bacteria

• Bacteroides species, Peptostreptococcus species, and Peptococcus species are the most common anaerobes isolated from the upper genital tract in 25-50% of acute PID cases 3, 2
• Anaerobic bacteria are recovered significantly more frequently in severe PID with abscess formation 4

Facultative/Aerobic Bacteria

• Gardnerella vaginalis, Streptococcus species, Escherichia coli, and Haemophilus influenzae are commonly isolated 3, 2
• These organisms are often associated with bacterial vaginosis, which serves as an antecedent to polymicrobial PID 3

Critical Clinical Distinction: Actinomyces

Actinomyces species are NOT the most common cause of IUD-associated PID—this is a widespread misconception. 3, 1

• Actinomyces infections are very uncommon and typically occur only in two specific settings: when infection is present at the time of IUD insertion, or when the IUD is left in place past the recommended removal time (typically >5 years) 3, 1
• Despite historical association with IUDs, Actinomyces does not represent the typical microbiology of IUD-associated PID 3

Pathophysiology of IUD-Associated PID

IUD insertion mechanically facilitates upward spread of vaginal and cervical bacteria through direct canalicular spread from the endocervix to the endometrium and fallopian tubes. 3, 2

• The insertion process disrupts the cervical barrier, allowing pre-existing lower genital tract organisms to ascend 2
• The absolute risk of PID following IUD insertion is low in women without pre-existing STIs, but significantly elevated in women with cervical infection at insertion 1, 2
• Women with current purulent cervicitis, chlamydial infection, or gonorrhea should not have an IUD inserted until infection is treated 2

Clinical Management Implications

• PID in IUD users should be diagnosed and managed as standard polymicrobial PID with broad-spectrum antibiotics covering N. gonorrhoeae, C. trachomatis, anaerobes, gram-negative facultative bacteria, and streptococci 5, 6
• Clinical outcomes do not differ whether the IUD is removed or left in place during treatment 1, 2
• All patients with suspected PID should be tested for C. trachomatis, N. gonorrhoeae, and HIV 3

Common Pitfalls to Avoid

• Do not assume Actinomyces is the primary pathogen in IUD-associated PID—this outdated concept leads to inappropriate narrow-spectrum therapy 3, 1
• Do not fail to screen for STIs before IUD insertion, as pre-existing cervical infection dramatically increases PID risk 1, 2
• Do not delay broad-spectrum antibiotic treatment while awaiting culture results, as prompt therapy is essential to prevent long-term sequelae including infertility and chronic pelvic pain 5, 6