Chapter 103: Pelvic Inflammatory Disease

INTRODUCTION AND EPIDEMIOLOGY

The term pelvic inflammatory disease (PID) comprises a spectrum of infections of the female upper reproductive tract. It is a common and serious disease initiated by ascending infection from the vagina and cervix. PID includes salpingitis, endometritis, myometritis, parametritis, oophoritis, and tubo-ovarian abscess and may extend to produce periappendicitis, pelvic peritonitis, and perihepatitis (Fitz-Hugh–Curtis syndrome). PID is the most common serious infection in sexually active women age 16 to 25 years.¹

Long-term sequelae, including tubal factor infertility, implantation failure after in vitro fertilization, ectopic pregnancy, and chronic pain, may ultimately affect 11% of reproductive-aged women.² The most common cause of death is rupture of a tubo-ovarian abscess, and the mortality associated with rupture remains at 5% to 10%, even with current treatment methods.

PATHOPHYSIOLOGY

ORGANISMS ASSOCIATED WITH PID

Neisseria gonorrhoeae and Chlamydia trachomatis can be isolated in many cases of PID, and therapy is directed primarily against these organisms. However, polymicrobial infection, including infection with anaerobic and aerobic vaginal flora, is evident from cultured material from the upper reproductive tract.³ Table 103-1 lists common pathogenic organisms associated with PID. N. gonorrhoeae and C. trachomatis are often instrumental in initial infection of the upper genital tract, whereas anaerobes, facultative anaerobes, and other bacteria are isolated increasingly as inflammation increases and abscesses form.

Bacterial vaginosis (BV) is frequently identified in women with PID, and the type of BV-associated microorganism (Gardnerella vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, pigmented or nonpigmented anaerobic gram-negative rods) may make a difference in the likelihood of developing PID.^4,5

Infection with Trichomonas vaginalis is associated with a fourfold increase in the incidence of acute endometritis. Co-infection with herpes simplex virus 2 and C. trachomatis, N. gonorrhoeae, or bacteria causing vaginosis is also associated with acute endometritis. Infection with herpes simplex virus 2 causes fallopian tube inflammation and lower tract ulceration that may disrupt the endocervical canal mucous barrier.⁶ Human immunodeficiency virus 1 (HIV-1) infection is associated with an increased incidence of C. trachomatis infection, increased incidence of co-infection with Candida and human papillomavirus, and increased risk of progression to PID.⁷

PID may result from Mycobacterium tuberculosis infection in endemic areas.⁸ Schistosomes can cause genital infection, including a PID-like tubal infection, infertility, and chronic abortion, and a recent ...