Description

• An acute infection of the upper genital tract in women caused by the ascent of organisms, often sexually transmitted, from the vagina and endocervix to the uterus, fallopian tubes, ovaries, and contiguous structures
• Pelvic inflammatory disease (PID) is a broad term that encompasses a variety of upper genital tract infections, including endometritis, salpingitis, oophoritis, tubo-ovarian abscess, peritonitis, and perihepatitis.
• Salpingitis is the most important component due to its impact on future fertility (1).
• Diagnosis may be challenging and incorrect in up to 1/3 of cases. No set of criteria is both sensitive and specific for the disease.
• System(s) affected: Reproductive

Epidemiology

• Predominant age: 15–25 years; this number has remained constant since early 1900s (2).
• Predominant sex: Female only

Incidence
770,000 cases of acute PID diagnosed annually in the USA. Incidence decreased from 1885–2001. Estimated annual health care cost is $2 billion/year.

Prevalence
100–120/100,000 women (3)

Risk Factors

• Sexually active and age <25 years
• First sexual activity at young age (<15 years)
• New/Multiple sexual partners
• Nonbarrier contraceptive methods (i.e., oral contraceptive pills)
• Previous history of PID; 20–25% will have a recurrence.
• History of Chlamydia trachomatis; 10–40% will develop PID.
• History of gonococcal cervicitis; 10–20% will develop PID (2).

General Prevention

• Educational programs about safer sex practices and STI prevention
• Barrier contraceptives, especially condoms and spermicidal creams or sponges, provide some protection.
• Early medical care with occurrence of genital lesions or abnormal discharge
• Intrauterine device (IUD) insertion is contraindicated in women with active (acute) cervical/pelvic infection, but not in most patients with a history of PID.

• Annual chlamydia screening of all sexually active women aged <25 years and of older women with risk factors (e.g., those who have a new sex partner/multiple sex partners
• Routine STI screening in pregnancy
• Evaluation and treatment of sexual partners after diagnosis with STI (2)

Pathophysiology

• The precise mechanism by which microorganisms ascend from the lower genital tract is unknown. Possible mechanisms include: (1) Ascent from cervix to endometrium to salpinx to peritoneal cavity; (2) lymphatic spread via infection of the parametrium; and (3) hematogenous route, although this is rare (2).
• Of cases, 75% occur within 7 days of menses, when cervical mucus favors ascent of organisms.

Etiology

Multiple organisms may be etiologic agents in PID. Most cases are polymicrobial:

• C. trachomatis, Neisseria gonorrhoeae, genital tract mycoplasmas (particularly Mycoplasma genitalium), aerobic and anaerobic (Bacteroides fragilis) and vaginal flora (e.g., Prevotella, Peptostreptococci, Gardnerella vaginalis, Escherichia coli, Haemophilus influenza) are recognized as etiologic agents.
• Many of nongonococcal, nonchlamydial microorganisms recovered from upper genital tract in acute PID are associated with bacterial vaginosis (esp. P. bivius, P. disiens and P. capillosus) (4)

Commonly Associated Conditions

• If PID is suspected in a patient with an IUD and a pelvic abscess is present, an Actinomyces infection requiring penicillin treatment may be present.
• Rupture of an adnexal abscess is rare but life threatening. Early surgical exploration is mandatory.
• Chlamydial or gonococcal perihepatitis may occur with PID. This combination is called Fitz-Hugh-Curtis (FHC) syndrome and is characterized by severe pleuritic right upper quadrant pain. FHC syndrome complicates 10% of PID cases.