Gonorrhea is a common sexually transmitted infection caused by the gram-negative bacterium Neisseria gonorrhoeae, which appears as spherical pairs called diplococci. This bacterium infects the mucous membranes of the reproductive tract in both males and females, primarily targeting epithelial cells. The infection can occur intracellularly, extracellularly, or between cells, particularly in areas lined with simple columnar mucous membranes such as the male urethra, female cervix, rectum, throat, and eyes.
The name "gonorrhea" originates from Greek, where "gon" means semen and "rhea" means flow, reflecting an early misconception that the discharge was excess semen. In reality, the discharge is pus resulting from infection. The bacteria adhere to epithelial cells using fimbriae, which are finger-like projections that facilitate attachment and invasion.
Symptoms in males typically include a painful, pus-filled urethral discharge, burning during urination (dysuria), and difficulty urinating. In contrast, females often experience asymptomatic infections, with 50% to 80% showing no symptoms. When symptoms do occur in females, they may include pain during intercourse, increased vaginal discharge, spotting between periods, or vaginal itching. Because many female cases are asymptomatic, untreated infections can lead to serious complications such as pelvic inflammatory disease (PID), which involves chronic inflammation of the fallopian tubes and uterus. PID can cause painful menstruation, infertility, and increased risk of miscarriage.
Gonorrhea can also be transmitted from an infected mother to her baby during childbirth, potentially causing eye infections that may lead to blindness. In many countries, pregnant women are routinely screened and treated for gonorrhea, and newborns receive antibiotic eye ointments to prevent this complication.
Diagnosing gonorrhea involves identifying gram-negative diplococci in pus samples from males or culturing bacteria from cervical swabs in females. Nucleic acid amplification tests (NAATs), such as polymerase chain reaction (PCR), are commonly used on urine samples, urethral swabs, or cervical swabs to detect the presence of N. gonorrhoeae. It is important to note that gonorrhea symptoms can be indistinguishable from chlamydia, and co-infections are common.
Treatment requires antibiotics, typically a combination of ceftriaxone and azithromycin. This dual therapy helps combat antibiotic resistance, which is an increasing concern with gonorrhea due to the bacterium’s evolving resistance mechanisms. There is no lasting immunity after infection, so reinfection is possible. Consistent and correct use of condoms remains one of the most effective methods to prevent transmission of gonorrhea and other sexually transmitted infections.