Neisseria gonorrhoeae infection: Clinical sciences

Neisseria gonorrhoeae is the second most common sexually transmitted bacterial infection in the United States, and it’s a mandatory reportable infection as a public health measure. It can affect multiple anatomic sites, most commonly the urethra and cervix, but also the eyes, oropharynx, and rectum. Many infections are asymptomatic.

Now, untreated infections can result in pelvic inflammatory disease, which increases the patient’s risk for ectopic pregnancy, infertility, and chronic pelvic pain. Transmission of gonorrhea to the neonate can occur during vaginal delivery. Gonorrhea in neonates can lead to infections such as ophthalmia neonatorum, also called gonococcal conjunctivitis, which may lead to blindness.

Your first step in evaluating a patient who presents with a chief concern suggesting Neisseria gonorrhoeae infection is a focused history and physical exam.

Let’s begin with biologically male patients. First, obtain a complete sexual history including questions about new partners and both oral and anal intercourse. Be sure to discuss sexual activity, particularly recent sexual activity or new partners. Provide a private, confidential discussion. Although it may be difficult, you should ask caregivers of young patients to step out of the room for this discussion. Additionally, always consider sexual assault or abuse whenever a young patient has a positive sexual activity history, especially if the patient is a child. If there is abuse going on, you will need to follow up with allegations of abuse in accordance with your State’s law.

Now patients may report a variety of symptoms, corresponding to the site of infection. They may describe a sore, itchy throat and difficulty swallowing or pelvic symptoms such as pelvic pain, dysuria, thick greenish or yellow urethral discharge, or testicular pain or swelling. Lastly, they might report rectal symptoms including painful bowel movements or rectal spotting.

On a physical exam, your findings will reflect the site of infection. Signs of conjunctivitis include erythema of the conjunctiva, swelling of the eyelid, or purulent ocular discharge. With pharyngitis, you might find an erythematous throat and cervical lymphadenopathy. Urethritis may present with purulent urethral discharge. In the case of epididymitis, you might find unilateral swelling and tenderness of a testicle as well as abdominal tenderness. Next, prostatitis typically presents with a firm, tender, and edematous prostate on a digital rectal exam. Lastly, proctitis may present with swollen, tender, and erythematous rectal mucosa.

Here is a high-yield fact! Disseminated gonococcal infections are unusual but clinically significant. These patients may present with a rash on the hands and feet, arthralgias, tenosynovitis, or septic arthritis, and they may develop endocarditis and meningitis. Additionally, biological females may have pelvic inflammatory disease and perihepatitis. Treatment includes hospitalization, appropriate antibiotics, and consultation with an infectious disease specialist.

Now back to the patient. If you suspect Neisseria gonorrhoeae infection, your next step is to perform laboratory testing for gonorrhea. Your history and physical exam will guide your testing sites. A nucleic acid amplification test, or NAAT, can be performed by swabbing the appropriate site, which may include the eye, throat, urethra, or rectum. A first-void urine collection can also be sent for NAAT testing to diagnose urogenital infections. Alternatively, a gonorrhea culture can be performed by swabbing the site of the suspected infection. Although historically culture was used for diagnosis, culture is rarely performed today. Finally, a gram stain of urethral discharge can be obtained if the patient has signs of urethritis.

Time for another high-yield fact! In biologically male patients, a positive gram stain of urethral discharge is highly specific and sensitive for diagnosing symptomatic gonococcal urethritis. A positive stain will demonstrate polymorphonuclear leukocytes with intracellular gram-negative diplococci. This test is not useful for screening for gonococcal infections of the throat or rectum. Also, be aware that in asymptomatic patients, a negative gram stain does not rule out infection.

Alright, now that we ordered tests, let’s talk about the results. If NAAT or culture are negative, consider an alternative diagnosis. However, if the NAAT, culture, or gram stain is positive, you have made your diagnosis of Neisseria gonorrhoeae infection.

Treat patients with an antibiotic, such as intramuscular ceftriaxone. Also, keep in mind that chlamydia coinfection is quite common; so if chlamydia infection has not been excluded, you should treat for chlamydia as well by adding an oral antibiotic like doxycycline or azithromycin. To ensure compliance, treat patients on-site or refer to an STI clinic for same-day treatment. After administering antibiotics to your patient, be sure to refer all sexual partners for evaluation and treatment as well. If partners cannot access services for evaluation and treatment, consider expedited partner therapy, or EPT, which allows you to treat their sexual partners without requiring them to come in for an examination. In addition, counsel patients to abstain from intercourse until 7 days following completion of treatment, and until symptoms have resolved and all partners are treated.

Since patients with one STI are at high risk for another, perform additional STI testing to screen for chlamydia, syphilis, and HIV. You should offer HIV pre-exposure prophylaxis, or PrEP, to patients who are HIV-negative because it reduces the risk of acquiring HIV. Finally, in cases of pharyngitis, perform a test of cure in 7 to 14 days. If tests remain positive or symptoms persist, be sure to obtain cultures with sensitivities. Pharyngitis is harder to eradicate than urogenital or rectal gonorrhea and is a large source of community transmission. Retest all patients, regardless of infection site, at 12 weeks after treatment, as there is a high prevalence of gonorrhea among patients with previous infections.