Does screening for chlamydia and gonorrhea (Neisseria gonorrhoeae) require a throat swab?

Throat Swabs for Chlamydia and Gonorrhea Screening

Throat swabs should be collected for chlamydia and gonorrhea screening in individuals who engage in receptive oral sex, as pharyngeal infections are often missed when only urogenital sites are tested. 1

Anatomical Site Distribution and Testing Recommendations

• Nucleic acid amplification tests (NAATs) are the recommended diagnostic method for chlamydia and gonorrhea detection due to their high sensitivity and specificity 1
• NAATs are FDA-cleared for urogenital sites (male and female urine, endocervical swabs, vaginal swabs, and male urethral specimens) but not officially cleared for rectal and pharyngeal specimens 1
• Despite lack of FDA clearance, rectal and pharyngeal swabs can be collected from persons who engage in receptive anal intercourse and oral sex, respectively 1
• Many laboratories have validated NAATs for extragenital sites through Clinical Laboratory Improvement Amendment (CLIA) requirements 1

Population-Specific Recommendations

Men Who Have Sex With Men (MSM)

• The American Academy of Pediatrics recommends routine annual screening for pharyngeal gonorrhea in sexually active adolescent and young adult MSM who engage in receptive oral intercourse 1
• The CDC recommends annual screening for chlamydia and gonorrhea in MSM based on exposure history, with more frequent screening (every 3-6 months) in higher-risk populations 1
• Studies show that a high proportion of infections would be missed if only urogenital screening is performed in MSM - up to 85.9% of chlamydia infections and 55.7% of gonorrhea infections would be missed without pharyngeal testing 2

Women

• While the USPSTF recommends screening for chlamydia and gonorrhea in all sexually active women 24 years or younger and in older women at increased risk, specific guidance on anatomical sites is limited 3
• Research shows that isolated non-urogenital infections account for up to 59% of all infections in high-risk women 4
• Testing should be guided by sexual history and practices 1

Clinical Considerations and Pitfalls

• Most pharyngeal infections are asymptomatic and would be missed without specific testing 2, 4
• Gram stain of pharyngeal specimens is not sufficient to detect infection and is not recommended 1
• Culture is traditionally the most widely available option for diagnosis of infection in nongenital sites, but NAATs are increasingly being used due to higher sensitivity 1
• Self-collected oropharyngeal swabs have acceptable performance characteristics compared to clinician-collected samples, with only slightly higher rates of equivocal or invalid results (1.6% vs 0.9%) 5
• The majority of infections at each anatomical site (pharyngeal, rectal, urogenital) are isolated to their respective sites, making multi-site testing necessary 2, 4

Testing Algorithm

1. Assess sexual practices: Determine if the patient engages in receptive oral sex 1
2. If yes to receptive oral sex: Include pharyngeal swab in screening protocol 1
3. If no to receptive oral sex: Pharyngeal testing is not necessary 1
4. For MSM: Annual pharyngeal screening is recommended, with more frequent screening (every 3-6 months) for those with higher risk factors 1
5. For women with risk factors: Consider pharyngeal testing based on sexual practices 4, 1

The "coincidental treatment" strategy (assuming pharyngeal infections will be treated when treating urogenital infections) is suboptimal for controlling transmission, as many infections would be missed without site-specific testing 4, 2.