Table 3.

How and when to test for sexually transmitted infections in men who have sex with men

INFECTION	HOW TO TEST	WHEN TO TEST	CONSIDERATIONS
Gonorrhea or chlamydia^1,3	First-catch urine	At presentation	Sensitivity: 97%-100%
Gonorrhea or chlamydia^1,3	Swabs: - Pharynx - Internal genitals, front holes, neovaginas - Rectum	At presentation	Use NAAT Sensitivities: 96%-100% Testing can be done immediately after exposure
Syphilis^1,3,15	Serology	At presentation ≥4 wk from potential exposure Repeat every 3 mo if ongoing risk	EIA screen, with or without RPR and TPPA assay Sensitivity: - 75% in primary infection - 98%-100% in secondary infection
Syphilis^1,3,15	DFA or PCR test	At presentation when lesions are present	Sensitivity: 73%-100% Can detect only in primary and secondary infection
Herpes simplex virus^1,3	Swabs	At presentation	Sensitivity: - 94% for vesicles - 87% for pustular lesions - 70% for ulcers Sensitivity decreases as time from onset to specimen collection increases
HIV^1,4	Serology	At presentation ≥6 wk from potential exposure Repeat every 3 mo if ongoing risk	Fourth-generation antigen and antibody test Sensitivity: 99.9%
Mpox^5,27	Swabs: - Lesions - Pharynx - Rectum	At presentation	Sensitivity: - 85%-90% for lesions - 60%-70% for pharynx - 40%-50% for serology Swab pharynx only when asymptomatic contact or lesions cannot be swabbed
Mpox^5,27	Serology	At presentation	Sensitivity: 40%-50% Do serology only when asymptomatic contact or lesions cannot be swabbed
Enteric bacteria and protozoa^6,7	Culture for enteric organisms Ova and parasite test for protozoa	At presentation	Test only if symptomatic 2-3 ova and parasite test specimens are required in low-prevalence settings

DFA—direct fluorescent antibody, EIA—enzyme immunoassay, NAAT—nucleic acid amplification test, PCR—polymerase chain reaction, RPR—rapid plasma reagin, TPPA—Treponema pallidum passive particle agglutination.