Concordance of chlamydia trachomatis infections within sexual partnerships.
OBJECTIVE
The enhanced sensitivity of nucleic acid amplification tests (NAAT) provides an opportunity for estimating the prevalence of untreated Chlamydia trachomatis infections. The transmissibility and public health significance of some NAAT-identified infections are, however, not known.


METHODS
Adults attending an urban emergency department provided specimens for C trachomatis screening using NAAT. Participants testing positive were offered follow-up including re-testing for C trachomatis using NAAT and traditional methods, eg culture and direct fluorescent antibody, and were treated. Partners were offered identical evaluation and treatment. Overall, 90 C trachomatis-positive participants had one or more sexual partners enrolled.


RESULTS
Evidence of transmission, as defined by infection concordance between partnerships, was observed among 75% of partners of index cases testing positive by both NAAT and traditional assay but only 45% of partners of index cases testing positive by NAAT only (prevalence ratio 1.7, 95% CI 1.1 to 2.5). Among index participants returning for follow-up, 17% had no evidence of C trachomatis infection by NAAT or traditional assay (median follow-up three weeks).


CONCLUSIONS
A substantial proportion of positive NAAT results for chlamydial infection may be of lower transmissibility and may not persist after a short follow-up. The long-term health effects of some positive NAAT are uncertain.
Rogers
S M
SM
Program in Health and Behavior Measurement, Research Triangle Institute, 701 13th St NW, Suite 750, Washington, DC 20005, USA. smr@rti.org
Miller
W C
WC
Turner
C F
CF
Ellen
J
J
Zenilman
J
J
Rothman
R
R
Villarroel
M A
MA
Al-Tayyib
A
A
Leone
P
P
Gaydos
C
C
Ganapathi
L
L
Hobbs
M
M
Kanouse
D
D
D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000175:diagnosis / Q000635:transmission*; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D012747:Sexual Partners; D014504:Urban Health