Evaluation of the Gen-Probe PACE 2 assay for the detection of asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees

A systematic review and meta-analysis of the prevalence of chlamydia, gonorrhoea and syphilis in incarcerated persons

Communicable diseases are common in people who are incarcerated. We aimed to define the prevalence of chlamydia, gonorrhoea and syphilis in people who are incarcerated and to identify subgroups with the highest risk of infection. We searched for prevalence studies of chlamydia, gonorrhoea or syphilis in incarcerated populations. Pooled estimates were generated, and meta-regression was conducted. Random effects models yielded pooled prevalence estimates of 5.75% (95% confidence interval [CI] 5.01, 6.48) and 12.31% (95% CI 10.61, 14.01) for chlamydia in men and women, 1.4% (95% CI 1.09, 1.70) and 5.73% (4.76, 6.69) for gonorrhoea in men and women, and 2.45% (95% CI 2.08, 2.82) and 6.10% (95% CI 4.75, 7.46) for syphilis in men and women, respectively. Each infection was associated with female gender in meta-regression models. Chlamydia, gonorrhoea and syphilis are highly prevalent in these populations. Primary and secondary prevention efforts could improve individual and population health.

Nucleic acid amplification testing for Neisseria gonorrhoeae: an ongoing challenge

Nucleic acid amplification tests (NAATs) for the detection of Neisseria gonorrhoeae became available in the early 1990s. Although offering several advantages over traditional detection methods, N. gonorrhoeae NAATs do have some limitations. These include cost, risk of carryover contamination, inhibition, and inability to provide antibiotic resistance data. In addition, there are sequence-related limitations that are unique to N. gonorrhoeae NAATs. In particular, false-positive results are a major consideration. These primarily stem from the frequent horizontal genetic exchange occurring within the Neisseria genus, leading to commensal Neisseria species acquiring N. gonorrhoeae genes. Furthermore, some N. gonorrhoeae subtypes may lack specific sequences targeted by a particular NAAT. Therefore, NAAT false-negative results because of sequence variation may occur in some gonococcal populations. Overall, the N. gonorrhoeae species continues to present a considerable challenge for molecular diagnostics. The need to evaluate N. gonorrhoeae NAATs before their use in any new patient population and to educate physicians on the limitations of these tests is emphasized in this review.

Impact of urine collection order on the ability of assays to identify Chlamydia trachomatis infections in men

BACKGROUND

Noninvasive urine samples have been used to diagnose Chlamydia trachomatis infections, with the assumption that the first-void urine (FVU), defined as the first 20 to 30 ml at any micturition, would be the optimal collection. We compared testing technologies on first, second, and third volumes for diagnosis.

GOAL

The goal was to test in nonculture assays three sequential volumes of urine from men also undergoing urethral swabbing for C trachomatis culture specimens.

STUDY DESIGN

A total of 237 men attending an STD clinic (C trachomatis prevalence, 11%) collected three containers of urine (each containing 20-30 mL) for testing in four nonculture assays. A urethral swab specimen was tested in cell culture.

RESULTS

The numbers of men positive by testing of FVU with nucleic acid amplification (LCx chlamydia), nucleic acid hybridization (PACE 2), enzyme immunoassay (Chlamydiazyme), and a leukocyte esterase dipstick were 26, 7, 14, and 11, respectively; urethral culture identified 6 of the infected men. Comparative testing of all voids from the 26 men positive by the FVU assays demonstrated a reduction of LCx-positives. Non-amplified-test positivity declined precipitously in subsequent voids, approaching zero in the third void. The presence of symptoms and time of last void up to 8 hours had little effect on the number of positives detected by LCx of FVU.

CONCLUSION

Amplified testing of FVU was most effective for diagnosing infection in these men.