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Durukan D, Read TRH, Bradshaw CS, Fairley CK, Williamson DA, De Petra V, Maddaford K, Wigan R, Chen MY, Tran A, Chow EPF. Pooling Pharyngeal, Anorectal, and Urogenital Samples for Screening Asymptomatic Men Who Have Sex with Men for Chlamydia trachomatis and Neisseria gonorrhoeae. J Clin Microbiol 2020; 58:e01969-19. [PMID: 32132192 PMCID: PMC7180234 DOI: 10.1128/jcm.01969-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/29/2020] [Indexed: 02/04/2023] Open
Abstract
Screening for Chlamydia trachomatis and Neisseria gonorrhoeae at the pharyngeal, urogenital, and anorectal sites is recommended for men who have sex with men (MSM). Combining the three individual-site samples into a single pooled sample could result in significant cost savings, provided there is no significant sensitivity reduction. The aim of this study was to examine the sensitivity of pooled samples for detecting chlamydia and gonorrhea in asymptomatic MSM using a nucleic acid amplification test. Asymptomatic MSM who tested positive for chlamydia or gonorrhoea were invited to participate. Paired samples were obtained from participants prior to administration of treatment. To form the pooled sample, the anorectal swab was agitated in the urine specimen transport tube and then discarded. The pharyngeal swab and 2 ml of urine sample were then added to the tube. The difference in sensitivity between testing of pooled samples and individual-site testing was calculated against an expanded gold standard, where an individual is considered positive if either pooled-sample or individual-site testing returns a positive result. All samples were tested using the Aptima Combo 2 assay. A total of 162 MSM were enrolled in the study. Sensitivities of pooled-sample testing were 86% (94/109; 95% confidence interval [CI], 79 to 92%]) for chlamydia and 91% (73/80; 95% CI, 83 to 96%) for gonorrhea. The sensitivity reduction was significant for chlamydia (P = 0.02) but not for gonorrhea (P = 0.34). Pooling caused 22 infections (15 chlamydia and 7 gonorrhoea) to be missed, and the majority were single-site infections (19/22). Pooling urogenital and extragenital samples from asymptomatic MSM reduced the sensitivity of detection by approximately 10% for chlamydia but not for gonorrhea.
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Affiliation(s)
- Duygu Durukan
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Tim R H Read
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Catriona S Bradshaw
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Christopher K Fairley
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Deborah A Williamson
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Vesna De Petra
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Kate Maddaford
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Rebecca Wigan
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Marcus Y Chen
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Anne Tran
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
| | - Eric P F Chow
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
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Shaw J, Saunders JM, Hughes G. Attitudes to, and experience of, pooled sampling for sexually transmitted infection testing: a web-based survey of English sexual health services. Int J STD AIDS 2017; 29:547-551. [PMID: 29157170 DOI: 10.1177/0956462417742318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Chlamydia trachomatis and Neisseria gonorrhoeae testing guidance recommends extragenital screening with locally validated nucleic acid amplification tests, with anatomical sites tested separately. Evidence supports multi-patient combined aliquot pooled sampling (PS) for population screening; evidence for within-patient PS is sparse. Within-patient PS could be more cost-effective for triple-site testing, but requires distinct clinical pathways and consideration over loss of information to guide risk assessments and treatment. We explored PS attitudes and practices amongst clinicians in England. A cross-sectional web-based survey was distributed to clinical leads of sexual health services throughout England in February 2016. Fifty-two (52/216, 23%) services responded. One service reported current within-patient PS and two were awaiting implementation. Of the 49 services not pooling, five were considering implementation. Concerns raised included the inability to distinguish infection site(s) (36/52, 69%), absence of national guidance (34/52, 65%) and reduced assay performance (18/52, 34%). Only 8/52 (15%) considered the current level of evidence sufficient to support PS, with 40/52 (77%) requesting further validation studies and 39/52 (77%) national guidance. PS was rarely used by respondents to this survey, although the response rate was low. The clinical challenges presented by PS need to be addressed through further development of the evidence base.
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Affiliation(s)
- Jonathan Shaw
- 1 The Centre: Incorporating Contraception, GUM and HIV Services, Exeter, UK
| | | | - Gwenda Hughes
- 2 HIV & STI Department, 371011 Public Health England , London, UK
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The "3 in 1" Study: Pooling Self-Taken Pharyngeal, Urethral, and Rectal Samples into a Single Sample for Analysis for Detection of Neisseria gonorrhoeae and Chlamydia trachomatis in Men Who Have Sex with Men. J Clin Microbiol 2015; 54:650-6. [PMID: 26719439 DOI: 10.1128/jcm.02460-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/22/2015] [Indexed: 11/20/2022] Open
Abstract
Triple-site testing (using pharyngeal, rectal, and urethral/first-void urine samples) for Neisseria gonorrhoeae and Chlamydia trachomatis using nucleic acid amplification tests detects greater numbers of infections among men who have sex with men (MSM). However, triple-site testing represents a cost pressure for services. MSM over 18 years of age were eligible if they requested testing for sexually transmitted infections (STIs), reported recent sexual contact with either C. trachomatis or N. gonorrhoeae, or had symptoms of an STI. Each patient underwent standard-of-care (SOC) triple-site testing, and swabs were taken to form a pooled sample (PS) (pharyngeal, rectal, and urine specimens). The PS was created using two methods during different periods at one clinic, but we analyzed the data in combination because the sensitivity of the two methods did not differ significantly for C. trachomatis (P = 0.774) or N. gonorrhoeae (P = 0.163). The sensitivity of PS testing (92%) was slightly lower than that of SOC testing (96%) for detecting C. trachomatis (P = 0.167). For N. gonorrhoeae, the sensitivity of PS testing (90%) was significantly lower than that of SOC testing (99%) (P < 0.001). When pharynx-only infections were excluded, the sensitivity of PS testing to detect N. gonorrhoeae infections increased to 94%. Our findings show that pooling of self-taken samples could be an effective and cost-saving method, with high negative predictive values. (Interim results of this study were presented at the BASHH 2013 summer meeting.).
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Abstract
Genital chlamydial infection, with its possible long-term morbidity, is a serious public health problem. The number of new diagnoses is rising rapidly and, in the UK, recent evidence suggests that the infection rate in young women exceeds 10%. Screening programmes can reduce the population prevalence of infection, but uncertainty remains as to the ideal screening model. This may prove to be opportunistic screening of sexually active young women, less than 25 years of age, in primary care settings, and contact tracing of the partners of those with chlamydia. Recent literature on the practicalities of genital chlamydia screening is reviewed.
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Affiliation(s)
- Jean M Tobin
- Department of Genitourinary Medicine, St Mary's Hospital, Milton Road, Portsmouth, Hampshire PO3 6AD, UK.
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