Added Value of Extragenital Sexually Transmitted Infection Testing in "IWantTheKit" Program Users.

BACKGROUND: The 2021 Centers for Disease Control and Prevention sexually transmitted infection treatment guidelines recommend extragenital testing for gonorrhea and chlamydia in men who have sex with men and for women based on reported behaviors and exposures. The "IWantTheKit (IWTK)" program is a free online platform for specimen self-collection and mail-in for combined chlamydia/gonorrhea testing. We sought to assess the additional diagnostic value of extragenital testing compared with genital testing only for chlamydia/gonorrhea and determine factors associated with a positive extragenital test result among IWTK users. METHODS: From August 2013 to January 2022, 7612 unique IWTK users returned swabs for testing; 3407 (45%) users requested both genital and extragenital tests and were included in this analysis. Descriptive statistics were summarized for demographic characteristics, reported behaviors, and genital and extragenital test results, and data were stratified by gender and age group. A logistic regression model was used to estimate associations between factors and extragenital sexually transmitted infection positivity. RESULTS: Chlamydia positivity rates were 4.7%, 2.4%, and 1.5% at genital, extragenital, and both sites, respectively; for gonorrhea, 0.4%, 1.1%, and 0.4% were positive at those sites, respectively. Among women, age 25 years and younger was significantly associated with extragenital chlamydia (odds ratio [OR], 4.0; P = 0.010). Being in high-risk quiz score group was associated with extragenital chlamydia (OR, 2.6; P = 0.005) and extragenital gonorrhea in men and women (OR, 8.5; P = 0.005). CONCLUSIONS: Extragenital testing detected additional chlamydia and gonorrhea cases in the IWTK user population that would have been missed by genital-only testing, especially for women younger than 25 years and people reported to be at high risk.

Factors Associated With New Sexual Partnerships During the COVID-19 Pandemic: A Survey of Online Sexually Transmitted Infection Testing Platform Users.

BACKGROUND: The COVID-19 pandemic has coincided with an explosion of online platforms for sexually transmitted infections (STIs) testing using self-collected, mail-in specimens. Reports on the effect of COVID-19-associated restrictions on sexual behaviors have been mixed, but STI transmissions have continued during the pandemic. We sought to understand the pandemic impact on sexual habits associated with STIs among IWantTheKit users. METHODS: Users of IWantTheKit, a free, online STI testing platform, were invited to complete an anonymous questionnaire. Descriptive statistics were used to describe survey responses. Associations with reports of new sex partnerships were explored as a marker of STI risk. Descriptive statistics, univariate and multivariate logistic regression models were used to analyze individual characteristics and reported behaviors associated with self-reported new sexual partnerships during the first 2 COVID-19 pandemic waves. RESULTS: Of the 3462 users of the online STI testing platform between June 2020 and February 2021, 1088 (31.4%) completed the online survey; 705 (66.2%) of 1065 reported a new sex partner. One-quarter met their sex partners using apps. Overall, 10% were symptomatic and almost 18% were concerned that their partner had an STI. White race in men (odds ratio, 1.81; 95% confidence interval, 1.04-3.16), women younger than 25 years (odds ratio, 1.85; 95% confidence interval, 1.09-3.14), and increased condom use in both men and women were significantly associated with reports of new sexual partnerships in adjusted analysis. CONCLUSIONS: Despite pandemic restrictions on social gatherings, new sexual partnerships were common in this population, associated with common risk factors, and may help to explain ongoing STI transmission.

Summary of the Fourth Annual American Sexually Transmitted Diseases Association Workshop on Improving Sexually Transmitted Infection Control Efforts Through Cross-Sector Collaboration.

ABSTRACT: The American Sexually Transmitted Diseases Association has, for several years, been conducting a cross-sector workshop to bring together a variety of stakeholders to develop ideas for collaboratively improving the sexually transmitted infection control efforts in the United States. In this summary, we share the content of discussions and ideas of the fourth annual workshop for future research and potential changes to practice with a focus on diagnostic capacity.

Rapid Uptake of Testing for Chlamydia, Gonorrhea, and HIV From an Online Platform, April-October 2020.

The Baltimore City Health Department (Baltimore, MD) promoted IWantTheKit for chlamydia, gonorrhea, and HIV testing to city residents and clinic patients when COVID-19 restricted in-person clinic services. From April to October 2020, monthly online IWantTheKit orders increased by 645%. A high prevalence of chlamydia and gonorrhea was detected, and 96% of users who tested positive for chlamydia and gonorrhea were successfully contacted for treatment. Uptake by Baltimore City Health Department priority populations and excellent treatment linkage demonstrated how a public health-academic partnership successfully addressed a service gap during the pandemic. (Am J Public Health. 2022;112(7):985-989. https://doi.org/10.2105/AJPH.2022.306835).

High burden of untreated syphilis, drug resistant Neisseria gonorrhoeae, and other sexually transmitted infections in men with urethral discharge syndrome in Kampala, Uganda.

OBJECTIVES: Prompt diagnosis and treatment of sexually transmitted infections (STIs) are essential to combat the STI epidemic in resource-limited settings. We characterized the burden of 5 curable STIs chlamydia, gonorrhea, trichomoniasis, Mycoplasma genitalium, syphilis, and HIV infection in Ugandan men with urethritis. METHODS: Participants were recruited from a gonococcal surveillance program in Kampala, Uganda. Questionnaires, penile swabs were collected and tested by nucleic acid amplification. Gonococcal isolates were tested for antimicrobial sensitivity. Sequential point-of-care tests on blood samples were used to screen for syphilis and HIV. Bivariable and multivariable multinomial logistic regression models were used to estimate odds ratios for preselected factors likely to be associated with STIs. Adherence to STI treatment guidelines were analyzed. RESULTS: From October 2019 to November 2020, positivity (95% CI) for gonorrhea, chlamydia, trichomoniasis, and Mycoplasma genitalium, were 66.4% (60.1%, 72.2%), 21.7% (16.8%, 27.4%), 2.0% (0.7%, 4.9%), and 12.4% (8.7%, 17.3%) respectively. All Neisseria gonorrhoeae isolates were resistant to ciprofloxacin, penicillin, and tetracycline, but susceptible to extended spectrum cephalosporins and azithromycin. HIV and syphilis prevalence was 20.0% (50/250) and 10.0% (25/250), and the proportion unaware of their infection was 4.0% and 80.0% respectively. Most participants were treated per national guidelines. Multivariable analysis demonstrated significant associations between curable STI coinfections and younger age, transactional sex, but not HIV status, nor condom or alcohol use. CONCLUSIONS: STI coinfections including HIV their associated risk factors, and gonococcal AMR were common in this population. The majority with syphilis were unaware of their infection and were untreated. Transactional sex was associated with STI coinfections, and > 80% of participants received appropriate treatment.

A Narrative Review of Where We Are With Point-of-Care Sexually Transmitted Infection Testing in the United States.

BACKGROUND: Point-of-care (POC) tests enable immediate diagnosis and targeted treatment of sexually transmitted infections (STIs), which could accelerate control of ongoing epidemics. Although older nucleic acid amplification tests have improved the accuracy of laboratory-based tests for STIs, newer POC tests can facilitate control efforts. We sought to review the performance and time to result of POC assays for STIs in the last 10 years. METHODS: The authors performed a PubMed, US National Library of Medicine, National Center for Biotechnology Information search for POC tests for STIs or sexually transmitted diseases. RESULTS: Diagnostic technology for POC assays for STIs has achieved high sensitivity and specificity (>90%) using recent molecular advances in the last 10 years. Three POC tests for chlamydia and gonorrhea and 2 for trichomonas have been cleared by the Food and Drug Administration and can provide rapid results during the clinical encounter. Two POC assays for syphilis are now cleared by the Food and Drug Administration. Other similar POC assays are in development. These "fast followers" have faster time to result and will extend the diagnostic armamentarium at POC. CONCLUSIONS: New technology has improved the performance accuracy of STI POC diagnostics. Innovation in device format has resulted in accurate POC assays, which can decrease the time to result and accelerate the detection and treatment of STIs during the clinical encounter. The full implementation potential of these newer tests will depend on the ability of these tests to achieve Clinical Laboratory Improvement Amendments-waived status so they can be performed by nonlaboratorians with no previous training.

Molecular Characterization of Markers Associated With Antimicrobial Resistance in Neisseria gonorrhoeae Identified From Residual Clinical Samples.

BACKGROUND: The emergence and spread of antimicrobial-resistant (AMR) Neisseria gonorrhoeae (NG) is a major public health concern. In the era of nucleic acid amplifications tests, rapid and accurate molecular approaches are needed to help increase surveillance, guide antimicrobial stewardship, and prevent outbreaks. METHODS: Residual urethral swabs, collected prospectively in the Baltimore City Health Department during a 6-month period, were analyzed by real-time polymerase chain reaction assays for NG DNA and AMR determinants to fluoroquinolones, penicillin, and extended-spectrum cephalosporins. RESULTS: N. gonorrhoeae DNA was detected in 34.8% (73/210) of samples, including 67.3% (68/101) of the swabs that had been previously identified as NG positive by culture. Markers associated with decreased susceptibility to fluoroquinolones were detected in 22.4% of the polymerase chain reaction NG-positive samples. The rate of penicillinase-producing NG was very low (1.6%), and no markers associated with decreased susceptibility to extended-spectrum cephalosporins were detected in this cohort of men using the AMR assays herein described. CONCLUSIONS: Detection of molecular markers associated with AMR in NG can be performed directly from residual clinical samples, although the recovery rate of adequate DNA for molecular testing from these samples can be suboptimal. A high number of samples with mutations associated with decreased susceptibility to fluoroquinolones were identified.

Microwave-accelerated method for ultra-rapid extraction of Neisseria gonorrhoeae DNA for downstream detection.

Nucleic acid-based detection of gonorrhea infections typically require a two-step process involving isolation of the nucleic acid, followed by detection of the genomic target often involving polymerase chain reaction (PCR)-based approaches. In an effort to improve on current detection approaches, we have developed a unique two-step microwave-accelerated approach for rapid extraction and detection of Neisseria gonorrhoeae (gonorrhea, GC) DNA. Our approach is based on the use of highly focused microwave radiation to rapidly lyse bacterial cells, release, and subsequently fragment microbial DNA. The DNA target is then detected by a process known as microwave-accelerated metal-enhanced fluorescence (MAMEF), an ultra-sensitive direct DNA detection analytical technique. In the current study, we show that highly focused microwaves at 2.45 GHz, using 12.3-mm gold film equilateral triangles, are able to rapidly lyse both bacteria cells and fragment DNA in a time- and microwave power-dependent manner. Detection of the extracted DNA can be performed by MAMEF, without the need for DNA amplification, in less than 10 min total time or by other PCR-based approaches. Collectively, the use of a microwave-accelerated method for the release and detection of DNA represents a significant step forward toward the development of a point-of-care (POC) platform for detection of gonorrhea infections.

Antibiotic overuse, poor antimicrobial stewardship, and low specificity of syndromic case management in a cross section of men with urethral discharge syndrome in Kampala, Uganda.

OBJECTIVE: High prevalence of sexually transmitted infections (STIs) combined with poor antimicrobial stewardship are drivers of STI antimicrobial resistance (AMR) especially in resource-limited settings where syndromic case management (SCM) is the norm. We characterized patterns of antibiotic use prior to clinic attendance and study enrollment in Ugandan men with urethral discharge syndrome (UDS), evaluated in-clinic prescribing, and the performance characteristics of SCM. METHODS: Participants were recruited from government clinics participating in an existing gonococcal surveillance program in Kampala, Uganda. Questionnaires including antimicrobial use prior to attendance, prior episodes of UDS, penile swabs, and blood samples were collected. Bivariable and multivariable logistic regression models were used to estimate odds ratios (OR) for preselected factors likely to be associated with antibiotic use. In-clinic antibiotic treatment data were extracted from clinical notes, and the performance of SCM against laboratory-based STI diagnoses was evaluated. FINDINGS: Between October 2019 and November 2020, 100(40%) of 250 men with UDS reported taking antibiotics in the 14days prior to attending the clinic. Of these 210(84%) had at least one curable STI and 20% had a reactive point-of-care HIV test. Multivariable analysis demonstrated significant associations between recent antimicrobial use and duration of UDS symptoms <6 days (OR 2.98(95%CI 1.07,8.36), p = 0.038), and sex with women only (OR 0.08(95%CI 0.01,0.82),p = 0.038). The sensitivity of SCM ranged from 80.0% to 94.4%; specificity was low between 5.6% and 33.1%. The positive predictive value of SCM ranged from 2.4(95%CI 0.7,6.0) for trichomoniasis to 63.4(95%CI 56.5,69.9) for gonorrhea. CONCLUSION: Pre-enrollment antibiotic use was common in this population at high risk of STI and HIV. Combined with the poor specificity of SCM for male UDS, extensive antibiotic use is a likely driver of STI-AMR in Ugandan men. Interventions to improve antimicrobial stewardship and deliver affordable diagnostics to augment SCM and decrease overtreatment of STI syndromes are required.

Blind evaluation of the microwave-accelerated metal-enhanced fluorescence ultrarapid and sensitive Chlamydia trachomatis test by use of clinical samples.

Accurate point-of-care (POC) diagnostic tests for Chlamydia trachomatis infection are urgently needed for the rapid treatment of patients. In a blind comparative study, we evaluated microwave-accelerated metal-enhanced fluorescence (MAMEF) assays for ultrafast and sensitive detection of C. trachomatis DNA from vaginal swabs. The results of two distinct MAMEF assays were compared to those of nucleic acid amplification tests (NAATs). The first assay targeted the C. trachomatis 16S rRNA gene, and the second assay targeted the C. trachomatis cryptic plasmid. Using pure C. trachomatis, the MAMEF assays detected as few as 10 inclusion-forming units/ml of C. trachomatis in less than 9 min, including DNA extraction and detection. A total of 257 dry vaginal swabs from 245 female adolescents aged 14 to 22 years were analyzed. Swabs were eluted with water, the solutions were lysed to release and to fragment genomic DNA, and MAMEF-based DNA detection was performed. The prevalence of C. trachomatis by NAATs was 17.5%. Of the 45 samples that were C. trachomatis positive and the 212 samples that were C. trachomatis negative by NAATs, 33/45 and 197/212 were correctly identified by the MAMEF assays if both assays were required to be positive (sensitivity, 73.3%; specificity, 92.9%). Using the plasmid-based assay alone, 37/45 C. trachomatis-positive and 197/212 C. trachomatis-negative samples were detected (sensitivity, 82.2%; specificity, 92.9%). Using the 16S rRNA assay alone, 34/45 C. trachomatis-positive and 197/212 C. trachomatis-negative samples were detected (sensitivity, 75.5%; specificity, 92.9%). The overall rates of agreement with NAAT results for the individual 16S rRNA and cryptic plasmid assays were 89.5% and 91.0%, respectively. Given the sensitivity, specificity, and rapid detection of the plasmid-based assay, the plasmid-based MAMEF assay appears to be suited for clinical POC testing.

High level of HIV viral suppression in a cross-sectional study of Ugandan men with urethritis and bacterial STI.

BACKGROUND: Urethritis associated with non-viral sexually transmitted infections (STI) increases the risk of HIV acquisition and transmission in those living with HIV (LWH) without viral load suppression (VLS). Compared to women, men typically have lower rates of HIV VLS. We assessed the prevalence of VLS and drug resistance mutations in men LWH and urethral discharge syndrome (UDS) in Kampala, Uganda. METHODS: Men with UDS were recruited in Kampala October 2019-November 2020. Medical, demographic, and behavioural data were collected with biological samples. All reactive HIV results (rapid, sequential algorithm) underwent confirmatory HIV antibody- and HIV incidence-testing, and viral load (VL) measurement. The pol and gp41 regions were sequenced on samples with VLs >1000 cpm, phylogenetic trees were generated, and resistance mutations were investigated. RESULTS: 50 of 250 participants (20%) had reactive HIV rapid tests and 48/50 (96%) were aware of their HIV status and using antiretroviral therapy (ART). The median age was 38 years (IQR 32-45), 27/50 (54%) had engaged in transactional sex, and 30/50 (60%) reported alcohol before sex. VLS was present in 46/50 (92%). There were no major resistance mutations present in any samples analyzed. CONCLUSIONS: The prevalence of HIV and VLS was greater in these men than in the general Ugandan adult population. Most men LWH were on ART and thus less likely to transmit HIV despite demonstrating sexual behaviours associated with high-risk of STIs. These data emphasize that high levels of ART coverage and VLS are achievable among men with UDS in urban Kampala.

Antimicrobial susceptibility testing of Neisseria gonorrhoeae using a phenotypic-molecular assay and lyophilized antimicrobials.

Gonorrhea is an urgent global public health threat as Neisseria gonorrhoeae (Ng) has progressively developed resistance to all antibiotics commonly used for treatment. Surveillance of antimicrobial susceptibility trends is critical to monitor the emergence and spread of antimicrobial resistance. The gold standard methods for antimicrobial susceptibility testing (AST) of Ng are laborious and time-consuming. We evaluated a phenotypic molecular approach, involving a short cultivation step and quantitative PCR, with lyophilized antimicrobials to characterize antimicrobial susceptibility in Ng. There was excellent concordance between AST performed with liquid and lyophilized ciprofloxacin, penicillin, and tetracycline using the pheno-molecular assay, following a 4-hour incubation step. The categorical agreement between the pheno-molecular assay and the gold standard AST results was 92.4% for characterization of antimicrobial susceptibility. Essential agreement between the 2 methods was 91.9%. Characterization of ceftriaxone susceptibility in Ng using the pheno-molecular assay required a 6-hour incubation step.

Bridging the gap between development of point-of-care nucleic acid testing and patient care for sexually transmitted infections.

The incidence rates of sexually transmitted infections (STIs), including the four major curable STIs - chlamydia, gonorrhea, trichomoniasis and, syphilis - continue to increase globally, causing medical cost burden and morbidity especially in low and middle-income countries (LMIC). There have seen significant advances in diagnostic testing, but commercial antigen-based point-of-care tests (POCTs) are often insufficiently sensitive and specific, while near-point-of-care (POC) instruments that can perform sensitive and specific nucleic acid amplification tests (NAATs) are technically complex and expensive, especially for LMIC. Thus, there remains a critical need for NAAT-based STI POCTs that can improve diagnosis and curb the ongoing epidemic. Unfortunately, the development of such POCTs has been challenging due to the gap between researchers developing new technologies and healthcare providers using these technologies. This review aims to bridge this gap. We first present a short introduction of the four major STIs, followed by a discussion on the current landscape of commercial near-POC instruments for the detection of these STIs. We present relevant research toward addressing the gaps in developing NAAT-based STI POCT technologies and supplement this discussion with technologies for HIV and other infectious diseases, which may be adapted for STIs. Additionally, as case studies, we highlight the developmental trajectory of two different POCT technologies, including one approved by the United States Food and Drug Administration (FDA). Finally, we offer our perspectives on future development of NAAT-based STI POCT technologies.

Retrospective Analysis of Ugandan Men with Urethritis Reveals Mycoplasma genitalium and Associated Macrolide Resistance.

The rising rates of antimicrobial resistance (AMR) in Mycoplasma genitalium globally and the association of this sexually transmitted infection (STI) with cervicitis, urethritis, and HIV are potentially of great public health concern. Data on the epidemiology of M. genitalium in men in sub-Saharan Africa are limited. We sought to determine the prevalence of M. genitalium and macrolide resistance in men with urethritis in Kampala, Uganda. Self-collected penile-meatal swabs and/or urine samples from men with symptomatic urethritis (n = 250) were retrospectively analyzed for the presence of M. genitalium and macrolide resistance markers with the Aptima M. genitalium and ResistancePlus M. genitalium assays. Additionally, demographic and STI coinfection data were used to investigate associations with M. genitalium infection. M. genitalium was detected in 12.8% (32/250) of individuals; 40.6% (n = 13) had M. genitalium monoinfection. Mutations associated with macrolide resistance were detected in 10.7% (3/28) of participants. Coinfection with Neisseria gonorrhoeae was common (41.0%), but M. genitalium was more prevalent in participants without N. gonorrhoeae coinfection (P = 0.001). M. genitalium is common in Ugandan men with urethritis both as a monoinfection and as a coinfection with other curable STIs. Macrolide resistance was present and warrants further research on treatment outcomes and the association between untreated M. genitalium and subsequent morbidity. IMPORTANCE Mycoplasma genitalium is a common sexually transmitted infection associated with urethritis in men. Little is known about M. genitalium infection in men with urethritis in Uganda. We report that 12% of participants in this study were positive for M. genitalium and that resistance to azithromycin, a macrolide antibiotic, is present. Furthermore, we show that either self-collected penile-meatal swabs or urine can be used for detection of M. genitalium.

Macroscale spatial variation in chronic wound microbiota: a cross-sectional study.

Controlling for sample site is considered to be an important aspect of chronic wound microbiological investigations; yet, macroscale spatial variation in wound microbiota has not been well characterized. A total of 31 curette samples were collected at the leading edge, opposing leading edge, and/or center of 13 chronic wounds. Bacterial community composition was characterized using a combination of 16S rRNA gene-based pyrosequencing; heat map display; hierarchical clustering; nonmetric multidimensional scaling; and permutation multivariate analysis of variance. A total of 58 bacterial families and 91 bacterial genera were characterized among the 13 wounds. While substantial macroscale spatial variation was observed among the wounds, bacterial communities at different sites within individual wounds were significantly more similar than those in different wounds (p=0.001). Our results support the prevalent opinion that controlling for sample site may improve the quality of wound microbiota studies; however, the significant similarity in bacterial communities from different sites within individual wounds indicates that studies failing to control for sampling site should not be disregarded based solely on this criterion. A composite sample from multiple sites across the surface of individual wounds may provide the most robust characterization of wound microbiota.

The importance of a multifaceted approach to characterizing the microbial flora of chronic wounds.

Chronic wounds contain complex polymicrobial communities of sessile organisms that have been underappreciated because of limitations of standard culture techniques. The aim of this work was to combine recently developed next-generation investigative techniques to comprehensively describe the microbial characteristics of chronic wounds. Tissue samples were obtained from 15 patients with chronic wounds presenting to the Johns Hopkins Wound Center. Standard bacteriological cultures demonstrated an average of three common bacterial species in wound samples. By contrast, high-throughput pyrosequencing revealed increased bacterial diversity with an average of 17 genera in each wound. Data from microbial community profiling of chronic wounds were compared with published sequenced analyses of bacteria from normal skin. Increased proportions of anaerobes, Gram-negative rods and Gram-positive cocci were found in chronic wounds. In addition, chronic wounds had significantly lower populations of Propionibacterium compared with normal skin. Using epifluorescence microscopy, wound bacteria were visualized in highly organized thick confluent biofilms or as scattered individual bacterial cells. Fluorescent in situ hybridization allowed for the visualization of Staphylococcus aureus cells in a wound sample. Quorum-sensing molecules were measured by bioassay to evaluate signaling patterns among bacteria in the wounds. A range of autoinducer-2 activities was detected in the wound samples. Collectively, these data provide new insights into the identity, organization, and behavior of bacteria in chronic wounds. Such information may provide important clues to effective future strategies in wound healing.

A portable magnetofluidic platform for detecting sexually transmitted infections and antimicrobial susceptibility.

Effective treatment of sexually transmitted infections (STIs) is limited by diagnostics that cannot deliver results rapidly while the patient is still in the clinic. The gold standard methods for identification of STIs are nucleic acid amplification tests (NAATs), which are too expensive for widespread use and have lengthy turnaround times. To address the need for fast and affordable diagnostics, we have developed a portable, rapid, on-cartridge magnetofluidic purification and testing (PROMPT) polymerase chain reaction (PCR) test. We show that it can detect Neisseria gonorrhoeae, the pathogen causing gonorrhea, with simultaneous genotyping of the pathogen for resistance to the antimicrobial drug ciprofloxacin in <15 min. The duplex test was integrated into a low-cost thermoplastic cartridge with automated processing of penile swab samples from patients using magnetic beads. A compact instrument conducted DNA extraction, PCR, and analysis of results while relaying data to the user via a smartphone app. This platform was tested on penile swab samples from sexual health clinics in Baltimore, MD, USA (n = 66) and Kampala, Uganda (n = 151) with an overall sensitivity and specificity of 97.7% (95% CI, 94.7 to 100%) and 97.6% (95% CI, 94.1 to 100%), respectively, for N. gonorrhoeae detection and 100% concordance with culture results for ciprofloxacin resistance. This study paves the way for delivering accessible PCR diagnostics for rapidly detecting STIs at the point of care, helping to guide treatment decisions and combat the rise of antimicrobial resistant pathogens.

Effect of menses on clearance of Y-chromosome in vaginal fluid: implications for a biomarker of recent sexual activity.

Self-reported sexual behaviors are subject to bias. We previously developed a polymerase chain reaction for the detection of Y-chromosome sequences in vaginal fluid as a potential biomarker of recent sexual activity. In this study, we found menses results in lower Y-chromosome concentrations but with similar decay patterns as non-menstrual samples.