Chlamydia trachomatis transmission between the oropharynx, urethra and anorectum in men who have sex with men: a mathematical model.

BACKGROUND: It has been presumed that Chlamydia trachomatis is transmitted between men only through anal or oral sex, but no mathematical models have tested this presumption. METHODS: To test this presumption, we created 20 compartmental mathematical models of different sexual practices that included both oral and anal sex and calibrated these models to the observed rates of Chlamydia trachomatis infection at three anatomical sites from 4888 men who have sex with men (MSM) in Melbourne Sexual Health Centre during 2018-2019. RESULTS: A model that included only oral and anal sex could replicate the observed rates of single-site infection at the oropharynx, urethra and rectum alone, but could not replicate infection at more than one of these sites (multisite). However, if we included transmission from sexual practices that followed one another in the same sexual episode (e.g. saliva contamination of the penis from oral sex transmitting chlamydia to the rectum by anal sex), we significantly improved the calibration of multisite infection rates substantially. CONCLUSIONS: Our modelling study suggests that transmission routes other than just oral and anal sex are necessary to explain the high rate of Chlamydia trachomatis infection at more than one site.

Self-Reported Screening for Rectal Sexually Transmitted Infections Among Men Who Have Sex With Men.

BACKGROUND: Rectal gonorrhea and chlamydia are common and predict human immunodeficiency virus (HIV) acquisition among men who have sex with men (MSM); however, screening for rectal sexually transmitted infections (STIs) is not routine. METHODS: In 2017, we recruited sexually active MSM in the Portland, Oregon metropolitan area through venue-based sampling. Our outcome of interest was self-reported rectal STI screening in the prior 12 months among those who had a health care visit in the same time period. Stratified by HIV status and preexposure prophylaxis (PrEP) use, we assessed the prevalence and predictors of screening. RESULTS: Of 403 participants, 162 (40.2%) reported rectal STI screening. Sixty (25.7%) of 233 HIV-negative men who did not report PrEP use in the prior 12 months; 61 (69.3%) of the 88 HIV-negative men who reported PrEP use in the prior 12 months; and, 41 (59.4%) of 69 men living with HIV-reported screening, respectively. Among HIV-negative men who did not report PrEP use in the prior 12 months, having a health care provider who offered HIV testing (adjusted prevalence ratio [aPR], 2.21; 95% confidence interval [CI], 1.38-3.52) and condomless anal sex with casual partners in the prior 12 months (aPR, 1.63; 95% CI, 1.01-2.65) were independently associated with rectal STI screening. The HIV-negative men on PrEP who had a syphilis diagnosis in the prior 12 months were more likely to be screened than those without syphilis (aPR, 1.33; 95% CI, 1.11-1.59). Men living with HIV who reported having a provider who always or often initiates conversations about sex were more likely to report screening compared with men who did not have such a provider (aPR, 1.46; 95% CI, 1.06-2.03). CONCLUSIONS: Rectal STI screening is not universal in a venue-based sample of sexually active MSM. Implementing innovative, acceptable, and accessible screening practices, enhancing health literacy around STI screening and improving provider comfort with talking about sex are paramount to increasing rectal STI screening.

HIV status and viral loads among men testing positive for rectal gonorrhoea and chlamydia, Maricopa County, Arizona, USA, 2011-2013.

OBJECTIVES: Men diagnosed with rectal gonorrhoea (GC) and chlamydia (CT) have engaged in unprotected receptive anal intercourse. We reviewed the HIV positivity and HIV viral loads (VLs) of men who had rectal GC and CT testing to evaluate potential HIV acquisition and transmission risk. METHODS: Rectal GC and CT testing data for men attending the Maricopa County STD clinic during the period from 1 October 2011 to 30 September 2013 were cross-matched with HIV surveillance data to identify men with HIV coinfection. We examined HIV status, HIV diagnosis date, and the values of VL collected nearest to the date of reported rectal infection. RESULTS: During the 2-year time period, 1591 men were tested for rectal GC and CT. Of the men tested, 506 (31.8%) were positive for GC (13.2%), CT (12.2%) or both (6.4%); 119 (23.5%) of those with rectal GC or CT were coinfected with HIV. Among the 275 men with HIV at the time of rectal testing, 54 (19.6%) had no reported VL; 63 (22.9%) had an undetectable VL (< 20 HIV-1 RNA copies/mL) and 158 (57.4%) had a detectable VL collected within 1 year of rectal diagnosis. Mean VL was higher among HIV and rectal GC/CT coinfected cases compared with men with HIV alone (174 316 vs. 57 717 copies/mL, respectively; P = 0.04). CONCLUSIONS: Approximately one-third of men undergoing rectal testing were positive for GC or CT and one-quarter of men with rectal GC or CT also had HIV infection. Of the HIV-infected men tested for rectal GC or CT, more than half had a detectable VL collected near the time of rectal testing, demonstrating a risk for transmitting HIV.

Cutting edge: novel vaccination modality provides significant protection against mucosal infection by highly pathogenic simian immunodeficiency virus.

Vaccine-induced protection against infection by HIV or highly pathogenic and virulent SIV strains has been limited. In a proof-of-concept study, we show that a novel vaccine approach significantly protects rhesus macaques from mucosal infection by the highly pathogenic strain SIVmac251. We vaccinated three cohorts of 12 macaques each with live, irradiated vaccine cells secreting the modified endoplasmic reticulum chaperone gp96-Ig. Cohort 1 was vaccinated with cells secreting gp96(SIV)Ig carrying SIV peptides. In addition, Cohort 2 received recombinant envelope protein SIV-gp120. Cohort 3 was injected with cells secreting gp96-Ig (no SIV Ags) vaccines. Cohort 2 was protected from infection. After seven rectal challenges with highly pathogenic SIVmac251, the hazard ratio was 0.27, corresponding to a highly significant, 73% reduced risk for viral acquisition. The apparent success of the novel vaccine modality recommends further study.

Anorectal human papillomavirus: current concepts.

Increased anorectal human papillomavirus (HPV) infection is related to the recent trends in sexual behavior in both homosexual and heterosexual groups and prevalence of infection with human immunodeficiency virus (HIV). Clinical presentation and natural history depend on the serotype involved. HPV 6 and 11 are found in the benign wart. Local control can be achieved with a wide selection of surgical and topical techniques. HPV 16, 18, and 31 are found in dysplastic lesions and have the potential to progress to invasive anal squamous cell carcinoma. Recognition and early management of dysplastic lesions is crucial to prevent the morbidity and mortality associated with anal cancer. While low-grade lesions can be closely observed, high-grade lesions should be eradicated. Different strategies can be used to eradicate the disease while preserving anorectal function. Studies on the efficacy of vaccination on anorectal HPV showed promising results in select population groups and led to the recent expansion of current vaccination recommendations.

HIV incidence among men with and those without sexually transmitted rectal infections: estimates from matching against an HIV case registry.

BACKGROUND: Sexually transmitted bacterial rectal infections are objective markers of HIV risk behavior. Quantifying HIV risk among men who have sex with men (MSM) who have had these infections can inform prevention efforts. We measured HIV risk among MSM who have and those who have not been diagnosed with rectal Chlamydia trachomatis (CT) and/or rectal Neisseria gonorrhoeae (GC). METHODS: HIV incidence among a cohort of 276 HIV-negative MSM diagnosed with rectal CT and/or GC in New York City sexually transmitted disease (STD) clinics was compared to HIV incidence among HIV-negative MSM without these infections. Matches against the citywide HIV/AIDS registry identified HIV diagnoses from STD clinics, and by other providers. Cox proportional hazards models were used to explore factors associated with HIV acquisition among MSM with rectal infections. RESULTS: HIV-negative MSM with rectal infections (>70% of which were asymptomatic) contributed 464.7 person-years of follow-up. Among them, 31 (11.2%) were diagnosed with HIV, of whom 14 (45%) were diagnosed by non-STD clinic providers. The annual HIV incidence was significantly higher among MSM with rectal infections (6.67%; 95% confidence interval [CI], 4.61%-9.35%) than among MSM without rectal infections (2.53%; 95% CI, 1.31%-4.42%). Black race (hazard ratio, 4.98; 95% CI, 1.75-14.17) was associated with incident HIV among MSM with rectal CT/GC. CONCLUSIONS: One in 15 MSM with rectal infections was diagnosed with HIV within a year, a higher risk than for MSM without rectal infections. Such data have implications for screening for rectal STD, and may be useful for targeting populations for risk-reduction counseling and other HIV prevention strategies, such as preexposure prophylaxis.

Decline in in-patient treatments of genital warts among young Australians following the national HPV vaccination program.

BACKGROUND: There has been a rapid decline in the number of young heterosexuals diagnosed with genital warts at outpatient sexual health services since the national human papillomavirus (HPV) vaccination program started in Australia in 2007. We assessed the impact of the vaccination program on the number of in-patient treatments for genital warts. METHODS: Data on in-patient treatments of genital warts in all private hospitals were extracted from the Medicare website. Medicare is the universal health insurance scheme of Australia. In the vaccine period (2007-2011) and pre-vaccine period (2000-2007) we calculated the percentage change in treatment numbers and trends in annual treatment rates in private hospitals. Australian population data were used to calculate rates. Summary rate ratios of average annual trends were determined. RESULTS: Between 2000 and 2011, 6,014 women and 936 men aged 15-44 years underwent in-patient treatment for genital warts in private hospitals. In 15-24 year old women, there was a significant decreasing trend in annual treatment rates of vulval/vaginal warts in the vaccine period (overall decrease of 85.3% in treatment numbers from 2007 to 2011) compared to no significant trend in the pre-vaccine period (summary rate ratio (SRR) = 0.33, p < 0.001). In 25-34 year old women, declining trends were seen in both vaccine and pre-vaccine periods (overall decrease of 33% vs. 24.3%), but the rate of change was greater in the vaccine period (SRR = 0.60, p < 0.001). In 35-44 year old women, there was no significant change in both periods (SRR = 0.91, p = 0.14). In 15-24 year old men, there was a significant decreasing trend in annual treatment rates of penile warts in the vaccine period (decrease of 70.6%) compared to an increasing trend in the pre-vaccine period (SRR = 0.76, p = 0.02). In 25-34 year old men there was a significant decreasing trend in the vaccine period compared to no change in the pre-vaccine period (SRR = 0.81, p = 0.04) and in 35-44 year old men there was no significant change in rates of penile warts both periods, but the rate of change was greater in the vaccine period (SRR = 0.70, p = 0.02). CONCLUSIONS: The marked decline in in-patient treatment of vulval/vaginal warts in the youngest women is probably attributable to the HPV vaccine program. The moderate decline in in-patient treatments for penile warts in men probably reflects herd immunity.

[Prevalence of ano-rectal pathology in HIV/AIDS patients]. / Prevalencia de patología ano-rectal en pacientes portadores de VIH/SIDA.

INTRODUCTION: The ano-rectal pathology (ARP) is the most common surgical condition in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). Our aim was to determine the current prevalence and clinical characteristics of the ARP in patients with HIV/AIDS in clinical control in the infectious diseases unit of the Hernán Henríquez Aravena Hospital in Temuco. STUDY DESIGN: Cross section. Location and period: Infectious Diseases Unit of the hospital during the month of June 2010. INCLUSION CRITERIA: Patients with HIV/AIDS under control in the unit, medical records were analyzed and complete physical examination was performed. RESULTS: In the period of study 384 patients were in control in the unit. Fifty had ARP which is a prevalence of 13%. Anal condyloma disease and hemorrhoidal disease were the most common diseases. Most patients (76%) were on antiretroviral therapy with good clinical response. CONCLUSION: The prevalence of ARP in HIV/AIDS patient has increased in recent years. This study shows a change in the pattern of presentation, being anal condyloma the most common ARP.

[A 32P application device for the treatment of condyloma acuminatum in the rectum].

OBJECTIVE: To investigate the use of a 32P application device (AD) in the treatment of condyloma acuminatum (CA) in the rectum, and to compare its clinical effect with that of the microwave therapy. METHODS: This study included 107 cases of CA in the rectum, 99 males and 8 females, aged 21-58 (33.6 +/- 9.4) years. Forty-six of the patients (the AD group) were treated with a self-made 32P application device, which, as a tube-shaped carrier of radionuclide 32P colloid, was fixed in the rectum at the diseased part for medication at 4.9-8.2 Gy for 3-5 hours once and 1-2 times a week. The other 61 (the microwave group) were treated by microwave burning under local anesthesia. Both groups of patients were followed up for over 3 months for comparison of the therapeutic results and observation of the stability and reliability of the 32P application device. RESULTS: The rates of cure, reoccurrence and adverse reaction were 84, 8%, 13.0% and 8.7% in the AD group, compared with 40.3%, 55.7% and 75.4% in the microwave group, with statistically significant differences between the two groups (P < 0.01). CONCLUSION: The 32P application device, with its advantages of low cost, easy operation, good effect, high safety and reliability, low recurrence, fewer adverse events and good acceptability, is highly valuable for the treatment of CA in the rectum.

Assessing Sexually Transmitted Infections and HIV Risk Among Transgender Women in Lima, Peru: Beyond Behavior.

Purpose: The purpose of this study was to explore risk factors for HIV and sexually transmitted infections (STIs) among transgender women (TW) in Lima, Peru. Methods: HIV-negative or serostatus unknown TW reporting recent condomless receptive anal intercourse underwent testing for STIs and HIV and completed a sociobehavioral survey. Results: Among 120 TW, 29.6% had rectal Neisseria gonorrhoeae (GC) or Chlamydia trachomatis (CT) and 12.6% had HIV. Age and migrant status were associated with rectal GC/CT, and rectal GC/CT predicted HIV infection. Conclusions: Further study is needed to understand individual and social factors that contribute to HIV/STI vulnerability among TW.

Sexually transmitted diseases of the anus and rectum: Causal agents, coinfections, HIV infection and high-risk sexual behaviour. / Infecciones de transmisión sexual con afectación anorrectal: agentes causales, coinfecciones, infección por el VIH y conductas de riesgo.

INTRODUCTION AND OBJECTIVE: Sexually transmitted infections of the rectum and anus (STI-RA) mainly affect men who have sex with men (MSM). The incidence of STI-RA among them has increased in recent years. MATERIAL AND METHODS: Retrospective study in patients with diagnoses of STI-RA in an STI unit during the years 2014 and 2015. Epidemiological, clinical and microbiological data were collected. RESULTS: We included 95 patients, all of whom were MSM; 88.42% were HIV+; 67.17% did not use a condom during their most recent sexual intercourse; 17.91% had had sex with sex workers and 72.22% had used drugs during sexual intercourse during the previous year. A percentage of 32.92 reported symptoms that had lasted longer than 30 days. Lymphogranuloma venereum (LGV) was diagnosed in 54.73% of the patients. All patients who presented with proctitis and perianal ulcers were diagnosed with LGV infection. All those who presented perianal ulcers without proctitis were diagnosed with syphilis. CONCLUSIONS: All the patients affected by STI-RA were MSM, most of them HIV+, had engaged in high-risk sexual behaviour and had suffered prolonged symptomatology. Clinical and microbiological characteristics of STI-AR could help adjust the empiric therapy.

Non-cutaneous AIDS-associated Kaposi's sarcoma presenting as recurrent rectal abscesses.

Kaposi's sarcoma is a fatal disease that typically presents with cutaneous manifestations in immunocompromised individuals. There are a small number of documented cases where patients diagnosed with this disease present without cutaneous lesions. We present a 35-year-old man with recurrent rectal abscesses and fistula-in-ano, which required multiple drainage procedures. Further investigation revealed a diagnosis of HIV-AIDS, and biopsy of a rectal mass confirmed the diagnosis of visceral Kaposi's sarcoma, despite the absence of cutaneous involvement. Workup revealed hepatic metastasis and a second pulmonary primary malignancy. The patient denied chemotherapy or further intervention and was subsequently lost to follow-up. Prompt diagnosis of Kaposi's sarcoma and initiation of treatment is vital to decrease disease progression. A high index of suspicion should be present in immunocompromised patients, and clinicians must recognise atypical presentations in order to improve long-term survival.

HIV-1 pathogenesis differs in rectosigmoid and tonsillar tissues infected ex vivo with CCR5- and CXCR4-tropic HIV-1.

Gut-associated lymphoid tissue (GALT) has been identified as the primary target of HIV-1 infection. To investigate why GALT is especially vulnerable to HIV-1, and to determine whether the selective transmission of CCR5-using viral variants (R5) in vivo is the result of a greater susceptibility of GALT to this viral variant, we performed comparative studies of CXCR4-using (X4) and R5 HIV-1 infections of human lymphoid (tonsillar) and rectosigmoid tissues ex vivo under controlled laboratory conditions. We found that the relative level of R5 replication in rectosigmoid tissue is much greater than in tonsillar tissue. This difference is associated with the expression of the CCR5 co-receptor on approximately 70% of CD4 T cells in rectosigmoid tissue, whereas in tonsillar tissue it is expressed on fewer than 15% of CD4 T cells. Furthermore, tonsillar tissue responds to X4 HIV-1 infection by upregulating the secretion of CC-chemokines, providing a potential CCR5 blockade and further resistance to R5 infection, whereas gut tissue failed to increase such innate immune responses. Our results show that rectosigmoid tissue is more prone than tonsillar lymphoid tissue to R5 HIV-1 infection, primarily because of the high prevalence and availability of R5 cell targets and reduced chemokine blockade. The majority of CD4 T cells express CXCR4, however, and X4 HIV-1 readily replicates in both tissues, suggesting that although the differential expression of co-receptors contributes to the GALT vulnerability to R5 HIV-1, it alone cannot account for the selective R5 infection of the rectal mucosa in vivo.

[Severe herpetic infection].

AIM: To study antiviral defense in patients with severe anogenital and labial herpetic infection, prevalence of herpetic infection and possible combination with other strains. MATERIAL AND METHODS: The immune status (basic lymphocyte subpopulations, IgA, IgM, IgG, circulating immune complexes in blood serum, cytokines, interferon status, functional activity of neutrophils) was investigated in 102 patients with severe Herpex simplex infection (HSI). RESULTS: Marked deficiency and hyporeactivity of natural and/or specific cytotoxicity were found in 70% HSI patients with severe disease. CONCLUSION: Severe HSI runs in serious combined secondary immunodeficiency, its complications and is an active mixed viral infection.

Impact of rectal gonorrhoea and chlamydia on HIV viral load in the rectum: potential significance for onward transmission.

The aim of this study was to investigate the effect of asymptomatic rectal bacterial sexually transmitted infections (STIs) on rectal HIV viral load (VL). A prospective cohort study of HIV-positive men who have sex with men attending a tertiary centre in London, UK, for their routine HIV care was performed. Forty-two HIV-positive men who have sex with men were recruited between January and August 2014. In participants on antiretroviral therapy (ART), there was no significant difference in rectal VL in those with and without STI ( p = 0.4). All rectal HIV VLs were below the limit of detection (<100 copies/µg of total RNA) whether an STI was present or not. In those not on ART, rectal HIV VL was on average 0.6log10 lower post STI treatment. The presence of asymptomatic rectal chlamydia and gonorrhoea was not associated with increased rectal HIV VL in those fully suppressed on ART. In the context of effective ART, the presence of rectal gonorrhoea or chlamydia does not appear to increase rectal HIV VL and the risk of increased viral infectivity.

HIV-1 infection, but not syphilis or HBV infection, is a strong risk factor for anorectal condyloma in Asian population: a prospective colonoscopy screening study.

OBJECTIVE: To investigate the association between anorectal precancerous lesions, including condyloma, and sexually transmitted infections (STI) in Asian population. METHODS: This prospective study enrolled 2677 patients who underwent high-resolution colonoscopy for anorectal cancer screening. Anorectal lesions were diagnosed based on endoscopic findings and confirmed by biopsy. The association of HIV-1 infection, syphilis, and HBV infection with anorectal lesion was estimated by multivariate logistic regression. In HIV-1-infected patients (n=244), anal canal HPV-DNA was screened and genotyped. RESULTS: Although no malignancy was identified, anorectal condyloma was diagnosed in 32 (1.2%) male patients. 41% of anorectal condyloma cases had no specific lower GI symptoms. Multivariate analysis identified HIV-1 infection, but not syphilis or HBV infection, as an independent significant factor for condyloma (OR: 176.5, 95%CI 22.52-1383, p<0.001). In HIV-1 infected patients, positive type 16/18 HPV-DNA (OR: 4.766, 95%CI 1.838-12.36, p=0.001), lower CD4 cell count (per 100/µl decrement, OR: 1.056, 95%CI 1.056-1.587, p=0.013), and current smoking (OR: 3.828, 95%CI 1.486-9.857, p=0.005) were independently associated with anorectal condyloma. CONCLUSIONS: HIV-1 infection, but not syphilis or HBV infection, was identified as a strong risk for anorectal condyloma. Anal HPV 16/18 was highly prevalent in patients with HIV-1 infection, especially in those with condyloma.

Nonoxynol-9 enhances rectal infection by herpes simplex virus in mice.

Pretreating the rectum of mice with nonoxynol-9 (N9) or spermicides containing N9 before infecting via the rectal route with herpes simplex virus 2 (HSV-2) increased the likelihood of infection and shortened the time until infection. Microscopic analysis indicated that N9 rapidly caused exfoliation of the rectal epithelium, exposing the underlying connective tissue. These findings suggest that use of N9-containing products during rectal intercourse may increase the risk of infection with HSV-2 or other sexually transmitted pathogens.