Neisseria gonorrhoeae lipooligosaccharide glycan epitopes recognized by bactericidal IgG antibodies elicited by the meningococcal group B-directed vaccine, MenB-4C

Introduction

Outer membrane vesicles (OMVs) of Neisseria meningitidis in the group B-directed vaccine MenB-4C (BexseroR) protect against infections with Neisseria gonorrhoeae. The immunological basis for protection remains unclear. N. meningitidis OMV vaccines generate human antibodies to N. meningitidis and N. gonorrhoeae lipooligosaccharide (LOS/endotoxin), but the structural specificity of these LOS antibodies is not defined.

Methods

Ten paired human sera obtained pre- and post-MenB-4C immunization were used in Western blots to probe N. meningitidis and N. gonorrhoeae LOS. Post-MenB-4C sera (7v5, 19v5, and 17v5), representing individual human variability in LOS recognition, were then used to interrogate structurally defined LOSs of N. meningitidis and N. gonorrhoeae strains and mutants and studied in bactericidal assays.

Results and discussion

Post-MenB-4C sera recognized both N. meningitidis and N. gonorrhoeae LOS species, ~10% of total IgG to gonococcal OMV antigens. N. meningitidis and N. gonorrhoeae LOSs were broadly recognized by post-IgG antibodies, but with individual variability for LOS structures. Deep truncation of LOS, specifically a rfaK mutant without α-, β-, or γ-chain glycosylation, eliminated LOS recognition by all post-vaccine sera. Serum 7v5 IgG antibodies recognized the unsialyated L1 α-chain, and a 3-PEA-HepII or 6-PEA-HepII was part of the conformational epitope. Replacing the 3-PEA on HepII with a 3-Glc blocked 7v5 IgG antibody recognition of N. meningitidis and N. gonorrhoeae LOSs. Serum 19v5 recognized lactoneotetrose (LNT) or L1 LOS-expressing N. meningitidis or N. gonorrhoeae with a minimal α-chain structure of Gal-Glc-HepI (L8), a 3-PEA-HepII or 6-PEA-HepII was again part of the conformational epitope and a 3-Glc-HepII blocked 19v5 antibody binding. Serum 17v5 LOS antibodies recognized LNT or L1 α-chains with a minimal HepI structure of three sugars and no requirement for HepII modifications. These LOS antibodies contributed to the serum bactericidal activity against N. gonorrhoeae. The MenB-4C vaccination elicits bactericidal IgG antibodies to N. gonorrhoeae conformational epitopes involving HepI and HepII glycosylated LOS structures shared between N. meningitidis and N. gonorrhoeae. LOS structures should be considered in next-generation gonococcal vaccine design.

STI prevalence, incidence, and partner notification among women in a periconception HIV prevention program in Uganda

BACKGROUND

We provided sexually transmitted infection (STI) screening and facilitated partner notification and treatment among women participating in a periconception HIV prevention program in southwestern Uganda to understand follow-up STI incidence.

METHODS

Women at-risk for HIV exposure while planning for pregnancy completed laboratory screening for chlamydia, gonorrhea, trichomoniasis, and syphilis at enrollment and 6 months of follow-up and/or incident pregnancy; facilitated partner notification and treatment were offered for those with positive tests. We performed a logistic regression to determine correlates of follow-up STI.

RESULTS

Ninety-four participants completed enrollment STI screening with a median age of 29 (IQR 26-34); 23 (24%) had ≥1 STI. Of the 23 participants with enrollment STI(s), all completed treatment and 19 (83%) returned for follow-up; 18 (78%) reported delivering partner notification cards and discussing STIs with partner(s), and 14 (61%) reported all partners received STI treatment. Of the 81 (86%) who successfully completed follow-up STI screening, 17 (21%) had ≥1 STI. The STI incidence rate was 29.0 per 100 person-years. In univariable regression analysis, enrollment STI, younger age, less education, and alcohol consumption were all significantly associated with follow-up STI.

CONCLUSIONS

We demonstrated high enrollment and follow-up STI rates and moderate participant-reported partner treatment among women planning for pregnancy in Uganda despite partner notification and treatment. Novel STI partner notification and treatment interventions are needed to decrease the STI burden, especially among women planning for and with pregnancy.

Sexually transmitted infections among HIV serodiscordant partners: A secondary analysis of HIV Prevention Trial Network 052

Sexually transmitted infections (STIs) remain a public health concern because of their interaction(s) with HIV. In the HPTN 052 study, STIs were evaluated in both HIV-positive index cases and their HIV-negative partners at enrollment and at yearly follow-up visits. Our definition for STI was based on any infection with Chlamydia trachomatis, Neisseria gonorrhoeae, syphilis, or Trichomonas vaginalis. We used log-binomial regression models to identify factors associated with prevalent STIs. Generalized estimating equation models with the Poisson distribution were used to compare STI incidence between HIV-positive index cases and HIV-negative partners. 8.1% of the participants had STIs at enrollment. The prevalence of STIs (8.9 vs. 7.2) was higher in HIV-positive index cases than HIV-negative partners. Being female (prevalence ratio (PR) = 1.61; 95% CI: 1.20-2.16) or unmarried (PR = 1.92; 95% CI: 1.17-3.14) was associated with prevalent STIs. Compared to HIV-negative male partners, HIV-positive female index cases had a higher risk of STI acquisition (incidence rate ratio (IRR) = 2.25; 95% CI: 1.70-2.97). While we are implementing HIV prevention interventions for HIV-negative people, we should also intensify targeted STI prevention interventions, especially among HIV-positive women.

Societal factors contributing to infections caused by Chlamydia trachomatis and Neisseria gonorrhoeae in a veteran population

BACKGROUND

Veterans have a higher incidence of sexually transmitted infections (STIs) compared to the general population. The objective of this study is to evaluate the association of societal factors on the risk of chlamydia or gonorrhea.

METHODS

This retrospective cohort study evaluated data from Veteran Health Administration. Patients tested for chlamydia or gonorrhea between January 2009 and January 2019 were included. Descriptive statistics and regression were used to evaluate societal factors.

RESULTS

A total of 1,232,173 tests for chlamydia or gonorrhea were performed. There were 51,987 (4.2%) positive cases with 74.18% for chlamydia and 24.96% for gonorrhea. In 13.6% of veterans with reported military sexual trauma, there was no difference in risk of positivity (p = 0.39). Veterans with a history of combat had lower odds of testing positive (OR, 0.94; 95% CI, 0.91-0.97). Tests in veterans who were married had a 24% less chance of positivity (OR, 0.76; 95% CI, 0.74-0.79) compared to tests in divorced veterans. Positive number of cases increased each year.

CONCLUSION

Sexually transmitted infections are a growing concern. Gender, age, ethnicity, marital status, and race are societal identifiers which influence likelihood of STI acquisition.

Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among women with genitourinary infection and pregnancy-related complications in Tehran: A cross-sectional study

The present study investigates the prevalence of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) among women with genitourinary infection and pregnancy-related complications in Tehran. It also evaluates the demographic information, symptoms, and sequelae. Endocervical samples were obtained over a period of eight months from 360 women including 180 symptomatic patients and 180 patients with pregnancy-related complications and infertility. CT, NG, and TV were detected in 10.8%, 6.9%, and 8.3% of all patients, respectively. The prevalence of CT, NG, and TV among women in the symptomatic group was 11.1%, 7.2%, and 13.3%, respectively, and among women with pregnancy-related complications and infertility was 10.6%, 6.7%, and 3.3%, respectively. Associations between chlamydia and ectopic pregnancy (p = 0.001), and infertility (p < 0.001) were observed. Abortion (p = 0.008), infertility (p = 0.005), and ectopic pregnancy (p < 0.001) were associated with gonorrhea. Abnormal vaginal discharge (p = 0.02) and vulvar itching (p = 0.02) were associated with trichomoniasis. Overall, the prevalence rates of CT, NG, and TV were high in these patient groups. These high prevalences suggest that screening programs are required to reduce the burden of these sexually transmitted infections and their effects on genitourinary symptoms, pregnancy-related complications, and infertility.

Partner notification and treatment outcomes among South African adolescents and young adults diagnosed with a sexually transmitted infection via laboratory-based screening

Partner notification and treatment are essential components of sexually transmitted infection (STI) management, but little is known about such practices among adolescents and young adults. Using data from a prospective cohort study (AYAZAZI) of youth aged 16-24 years in Durban, South Africa, we assessed the STI care cascade across participant diagnosis, STI treatment, partner notification, and partner treatment; index recurrent STI and associated factors; and reasons for not notifying partner of STI. Participants completed laboratory-based STI screening (Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis) at enrollment and at 12 months. Of the 37/216 participants with STI (17%), 27/37 (73%) were women and 10/37 (27%) were men. Median age was 19 years (IQR: 18-20). Of the participants with STI, 23/37 (62%) completed a Treatment and Partner Tracing Survey within 6 months of diagnosis. All survey participants reported completing STI treatment (100%), 17/23 (74%) notified a partner, and 6/23 (35%) reported partner treatment. Overall, 4/23 (11%) participants had 12-month recurrent C. trachomatis infection, with no association with partner notification or treatment. Stigma and lack of STI knowledge were reasons for not notifying partner of STI. STI partner notification and treatment is a challenge among youth. Novel strategies are needed to overcome barriers along the STI care cascade.

Lost opportunity to save newborn lives: variable national antenatal screening policies for Neisseria gonorrhoeae and Chlamydia trachomatis

Unfavorable pregnancy outcomes caused by Chlamydia trachomatis or Neisseria gonorrhoeae infection are well known. The first step in addressing antenatal C. trachomatis and N. gonorrhoeae infection is a national policy to screen all pregnant women for C. trachomatis and N. gonorrhoeae, regardless of symptoms. The aim of this study was to inform policy makers on the presence of antenatal screening recommendations for C. trachomatis and N. gonorrhoeae infection. We conducted a three-part study from June 2015 to February 2016. We analyzed English and French language information online on Ministry of Health websites regarding C. trachomatis and N. gonorrhoeae antenatal screening. We referenced both primary official country and regional policy documents. We contacted the Ministry of Health directly if the information on the national antenatal screening was outdated or unavailable. In parallel, we sent a survey to the regional representative from the World Health Organization to help collect country-level data. Fourteen countries have current policies for antenatal screening of C. trachomatis and/or N. gonorrhoeae infection: Australia, the Bahamas, Bulgaria, Canada, Estonia, Japan, Germany, Latvia, New Zealand, Democratic People's Republic of Korea, Romania, Sweden, the United Kingdom, and the United States. Australia, New Zealand, and Latvia and the United States restricted antenatal screening to women ≤25 years old and those of higher risk. Several countries responded that they had policies to treat pregnant women with symptoms. This is the currently recommended WHO guideline but is not the same as universal screening. North Korea had policies in place which were not implemented due to lack of personnel and/or supplies. National level policies to support routine screening for C. trachomatis and N. gonorrhoeae infection to prevent adverse pregnancy and newborn outcomes are uncommon.

High prevalence of extra-genital chlamydial or gonococcal infections among men who have sex with men and transgender women in Lima, Peru

Chlamydia trachomatis and Neisseria gonorrhoeae are among the most common sexually transmitted bacterial infections in the world. Data are limited, however, on the burden of extra-genital chlamydial and gonococcal infections among men who have sex with men and transgender women in Lima, Peru. Data were gathered from self-collected anal or pharyngeal swabs from participants in Lima, Peru, and analyzed via cross-sectional methods. Prevalence ratios for the association between extra-genital infection with socio-demographic and sexual behaviors were determined. Overall, 127 (32.8%) participants had anal or pharyngeal infections. On multivariate modeling, anal infection was positively associated with practicing both receptive and insertive anal sex, when compared to insertive alone (PR = 2.49; 95% CI = 1.32-4.71), and negatively associated with any antibiotic use in the prior three months (PR = 0.60; 95% CI = 0.39-0.91). Pharyngeal infection was negatively associated with age greater than 30 years compared to 18-30 years (PR = 0.54; 95% CI = 0.30-0.96), and positively associated with gender identity of transgender women (PR = 2.12; 95% CI = 1.20-3.73). This study demonstrates considerable burden of extra-genital chlamydial and gonococcal infections among men who have sex with men and transgender women in Lima, Peru.

Sexual behaviour and sexually transmitted infections in sexually transmitted infection clinic attendees in the Netherlands, 2007-2011

High annual figures of sexually transmitted infections (STIs) are diagnosed in the Netherlands despite significant efforts to control them. Herein, we analyse trends and determinants of STI diagnoses, co-infections, and sexual risks among visitors of 26 STI clinics between 2007 and 2011. We recorded increased positivity rates of STIs (chlamydia, syphilis, gonorrhoea, and/or HIV) in women and heterosexual men up to 12.6% and 13.4%, respectively, in 2011, while rates in men having sex with men (MSM) were stable but high (18.8%) through the documented years. Younger age, origin from Surinam/Antilles, history of previous STI, multiple partners, or a previous notification are the identified risk factors for an STI in this population. Known HIV-infected men (MSM and heterosexuals) were at highest risk for co-infections (relative rate heterosexual men: 15.6; MSM: 11.6). STI positivity rates remained high (MSM) or increased over time (women and heterosexual men), a fact that highlights the importance of continuing STI prevention. Most importantly, the very high STI co-infection rates among HIV-positive men requires intensified STI reduction strategies to put an end to the vicious circle of re-infection and spread of HIV and other STIs.