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PurposeMeasures to control COVID-19 reduced face-to-face appointments and walk-ins at sexual health services (SHSs). Remote access to SHSs through online self-sampling for STIs was increased. This analysis assesses how these changes affected service use and STI testing among young people in England.MethodsData on all chlamydia, gonorrhoea and syphilis tests from 2019-2020 amongst English-resident 15-24 year olds (hereafter referred to as ‘young people’) were obtained from national STI surveillance datasets. We calculated proportional differences in tests and diagnoses for each STI, by demographic characteristics including age and socioeconomic deprivation, between 2019 and 2020. Among those tested for chlamydia, we used binary logistic regression to determine crude and adjusted odds ratios (OR) between demographic characteristics and being tested for chlamydia by an online service.ResultsCompared to 2019, there were declines in testing (30% for chlamydia, 26% for gonorrhoea, 36% for syphilis) and diagnoses (31% for chlamydia, 25% for gonorrhoea and 23% for syphilis) among young people in 2020. These reductions were greater amongst 15-19 year-olds (vs. 20-24 year-olds). Among young people tested for chlamydia, those living in the least deprived areas were more likely to be tested using an online self-sampling kit compared to those living in the most deprived areas (males; OR=1.24[1.22-1.26], females; OR=1.28[1.27-1.30]).ConclusionThe first year of the COVID-19 pandemic in England saw declines in STI testing and diagnoses in young people and disparities in the use of online chlamydia self-sampling which risk widening existing health inequalities.Implications and contributionsThere was a decrease in STI testing of young people during the first year of the COVID-19 pandemic in England with larger reductions among teenagers. There was an increase in use of online STI self-sampling services but with inequalities in provision which risk widening existing inequalities in sexual health.

© 2018 Elsevier Ltd Genital Chlamydia trachomatis infection is the most commonly diagnosed sexually transmitted infection. Trachoma is caused by ocular infection with C trachomatis and is the leading infectious cause of blindness worldwide. New serological assays for C trachomatis could facilitate improved understanding of C trachomatis epidemiology and prevention. C trachomatis serology offers a means of investigating the incidence of chlamydia infection and might be developed as a biomarker of scarring sequelae, such as pelvic inflammatory disease. Therefore, serological assays have potential as epidemiological tools to quantify unmet need, inform service planning, evaluate interventions including screening and treatment, and to assess new vaccine candidates. However, questions about the performance characteristics and interpretation of C trachomatis serological assays remain, which must be addressed to advance development within this field. In this Personal View, we explore the available information about C trachomatis serology and propose several priority actions. These actions involve development of target product profiles to guide assay selection and assessment across multiple applications and populations, establishment of a serum bank to facilitate assay development and evaluation, and development of technical and statistical methods for assay evaluation and analysis of serological findings. The field of C trachomatis serology will benefit from collaboration across the public health community to align technological developments with their potential applications.

Objective In some Pacific Island countries, such as Solomon Islands and Fiji, active trachoma is common, but ocular Chlamydia trachomatis (Ct) infection and trachomatous trichiasis (TT) are rare. On Tarawa, the most populous Kiribati island, both the active trachoma sign “trachomatous inflammation—follicular” (TF) and TT are present at prevalences warranting intervention. We sought to estimate prevalences of TF, TT, ocular Ct infection, and anti-Ct antibodies on Kiritimati Island, Kiribati, to assess local relationships between these parameters, and to help determine the need for interventions against trachoma on Kiribati islands other than Tarawa. Methods As part of the Global Trachoma Mapping Project (GTMP), on Kiritimati, we examined 406 children aged 1–9 years for active trachoma. We collected conjunctival swabs (for droplet digital PCR against Ct plasmid targets) from 1–9-year-olds with active trachoma, and a systematic selection of 1–9-year-olds without active trachoma. We collected dried blood spots (for anti-Pgp3 ELISA) from all 1–9-year-old children. We also examined 416 adults aged ≥15 years for TT. Prevalence of TF and TT was adjusted for age (TF) or age and gender (TT) in five-year age bands. Results The age-adjusted prevalence of TF in 1–9-year-olds was 28% (95% confidence interval [CI]: 24–35). The age- and gender-adjusted prevalence of TT in those aged ≥15 years was 0.2% (95% CI: 0.1–0.3%). Twenty-six (13.5%) of 193 swabs from children without active trachoma, and 58 (49.2%) of 118 swabs from children with active trachoma were positive for Ct DNA. Two hundred and ten (53%) of 397 children had anti-Pgp3 antibodies. Both infection (p, Author summary Ocular infection with Chlamydia trachomatis causes trachoma. It is the leading infectious cause of blindness, and the target of an international campaign for elimination as a public health problem. Trachoma is endemic to Tarawa, the most populated island of Kiribati, housing approximately half the national population. However, the country has 20 inhabited islands and there were no previous trachoma prevalence data from Kiribati outside Tarawa. We set out to determine the prevalence of trachoma in the second most populated island, Kiritimati, located over 3000 km from Tarawa. In some other Pacific Island countries, ocular C. trachomatis infection is much less prevalent than the clinical signs that are used to guide interventions; we therefore looked for PCR-based evidence of current infection and antibodies to chlamydial proteins, in addition to recording clinical signs of trachoma. Our results indicate that trachoma and ocular C. trachomatis infection are prevalent on Kiritimati, and suggest that interventions are required here. The combined application of antibody, nucleic acid and clinical tools in an intervention-naïve population provides insight into their inter-relationships and the data are, therefore, of considerable interest to elimination programmes within and beyond the Pacific.

Trachoma is caused byChlamydia trachomatis(Ct). It is targeted for global elimination as a public health problem. In 2014, a population-based cross-sectional study was performed in two previously trachoma-endemic areas of The Gambia. Participants of all ages from Lower River Region (LRR) (N = 1028) and Upper River Region (URR) (N = 840) underwent examination for trachoma and had blood collected for detection of antibodies against the Ct antigen Pgp3, by ELISA. Overall, 30 (1.6%) individuals had active trachoma; the prevalence in children aged 1–9 years was 3.4% (25/742) with no statistically significant difference in prevalence between the regions. There was a significant difference in overall seroprevalence by region: 26.2% in LRR and 17.1% in URR (p

Background Efforts are underway to eliminate trachoma as a public health problem by 2020. Programmatic guidelines are based on clinical signs that correlate poorly with Chlamydia trachomatis (Ct) infection in post-treatment and low-endemicity settings. Age-specific seroprevalence of anti Ct Pgp3 antibodies has been proposed as an alternative indicator of the need for intervention. To standardise the use of these tools, it is necessary to develop an analytical approach that performs reproducibly both within and between studies. Methodology Dried blood spots were collected in 2014 from children aged 1–9 years in Laos (n = 952) and Uganda (n = 2700) and from people aged 1–90 years in The Gambia (n = 1868). Anti-Pgp3 antibodies were detected by ELISA. A number of visual and statistical analytical approaches for defining serological status were compared. Principal Findings Seroprevalence was estimated at 11.3% (Laos), 13.4% (Uganda) and 29.3% (The Gambia) by visual inspection of the inflection point. The expectation-maximisation algorithm estimated seroprevalence at 10.4% (Laos), 24.3% (Uganda) and 29.3% (The Gambia). Finite mixture model estimates were 15.6% (Laos), 17.1% (Uganda) and 26.2% (The Gambia). Receiver operating characteristic (ROC) curve analysis using a threshold calibrated against external reference specimens estimated the seroprevalence at 6.7% (Laos), 6.8% (Uganda) and 20.9% (The Gambia) when the threshold was set to optimise Youden’s J index. The ROC curve analysis was found to estimate seroprevalence at lower levels than estimates based on thresholds established using internal reference data. Thresholds defined using internal reference threshold methods did not vary substantially between population samples. Conclusions Internally calibrated approaches to threshold specification are reproducible and consistent and thus have advantages over methods that require external calibrators. We propose that future serological analyses in trachoma use a finite mixture model or expectation-maximisation algorithm as a means of setting the threshold for ELISA data. This will facilitate standardisation and harmonisation between studies and eliminate the need to establish and maintain a global calibration standard., Author Summary Trachoma is caused by the bacterium Chlamydia trachomatis (Ct). Individuals who have previously been infected with Ct carry specific antibodies in their blood. Recent studies have suggested that these antibodies may be a good way to estimate the intensity of transmission of this bacterium in a population. Among people who do have antibodies (seropositives) there is variation in the amount that is detectable in their blood. Some people have such low levels that differentiating them from those who don’t have antibodies (seronegatives) is challenging. We used a new test for Ct antibodies on blood specimens from three countries. Our test worked extremely well, giving reproducible results when we tested the same samples multiple times. We compared four different methods for setting the position of the threshold line between seronegatives and seropositives. The estimated transmission intensity in each country varied depending on the threshold method used, but two methods that used statistical modelling algorithms to define the two groups performed consistently across all three countries’ samples. We recommend that future studies should consider adopting the statistical modelling approaches, as they are objective tests that require no reference material and allow for standardisation between studies.

Currently available rapid diagnostic tests (RDTs) for malaria show large variation in sensitivity and specificity, and there are concerns about their stability under field conditions. To improve current RDTs, monoclonal antibodies (mAbs) for novel malaria antigens have been developed and screened for their possible use in new diagnostic tests. Three antigens, glutamate rich protein (GLURP),dihydrofolate reductase-thymidylate synthase (DHFR-TS) and heme detoxification protein (HDP), were selected based on literature searches. Recombinant antigens were produced and used to immunize mice. Antibody-producing cell lines were subsequently selected and the resulting antibodies were screened for specificity against Plasmodium falciparum and Plasmodium vivax. The most optimal antibody couples were selected based on antibody affinity (expressed as dissociation constants, K-D) and detection limit of crude antigen extract from P. falciparum 3D7 culture. The highest affinity antibodies have K-D values of 0.10 nM +/- 0.014 (D5) and 0.068 +/- 0.015 nM (D6) for DHFR-TS mAbs, 0.10 +/- 0.022 nM (H16) and 0.21 +/- 0.022 nM (H18) for HDP mAbs and 0.11 +/- 0.028 nM (G23) and 0.33 +/- 0.093 nM (G22) for GLURP mAbs. The newly developed antibodies performed at least as well as commercially available histidine rich protein antibodies (K-D of 0.16 +/- 0.13 nM for PTL3 and 1.0 +/- 0.049 nM for C1-13), making them promising reagents for further test development

Human African trypanosomiasis (HAT) is caused by sub-species of the parasitic protozoan Trypanosoma brucei and is transmitted by tsetse flies, both of which are endemic only to sub-Saharan Africa. Several cases have been reported in non-endemic areas, such as North America and Europe, due to travelers, ex-patriots or military personnel returning from abroad or due to immigrants from endemic areas. In this paper, non-endemic cases reported over the past 20 years are reviewed; a total of 68 cases are reported, 19 cases of Trypanosoma brucei gambiense HAT and 49 cases of Trypanosoma brucei rhodesiense HAT. Patients ranged in age from 19 months to 72 years and all but two patients survived. Physicians in non-endemic areas should be aware of the signs and symptoms of this disease, as well as methods of diagnosis and treatment, especially as travel to HAT endemic areas increases. We recommend extension of the current surveillance systems such as TropNetEurop and maintaining and promotion of existing reference centers of diagnostics and expertise. Important contact information is also included, should physicians require assistance in diagnosing or treating HAT. (C) 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved