Knowledge, attitudes and practices towards yaws in endemic areas of Ghana, Cameroon and Côte d'Ivoire.

Yaws, caused by Treponema pallidum ssp. pertenue, remains a significant public health concern in tropical regions of West Africa and the South Pacific, primarily affecting children in remote areas with limited access to hygiene and sanitation. In this study, conducted in three endemic countries of West Africa where yaws remains a significant public health concern (Ghana, Cameroon, and Côte d'Ivoire), we aimed to assess the knowledge, attitudes, and practices related to yaws among community members, community health workers (CHWs), and traditional healers. The study revealed variations in the perception of causes of yaws among community members: the majority or participants in Ghana attributed yaws to germs (60.2%); in Cameroon the most reported form of transmission was contact with or drinking infected water sources (44.6%); and in Côte d'Ivoire both of these answers were also the most prevalent (60.3% germs and 93.% water sources). A substantial proportion of participants in Côte d'Ivoire also associated yaws with witchcraft and divine punishment (44.8%). Only a small proportion of individuals in Ghana and Côte d'Ivoire correctly identified contact with an infected person as a form of transmission (11.9% and 20.7%, respectively) and less than half in Cameroon (42.6%), although more than 98% of all participants reported avoidance behaviours towards yaws infected people due to fear of getting infected. Most participants expressed a preference for seeking care at hospitals (49.2%, 60.6%, 86.2%) or health care professionals including doctors and nurses (58.5%, 41,5% and 17.2%) if they were diagnosed with yaws, although a quarter of participants in Côte d'Ivoire also sought support from traditional healers. The CHWs interviewed were generally well-trained on yaws causes and treatment options, although they often reported low availability of treatment and diagnostic tests for yaws. Our findings underscore the need for community education, awareness campaigns, ongoing CHW training, and improved access to yaws treatment and diagnostic resources. The data also suggest that collaboration with traditional healers, who usually hold a highly esteemed position in the society, such as giving training on yaws causes and transmission or exchanging knowledge on treatment options, could be beneficial in certain regions, particularly in Côte d'Ivoire.

Acceptability and feasibility of tests for infection, serological testing, and photography to define need for interventions against trachoma.

BACKGROUND: Trachoma causes blindness due to repeated conjunctival infection by Chlamydia trachomatis (Ct). Transmission intensity is estimated, for programmatic decision-making, by prevalence of the clinical sign trachomatous inflammation-follicular (TF) in children aged 1-9 years. Research into complementary indicators to field-graded TF includes work on conjunctival photography, tests for ocular Ct infection, and serology. The perceived acceptability and feasibility of these indicators among a variety of stakeholders is unknown. METHODOLOGY: Focus group discussions (FGDs) with community members and in-depth interviews (IDIs) with public health practitioners in Tanzania were conducted. FGDs explored themes including participants' experience with, and thoughts about, different diagnostic approaches. The framework method for content analysis was used. IDIs yielded lists of perceived strengths of, and barriers to, implementation for programmatic use of each indicator. These were used to form an online quantitative survey on complementary indicators distributed to global stakeholders via meetings, mailing lists, and social media posts. RESULTS: Sixteen FGDs and 11 IDIs were conducted in October-November 2022. In general, all proposed sample methods were deemed acceptable by community members. Common themes included not wanting undue discomfort and a preference for tests perceived as accurate. Health workers noted the importance of community education for some sample types. The online survey was conducted in April-May 2023 with 98 starting the questionnaire and 81 completing it. Regarding barriers to implementing diagnostics, the highest agreement items related to feasibility, rather than acceptability. No evidence of significant differences was found in responses pertaining to community acceptability based on participant characteristics. CONCLUSIONS: All of the indicators included were generally deemed acceptable by all stakeholders in Tanzania, although community education around the benefits and risks of different sample types, as well as addressing issues around feasibility, will be key to successful, sustainable integration of these indicators into trachoma programs.

Progress towards the elimination of trachoma in Nigeria.

Trachoma is targeted for elimination as a public health problem worldwide by 2030. In Nigeria, elimination activities are implemented at the local government area (LGA) level. They started in 2002 by conducting baseline population-based prevalence surveys (PBPSs), which continued in a systematic manner with engagement from the Global Trachoma Mapping Project in 2013, and subsequently Tropical Data. The results led to the development of Nigeria's first trachoma action plan and its subsequent revision with additional information. Following 449 baseline PBPSs, 122 LGAs had an active trachoma prevalence above the elimination threshold, requiring interventions, while 231 LGAs required community-based interventions for trichiasis management. By 2021, >34 million antibiotic treatments had been provided in 104 LGAs, with 89 LGAs eliminating active trachoma. Nationally, water and sanitation coverages increased by 3% and 18%, respectively, in 7 y. Systematic trichiasis case finding and management were carried out in 231 LGAs, resulting in the management of 102 527 people. Fifty-four LGAs decreased trichiasis prevalence unknown to the health system to <0.2% in persons ≥15 y of age. Where this elimination prevalence threshold was reached, trichiasis services were transitioned to routine eye/healthcare systems. Such progress relied on strong leadership and coordination from the national trachoma program and tremendous support provided by partners. Attaining elimination of trachoma as a public health problem in Nigeria by 2030 is feasible if funding support is sustained.

Using 16s rRNA sequencing to characterize the microbiome of tropical cutaneous ulcer disease: insights into the microbial landscape and implications for diagnosis and treatment.

Cutaneous ulcers are common in yaws-endemic areas. Although often attributed to 'Treponema pallidum subsp. pertenue' and Haemophilus ducreyi, quantitative PCR has highlighted a significant proportion of these ulcers are negative for both pathogens and are considered idiopathic. This is a retrospective analysis utilising existing 16S rRNA sequencing data from two independent yaws studies that took place in Ghana and the Solomon Islands. We characterized bacterial diversity in 38 samples to identify potential causative agents for idiopathic cutaneous ulcers. We identified a diverse bacterial profile, including Arcanobacterium haemolyticum, Campylobacter concisus, Corynebacterium diphtheriae, Staphylococcus spp. and Streptococcus pyogenes, consistent with findings from previous cutaneous ulcer microbiome studies. No single bacterial species was universally present across all samples. The most prevalent bacterium, Campylobacter ureolyticus, appeared in 42% of samples, suggesting a multifactorial aetiology for cutaneous ulcers in yaws-endemic areas. This study emphasizes the need for a nuanced understanding of potential causative agents. The findings prompt further exploration into the intricate microbial interactions contributing to idiopathic yaw-like ulcers, guiding future research toward comprehensive diagnostic and therapeutic strategies.

Novel point-of-care cytokine biomarker lateral flow test for the screening for sexually transmitted infections and bacterial vaginosis: study protocol of a multicentre multidisciplinary prospective observational clinical study to evaluate the performance and feasibility of the Genital InFlammation Test (GIFT).

INTRODUCTION: A prototype lateral flow device detecting cytokine biomarkers interleukin (IL)-1α and IL-1ß has been developed as a point-of-care test-called the Genital InFlammation Test (GIFT)-for detecting genital inflammation associated with sexually transmitted infections (STIs) and/or bacterial vaginosis (BV) in women. In this paper, we describe the rationale and design for studies that will be conducted in South Africa, Zimbabwe and Madagascar to evaluate the performance of GIFT and how it could be integrated into routine care. METHODS AND ANALYSIS: We will conduct a prospective, multidisciplinary, multicentre, cross-sectional and observational clinical study comprising two distinct components: a biomedical ('diagnostic study') and a qualitative, modelling and economic ('an integration into care study') part. The diagnostic study aims to evaluate GIFT's performance in identifying asymptomatic women with discharge-causing STIs (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG)) and BV. Study participants will be recruited from women attending research sites and family planning services. Several vaginal swabs will be collected for the evaluation of cytokine concentrations (ELISA), STIs (nucleic acid amplification tests), BV (Nugent score) and vaginal microbiome characteristics (16S rRNA gene sequencing). The first collected vaginal swab will be used for the GIFT assay which will be performed in parallel by a healthcare worker in the clinic near the participant, and by a technician in the laboratory. The integration into care study aims to explore how GIFT could be integrated into routine care. Four activities will be conducted: user experiences and/or perceptions of the GIFT device involving qualitative focus group discussions and in-depth interviews with key stakeholders; discrete choice experiments; development of a decision tree classification algorithm; and economic evaluation of defined management algorithms. ETHICS AND DISSEMINATION: Findings will be reported to participants, collaborators and local government for the three sites, presented at national and international conferences, and disseminated in peer-reviewed publications.The protocol and all study documents such as informed consent forms were reviewed and approved by the University of Cape Town Human Research Ethics Committee (HREC reference 366/2022), Medical Research Council of Zimbabwe (MRCZ/A/2966), Comité d'Ethique pour la Recherche Biomédicale de Madagascar (N° 143 MNSAP/SG/AMM/CERBM) and the London School of Hygiene and Tropical Medicine ethics committee (LSHTM reference 28046).Before the start, this study was submitted to the Clinicaltrials.gov public registry (NCT05723484). TRIAL REGISTRATION NUMBER: NCT05723484.

Epidemiology of gonorrhoea: systematic review, meta-analyses, and meta-regressions, World Health Organization European Region, 1949 to 2021.

BackgroundEpidemiology of Neisseria gonorrhoeae (NG) infection remains inadequately understood.AimWe aimed to characterise NG epidemiology in Europe.MethodsWe used Cochrane and PRISMA guidelines to systematically review, report, synthesise and analyse NG prevalence data from 1949 to 30 September 2021. Random-effects meta-analyses estimated pooled prevalence. Meta-regression analyses investigated associations and sources of heterogeneity.ResultsThe 844 included publications yielded 1,573 prevalence measures. Pooled prevalence of current urogenital infection was 1.0% (95% CI: 0.7-1.2%) among general populations, 3.2% (95% CI: 1.8-4.8%) among female sex workers, 4.9% (95% CI: 4.2-5.6%) among sexually transmitted infection clinic attendees and 12.1% (95% CI: 8.8-15.8%) among symptomatic men. Among men who have sex with men, pooled prevalence was 0.9% (95% CI: 0.5-1.4%), 5.6% (95% CI: 3.6-8.1%), and 3.8% (95% CI: 2.5-5.4%), respectively, for current urogenital, anorectal or oropharyngeal infection. Current urogenital, anorectal or oropharyngeal infection was 1.45-fold (95% CI: 1.19-1.77%), 2.75-fold (95% CI: 1.89-4.02%) and 2.64-fold (95% CI: 1.77-3.93%) higher among men than women. Current urogenital infection declined 0.97-fold (95% CI: 0.96-0.98%) yearly, but anorectal and oropharyngeal infection increased (1.02-fold; 95% CI: 1.01-1.04% and 1.02-fold; 95% CI: 1.00-1.04%), respectively.ConclusionsNeisseria gonorrhoeae epidemiology in Europe has distinct and contrasting epidemiologies for vaginal sex transmission in heterosexual sex networks vs anal and oral sex transmission in MSM sexual networks. Increased transmission may facilitate drug-resistant strain emergence. Europe is far from achieving the World Health Organization target of 90% incidence reduction by 2030.

Corneal pannus, Herbert's pits and conjunctival inflammation in older children in Papua New Guinea.

PURPOSE: The prevalence of trachomatous inflammation-follicular (TF) in Papua New Guinea (PNG) suggests antibiotic mass drug administration (MDA) is needed to eliminate trachoma as a public health problem but the burden of trichiasis is low. As a result, WHO issued bespoke recommendations for the region. If ≥ 20% of 10-14-year-olds have both any conjunctival scarring (C1 or C2 or C3) and corneal pannus and/or Herbert's pits, MDA should be continued. Equally, if ≥ 5% of that group have both moderate/severe conjunctival scarring (C2 or C3) and corneal pannus and/or Herbert's pits, MDA should be continued. METHODS: We identified 14 villages where > 20% of 1-9-year-olds had TF during baseline mapping undertaken 4 years and 1 month previously. Every child aged 10-14 years in those villages was eligible to be examined for clinical signs of corneal pannus, Herbert's pits and conjunctival scarring. A grading system that built on existing WHO grading systems was used. RESULTS: Of 1,293 resident children, 1,181 (91%) were examined. Of 1,178 with complete examination data, only one (0.08%) individual had concurrent scarring and limbal signs. CONCLUSIONS: The WHO-predefined criteria for continuation of MDA were not met. Ongoing behavioural and environmental improvement aspects of the SAFE strategy may contribute to integrated NTD control. Surveillance methods should be strengthened to enable PNG health authorities to identify future changes in disease prevalence.

Accuracy, acceptability and feasibility of photography for use in trachoma surveys: a mixed methods study in Tanzania.

BACKGROUND: Photography could be used to train individuals to diagnose trachomatous inflammation-follicular (TF) as trachoma prevalence decreases and to ensure accurate field TF grading in trachoma prevalence surveys. We compared photograph and field TF grading and determined the acceptability and feasibility of eyelid photography to community members and trachoma survey trainers. METHODS: A total of 100 children ages 1-9 y were examined for TF in two Maasai villages in Tanzania. Two images of the right everted superior tarsal conjunctiva of each child were taken with a smartphone and a digital single-lens reflex (DSLR) camera. Two graders independently graded all photos. Focus group discussions (FGDs) were conducted with community members and Tropical Data trainers. RESULTS: Of 391 photos, one-fifth were discarded as ungradable. Compared with field grading, photo grading consistently underdiagnosed TF. Compared with field grading, DSLR photo grading resulted in a higher prevalence and sensitivity than smartphone photo grading. FGDs indicated that communities and trainers found photography acceptable and preferred smartphones to DSLR in terms of practicalities, but image quality was of paramount importance for trainers. CONCLUSIONS: Photography is acceptable and feasible, but further work is needed to ensure high-quality images that enable accurate and consistent grading before being routinely implemented in trachoma surveys.

Explaining the continuing high prevalence of trachomatous trichiasis unknown to the health system in evaluation units: a mixed methods explanatory study in four trachoma-endemic countries.

BACKGROUND: We explored reasons for continuing higher-than-anticipated prevalence of trachomatous trichiasis (TT) unknown to the health system in population-based prevalence surveys in evaluation units where full geographical coverage of TT case finding was reported. METHODS: A mixed-methods study in Ethiopia, Kenya, Nigeria and Tanzania was conducted. We compared data from clinical examination, campaign documentation and interviews with original trachoma impact survey (TIS) results. RESULTS: Of 169 TT cases identified by TIS teams, 130 (77%) were examined in this study. Of those, 90 (69%) were a match (both TIS and study teams agreed on TT classification) and 40 (31%) were a mismatch. Of the 40 mismatches, 22 (55%) were identified as unknown to the health system by the study team but as known to the health system by the TIS team; 12 (30%) were identified as not having TT by the study team but as having TT by the TIS team; and six (15%) were identified as unknown to the health system in the TIS team but as known to the health system by the study team based on documentation reviewed. CONCLUSIONS: Incorrectly reported geographical coverage of case-finding activities, and discrepancies in TT status between TIS results and more detailed assessments, are the key reasons identified for continuing high TT prevalence.

Prevalence of trachoma in Somali region, Ethiopia: results from trachoma impact surveys in 50 woredas.

BACKGROUND: Following interventions to eliminate trachoma in Somali region, Ethiopia, we aimed to re-estimate the prevalence of trachomatous trichiasis (TT) and trachomatous inflammation-follicular (TF) at woreda level and identify the factors associated with the disease. METHODS: We implemented cross-sectional community-based surveys in 50 trachoma-endemic woredas, using a standardized survey. Households were the secondary sampling unit. Surveys were undertaken through a combination of interviews of household heads and direct inspection of water, sanitation and hygiene (WASH) access, plus clinical evaluation of eligible household members for TT and TF. RESULTS: Overall, 41 (82%) of the 50 woredas had met the WHO-recommended active trachoma elimination threshold (prevalence of TF <5% in 1-9-y-olds) and 42 (84%) had met the TT threshold (prevalence of TT unknown to the health system <0.2% in ≥15-y-olds). Only 18% of households had access to an improved drinking water source within a 30-min trip and only 25% had an improved latrine. CONCLUSIONS: Additional rounds of antibiotic mass drug administration, plus interventions to enhance facial cleanliness and improve the environment, are required in nine woredas. TT surgical campaigns are needed in eight woredas. Greater access to WASH is required across all the woredas that were surveyed.

High prevalence of trachomatous inflammation-follicular with no trachomatous trichiasis: can alternative indicators explain the epidemiology of trachoma in Côte d'Ivoire?

Baseline trachoma surveys in Côte d'Ivoire (2019) identified seven evaluation units (EUs) with a trachomatous inflammation-follicular (TF) prevalence ≥10%, but a trachomatous trichiasis (TT) prevalence in individuals ≥15 y of age below the elimination threshold (0.2%). Two of these EUs, Bondoukou 1 and Bangolo 2, were selected for a follow-up survey to understand the epidemiology of trachoma using additional indicators of Chlamydia trachomatis infection (DNA from conjunctival swabs) and exposure (anti-Pgp3 and Ct694 antibodies from dried blood spots [DBSs]). A two-stage cluster sampling methodology was used to select villages and households. All individuals 1-9 y of age from each selected household were recruited, graded for trachoma and had a conjunctival swab and DBS collected. Conjunctival swabs and DBSs were tested using Cepheid GeneXpert and a multiplex bead assay, respectively. The age-adjusted TF and infection prevalence in 1- to 9-year-olds was <1% and <0.3% in both EUs. Age-adjusted seroprevalence was 5.3% (95% confidence interval [CI] 1.5 to 15.6) in Bondoukou 1 and 8.2% (95% CI 4.3 to 13.7) in Bangolo 2. The seroconversion rate for Pgp3 was low, at 1.23 seroconversions/100 children/year (95% CI 0.78 to 1.75) in Bondoukou 1 and 1.91 (95% CI 1.58 to 2.24) in Bangolo 2. Similar results were seen for CT694. These infection, antibody and clinical data provide strong evidence that trachoma is not a public health problem in either EU.

Gender differences in the surgical management of trachomatous trichiasis: an exploratory analysis of global trachoma survey data, 2015-2019.

BACKGROUND: Trachomatous trichiasis (TT) is a painful, potentially blinding eye condition that can be managed through epilation or surgery. Women are affected by TT approximately twice as often as men and are believed to face gendered barriers to receiving surgical care to prevent vision loss. METHODS: We used data from 817 cross-sectional surveys conducted during 2015-2019 in 20 African countries to estimate the prevalence difference (PD) between female and male eyes for four outcomes potentially indicating gender-related differences in TT management: (1) received surgery and developed postoperative TT (PTT), (2) never offered surgery, (3) offered surgery but declined it, and (4) offered epilation but never offered surgery. RESULTS: The prevalence was modestly elevated among female eyes compared with male eyes for having PTT (PD:1.8 [95% confidence limits (CL): 0.6, 3.0]) and having declined surgery for the eye (PD: 6.2 [95% CL: 1.8, 10.7]). The proportion offered epilation was similar by gender (PD:0.5 [95% CL: -0.4, 1.3]), while never having been offered surgery was somewhat more prevalent among male eyes (PD: -2.1 [95% CL: -3.5, -0.7]). CONCLUSIONS: Our results suggest potential gender differences in TT management. More research is needed to determine the causes and implications of the observed differences.

Tropical Data: Approach and Methodology as Applied to Trachoma Prevalence Surveys.

PURPOSE: Population-based prevalence surveys are essential for decision-making on interventions to achieve trachoma elimination as a public health problem. This paper outlines the methodologies of Tropical Data, which supports work to undertake those surveys. METHODS: Tropical Data is a consortium of partners that supports health ministries worldwide to conduct globally standardised prevalence surveys that conform to World Health Organization recommendations. Founding principles are health ministry ownership, partnership and collaboration, and quality assurance and quality control at every step of the survey process. Support covers survey planning, survey design, training, electronic data collection and fieldwork, and data management, analysis and dissemination. Methods are adapted to meet local context and needs. Customisations, operational research and integration of other diseases into routine trachoma surveys have also been supported. RESULTS: Between 29th February 2016 and 24th April 2023, 3373 trachoma surveys across 50 countries have been supported, resulting in 10,818,502 people being examined for trachoma. CONCLUSION: This health ministry-led, standardised approach, with support from the start to the end of the survey process, has helped all trachoma elimination stakeholders to know where interventions are needed, where interventions can be stopped, and when elimination as a public health problem has been achieved. Flexibility to meet specific country contexts, adaptation to changes in global guidance and adjustments in response to user feedback have facilitated innovation in evidence-based methodologies, and supported health ministries to strive for global disease control targets.

Prevalence and risk factors associated with Haemophilus ducreyi cutaneous ulcers in Cameroon.

Epidemics of yaws-like cutaneous ulcers are regularly documented in children in the tropics. They occur mainly in poor and remote communities without access to health facilities. The integration of molecular tools into yaws control efforts has made it possible to describe Haemophilus ducreyi (HD) as a major cause of cutaneous ulcers. The objective of this study was to determine the prevalence of HD as cause of cutaneous ulcers, investigate its presence in asymptomatic individuals and identify associated risk factors. A cross-sectional study was conducted in yaws endemic districts of Cameroon. Participants included people presenting yaws-like ulcers and asymptomatic individuals. Swab samples were collected from each participant and tested for HD and Treponema pallidum (TP) using an established qPCR method. Additionally, demographic, habitat, proximity, and hygiene characteristics were collected using a structured questionnaire. A total of 443 individuals participated in the study, including 271 ulcer cases and 172 asymptomatic contacts. The prevalence of HD in ulcers was 30.3% (Confidence Interval (CI) 95% [24.8-35.7]) and the prevalence of asymptomatic HD carriage was 8.6% (CI95% [4.5-12.9]). TP was also detected in our sample among ulcer cases but in lower proportion (5.2% CI95% [2.5-7.8]) compared to HD. The adjusted logistic regression model showed that women were as much at risk of having HD cutaneous ulcer as men regardless of age. Physical proximity to a confirmed ulcer case was the major factor identified favouring HD transmission. HD ulcers were more likely to be present on Bantu individuals compared to Baka as well as HD colonization. These findings highlight HD as the most common cause of cutaneous ulcers in yaws-endemic communities in Cameroon. The exact implications of detecting HD on intact skin are not yet clear. Further studies are needed to understand the significance of this carriage in the spread dynamics of the disease.

Twenty-Three Population-Based Trachoma Prevalence Surveys in the Central and Northern Regions of Benin, 2018-2022.

PURPOSE: Trachoma is an infectious eye disease caused by Chlamydia trachomatis. Infection causes conjunctival inflammation, which can be manifested by the sign known as trachomatous inflammation-follicular (TF). Repeated inflammation leads to eyelid scarring, which in susceptible individuals can cause in-turning of the eyelashes, referred to as trachomatous trichiasis (TT). This article describes 23 population-based surveys conducted in northern and central Benin to determine TF and/or TT prevalence for trachoma elimination purposes. METHODS: A total of 18 surveys estimated the prevalence of both TF and TT: two baseline surveys, eight impact surveys after implementation of interventions against trachoma, and eight surveillance surveys. Five other evaluation units (EUs) were surveyed for TT only. To estimate the TF prevalence, a target sample size of 1701 (baseline) and 1164 1-9-year-olds (impact and surveillance) was required, whereas 2818 ≥ 15-year-olds were required to estimate the less prevalent TT. In each EU, individuals were selected by two-stage cluster sampling and examined by certified graders for TF and/or TT. RESULTS: A total of 68,613 people were examined. TF prevalence estimates were under the 5% elimination threshold in all surveys. TT prevalence estimates were above the 0.2% elimination threshold in all five TT-only surveys and in four impact surveys, ranging from 0.2-0.57. CONCLUSION: TF prevalence in Benin is low, but TT was above 0.2% in nine districts. Increased case-finding and continuing efforts to improve surgery accessibility will be needed to reduce the burden of TT in Benin.

Prevalence of Trachoma After Three Rounds of Antibiotic Mass Drug Administration in 13 Woredas of Gambella Region, Ethiopia.

BACKGROUND: Following baseline surveys in 2013 and 2014, trachoma elimination interventions, including three rounds of azithromycin mass drug administration (MDA), were implemented in 13 woredas (administrative districts) of Gambella Regional State, Ethiopia. We conducted impact surveys to determine if elimination thresholds have been met or if additional interventions are required. METHODS: Cross-sectional population-based surveys were conducted in 13 woredas of Gambella Regional State, combined into five evaluation units (EUs), 6─12 months after their last MDA round. A two-stage systematic (first stage) and random (second stage) sampling technique was used. WHO-recommended protocols were implemented with the support of Tropical Data. Household water, sanitation and hygiene (WASH) access was assessed. RESULTS: The age-adjusted prevalence of trachomatous inflammation - follicular (TF) in 1-9-year-olds in the five EUs ranged from 0.3-19.2%, representing a general decline in TF prevalence compared to baseline estimates. The age- and gender-adjusted prevalence of trachomatous trichiasis (TT) unknown to the health system in those aged ≥ 15 years ranged from 0.47-3.08%. Of households surveyed, 44% had access to an improved drinking water source within a 30-minute return journey of the house, but only 3% had access to an improved latrine. CONCLUSION: In two EUs, no further MDA should be delivered, and a surveillance survey should be conducted after two years without MDA. In one EU, one further round of MDA should be conducted followed by another impact survey. In two EUs, three further MDA rounds are required. Surgery, facial cleanliness and environmental improvement interventions are needed throughout the region.

When Bacteria and Viruses Collide: A Tale of Chlamydia trachomatis and Sexually Transmitted Viruses.

The global incidence of sexually transmitted infections (STIs) remains high, with the World Health Organization (WHO) estimating that over 1 million people acquire STIs daily. STIs can lead to infertility, pregnancy complications, and cancers. Co-infections with multiple pathogens are prevalent among individuals with an STI and can lead to heightened infectivity and more severe clinical manifestations. Chlamydia trachomatis (CT) is the most reported bacterial STI worldwide in both men and women, and several studies have demonstrated co-infection of CT with viral and other bacterial STIs. CT is a gram-negative bacterium with a unique biphasic developmental cycle including infectious extracellular elementary bodies (EBs) and metabolically active intracellular reticulate bodies (RBs). The intracellular form of this organism, RBs, has evolved mechanisms to persist for long periods within host epithelial cells in a viable but non-cultivable state. The co-infections of CT with the most frequently reported sexually transmitted viruses: human immunodeficiency virus (HIV), human papillomavirus (HPV), and herpes simplex virus (HSV) have been investigated through in vitro and in vivo studies. These research studies have made significant strides in unraveling the intricate interactions between CT, these viral STIs, and their eukaryotic host. In this review, we present an overview of the epidemiology of these co-infections, while specifically delineating the underlying mechanisms by which CT influences the transmission and infection dynamics of HIV and HSV. Furthermore, we explore the intricate relationship between CT and HPV infection, with a particular emphasis on the heightened risk of cervical cancer. By consolidating the current body of knowledge, we provide valuable insights into the complex dynamics and implications of co-infection involving CT and sexually transmitted viruses.

Using model-based geostatistics for assessing the elimination of trachoma.

BACKGROUND: Trachoma is the commonest infectious cause of blindness worldwide. Efforts are being made to eliminate trachoma as a public health problem globally. However, as prevalence decreases, it becomes more challenging to precisely predict prevalence. We demonstrate how model-based geostatistics (MBG) can be used as a reliable, efficient, and widely applicable tool to assess the elimination status of trachoma. METHODS: We analysed trachoma surveillance data from Brazil, Malawi, and Niger. We developed geostatistical Binomial models to predict trachomatous inflammation-follicular (TF) and trachomatous trichiasis (TT) prevalence. We proposed a general framework to incorporate age and gender in the geostatistical models, whilst accounting for residual spatial and non-spatial variation in prevalence through the use of random effects. We also used predictive probabilities generated by the geostatistical models to quantify the likelihood of having achieved the elimination target in each evaluation unit (EU). RESULTS: TF and TT prevalence varied considerably by country, with Brazil showing the lowest prevalence and Niger the highest. Brazil and Malawi are highly likely to have met the elimination criteria for TF in each EU, but, for some EUs, there was high uncertainty in relation to the elimination of TT according to the model alone. In Niger, the predicted prevalence varied significantly across EUs, with the probability of having achieved the elimination target ranging from values close to 0% to 100%, for both TF and TT. CONCLUSIONS: We demonstrated the wide applicability of MBG for trachoma programmes, using data from different epidemiological settings. Unlike the standard trachoma prevalence survey approach, MBG provides a more statistically rigorous way of quantifying uncertainty around the achievement of elimination prevalence targets, through the use of spatial correlation. In addition to the analysis of existing survey data, MBG also provides an approach to identify areas in which more sampling effort is needed to improve EU classification. We advocate MBG as the new standard method for analysing trachoma survey outputs.

Baseline, Impact and Surveillance Trachoma Prevalence Surveys in Burundi, 2018-2021.

PURPOSE: Trachoma is an eye disease caused by the bacterium Chlamydia trachomatis (Ct). It can lead to permanent vision loss. Since 2007, Burundi has included trachoma elimination as part of its fight against neglected tropical diseases and blindness. This study presents the results of trachoma baseline, impact and surveillance surveys conducted in Burundi between 2018 and 2021. METHODS: Areas were grouped into evaluation units (EU) with resident populations of between 100,000 and 250,000 people. Baseline surveys were conducted in 15 EUs, impact surveys in 2 EUs and surveillance surveys in 5 EUs; in each survey, 23 clusters of about 30 households were included. Consenting residents of those households were screened for clinical signs of trachoma. Access to water, sanitation and hygiene (WASH) was recorded. RESULTS: A total of 63,800 individuals were examined. The prevalence of TF in 1-9-year-olds was above the elimination threshold of 5% in a single EU at baseline, but fell below the threshold in subsequent impact and surveillance surveys. The prevalence of TT was below the 0.2% elimination threshold in ≥15-year-olds in all EUs surveyed. A high proportion (83%) of households had access to safe drinking water, while only a minority (~8%) had access to improved latrines. CONCLUSION: Burundi has demonstrated the prevalence levels necessary for trachoma elimination status. With continued effort and the maintenance of existing management plans, trachoma elimination in Burundi is within reach.

The Gambia Trachomatous Trichiasis Surveys: Results from Five Evaluation Units Confirm Attainment of Trachoma Elimination Thresholds.

INTRODUCTION: Trichiasis is present when in-turned eyelashes touch the eyeball. It may result in permanent vision loss. Trachomatous trichiasis (TT) is caused by multiple rounds of inflammation associated with conjunctival Chlamydia trachomatis infection. Surveys have been designed to estimate the prevalence of TT in evaluation units (EUs) of trachoma-endemic countries in order to help develop appropriate programme-level plans. In this study, TT-only surveys were conducted in five EUs of The Gambia to determine whether further intensive programmatic action was required. METHODS: Two-stage cluster sampling was used to select 27 villages per EU and ~25 households per village. Graders assessed the TT status of individuals aged ≥15 years in each selected household, including the presence or absence of conjunctival scarring in those with TT. RESULTS: From February to March 2019, 11595 people aged ≥15 years were examined. A total of 34 cases of TT were identified. All five EUs had an age- and gender-adjusted prevalence of TT unknown to the health system <0.2%. Three of five EUs had a prevalence of 0.0%. CONCLUSION: Using these and other previously collected data, in 2021, The Gambia was validated as having achieved national elimination of trachoma as a public health problem. Trachoma is still present in the population, but as its prevalence is low, it is unlikely that today's youth will experience the exposure to C. trachomatis required to precipitate TT. The Gambia demonstrates that with political will and consistent application of human and financial resources, trachoma can be eliminated as a public health problem.