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1.
Am J Trop Med Hyg ; 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-39353419

ABSTRACT

The purpose of this study was to investigate the correlation between bacterial load of Chlamydia trachomatis as measured from quantitative polymerase chain reaction (qPCR) and the relative clinical severity of trachomatous inflammation. Individuals with trachoma from rural communities in Ethiopia had photographs taken as well as swabs obtained of the upper tarsal conjunctivas. Conjunctival swabs were processed with PCR assay, which provided quantitative results of ocular chlamydial load. A series of 125 conjunctival photographs were ranked from least to most severe according to clinical severity for follicular and papillary conjunctivitis. Higher intensity rankings of trachomatous inflammation were associated with higher chlamydial load for both follicular inflammation (Spearman's ρ = 0.43; P <0.001) and papillary inflammation (Spearman's ρ = 0.50; P <0.001). Rankings of trachomatous inflammation may be a clinically meaningful indicator of trachoma.

2.
Cornea ; 2024 Sep 20.
Article in English | MEDLINE | ID: mdl-39312712

ABSTRACT

PURPOSE: Trachoma surveys are used to estimate the prevalence of trachomatous inflammation-follicular (TF) to guide mass antibiotic distribution. These surveys currently rely on human graders, introducing a significant resource burden and potential for human error. This study describes the development and evaluation of machine learning models intended to reduce cost and improve reliability of these surveys. METHODS: Fifty-six thousand seven hundred twenty-five everted eyelid photographs were obtained from 11,358 children of age 0 to 9 years in a single trachoma-endemic region of Ethiopia over a 3-year period. Expert graders reviewed all images from each examination to determine the estimated number of tarsal conjunctival follicles and the degree of trachomatous inflammation-intense. The median estimate of the 3 grader groups was used as the ground truth to train a MobileNetV3 large deep convolutional neural network to detect cases with TF. RESULTS: The classification model predicted a TF prevalence of 32%, which was not significantly different from the human consensus estimate (30%; 95% confidence interval of difference, -2 to +4%). The model had an area under the receiver operating characteristic curve of 0.943, F1 score of 0.923, 88% accuracy, 83% sensitivity, and 91% specificity. The area under the receiver operating characteristic curve increased to 0.995 when interpreting nonborderline cases of TF. CONCLUSIONS: Deep convolutional neural network models performed well at classifying TF and detecting the number of follicles evident in conjunctival photographs. Implementation of similar models may enable accurate, efficient, large-scale trachoma screening. Further validation in diverse populations with varying TF prevalence is needed before implementation at scale.

3.
Trop Med Int Health ; 29(10): 869-874, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39142662

ABSTRACT

OBJECTIVES: A 6-week course of tetracycline eye ointment is an alternative to single -dose oral azithromycin in annual mass drug administration for trachoma control. Compliance with the recommended tetracycline eye ointment regimen has not been well characterised when administered as part of a trachoma control program. METHODS: A routine mass drug administration for trachoma was carried out in 40 communities in the Amhara region of Ethiopia. Two tubes of tetracycline eye ointment, to be administered twice daily for 6 weeks, was offered to all children under 6 months of age, to pregnant women who declined to take azithromycin, and to all individuals with a macrolide allergy. Seven weeks following the mass drug administration, a treatment compliance survey was performed for all community members documented to have received tetracycline eye ointment during the mass drug administration. RESULTS: Of the 491 individuals documented as having received tetracycline eye ointment from the treatment records, 367 completed the survey, of which 214 recalled being offered tetracycline eye ointment. A total of 105 (49%) respondents reported taking ≥1 daily dose of tetracycline eye ointment on most days of the week for at least the first week. Only 20 (9%) respondents reported taking at least 1 tetracycline eye ointment dose per week for 6 weeks. The most common reasons for low compliance included 'saving it for a future infection' and 'stopped because I (or my child) seemed healthy'. The odds of low compliance were greater for those who reported not having adequate counselling (e.g., odds ratio [OR] 5.3, 95% CI 2.5-28.9 when low compliance was defined as not taking a tetracycline eye ointment dose for most days of at least the first week). CONCLUSIONS: Compliance with tetracycline eye ointment was low when administered by a trachoma program during a routine mass drug administration, especially for those reporting inadequate counselling. Further research with a larger sample size and varied settings is warranted to better understand and improve compliance.


Subject(s)
Anti-Bacterial Agents , Mass Drug Administration , Ointments , Tetracycline , Trachoma , Humans , Trachoma/drug therapy , Trachoma/prevention & control , Ethiopia , Tetracycline/administration & dosage , Tetracycline/therapeutic use , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Female , Male , Adult , Infant , Child, Preschool , Adolescent , Young Adult , Child , Azithromycin/administration & dosage , Azithromycin/therapeutic use , Medication Adherence/statistics & numerical data , Middle Aged , Pregnancy
4.
PLOS Glob Public Health ; 4(7): e0003242, 2024.
Article in English | MEDLINE | ID: mdl-39028729

ABSTRACT

Community-wide distribution of azithromycin, otherwise known as mass drug administration (MDA), is a component of the World Health Organization-endorsed SAFE strategy for the elimination of trachoma as a public health problem. In the Republic of South Sudan, 2.9 million people are known to live in areas that are known to require interventions and warrant MDA. This study estimated the total costs and cost per person treated during MDA in two counties, Kapoeta North and Kapoeta East, in South Sudan. MDA was conducted in Kapoeta North and Kapoeta East counties from October 2020 to January 2021. Following training and community sensitization, a core team, consisting of a height measurer, a drug dispenser, and a data recorder, delivered the intervention. A detailed costing database was developed in Microsoft Excel. An ingredients approach was used to capture all financial and economic costs incurred from a payer perspective. Primary outcomes included the total cost of MDA in each county and the cost per person treated in each county. In Kapoeta North, 58,226 people were treated at a financial cost of $71,350 USD. This corresponds to a unit cost of $1.22 per person treated. The total economic cost of the intervention was $99,036, at a unit cost of $1.70 per person treated. In Kapoeta East, 156,092 people were treated at a total financial cost of $168,404. This corresponds to a unit cost of $1.08 per person treated. The total economic cost of the intervention was $243,205, at a unit cost of $1.56 per person treated. The study highlights the cost variation for MDA implementation across two counties of South Sudan. As the South Sudan trachoma program expands, this information will be valuable for program planning.

5.
Am J Trop Med Hyg ; 111(3_Suppl): 105-113, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-38955191

ABSTRACT

Persistent trachoma is a growing concern to trachoma control programs globally and programs serving Ethiopia specifically. Persistent trachoma is defined as a district with two or more trachoma impact surveys (TISs) at which the prevalence of trachomatous inflammation-follicular (TF) among children ages 1-9 years is ≥5%, the elimination threshold. Because the global target for trachoma elimination as a public health problem is 2030, research is needed to better characterize persistent trachoma. This study described the epidemiology of ocular Chlamydia trachomatis infection, the causative bacteria of trachoma, in seven contiguous districts experiencing persistent trachoma. In 2019, multistage cluster random sampling TISs were conducted in the seven districts after 10 years of interventions. All individuals ages ≥1 year were examined for trachoma clinical signs by certified graders, and conjunctival swabs were collected from children ages 1-5 years to test for C. trachomatis infection. The district TF prevalence ranged from 11.8% (95% CI:7.6-16.0%) to 36.1% (95% CI:27.4-44.3%). The range of district-level C. trachomatis infection prevalence was between 2.7% and 34.4%. Statistically significant spatial clustering of high-infection communities was observed in the study districts, and children with infection were more likely than those without to be found in households with clinical signs of trachoma and those without latrines. These seven districts appear to constitute a persistent hotspot in Amhara, where an additional 3-5 years or more of interventions will be required. The global program will need to strengthen and enhance intervention strategies within persistent districts if elimination by 2030 is to be achieved.


Subject(s)
Chlamydia trachomatis , Trachoma , Humans , Trachoma/epidemiology , Trachoma/microbiology , Ethiopia/epidemiology , Chlamydia trachomatis/isolation & purification , Child, Preschool , Infant , Female , Male , Child , Prevalence , Endemic Diseases
6.
PLoS Negl Trop Dis ; 18(7): e0012257, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38991011

ABSTRACT

BACKGROUND: Promotion of facial cleanliness is recommended for the elimination of blinding trachoma, largely because of observational studies that have found an association between various measures of facial uncleanliness and trachoma. However, when a field grader assesses both facial cleanliness and trachoma, associations may be biased. Assessment of photographs of the face and conjunctiva by masked graders may provide a less biased estimate of the relationship between facial cleanliness and trachoma. METHODS: Face photographs, conjunctival photographs, and conjunctival swabs were obtained on a random sample of 0-9-year-old children from each of 40 communities in Amhara region, Ethiopia. Face photographs were assessed for the presence of seven measures of an unclean face (i.e., wet nasal discharge, dry nasal discharge, wet ocular discharge, dry ocular discharge, food, dust/dirt, and flies) by three independent masked photo-graders. Conjunctival photographs were similarly graded in a masked fashion for signs of clinically active trachoma. Conjunctival swabs were processed for Chlamydia trachomatis DNA. RESULTS: Of 2073 children with complete data, 808 (39%) had evidence of clinically active trachoma, 150 (7%) had evidence of ocular chlamydia infection, and 2524 (91%) had at least one measure of an unclean face. Dry ocular discharge had the strongest association with clinically active trachoma (age- and sex-adjusted prevalence ratio [PR] 1.4, 95% CI 1.2-1.6) and ocular chlamydia infection (PR 1.9, 95%CI 1.3-2.9), although significant associations were observed between each of the measures of facial uncleanliness and trachoma. CONCLUSIONS: Masked assessment of face and conjunctival photographs confirmed prior observational studies that have noted associations between various measures of facial uncleanliness and trachoma. The causal relationship between facial uncleanliness and trachoma is unclear since many features used to measure facial cleanliness (e.g., ocular discharge, nasal discharge, and flies) could be consequences of antecedent ocular chlamydia infection. TRIAL REGISTRATION: NCT02754583, clinicaltrials.gov.


Subject(s)
Conjunctiva , Face , Hygiene , Photography , Trachoma , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Chlamydia trachomatis/isolation & purification , Chlamydia trachomatis/genetics , Conjunctiva/microbiology , Conjunctiva/pathology , Cross-Sectional Studies , Ethiopia/epidemiology , Face/microbiology , Face/pathology , Trachoma/epidemiology , Trachoma/microbiology
7.
Am J Trop Med Hyg ; 111(3_Suppl): 121-126, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-38917786

ABSTRACT

Trachomatous scarring has been shown to progress regardless of active ocular Chlamydia trachomatis infection, indicating that scarring drivers may be unrelated to ongoing transmission. Although scarring prevalence is commonly associated with older age and female sex, less is known about other potential contributors to its development. This study identified and assessed risk factors associated with scarring magnitude in a trachoma-endemic setting, utilizing a five-point photographic scale (S0-S4). During 2017 trachoma surveys of Amhara, Ethiopia, photographers captured left and right conjunctival images of adults (ages 15 years and older) from 10 districts. Subsequently, two graders independently assessed photographs for scarring, with discrepancies adjudicated by an expert grader. Scarring scores for 729 individuals were aggregated from the eye level to the participant level, excluding 17 participants because of poor photograph quality. Among those with scarring, most cases (20.4%) were severe (S4, comprising more than 90% of the tarsal conjunctiva) compared with the prevalence of moderate S3-A/B (11.2%), S2 (8.3%), and mild S1 (19.2%). The youngest group (ages 15-19 years) exhibited all scarring stages. Older participants (60 years and older) experienced a greater burden of severe scarring (S4 prevalence: 32.6%) than their younger (15-19 years) counterparts (6.2%). Multivariate ordinal logistic regression models indicated female sex, increasing age, and district-level trachomatous follicular-inflammation prevalence were significant predictors of scarring severity. Trachomatous scarring and its progression to trichiasis, may prove a barrier to meeting WHO timelines for trachoma elimination and will necessitate ongoing surveillance and interventions after elimination thresholds have been met.


Subject(s)
Cicatrix , Trachoma , Humans , Trachoma/epidemiology , Ethiopia/epidemiology , Female , Male , Adult , Middle Aged , Cicatrix/epidemiology , Young Adult , Adolescent , Prevalence , Risk Factors , Aged , Chlamydia trachomatis , Endemic Diseases , Severity of Illness Index
8.
Am J Trop Med Hyg ; 111(3_Suppl): 58-68, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-38917816

ABSTRACT

Sudan is endemic for multiple neglected tropical diseases, including trachoma, onchocerciasis (OV), lymphatic filariasis (LF), and schistosomiasis (SCH). In 2019, dried blood spot samples were collected for a baseline trachoma serosurvey in three localities (El Seraif, Kotom, and Saraf Omrah) in North Darfur State. None were classified previously as OV- or LF-endemic, although low levels of SCH had been identified in all three. Approximately 30 households from 25 communities in each locality were selected by multistage cluster random sampling. Collections of DBSs were analyzed by multiplex bead assay for antibodies to multiple pathogens. This paper presents data on OV (Ov16), LF (Wb123, Bm14, Bm33), and SCH (soluble egg antigen [SEA], Sm25) antibodies among 8,322 individuals from 2,119 households. The survey-adjusted seroprevalence estimates for Ov16 were <0.3% in all localities. Lymphatic filariasis-antigen seroprevalences were discordant. Seroprevalence estimates ranged from 4.6-6.0% (Wb123), 0.99-1.4% (Bm14), and 29.2-33.3% (Bm33). Schistosomiasis seroprevalence estimates among school-aged children ranged from 2.7-8.0% (SEA) and 10.9-15.6% (Sm25). Ov16 seropositivity was low and supported the localities' classification as nonendemic. The results suggested LF exposure, but discordance between antigens, challenges defining seropositivity thresholds, and the absence of programmatic guidance based on antibody serology alone for Wuchereria bancrofti indicate a need for remapping surveys to confirm transmission. Schistosomiasis antibody levels were high enough to warrant further mapping to guide treatment decisions. The lack of gold standards limited interpretation of results, particularly for LF, but in resource-challenged areas, integrated serological surveillance offers the possibility of efficient monitoring of exposure to multiple diseases.


Subject(s)
Elephantiasis, Filarial , Onchocerciasis , Schistosomiasis , Humans , Sudan/epidemiology , Elephantiasis, Filarial/epidemiology , Elephantiasis, Filarial/immunology , Elephantiasis, Filarial/blood , Onchocerciasis/epidemiology , Onchocerciasis/blood , Onchocerciasis/immunology , Child , Adolescent , Male , Seroepidemiologic Studies , Female , Adult , Child, Preschool , Young Adult , Schistosomiasis/epidemiology , Schistosomiasis/blood , Middle Aged , Antibodies, Helminth/blood , Infant , Animals , Aged
9.
Am J Trop Med Hyg ; 111(3_Suppl): 114-120, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-38806020

ABSTRACT

The SAFE (Surgery, Antibiotics, Facial cleanliness, Environmental improvement) strategy is the WHO's endorsed approach for eliminating trachoma as a public health problem; however, not all components have been treated equally. Historically, the F and E components have not been prioritized owing to their perceived complexity. With school enrollment increasing in Ethiopia, development of a national school health program that is focused on the F and E components represents an opportunity to strengthen the SAFE strategy in the country. In 2016, the Trachoma Control Program in Amhara, Ethiopia, along with its partners, developed a School Trachoma Program (STP) that offers grade-specific lessons to improve sanitation and hygiene knowledge and practices among primary school-aged children. To assess its impact, schools were sampled before implementation and then up to 1 year after STP rollout. The aim of this report is to detail STP outcomes and the associations between outcomes and school-level variables. By 2018, adoption of an STP was strong within Amhara, with 85% of the 137 surveyed schools completing their quarterly reports and nearly 80% having at least one teacher trained in the STP. By the end of the third quarter, nearly all schools (86%) had access to a latrine, and 89% of students had a clean face. A schoolwide orientation was associated with increased STP lessons and activities (P = 0.01). Development of an STP, with buy-in from principals and teachers, represents a promising approach for the adoption of a new F- and E-specific curriculum and may help advance efforts to eliminate trachoma.


Subject(s)
Hygiene , Schools , Trachoma , Trachoma/prevention & control , Trachoma/epidemiology , Humans , Ethiopia/epidemiology , Child , Hygiene/standards , Sanitation/standards , School Health Services , Female , Male , Face , Anti-Bacterial Agents/therapeutic use , Health Knowledge, Attitudes, Practice
10.
PLoS Negl Trop Dis ; 18(4): e0012143, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38662795

ABSTRACT

Trachoma is the leading infectious cause of blindness worldwide and is now largely confined to around 40 low- and middle-income countries. It is caused by Chlamydia trachomatis (Ct), a contagious intracellular bacterium. The World Health Organization recommends mass drug administration (MDA) with azithromycin for treatment and control of ocular Ct infections, alongside improving facial cleanliness and environmental conditions to reduce transmission. To understand the molecular epidemiology of trachoma, especially in the context of MDA and transmission dynamics, the identification of Ct genotypes could be useful. While many studies have used the Ct major outer membrane protein gene (ompA) for genotyping, it has limitations. Our study applies a typing system novel to trachoma, Multiple Loci Variable Number Tandem Repeat Analysis combined with ompA (MLVA-ompA). Ocular swabs were collected post-MDA from four trachoma-endemic zones in Ethiopia between 2011-2017. DNA from 300 children with high Ct polymerase chain reaction (PCR) loads was typed using MLVA-ompA, utilizing 3 variable number tandem repeat (VNTR) loci within the Ct genome. Results show that MLVA-ompA exhibited high discriminatory power (0.981) surpassing the recommended threshold for epidemiological studies. We identified 87 MLVA-ompA variants across 26 districts. No significant associations were found between variants and clinical signs or chlamydial load. Notably, overall Ct diversity significantly decreased after additional MDA rounds, with a higher proportion of serovar A post-MDA. Despite challenges in sequencing one VNTR locus (CT1299), MLVA-ompA demonstrated cost-effectiveness and efficiency relative to whole genome sequencing, providing valuable information for trachoma control programs on local epidemiology. The findings suggest the potential of MLVA-ompA as a reliable tool for typing ocular Ct and understanding transmission dynamics, aiding in the development of targeted interventions for trachoma control.


Subject(s)
Bacterial Outer Membrane Proteins , Chlamydia trachomatis , Genotype , Minisatellite Repeats , Trachoma , Chlamydia trachomatis/genetics , Chlamydia trachomatis/isolation & purification , Chlamydia trachomatis/classification , Trachoma/epidemiology , Trachoma/microbiology , Trachoma/drug therapy , Humans , Ethiopia/epidemiology , Minisatellite Repeats/genetics , Bacterial Outer Membrane Proteins/genetics , Female , Male , Child, Preschool , Molecular Typing/methods , Azithromycin/therapeutic use , Genetic Variation , Infant , Child , Anti-Bacterial Agents/pharmacology , DNA, Bacterial/genetics
11.
Am J Trop Med Hyg ; 111(3_Suppl): 49-57, 2024 Sep 03.
Article in English | MEDLINE | ID: mdl-38507810

ABSTRACT

After years of programmatic inaccessibility, in 2019-2020 the Sudan Federal Ministry of Health Trachoma Control Program conducted population-based trachoma surveys in three localities (districts) in North Darfur state, Sudan. These baseline surveys were to determine the prevalence of trachomatous inflammation-follicular (TF) among children aged 1-9 years and to further use serological markers to understand the historical trachoma burden within this mass drug administration (MDA)-naive area. Trained and certified graders collected trachoma clinical data, and trained nurses collected dried blood spot (DBS) samples. The DBSs were assayed on a multiplex bead array for antibody responses to the Chlamydia trachomatis antigens Pgp3 and CT694. Across the three localities, 3,613 individuals aged 1-9 years and 3,542 individuals aged ≥15 years were examined for clinical signs, and 8,322 DBSs were collected. The prevalence of TF among children aged 1-9 years was endemic (≥5%) in two localities (El Seraif, 15.6%, and Saraf Omrah, 11.0%) and below the TF elimination threshold (<5%) in the third (Kotom, 1.4%). The Pgp3 seroprevalence among children aged 1-9 years was 34.1% in El Seraif, 35.0% in Saraf Omrah, and 11.0% in Kotom. Locality prevalence results were similar for Pgp3 and CT694. Seroprevalence increased with age in all three localities. Serological data collected within these surveys demonstrate that all three localities have had a long history of exposure to Chlamydia trachomatis and that two of the three localities require MDA to reach elimination as a public health problem threshold.


Subject(s)
Antibodies, Bacterial , Antigens, Bacterial , Chlamydia trachomatis , Mass Drug Administration , Trachoma , Humans , Trachoma/epidemiology , Sudan/epidemiology , Child , Child, Preschool , Infant , Chlamydia trachomatis/immunology , Female , Adolescent , Antigens, Bacterial/immunology , Male , Adult , Antibodies, Bacterial/blood , Young Adult , Prevalence , Seroepidemiologic Studies , Middle Aged , Dried Blood Spot Testing
12.
PLoS Negl Trop Dis ; 18(2): e0011986, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38386689

ABSTRACT

BACKGROUND: Trachoma recrudescence after elimination as a public health problem has been reached is a concern for control programs globally. Programs typically conduct district-level trachoma surveillance surveys (TSS) ≥ 2 years after the elimination threshold is achieved to determine whether the prevalence of trachomatous inflammation-follicular (TF) among children ages 1 to 9 years remains <5%. Many TSS are resulting in a TF prevalence ≥5%. Once a district returns to TF ≥5%, a program typically restarts costly mass drug administration (MDA) campaigns and surveys at least twice, for impact and another TSS. In Amhara, Ethiopia, most TSS which result in a TF ≥5% have a prevalence close to 5%, making it difficult to determine whether the result is due to true recrudescence or to statistical variability. This study's aim was to monitor recrudescence within Amhara by waiting to restart MDA within 2 districts with a TF prevalence ≥5% at TSS, Metema = 5.2% and Woreta Town = 5.1%. The districts were resurveyed 1 year later using traditional and alternative indicators, such as measures of infection and serology, a "wait and watch" approach. METHODS/PRINCIPAL FINDINGS: These post-surveillance surveys, conducted in 2021, were multi-stage cluster surveys whereby certified graders assessed trachoma signs. Children ages 1 to 9 years provided a dried blood spot and children ages 1 to 5 years provided a conjunctival swab. TF prevalence in Metema and Woreta Town were 3.6% (95% Confidence Interval [CI]:1.4-6.4) and 2.5% (95% CI:0.8-4.5) respectively. Infection prevalence was 1.2% in Woreta Town and 0% in Metema. Seroconversion rates to Pgp3 in Metema and Woreta Town were 0.4 (95% CI:0.2-0.7) seroconversions per 100 child-years and 0.9 (95% CI:0.6-1.5) respectively. CONCLUSIONS/SIGNIFICANCE: Both study districts had a TF prevalence <5% with low levels of Chlamydia trachomatis infection and transmission, and thus MDA interventions are no longer warranted. The wait and watch approach represents a surveillance strategy which could lead to fewer MDA campaigns and surveys and thus cost savings with reduced antibiotic usage.


Subject(s)
Trachoma , Humans , Infant , Trachoma/drug therapy , Trachoma/epidemiology , Trachoma/prevention & control , Ethiopia/epidemiology , Anti-Bacterial Agents/therapeutic use , Inflammation/drug therapy , Prevalence , Recurrence , Chlamydia trachomatis
13.
J Infect Dis ; 230(2): 293-297, 2024 Aug 16.
Article in English | MEDLINE | ID: mdl-38134305

ABSTRACT

Monitoring trachoma transmission with antibody data requires characterization of decay in IgG to Chlamydia trachomatis antigens. In a 3-year longitudinal cohort in a high-transmission setting, we estimated a median IgG half-life of 3 years and a seroreversion rate of 2.5 per 100 person-years (95% confidence interval, 1.6-3.5). Clinical Trials Registration NCT02754583.


Subject(s)
Antibodies, Bacterial , Antigens, Bacterial , Bacterial Proteins , Chlamydia trachomatis , Immunoglobulin G , Trachoma , Humans , Ethiopia/epidemiology , Chlamydia trachomatis/immunology , Antigens, Bacterial/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Trachoma/epidemiology , Trachoma/microbiology , Trachoma/immunology , Child, Preschool , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Female , Male , Bacterial Proteins/immunology , Infant , Longitudinal Studies , Child , Endemic Diseases
14.
Nat Commun ; 14(1): 3269, 2023 06 05.
Article in English | MEDLINE | ID: mdl-37277341

ABSTRACT

Trachoma, caused by ocular Chlamydia trachomatis infection, is targeted for global elimination as a public health problem by 2030. To provide evidence for use of antibodies to monitor C. trachomatis transmission, we collated IgG responses to Pgp3 antigen, PCR positivity, and clinical observations from 19,811 children aged 1-9 years in 14 populations. We demonstrate that age-seroprevalence curves consistently shift along a gradient of transmission intensity: rising steeply in populations with high levels of infection and active trachoma and becoming flat in populations near elimination. Seroprevalence (range: 0-54%) and seroconversion rates (range: 0-15 per 100 person-years) correlate with PCR prevalence (r: 0.87, 95% CI: 0.57, 0.97). A seroprevalence threshold of 13.5% (seroconversion rate 2.75 per 100 person-years) identifies clusters with any PCR-identified infection at high sensitivity ( >90%) and moderate specificity (69-75%). Antibody responses in young children provide a robust, generalizable approach to monitor population progress toward and beyond trachoma elimination.


Subject(s)
Trachoma , Child , Humans , Infant , Child, Preschool , Trachoma/diagnosis , Trachoma/epidemiology , Seroepidemiologic Studies , Antigens, Bacterial , Antibodies, Bacterial , Chlamydia trachomatis , Prevalence
15.
BMJ Glob Health ; 8(5)2023 05.
Article in English | MEDLINE | ID: mdl-37142297

ABSTRACT

INTRODUCTION: Delivering preventive chemotherapy through mass drug administration (MDA) is a central approach in controlling or eliminating several neglected tropical diseases (NTDs). Treatment coverage, a primary indicator of MDA performance, can be measured through routinely reported programmatic data or population-based coverage evaluation surveys. Reported coverage is often the easiest and least expensive way to estimate coverage; however, it is prone to inaccuracies due to errors in data compilation and imprecise denominators, and in some cases measures treatments offered as opposed to treatments swallowed. OBJECTIVE: Analyses presented here aimed to understand (1) how often coverage calculated using routinely reported data and survey data would lead programme managers to make the same programmatic decisions; (2) the magnitude and direction of the difference between these two estimates, and (3) whether there is meaningful variation by region, age group or country. METHODS: We analysed and compared reported and surveyed treatment coverage data from 214 MDAs implemented between 2008 and 2017 in 15 countries in Africa, Asia and the Caribbean. Routinely reported treatment coverage was compiled using data reported by national NTD programmes to donors, either directly or via NTD implementing partners, following the implementation of a district-level MDA campaign; coverage was calculated by dividing the number of individuals treated by a population value, which is typically based on national census projections and occasionally community registers. Surveyed treatment coverage came from post-MDA community-based coverage evaluation surveys, which were conducted as per standardised WHO recommended methodology. RESULTS: Coverage estimates using routine reporting and surveys gave the same result in terms of whether the minimum coverage threshold was reached in 72% of the MDAs surveyed in the Africa region and in 52% in the Asia region. The reported coverage value was within ±10 percentage points of the surveyed coverage value in 58/124 of the surveyed MDAs in the Africa region and 19/77 in the Asia region. Concordance between routinely reported and surveyed coverage estimates was 64% for the total population and 72% for school-age children. The study data showed variation across countries in the number of surveys conducted as well as the frequency with which there was concordance between the two coverage estimates. CONCLUSIONS: Programme managers must grapple with making decisions based on imperfect information, balancing needs for accuracy with cost and available capacity. The study shows that for many of the MDAs surveyed, based on the concordance with respect to reaching the minimum coverage thresholds, the routinely reported data were accurate enough to make programmatic decisions. Where coverage surveys do show a need to improve accuracy of routinely reported results, NTD programme managers should use various tools and approaches to strengthen data quality in order to use data for decision-making to achieve NTD control and elimination goals.


Subject(s)
Elephantiasis, Filarial , Mass Drug Administration , Child , Humans , Elephantiasis, Filarial/drug therapy , Elephantiasis, Filarial/epidemiology , Elephantiasis, Filarial/prevention & control , Surveys and Questionnaires , Africa , Neglected Diseases/epidemiology
16.
medRxiv ; 2023 May 17.
Article in English | MEDLINE | ID: mdl-36824972

ABSTRACT

Trachoma, caused by ocular Chlamydia trachomatis infection, is targeted for global elimination as a public health problem by 2030. To provide evidence for use of antibodies to monitor C. trachomatis transmission, we collated IgG responses to Pgp3 antigen, PCR positivity, and clinical observations from 19,811 children aged 1- 9 years in 14 populations. We demonstrate that age-seroprevalence curves consistently shift along a gradient of transmission intensity: rising steeply in populations with high levels of infection and active trachoma and becoming flat in populations near elimination. Seroprevalence (range: 0-54%) and seroconversion rates (range: 0-15 per 100 person-years) correlate with PCR prevalence (r: 0.87, 95% CI: 0.57, 0.97). A seroprevalence threshold of 13.5% (seroconversion rate 2.75 per 100 person-years) identifies clusters with any PCR-identified infection at high sensitivity (>90%) and moderate specificity (69-75%). Antibody responses in young children provide a robust, generalizable approach to monitor population progress toward and beyond trachoma elimination.

17.
medRxiv ; 2023 Dec 21.
Article in English | MEDLINE | ID: mdl-36798251

ABSTRACT

Monitoring trachoma transmission with antibody data requires characterization of decay in IgG to Chlamydia trachomatis antigens. In a three-year longitudinal cohort in a high transmission setting, we estimated a median IgG half-life of 3 years and a seroreversion rate of 2.5 (95% CI: 1.6, 3.5) per 100 person-years.

18.
BMC Ophthalmol ; 23(1): 51, 2023 Feb 06.
Article in English | MEDLINE | ID: mdl-36747194

ABSTRACT

BACKGROUND: The World Health Organization targeted trachoma for global elimination as a public health problem by 2030. Reaching elimination thresholds by the year 2030 in the Republic of South Sudan will be a considerable challenge, as the country currently has many counties considered hyper-endemic (> 30% trachomatous inflammation-follicular [TF]) that have yet to receive interventions. Evidence from randomized trials, modeling, and population-based surveys suggests that enhancements may be needed to the standard-of-care annual mass drug administration (MDA) to reach elimination thresholds in a timely manner within highly endemic areas. We describe a protocol for a study to determine the cost and community acceptability of enhanced antibiotic strategies for trachoma in South Sudan. METHODS: The Enhancing the A in SAFE (ETAS) study is a community randomized intervention costing and community acceptability study. Following a population-based trachoma prevalence survey in 1 county, 30 communities will be randomized 1:1 to receive 1 of 2 enhanced MDA interventions, with the remaining communities receiving standard-of-care annual MDA. The first intervention strategy will consist of a community-wide MDA followed by 2 rounds of targeted treatment to children ages 6 months to 9 years, 2 weeks and 4 weeks after the community MDA. The second strategy will consist of a community-wide biannual MDA approximately 6 to 8 months apart. The costing analysis will use a payer perspective and identify the total cost of the enhanced interventions and annual MDA. Community acceptability will be assessed through MDA coverage monitoring and mixed-methods research involving community stakeholders. A second trachoma-specific survey will be conducted 12 months following the original survey. DISCUSSION: ETAS has received ethical clearance and is expected to be conducted between 2022 and 2023. Results will be shared through subsequent manuscripts. The study's results will provide information to trachoma programs on whether enhanced interventions are affordable and acceptable to communities. These results will further help in the design of future trachoma-specific antibiotic efficacy trials. Enhanced MDA approaches could help countries recover from delays caused by conflict or humanitarian emergencies and could also assist countries such as South Sudan in reaching trachoma elimination as a public health problem by 2030. TRIAL REGISTRATION: This trial was registered on December 1st, 2022 (clinicaltrails.org: NCT05634759).


Subject(s)
Anti-Bacterial Agents , Trachoma , Child , Humans , Infant , Anti-Bacterial Agents/therapeutic use , Trachoma/drug therapy , Trachoma/epidemiology , South Sudan , Inflammation/drug therapy , Surveys and Questionnaires , Prevalence
19.
Am J Trop Med Hyg ; 108(2): 261-267, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36623484

ABSTRACT

Although trachoma mass drug administration (MDA) programs target ocular Chlamydia trachomatis, the global trachoma control program does not monitor infection as a measure of impact but instead relies on monitoring clinical indicators. This study aimed to monitor the prevalence of ocular C. trachomatis among a population-based sample of children ages 1-5 years throughout Amhara, Ethiopia, a region that has received approximately 8 years of annual MDA as part of trachoma control. Between 2014 and 2021, trachoma impact surveys and surveillance surveys were conducted in all 156 districts of Amhara using a multistage cluster randomized methodology. Certified graders assessed individuals ages ≥ 1 year for trachomatous inflammation-follicular (TF), and a random subset of children ages 1-5 years also provided a conjunctival swab. Polymerase chain reaction was used to test for C. trachomatis. A total of 28,410 conjunctival swabs were collected from children ages 1-5 years across Amhara. The regional C. trachomatis infection prevalence was 4.7% (95% uncertainty interval: 4.3-5.1%). Infection was detected in all 10 zones of the region and ranged from 0.2% in Awi Zone to 11.9% in Waghemra Zone. Infection was detected in 17 (26%) districts with a TF prevalence < 10% and in 7 (21%) districts with a TF prevalence < 5%. Through programmatic monitoring of C. trachomatis infection, this study demonstrated that considerable infection remained throughout Amhara despite approximately 8 years of trachoma interventions and that enhanced interventions such as more frequent than annual MDA will be needed if elimination thresholds are to be reached.


Subject(s)
Trachoma , Child , Child, Preschool , Humans , Infant , Anti-Bacterial Agents/therapeutic use , Chlamydia trachomatis , Ethiopia/epidemiology , Prevalence , Trachoma/drug therapy , Trachoma/epidemiology , Trachoma/prevention & control
20.
Trans R Soc Trop Med Hyg ; 117(2): 111-117, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36162054

ABSTRACT

BACKGROUND: As countries reach the trachoma elimination threshold and cases of trachomatous inflammation follicular (TF) become rare, it becomes difficult to train survey graders to recognize clinical signs. We assess the use of photography as a grading tool, the efficiency of an in-country grading center and the comparability of field and photographic grading. METHODS: During January-February 2017 surveys in Amhara, Ethiopia, field graders assessed TF, trachomatous inflammation intense (TI) and trachomatous scarring (TS). Photographs were taken from each conjunctiva and later graded at the Gondar Grading Center (GGC) at the University of Gondar in Amhara. Two trained ophthalmology residents graded each set of photographs and a third grader provided an adjudicating grade when needed. RESULTS: A total of 4953 photographs of 2477 conjunctivae from 1241 participants in 10 communities were graded over 5 d at the GGC. Six examined participants were not photographed. Agreement between field and photographic grades were for TF: percent agreement (PA) 96.7%, κ=0.70 (95% confidence interval [CI] 0.64 to 0.77; for TI: PA 94.7%, κ=0.32 (95% CI 0.20 to 0.43); and for TS: PA 83.5%, κ=0.22 (95% CI 0.15 to 0.29). CONCLUSIONS: Conjunctival photography may be a solution for programs near the elimination threshold where there are few available community cases for training field graders.


Subject(s)
Trachoma , Humans , Infant , Trachoma/diagnosis , Trachoma/epidemiology , Ethiopia/epidemiology , Conjunctiva , Photography , Inflammation , Prevalence
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