RESUMEN
Assessing the feasibility of 2030 as a target date for global elimination of trachoma, and identification of districts that may require enhanced treatment to meet World Health Organization (WHO) elimination criteria by this date are key challenges in operational planning for trachoma programmes. Here we address these challenges by prospectively evaluating forecasting models of trachomatous inflammation-follicular (TF) prevalence, leveraging ensemble-based approaches. Seven candidate probabilistic models were developed to forecast district-wise TF prevalence in 11 760 districts, trained using district-level data on the population prevalence of TF in children aged 1-9 years from 2004 to 2022. Geographical location, history of mass drug administration treatment, and previously measured prevalence data were included in these models as key predictors. The best-performing models were included in an ensemble, using weights derived from their relative likelihood scores. To incorporate the inherent stochasticity of disease transmission and challenges of population-level surveillance, we forecasted probability distributions for the TF prevalence in each geographic district, rather than predicting a single value. Based on our probabilistic forecasts, 1.46% (95% confidence interval [CI]: 1.43-1.48%) of all districts in trachoma-endemic countries, equivalent to 172 districts, will exceed the 5% TF control threshold in 2030 with the current interventions. Global elimination of trachoma as a public health problem by 2030 may require enhanced intervention and/or surveillance of high-risk districts.
Asunto(s)
Erradicación de la Enfermedad , Predicción , Salud Pública , Tracoma , Tracoma/epidemiología , Tracoma/prevención & control , Humanos , Preescolar , Lactante , Niño , Erradicación de la Enfermedad/métodos , Prevalencia , Modelos Estadísticos , Administración Masiva de Medicamentos , Organización Mundial de la Salud , Salud Global , Masculino , FemeninoRESUMEN
BACKGROUND: As the World Health Organization seeks to eliminate trachoma by 2020, countries are beginning to control the transmission of trachomatous inflammation-follicular (TF) and discontinue mass drug administration (MDA) with oral azithromycin. We evaluated the effect of MDA discontinuation on TF1-9 prevalence at the district level. METHODS: We extracted from the available data districts with an impact survey at the end of their program cycle that initiated discontinuation of MDA (TF1-9 prevalence <5%), followed by a surveillance survey conducted to determine whether TF1-9 prevalence remained below the 5% threshold, warranting discontinuation of MDA. Two independent analyses were performed, 1 regression based and 1 simulation based, that assessed the change in TF1-9 from the impact survey to the surveillance survey. RESULTS: Of the 220 districts included, TF1-9 prevalence increased to >5% from impact to surveillance survey in 9% of districts. Regression analysis indicated that impact survey TF1-9 prevalence was a significant predictor of surveillance survey TF1-9 prevalence. The proportion of simulations with >5% TF1-9 prevalence in the surveillance survey was 2%, assuming the survey was conducted 4 years after MDA. CONCLUSION: An increase in TF1-9 prevalence may represent disease resurgence but could also be due to measurement error. Improved diagnostic tests are crucial to elimination of TF1-9 as a public health problem.
Asunto(s)
Antibacterianos/administración & dosificación , Azitromicina/administración & dosificación , Administración Masiva de Medicamentos , Tracoma/tratamiento farmacológico , Tracoma/epidemiología , Administración Oral , Niño , Preescolar , Bases de Datos Factuales , Salud Global , Humanos , Lactante , Modelos Lineales , Prevalencia , Salud Pública , Procesos Estocásticos , Tracoma/prevención & control , Organización Mundial de la SaludRESUMEN
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.
Asunto(s)
Fotograbar , Tracoma , Tracoma/diagnóstico , Humanos , Tanzanía/epidemiología , Femenino , Masculino , Adulto , Niño , Grupos Focales , Preescolar , Estudios de Factibilidad , Pruebas Serológicas/métodos , Chlamydia trachomatis/aislamiento & purificación , Lactante , Persona de Mediana Edad , Adulto Joven , AdolescenteRESUMEN
BACKGROUND: Great progress has been made toward the elimination of trachoma as a public-health problem. Mathematical and statistical models have been used to forecast when the program will attain the goal of the elimination of active trachoma, defined as prevalence of trachomatous inflammation-follicular in 1-9 year olds (TF1-9) <5%. Here we use program data to create an empirical model predicting the year of attaining global elimination of TF1-9. METHODOLOGY/PRINCIPAL FINDINGS: We calculated the mean number of years (95% CI) observed for an implementation unit (IU) to move from a baseline TF1-9 prevalence ≥5% to the elimination threshold, based on the region (Ethiopia vs. non-Ethiopia) and baseline prevalence category. Ethiopia IUs had significantly different rates of reaching the TF1-9 elimination threshold after a trachoma impact survey (TIS) compared to non-Ethiopia IUs across all baseline categories. We used those estimates to predict when remaining active trachoma-endemic IUs (TF1-9 ≥5%) would have their last round of mass drug administration (MDA) based on the mean number of years required and number of MDA rounds already completed. Our model predicts that elimination of TF1-9 will be achieved in 2028 in Ethiopia (95% CI: 2026-2033) and 2029 outside of Ethiopia (95% CI: 2023-2034), with some IUs in East Africa predicted to be the last requiring MDA globally. CONCLUSIONS/SIGNIFICANCE: Our empirical estimate is similar to those resulting from previous susceptible-infectious-susceptible (SIS) and mathematical models, suggesting that the forecast achievement of TF1-9 elimination is realistic with the caveat that although disease elimination progress can be predicted for most IUs, there is an important minority of IUs that is not declining or has not yet started trachoma elimination activities. These IUs represent an important barrier to the timely global elimination of active trachoma.
Asunto(s)
Enfermedades del Recién Nacido , Tracoma , Estudios Transversales , Erradicación de la Enfermedad , Humanos , Lactante , Recién Nacido , Administración Masiva de Medicamentos , Prevalencia , Tracoma/tratamiento farmacológico , Tracoma/epidemiología , Tracoma/prevención & controlRESUMEN
BACKGROUND: The International Trachoma Initiative (ITI) provides azithromycin for mass drug administration (MDA) to eliminate trachoma as a public health problem. Azithromycin is given as tablets for adults and powder for oral suspension (POS) is recommended for children aged <7 y, children <120 cm in height (regardless of age) or anyone who reports difficulty in swallowing tablets. An observational assessment of MDA for trachoma was conducted to determine the frequency with which children aged 6 mo through 14 y received the recommended dose and form of azithromycin according to current dosing guidelines and to assess risk factors for choking and adverse swallowing events (ASEs). METHODS: MDA was observed in three regions of Ethiopia and data were collected on azithromycin administration and ASEs. RESULTS: A total of 6477 azithromycin administrations were observed; 97.9% of children received the exact recommended dose. Of children aged 6 mo to <7 y or <120 cm in height, 99.6% received POS. One child experienced choking and 132 (2%) experienced ≥1 ASEs. Factors significantly associated with ASEs included age 6-11 mo or 1-6 y, non-calm demeanor and requiring coaxing prior to drug administration. CONCLUSIONS: There is a high level of adherence to the revised azithromycin dosing guidelines and low incidence of choking and ASEs.
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Obstrucción de las Vías Aéreas , Tracoma , Adulto , Obstrucción de las Vías Aéreas/tratamiento farmacológico , Antibacterianos/efectos adversos , Azitromicina/efectos adversos , Niño , Etiopía/epidemiología , Humanos , Lactante , Administración Masiva de Medicamentos , Polvos/uso terapéutico , Tracoma/tratamiento farmacológico , Tracoma/epidemiologíaRESUMEN
BACKGROUND: To facilitate mass distribution of azithromycin, trachoma control programmes use height instead of weight to determine dose for children 6 months to 15 years old. WHO has recommended azithromycin distribution to children 1-11 months old to reduce mortality in high mortality settings under carefully monitored conditions. Weight was used to determine dose in children 1-5 months old in studies of azithromycin distribution for child survival, but a simplified approach using age or height for all aged 1-11 months old could increase programme efficiency in real-world settings. METHODS: This secondary analysis used data from two cluster randomised trials of azithromycin distribution for child mortality in Niger and Burkina Faso. An exhaustive search algorithm was developed to determine the optimal dose for different age groups, using tolerance limits of 10-20 mg/kg for children 1-2 months old and 15-30 mg/kg for children 3-11 months old. Height-based dosing was evaluated against the existing trachoma dosing pole and with a similar exhaustive search. RESULTS: The optimal two-tiered age-based approach suggested a dose of 80 mg (2 mL) for children 1-2 months old and 160 mg (4 mL) for children 3-11 months old. Under this schedule, 89%-93% of children would have received doses within tolerance limits in both study populations. Accuracy was 93%-94% with a three-tiered approach, which resulted in doses of 80 mg (2 mL), 120 mg (3 mL) and 160 mg (4 mL) for children 1-2, 3-4 and 5-11 months old, respectively. For children 1-5 months old, the existing height pole would result in 70% of doses within tolerance limits. The optimisation identified height-based dosing options with 95% accuracy, although this would require changes to the existing dosing pole as well as additional training to measure infants lying flat. CONCLUSIONS: Overall, an age-based approach with two age tiers resulted in high accuracy while considering both concerns about overdosing in this young population and simplicity of field operations.
Asunto(s)
Azitromicina , Tracoma , Antibacterianos/uso terapéutico , Estatura , Niño , Mortalidad del Niño , Humanos , Lactante , Tracoma/tratamiento farmacológico , Tracoma/epidemiologíaRESUMEN
BACKGROUND: Global elimination of trachoma as a public health problem was targeted for 2020. We reviewed progress towards the elimination of active trachoma by country and geographical group. METHODS: In this retrospective analysis of national survey and implementation data, all countries ever known to be endemic for trachoma that had either implemented at least one trachoma impact survey shown in the publicly available Trachoma Atlas, or are in Africa were invited to participate in this study. Scale-up was described according to the number of known endemic implementation units and mass drug administration implementation over time. The prevalence of active trachoma-follicular among children aged 1-9 years (TF1-9) from baseline, impact, and surveillance surveys was categorised and used to show programme progress towards reaching the elimination threshold (TF1-9 <5%) using dot maps, spaghetti plots, and boxplots. FINDINGS: We included data until Nov 10, 2021, for 38 countries, representing 2097 ever-endemic implementation units. Of these, 1923 (91·7%) have had mass drug administration. Of 1731 implementation units with a trachoma impact survey, the prevalence of TF1-9 had reduced by at least 50% in 1465 (84·6%) implementation units and 1182 (56·4%) of 2097 ever-endemic implementation units had reached the elimination threshold. 2 years after reaching a TF1-9 prevalence below 5%, most implementation units sustained this target; however, 58 (56·3%) of 103 implementation units in Ethiopia showed recrudescence. INTERPRETATION: Global elimination of trachoma as a public health problem by 2020 was not possible, but this finding masks the great progress achieved. Implementation units in high baseline categories and recrudescent TF1-9 might prolong the attainment of elimination of active trachoma. Elimination is delayed but, with an understanding of the patterns and timelines to reaching elimination targets and a commitment toward meeting future targets, global elimination can still be achieved by 2030. FUNDING: None.
Asunto(s)
Enfermedades del Recién Nacido , Tracoma , Niño , Preescolar , Etiopía/epidemiología , Humanos , Lactante , Recién Nacido , Administración Masiva de Medicamentos , Prevalencia , Salud Pública , Estudios Retrospectivos , Tracoma/epidemiología , Tracoma/prevención & controlRESUMEN
Models predict that the negative effects of delayed implementation in trachoma elimination programmes caused by the COVID-19 pandemic will be minimal, except in high prevalence districts where progress may be reversed. During times of change we must stand by our principles of evidence-based decision-making, but also be willing to show flexibility. Slow progress to elimination in high prevalence districts was already a significant challenge to the global programme and mitigation of COVID-related delays with enhanced implementation provides an opportunity to simultaneously address an unprecedented challenge and a pre-existing one.
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COVID-19/epidemiología , Control de Enfermedades Transmisibles/organización & administración , Enfermedades Desatendidas/epidemiología , Enfermedades Desatendidas/prevención & control , Tracoma/epidemiología , Tracoma/prevención & control , Humanos , Modelos Teóricos , Pandemias , Prevalencia , SARS-CoV-2 , Organización Mundial de la SaludRESUMEN
During its first 8 years, the Global Programme to Eliminate Lymphatic Filariasis provided more than 1900 million treatments with antifilarial drugs (albendazole, ivermectin and diethylcarbamazine) to at least 570 million people in 48 countries with endemic lymphatic filariasis (LF). As a result of this impressive global effort and an unprecedented public-private partnership, 8 years of mass drug administration (MDA) have prevented the spread of filarial infection to an estimated 6.6 million newborns, stopped the progression to clinical morbidity in 9.5 million individuals already infected with the parasites that cause LF, and drastically reduced the burden of several co-infections. The resulting health benefits of the MDA, in terms of reduced morbidity and disability-adjusted life-years, are thus enormous. The next step should be an analysis of the Global Programme's economic impact from its first 8 years of MDA.
Asunto(s)
Albendazol/uso terapéutico , Filariasis Linfática/prevención & control , Filaricidas/uso terapéutico , Enfermedades del Recién Nacido/prevención & control , Ivermectina/uso terapéutico , Albendazol/provisión & distribución , Animales , Niño , Control de Enfermedades Transmisibles , Progresión de la Enfermedad , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Filaricidas/provisión & distribución , Salud Global , Humanos , Recién Nacido , Enfermedades del Recién Nacido/tratamiento farmacológico , Enfermedades del Recién Nacido/parasitología , Ivermectina/provisión & distribución , Evaluación de Programas y Proyectos de Salud , Factores de TiempoRESUMEN
Mass azithromycin distribution is a core component of trachoma control programmes and could reduce mortality in children younger than 5 years in some settings. In this systematic review we synthesise evidence on the emergence of antimicrobial resistance after mass azithromycin distribution. We searched electronic databases for publications up to June 14, 2018. We included studies of any type (excluding modelling studies, surveillance reports, and review articles) on community-wide distribution of oral azithromycin for the prevention and treatment of trachoma that assessed macrolide resistance, without restrictions to the type of organism. We extracted prevalence of resistance from published reports and requested unpublished data from authors of included studies. Of 213 identified studies, 19 met inclusion criteria (12 assessed Streptococcus pneumoniae) and were used for qualitative synthesis. Macrolide resistance after azithromycin distribution was reported in three of the five organisms studied. The lack of resistance in Chlamydia trachomatis suggests that azithromycin might remain effective for trachoma programmes, but evidence is scarce. As mass azithromycin distribution for trachoma continues and is considered for other indications, ongoing monitoring of antimicrobial resistance will be required.
Asunto(s)
Antibacterianos/uso terapéutico , Azitromicina/uso terapéutico , Chlamydia trachomatis/efectos de los fármacos , Farmacorresistencia Bacteriana/efectos de los fármacos , Tracoma/tratamiento farmacológico , Tracoma/epidemiología , Administración Oral , Adolescente , Antibacterianos/administración & dosificación , Antibacterianos/efectos adversos , Azitromicina/administración & dosificación , Azitromicina/efectos adversos , Niño , Preescolar , Femenino , Humanos , Lactante , Macrólidos/efectos adversos , Macrólidos/uso terapéutico , Masculino , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/microbiología , Prevalencia , Streptococcus pneumoniae/efectos de los fármacos , Tracoma/microbiología , Resultado del TratamientoRESUMEN
In collaboration with the health ministries that we serve and other partners, we set out to complete the multiple-country Global Trachoma Mapping Project. To maximize the accuracy and reliability of its outputs, we needed in-built, practical mechanisms for quality assurance and quality control. This article describes how those mechanisms were created and deployed. Using expert opinion, computer simulation, working groups, field trials, progressively accumulated in-project experience, and external evaluations, we developed 1) criteria for where and where not to undertake population-based prevalence surveys for trachoma; 2) three iterations of a standardized training and certification system for field teams; 3) a customized Android phone-based data collection app; 4) comprehensive support systems; and 5) a secure end-to-end pipeline for data upload, storage, cleaning by objective data managers, analysis, health ministry review and approval, and online display. We are now supporting peer-reviewed publication. Our experience shows that it is possible to quality control and quality assure prevalence surveys in such a way as to maximize comparability of prevalence estimates between countries and permit high-speed, high-fidelity data processing and storage, while protecting the interests of health ministries.
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Recolección de Datos/métodos , Salud Global/estadística & datos numéricos , Encuestas Epidemiológicas/normas , Enfermedades Desatendidas/epidemiología , Tracoma/epidemiología , Chlamydia trachomatis/patogenicidad , Humanos , Almacenamiento y Recuperación de la Información , Cooperación Internacional , Enfermedades Desatendidas/microbiología , Enfermedades Desatendidas/patología , Prevalencia , Control de Calidad , Tracoma/microbiología , Tracoma/patologíaRESUMEN
Peripheral blood stem cell (PBSC) transplantation is a promising new therapy in the treatment of malignancies. It is being used to supplement and in place of bone marrow transplantation to restore hematopoiesis after myeloablative therapy. PBSCs are collected through apheresis, generally after a course of myelosuppressive therapy to prime the progenitor cells. Problems that potentially could arise during PBSC collection include citrate toxicity, hypovolemia, and thrombocytopenia. PBSC infusion is similar to the infusion of bone marrow. Engraftment following PBSC transplantation progresses rapidly, resulting in shorter hospital stays. The future of PBSC therapy looks promising, but much still has to be learned about this innovative treatment.