The population-based prevalence of trachomatous scarring in a trachoma hyperendemic setting: results from 152 impact surveys in Amhara, Ethiopia.

BACKGROUND: Trachomatous scarring (TS) results from repeated infection with the bacterium Chlamydia trachomatis. Pronounced scarring is an underlying cause of trachomatous trichiasis (TT) that can lead to blindness. Since the condition is irreversible, TS in adults has been considered a marker of past exposure to trachoma infection. The aim of this report was to estimate the population-based prevalence of TS within Amhara, Ethiopia, a region with a historically high burden of trachoma. METHODS: District-level multi-stage cluster surveys were conducted in all districts between 2010 and 2015 to monitor the impact of approximately 5 years of trachoma interventions. Approximately 40 households were sampled per cluster and all participants ages ≥ 1 year were graded for the 5 World Health Organization simplified signs. Before each survey round, trachoma graders participated in a 7-day training and reliability exam that included cases of TS. TS prevalence estimates were weighted to account for sampling design and adjusted for age and sex using post-stratification weighting. RESULTS: Across the 152 districts in Amhara, 208,510 individuals ages 1 year and older were examined for the signs of trachoma. Region-wide, the prevalence of TS was 8.2 %, (95 % Confidence Interval [CI]: 7.7-8.6 %), and the prevalence among individuals ages 15 years and older (n = 110,137) was 12.6 % (95 % CI: 12.0-13.3 %). District-level TS prevalence among individuals ages 15 years and older ranged from 0.9 to 36.9 % and was moderately correlated with district prevalence of TT (r = 0.31; P < 0.001). The prevalence of TS increased with age, reaching 22.4 % among those ages 56 to 60 years and 24.2 % among those ages 61 to 65 years. Among children ages 1 to 15 years TS prevalence was 2.2 % (95 % CI: 1.8-2.8 %), increased with age (P < 0.001), and 5 % of individuals with TS also had trachomatous inflammation-intense (TI). CONCLUSIONS: These results suggest that Amhara has had a long history of trachoma exposure and that a large population remains at risk for developing TT. It is promising, however, that children, many born after interventions began, have low levels of TS compared to other known trachoma-hyperendemic areas.

Population coverage and factors associated with participation following a mass drug administration of azithromycin for trachoma elimination in Amhara, Ethiopia.

OBJECTIVES: Mass drug administration (MDA) with azithromycin is a core component of the WHO-recommended strategy to eliminate trachoma as a public health problem, but low participation rates in MDA campaigns may undermine the effectiveness of this intervention. We explored factors associated with individual MDA participation at the individual, head of household and household levels in Amhara, Ethiopia. METHODS: We conducted four district-level, multilevel cluster random coverage surveys to collect data on self-reported MDA participation and predictors. Random-effects logistic regression modelling was used to identify correlates of MDA participation while adjusting for nesting of individuals at the household and village level. RESULTS: The district-level self-reported participation in the trachoma MDA ranged from 78.5% to 86.9%. Excellent and fair health status (Odds ratio [OR] = 5.77; 95% Confidence interval [CI]: 3.04, 10.95; OR = 7.08; 95% CI: 3.47, 14.46), advanced knowledge of the MDA campaign (OR = 2.93; 95% CI: 2.04, 4.21) and knowledge of trachoma (OR = 1.60; 95% CI: 1.17, 2.19) were all positively associated with MDA participation. When excluding heads of household from the model, correlates retained similar positive associations to participation, in addition to the head of household participation (OR = 3.34; 95% CI: 2.46, 4.54). CONCLUSIONS: To increase the impact of MDA campaigns, MDA mobilisation strategies-including comprehensive trachoma and azithromycin messaging and MDA campaign awareness-should target heads of household, those in poorer health and older age groups.

OBJECTIFS: La distribution en masse de médicaments (DMM) avec l'azithromycine est un élément central de la stratégie recommandée par l'OMS pour éliminer le trachome en tant que problème de santé publique, mais le faible taux de participation aux campagnes de DMM pourrait nuire à l'efficacité de cette intervention. Nous avons exploré les facteurs associés à la participation individuelle à la DMM au niveau de l'individu, du chef de ménage et du ménage à Amhara, en Ethiopie. MÉTHODES: Nous avons mené 4 surveillances de la couverture par grappes, aléatoire, à plusieurs niveaux au niveau du district afin de collecter des données sur la participation auto-déclarée à la DMM et les prédicteurs. Une modélisation par régression logistique à effets aléatoires a été utilisée pour identifier les corrélats de la participation à la DMM tout en ajustant la nidification des individus au niveau du ménage et du village. RÉSULTATS: La participation auto-déclarée au niveau du district à la DMM contre le trachome variait de 78,5% à 86,9%. L'état de santé excellent et passable (rapport de cotes [OR] = 5,77; intervalle de confiance à 95% [IC]: 3,04 -10,95 et OR = 7,08; IC95%: 3,47-14,46), la connaissance poussée sur la campagne de DMM (OR = 2,93; IC95%: 2,04, 4,21) et la connaissance sur le trachome (OR = 1,60; IC95%: 1,17, 2,19) étaient tous positivement associés à la participation à la DMM. En excluant les chefs de ménage du modèle, les corrélats ont conservé des associations positives similaires à la participation, en plus de la participation du chef de ménage (OR = 3,34; IC95%: 2,46, 4,54). CONCLUSIONS: Pour accroître l'impact des campagnes de DMM, les stratégies de mobilisation de la DMM, y compris le message complet sur le trachome et l'azithromycine, et la sensibilisation à la campagne de DMM, devraient cibler les chefs de famille, les personnes en mauvaise santé et les groupes de personnes plus âgées.

Population-Based Prevalence of Chlamydia trachomatis Infection and Antibodies in Four Districts with Varying Levels of Trachoma Endemicity in Amhara, Ethiopia.

The Trachoma Control Program in Amhara region, Ethiopia, scaled up the surgery, antibiotics, facial cleanliness, and environmental improvement (SAFE) strategy in all districts starting in 2007. Despite these efforts, many districts still require additional years of SAFE. In 2017, four districts were selected for the assessment of antibody responses against Chlamydia trachomatis antigens and C. trachomatis infection to better understand transmission. Districts with differing endemicity were chosen, whereby one had a previous trachomatous inflammation-follicular (TF) prevalence of ≥ 30% (Andabet), one had a prevalence between 10% and 29.9% (Dera), one had a prevalence between 5% and 10% (Woreta town), and one had a previous TF prevalence of < 5% (Alefa) and had not received antibiotic intervention for 2 years. Survey teams assessed trachoma clinical signs and took conjunctival swabs and dried blood spots (DBS) to measure infection and antibody responses. Trachomatous inflammation-follicular prevalence among children aged 1-9 years was 37.0% (95% CI: 31.1-43.3) for Andabet, 14.7% (95% CI: 10.0-20.5) for Dera, and < 5% for Woreta town and Alefa. Chlamydia trachomatis infection was only detected in Andabet (11.3%). Within these districts, 2,195 children provided DBS. The prevalence of antibody responses to the antigen Pgp3 was 36.9% (95% CI: 29.0-45.6%) for Andabet, 11.3% (95% CI: 5.9-20.6%) for Dera, and < 5% for Woreta town and Alefa. Seroconversion rate for Pgp3 in Andabet was 0.094 (95% CI: 0.069-0.128) events per year. In Andabet district, where SAFE implementation has occurred for 11 years, the antibody data support the finding of persistently high levels of trachoma transmission.

Ocular Chlamydia trachomatis infection and infectious load among pre-school aged children within trachoma hyperendemic districts receiving the SAFE strategy, Amhara region, Ethiopia.

BACKGROUND: After approximately 5 years of SAFE (surgery, antibiotics, facial cleanliness, environmental improvement) interventions for trachoma, hyperendemic (trachomatous inflammation-follicular (TF) ≥30%) districts remained in Amhara, Ethiopia. This study's aim was to characterize the epidemiology of Chlamydia trachomatis (Ct) infection and load among pre-school aged children living under the SAFE strategy. METHODS: Conjunctival swabs from a population-based sample of children aged 1-5 years collected between 2011 and 2015 were assayed to provide Ct infection data from 4 endemic zones (comprised of 58 districts). Ct load was determined using a calibration curve. Children were graded for TF and trachomatous inflammation-intense (TI). RESULTS: 7,441 children were swabbed in 4 zones. TF and TI prevalence were 39.9% (95% confidence Interval [CI]: 37.5%, 42.4%), and 9.2% (95% CI: 8.1%, 10.3%) respectively. Ct infection prevalence was 6.0% (95% CI: 5.0%, 7.2%). Infection was highest among children aged 2 to 4 years (6.6%-7.0%). Approximately 10% of infection occurred among children aged 1 year. Ct load decreased with age (P = 0.002), with the highest loads observed in children aged 1 year (P = 0.01) vs. aged 5 years. Participants with TF (P = 0.20) and TI (P<0.01) had loads greater than individuals without active trachoma. CONCLUSIONS: In this hyperendemic setting, it appears that the youngest children may contribute in meaningful ways towards persistent active trachoma.

Associations between Water, Sanitation and Hygiene (WASH) and trachoma clustering at aggregate spatial scales, Amhara, Ethiopia.

BACKGROUND: Trachoma is the leading infectious cause of blindness globally. The WHO has recommended the SAFE (Surgery, Antibiotics, Facial cleanliness and Environmental improvements) strategy to eliminate trachoma as a public health problem. The F and E arms of the strategy will likely be important for sustained disease reductions, yet more evidence is needed detailing relationships between hygiene, sanitation and trachoma in areas with differing endemicity. This study addressed whether the regional differences in water, sanitation, and hygiene (WASH) variables were associated with the spatial distribution of trachomatous inflammation-follicular (TF) among children aged 1 to 9 years in the Amhara National Regional State of Ethiopia. METHODS: Data from 152 multi-stage cluster random trachoma surveys were used to understand the degree of clustering of trachoma on two spatial scales (district and village) in Amhara using a geographical information system and the Getis-Ord Gi* (d) statistic for local clustering. Trained and certified graders examined children for the clinical signs of trachoma using the WHO simplified system. Socio-demographic, community, and geoclimatic factors thought to promote the clustering of the disease were included as covariates in a logistic regression model. RESULTS: The mean district prevalence of TF among children aged 1 to 9 years in Amhara was 25.1% (standard deviation = 16.2%). The spatial distribution of TF was found to exhibit global spatial dependency with neighboring evaluation units at both district and village level. Specific clusters of high TF were identified at both the district and the village scale of analysis using weighted estimates of the prevalence of the disease. Increased prevalence of children without nasal and ocular discharge as well as increased prevalence of households with access to a water source within 30 minutes were statistically significantly negatively associated with clusters of high TF prevalence. CONCLUSIONS: Water access and facial cleanliness were important factors in the clustering of trachoma within this hyperendemic region. Intensified promotion of structural and behavioral interventions to increase WASH coverage may be necessary to eliminate trachoma as a public health problem in Amhara and perhaps other hyper-endemic settings.

Self-Reported Side Effects following Mass Administration of Azithromycin to Eliminate Trachoma in Amhara, Ethiopia: Results from a Region-Wide Population-Based Survey.

A region-wide population-based post-mass drug administration (MDA) coverage survey was conducted 3 weeks following the 2016 trachoma MDA in Amhara, Ethiopia. The prevalence of self-reported side effects was assessed among those who self-reported receiving azithromycin. A total of 16,773 individuals from 5,129 households reported taking azithromycin during the 2016 MDA in Amhara. The regional prevalence of any self-reported side effect was 9.6% (95% CI: 8.3-11.2%) and ranged from 3.9% to 12.4% among the 10 zones. The most common reported side effects were abdominal pain (53.1%), nausea (21.7%), vomiting (12.8%), and diarrhea (12.5%). Side-effect prevalence among female members was higher than in male members (11.6% versus 7.6%; P < 0.001) and increased with age. After an average of 8 years of annual MDA, the prevalence of self-reported side effects was less than 10% in this population.

Trachoma prevalence remains below threshold in five districts after stopping mass drug administration: results of five surveillance surveys within a hyperendemic setting in Amhara, Ethiopia.

Background: The World Health Organization (WHO) recommends conducting trachoma surveillance surveys in districts where the elimination targets have been met and following a minimum 2-year period after cessation of mass drug administration (MDA) in order to determine the sustainability of low trachoma levels. Methods: In 2015, population-based surveillance surveys were conducted in five districts of Amhara, Ethiopia. All five districts had a prior trachomatous inflammation-follicular (TF) prevalence among children 1-9 y of age of <5% determined by an impact survey and had not received MDA for ≥2 y. Surveys included examinations for trachoma clinical signs and conjunctival swabbing to determine Chlamydia trachomatis infection prevalence. Results: Approximately 1000 children 1-9 y of age were examined for TF and 200 children 1-5 y of age were swabbed per district. All five surveillance districts had a TF prevalence of <5% and infection was only detected in one district. The prevalence of trachomatous trichiasis in adults ≥15 y of age was ≥1% in all districts. Conclusions: In a trachoma hyperendemic region, a TF prevalence <5% was successfully maintained in five districts for ≥2 years after stopping MDA. MDA is still not warranted for these districts, however, the S, F and E components of the SAFE strategy should continue.

Population-based coverage survey results following the mass drug administration of azithromycin for the treatment of trachoma in Amhara, Ethiopia.

BACKGROUND: Trachoma is the leading infectious cause of blindness worldwide. In communities where the district level prevalence of trachomatous inflammation-follicular among children ages 1-9 years is ≥5%, WHO recommends annual mass drug administration (MDA) of antibiotics with the aim of at least 80% coverage. Population-based post-MDA coverage surveys are essential to understand the effectiveness of MDA programs, yet published reports from trachoma programs are rare. METHODS: In the Amhara region of Ethiopia, a population-based MDA coverage survey was conducted 3 weeks following the 2016 MDA to estimate the zonal prevalence of self-reported drug coverage in all 10 administrative zones. Survey households were selected using a multi-stage cluster random sampling design and all individuals in selected households were presented with a drug sample and asked about taking the drug during the campaign. Zonal estimates were weighted and confidence intervals were calculated using survey procedures. Self-reported drug coverage was then compared with regional reported administrative coverage. RESULTS: Region-wide, 24,248 individuals were enumerated, of which, 20,942 (86.4%) individuals were present. The regional self-reported antibiotic coverage was 76.8% (95%Confidence Interval (CI):69.3-82.9%) in the population overall and 77.4% (95%CI = 65.7-85.9%) among children ages 1-9 years old. Zonal coverage ranged from 67.8% to 90.2%. Five out of 10 zones achieved a coverage >80%. In all zones, the reported administrative coverage was greater than 90% and was considerably higher than self-reported MDA coverage. Main reasons reported for MDA campaign non-attendance included being physically unable to get to MDA site (22.5%), traveling (20.6%), and not knowing about the campaign (21.0%). MDA refusal was low (2.8%) in this population. CONCLUSIONS: Although self-reported MDA coverage in Amhara was greater than 80% in some zones, programmatic improvements are warranted throughout Amhara to achieve higher coverage. These results will be used to enhance community mobilization and improve training for MDA distributors and supervisors to improve coverage in future MDAs.