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 of visual impairment among school children in three primary schools of Sekela Woreda, Amhara regional state, north-west Ethiopia.

BACKGROUND: Although there are limited studies, recent data are lacking to determine the prevalence of eye problems in Ethiopia accurately and there is no scientific evidence of such study in Sekela Woreda. The purpose of this study was to determine the prevalence of visual impairment among school children in Sekela Woreda, Ethiopia. METHODS: The study design was a community-based analytical cross-sectional with a multi-stage cluster random sampling technique from September to November 2016.Visual acuity was tested using Snellen's "E" chart while color vision was tested using Ishihara chart. The data were analyzed using SPSS version 20 software, and binary logistic regression was used to identify factors associated with visual impairment. RESULTS: A total of 875 participants, 466 (53.3%) males and 409 (46.7%) females, with an age range of 8-18 years were screened for visual acuity and color vision deficiency. The prevalence of visual impairment (visual acuity ⩽ 6/12) in "either eye" was 70 (8.0%). Among these, 37 (52.9%) were males and 33 (41.1%) were females. The prevalence of low vision (visual acuity ≤ 6 / 36 ) and blindness (visual acuity < 3/60) in "either eye" were 28 (3.2%) and 10 (1.1%), respectively. Thirty two (3.7%) had mild visual impairment ( v i s u a l a c u i t y ≤ 6 / 12 t o ≥ 6 / 18 ) . The prevalence of color vision deficiency was 36 (4.1%). Among these, 27 (3%) were males and 9 (1.1%) were females. The variables age (adjusted odds ratio (95% confidence interval) = 1.14 (1.01-1.28) and color blindness (adjusted odds ratio (95% confidence interval) = 3.93(1.69-9.09) were significantly associated with visual impairment. CONCLUSION: The prevalence of blindness and low vision in school children were higher than the national prevalence in Ethiopia. Increasing age and color defective vision were factors associated with the children's visual impairment. The Woreda health office ought to work with responsible stakeholders to tackle the situation in early childhood.

Optimising age adjustment of trichiasis prevalence estimates using data from 162 standardised surveys from seven regions of Ethiopia.

PURPOSE: The prevalence of trichiasis is higher in females and increases markedly with age. Surveys carried out in the daytime, particularly in developing countries, are prone to find older individuals and females at home at the time of the survey. Population-level trichiasis estimates should adjust sample proportions to reflect the demographic breakdown of the population, although the most accurate method of doing this is unclear. METHODS: Having obtained data from 162 surveys carried out in Ethiopia as part of the Global Trachoma Mapping Project from 2012 to 2015, we used internal validation with both Brier and Logarithmic forecast scoring to test stratification models to identify those models with the highest predictive accuracy. Selection of partitions was undertaken by both simple random sampling (SRS) and cluster sampling (CS) over 8192 selections. RESULTS: A total of 4529 (1.9%) cases of trichiasis were identified from 241,139 individuals aged ≥15 years from a total of 4210 kebeles and 122,090 households visited. Overall, the binning method using 5-year bands from age 15 to 69 years, with coarser binning in 20-year age-bands above this age, provided the best predictive accuracy, in both SRS and CS methodologies and for both the Brier and Logarithmic scoring rules. CONCLUSION: The greatest predictive accuracy for trichiasis estimates was found by adjusting for sex and in 5-year age-bands from the age of 15 to 69 years and in 20-year age-bands in those aged 70 years and greater. Trichiasis surveys attempting to make population-level inferences should use this method to optimise surgery backlog estimates.

Prevalence of color blindness among school children in three primary schools of Gish -Abay town district, Amhara regional state, north-west Ethiopia.

BACKGROUND: Although there are limited studies, recent data are lacking to accurately determine the magnitude of color blindness in Ethiopia and there is no evidence of such a study in Gish Abay town district. The purpose of thie study was to assess the prevalence of color blindness among school children in Gish Abaya town district, Ethiopia. METHODS: The study used a community-based analytical cross-sectional study design with multistage cluster random sampling technique from September to October 2016. Three primary schools were selected randomly in the district of Gish Abay town district. Ishihara color plates (24 -edition) was used for color vision test and Snellen' tumbling 'E' chart was used for visual acuity test. The data was analyzed using Statistical Package for Social Sciences (SPSS) version 20 statistical software and binary logistic regression was used to identify factors associated with color blindness. RESULTS: Among a total of 854 subjects, 850 participants with age range of 8-18 years were screened for color vision test giving a response rate of 99.53%. Among the participants, 452 (53.2%) were males and 398 (46.8%) were females. There were 36 (4.24%) cases of impaired color vision. Among these, 27 (3.18%) were males and 9 (1.06%) were females. Out of 36 cases of color blindness, 15 (1.77%) were deutan, 7 (0.82%) were protan and 14(1.65%) were unclassified (both deutan and protan forms). The variables; sex adjusted odds ratio (AOR [95% Confidence Interval] =3.19 [1.45; 6.98], p-value = 0.004); and visual impairment (AOR [95% CI] =4.15 [1.77; 9.75], p-value = 0.001) were significantly associated with color impairment. CONCLUSION: The prevalence of childhood color blindness in Gish Abay town district was relatively similar with other studies in Ethiopia. Sex and visual impairment are factors found to be related with the children's color blindness. Periodical eye examination at the time of school admission is recommended to adjust the children's occupation early in life.

Prevalence of Trachoma in 47 Administrative Districts of Zambia: Results of 32 Population-Based Prevalence Surveys.

PURPOSE: A number of previous administrative-district-level baseline trachoma prevalence estimates in Zambia required verification. We used methodologies and systems for trachoma surveys considered to represent international best practice in order to generate reliable estimates of the prevalence of trachoma. METHODS: Between March 2016 and July 2017, we undertook 32 population-based prevalence surveys covering 47 administrative districts. In each of the 32 evaluation units (EUs), we selected 31 households in each of 24 clusters. In selected households, trained, certified graders examined all residents aged 1 year and above for evidence of trachomatous inflammation-follicular (TF) and trichiasis. In eyes that had trichiasis, the presence or absence of trachomatous scarring (TS) was recorded, and the subject was asked about previous trichiasis management recommendations from health workers. RESULTS: Five EUs (encompassing seven administrative districts) had prevalence estimates of trichiasis+TS unknown to the health system in ≥15-year-olds of ≥0.2%, and require public-health-level implementation of trichiasis surgery services. Eleven EUs (encompassing 16 administrative districts) had TF prevalence estimates in 1-9-year-olds of ≥5%. Intervention with the A, F and E components of the SAFE strategy for trachoma elimination is required for nearly 1.5 million people. CONCLUSION: Trachoma is a public health problem in some parts of Zambia. The Ministry of Health will continue to partner with other stakeholders to implement the multi-sectoral SAFE strategy. Consideration should be given to re-surveying other suspected-endemic administrative districts in which surveys using older methodologies returned TF prevalence estimates ≥5%.

Prevalence of trachoma in the Afar Region of Ethiopia: results of seven population-based surveys from the Global Trachoma Mapping Project.

PURPOSE: Trachoma is to be eliminated as a public health problem by 2020. To help the process of planning interventions where needed, and to provide a baseline for later comparison, we set out to complete the map of trachoma in Afar, Ethiopia, by estimating trachoma prevalence in evaluation units (EUs) of grouped districts ("woredas"). METHODS: We conducted seven community-based surveys from August to October 2013, using standardised Global Trachoma Mapping Project (GTMP) survey methodologies. RESULTS: We enumerated 5065 households and 18,177 individuals in seven EUs covering 19 of Afar's 29 woredas; the other ten were not accessible. 16,905 individuals (93.0%) were examined, of whom 9410 (55.7%) were female. One EU incorporating four woredas (Telalak, Dalefage, Dewe, Hadele Ele) was shown to require full implementation of the SAFE strategy for three years before impact survey, with a trachomatous inflammation-follicular (TF) prevalence in 1-9-year-olds of 17.1% (95%CI 9.4-25.5), and a trichiasis prevalence in adults aged ≥15 years of 1.2% (95%CI 0.6-2.0). Five EUs, covering 13 woredas (Berahle, Aba'ala, Dupti, Kurri, Elidihare, Ayesayeta, Afamboo, Bure Mudaitu, Gewane, Amibara, Dulecho, Dalolo, and Konebo), had TF prevalences in children of 5-9.9% and need one round of azithromycin mass treatment and implementation of the F and E components of SAFE before re-survey; three of these EUs had trichiasis prevalences in adults ≥0.2%. The final EU (Mile, Ada'ar) had a sub-threshold TF prevalence and a trichiasis prevalence in adults just >0.2%. CONCLUSION: Trachoma is a public health problem in Afar, and implementation of the SAFE strategy is required.

Success rate of probing in children with congenital nasolacrimal duct obstruction in Menellik II referral hospital

Introduction: The timing of probing for congenital nasolacrimal duct obstruction (CNLDO) has been a matter of controversy. This study was conducted to assess the success rate of probing in children with congenital nasolacrimal duct obstruction and to evaluate the association between success rate and age at the time of intervention. Methods: A prospective study was conducted between April 2014 and March 2015 on 71 children diagnosed to have congenital nasolacrimal duct obstruction. Patients were divided into three age categories. Group A was (1-4 years), group B (4- 7 years), and Group C (7-9 years). Probing was performed by two ophthalmic plastic and lacrimal surgeons under light sedation. Statistical analysis was conducted using Statistical Package for Social Sciences version 17.0. Chi-square test and Fisher's exact test with P value less than 0.05 were used to examine the relationship between success rates of probing and age.Results: A total of 101 eyes of 71 children, were included in the analysis. The overall probing success rate was found to be 88.1%. The success rate of probing was 96.0 % in group A, 82.4% in Group B and 33.3% in group C. Statistical analyses showed that there were significant differences in the success rate among these age groups (P< 0.0001).Conclusion: This study confirmed that success rate of probing is greatest in children between 1-4 years and declines with increasing age. Hence, earlier diagnosis and probing are recommended and can be taken as a first line treatment for children with reasonable outcome

Prevalence of and Risk Factors for Trachoma in Southern Nations, Nationalities, and Peoples' Region, Ethiopia: Results of 40 Population-Based Prevalence Surveys Carried Out with the Global Trachoma Mapping Project.

PURPOSE: We sought to estimate the prevalence of trachoma at sufficiently fine resolution to allow elimination interventions to begin, where required, in the Southern Nations, Nationalities, and Peoples' Region (SNNPR) of Ethiopia. METHODS: We carried out cross-sectional population-based surveys in 14 rural zones. A 2-stage cluster randomized sampling technique was used. A total of 40 evaluation units (EUs) covering 110 districts ("woredas") were surveyed from February 2013 to May 2014 as part of the Global Trachoma Mapping Project (GTMP), using the standardized GTMP training package and methodology. RESULTS: A total of 30,187 households were visited in 1047 kebeles (clusters). A total of 131,926 people were enumerated, with 121,397 (92.0%) consenting to examination. Of these, 65,903 (54.3%) were female. In 38 EUs (108 woredas), TF prevalence was above the 10% threshold at which the World Health Organization recommends mass drug administration with azithromycin annually for at least 3 years. The region-level age- and sex-adjusted trichiasis prevalence was 1.5%, with the highest prevalence of 6.1% found in Cheha woreda in Gurage zone. The region-level age-adjusted TF prevalence was 25.9%. The highest TF prevalence found was 48.5% in Amaro and Burji woredas. In children aged 1-9 years, TF was associated with being a younger child, living at an altitude <2500m, living in an area where the annual mean temperature was >15°C, and the use of open defecation by household members. CONCLUSION: Active trachoma and trichiasis are significant public health problems in SNNPR, requiring full implementation of the SAFE strategy (surgery, antibiotics, facial cleanliness, and environmental improvement).

Prevalence of Trachoma in Benishangul Gumuz Region, Ethiopia: Results of Seven Population-Based Surveys from the Global Trachoma Mapping Project.

PURPOSE: Trachoma is a major cause of blindness in Ethiopia, and targeted for elimination as a public health problem by the year 2020. Prevalence data are needed to plan interventions. We set out to estimate the prevalence of trachoma in each evaluation unit of grouped districts ("woredas") in Benishangul Gumuz region, Ethiopia. METHODS: We conducted seven cross-sectional community-based surveys, covering 20 woredas, between December 2013 and January 2014, as part of the Global Trachoma Mapping Project (GTMP). The standardized GTMP training package and methodologies were used. RESULTS: A total of 5828 households and 21,919 individuals were enumerated in the surveys. 19,583 people (89.3%) were present when survey teams visited. A total of 19,530 (99.7%) consented to examination, 11,063 (56.6%) of whom were female. The region-wide age- and sex-adjusted trichiasis prevalence in adults aged ≥15 years was 1.3%. Two evaluation units covering four woredas (Pawe, Mandura, Bulen and Dibate) with a combined rural population of 166,959 require implementation of the A, F and E components of the SAFE strategy (surgery, antibiotics, facial cleanliness and environmental improvement) for at least three years before re-survey, and intervention planning should begin for these woredas as soon as possible. CONCLUSION: Both active trachoma and trichiasis are public health problems in Benishangul Gumuz, which needs implementation of the full SAFE strategy.

Prevalence of and Risk Factors for Trachoma in Oromia Regional State of Ethiopia: Results of 79 Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project.

PURPOSE: To complete the baseline trachoma map in Oromia, Ethiopia, by determining prevalences of trichiasis and trachomatous inflammation - follicular (TF) at evaluation unit (EU) level, covering all districts (woredas) without current prevalence data or active control programs, and to identify factors associated with disease. METHODS: Using standardized methodologies and training developed for the Global Trachoma Mapping Project, we conducted cross-sectional community-based surveys from December 2012 to July 2014. RESULTS: Teams visited 46,244 households in 2037 clusters from 252 woredas (79 EUs). A total of 127,357 individuals were examined. The overall age- and sex-adjusted prevalence of trichiasis in adults was 0.82% (95% confidence interval, CI, 0.70-0.94%), with 72 EUs covering 240 woredas having trichiasis prevalences above the elimination threshold of 0.2% in those aged ≥15 years. The overall age-adjusted TF prevalence in 1-9-year-olds was 23.4%, with 56 EUs covering 218 woredas shown to need implementation of the A, F and E components of the SAFE strategy (surgery, antibiotics, facial cleanliness and environmental improvement) for 3 years before impact surveys. Younger age, female sex, increased time to the main source of water for face-washing, household use of open defecation, low mean precipitation, low mean annual temperature, and lower altitude, were independently associated with TF in children. The 232 woredas in 64 EUs in which TF prevalence was ≥5% require implementation of the F and E components of the SAFE strategy. CONCLUSION: Both active trachoma and trichiasis are highly prevalent in much of Oromia, constituting a significant public health problem for the region.

Bacteriological study of dacryocystitis among patients attending in Menelik II Hospital, Addis Ababa, Ethiopia.

BACKGROUND: Dacryocystitis usually results from blockage of the nasolacrimal duct. The treatment of such obstruction is surgery. There is a fivefold risk of soft tissue infection after open lacrimal surgery without systemic antibiotic prophylaxis that represents a significant risk of failure in lacrimal surgery. PURPOSE: To determine the current bacteriology of dacryocystitis and their sensitivity to different antibiotics at Menelik II Hospital. METHOD: Consecutive patients with dacryocystitis who presented to the department of ophthalmology at Menelik II Hospital between May 2004 and September 2005 were included in the study. Each patient was sent for culture and sensitivity test. Culture and sensitivity tests were obtained from Ethiopian National Health Research Institute (ENHRI), Arsho, Black Lion and Emmanuel Higher clinic laboratories. RESULTS: One hundred fourteen patients, 58 (50.9%) males and 56 (49.1%) females, with dacryocystitis were examined The majority of cases, 82 (71.9%), were under 30 years of age. Positive results were obtained from 91 (79.8%) patients. Gram-positive and gram negative organisms were isolated from 57 (62.6%) and 34 (37.4%) samples respectively. The five most common isolates were Streptococcus pneumoniae (23%), Streptococcus pyogens (14.3%), Staphylococcus aureus (12.1%), Streptococcus viridans (9.9%) and Haemophilus influenzae (9.9%). The antibiotics to which the majority of the isolates sensitive to were chloramphenicol (82.4%), gentamycin (79.1%), erythromycin (68.1%) and tetracycline (61.5%). While Streptococcus pneumoniae was sensitive to chloramphenicol in 95.2%. its sensitivity to tetracycline was 100%. Haemophilus influenzae was sensitive to tetracycline and chloramphenicol in 88.9% and 77.8% respectively. CONCLUSION: Gram positive organisms were the most common causes of dacryocystitis. Streptococcus pneumoniae and Haemophilus Influenza was the commonest gram positive and gram negative organisms identified respectively. Chloramphenicol and tetracycline were effective against these common organisms and are recommended for the clinical treatment of dacryocystitis.

Outcome of external dacryocystorhinostomy in Ethiopian patients.

BACKGROUND: An imbalance between tear production and drainage results in epiphora, which is an annoying symptom embarrassing the patient socially and functionally. The two widely accepted modalities of treatment for nasolacrimal duct obstruction (NLDO) are external dacryocystorhinostomy (EDCR) and endoscopic dacryocystorhinostomy. EDCR is the mainstay of treatment of NLDO and it remains to be the gold standard with which all other methods must be compared. OBJECTIVE: To determine the outcome of EDCR in Menelik II hospital, Addis Ababa, Ethiopia. The study was also intended to give a baseline data at a tertiary eye care center. METHODS: A prospective study was done in Menelik II Hospital. All patients scheduled for EDCR between June 2005 and May 2006 were included in the study. EDCR was done for all our cases. Success was defined by patient satisfaction (no complaint of tearing) supported by examination for regurgitation of fluid on pressing the lacrimal sac; and slit lamp assessment for increased tear meniscus. RESULTS: One hundred and twenty eight eyes of 106 patients were included in the study, 36 (34%) were males and 70 (66%) were females. The male to female ratio was approximately 1:2. The commonest indication for dacryocystorhinostomy was chronic dacryocystitis 93 (72.7%). Patients were followed postoperatively for a mean follow up period of 9.3 months (6-12 months). Success was recorded in 119 (93%) of operated eyes. Patients graded incision scar as excellent in 107 (83.6%) eyes, good in 9 (14.8%) and bad in 2 (1.6%) eyes. All patients respond that they would recommend operation for others. CONCLUSION: The success rate of EDCR in our set up is comparable to studies done in other parts of the world and EDCR is a very effective surgical procedure for our patients with NLDO.

Modified grading system for upper eyelid trachomatous trichiasis.

AIM: This study was conducted to determine the level of inter-observer agreement in the modified grading scheme for trichiasis of the upper eyelid. METHODS: A grading system that covers the entire spectrum of trachomatous trichiasis, extending from the simple to the severe forms, was initially developed by the first and second authors and field-tested. The grading scheme recognizes three levels of severity, based on deviation of the lid margin (TT1, TT2 and TT3); and four anatomical locations indicating where the eyelashes touch the globe in TT1 (nasal, central, temporal, or combined). The grading of trichiasis patients was then conducted on the basis of the modified grading scheme. RESULTS: The inter-observer agreement between the grades of simple trichiasis (TT1) and entropion (TT2) using Cronbach's alpha was 0.84, and the agreement within each sub-grade was 0.86. The weighted Kappa value was 0.68 (95% CI 0.57-0.79) for the main grades and 0.49 (95% CI 0.23-0.79) for the sub-grades. CONCLUSIONS: The inter-observer agreement was very reliable and could easily be attained by all levels of ophthalmic professionals. As the grading follows the natural progression of trichiasis from the simple to the severe forms in relation to the anatomical site involved, it helps to determine the degree of correction and how far to extend the surgical incision.

Accidentally discovered large metallic intra-orbital foreign body.

A 6.2 cm long and 2.7 cm thick metallic foreign body was accidentally found and removed from a 62 years old man. He was sent to a minor operation theater for repair of left lower lid laceration secondary to trauma after a fight. Subsequent investigation, management, patient follow-up and outcome are discussed. Importance of careful history taking, thorough physical examination and proper investigations are stressed.

A randomized clinical trial of the success rates of bilamellar tarsal rotation and tarsotomy for upper eyelid trachomatous trichiasis.

A randomized clinical trial study was conducted to compare the success rates of two surgical methods: Bilamellar Tarsal Rotation (BTR) and Tarsotomy (Transverse Tarsotomy and lid margin Rotation = TTR) for trachomatous trichiasis of the upper lid; where success was defined as no lash/eyeball contact in all positions of gaze, complete lid closure, no under or over correction. The study was conducted at Minellik II Hospital, Addis Ababa. Two hundred fifty six upper eyelids of 153 patients with entropion/trichiasis related to trachoma were enrolled in the two groups. Patients were randomly allocated for the BTR (124) and TTR (132) procedures. Out of these, 237 (92.6%) came for the third month follow-up. One hundred fifteen (48.5%) lids underwent BTR and the remaining 122 (51.5%) underwent TTR. In total, from 141 patients who came for the last follow up, 109 (77.3%) were females. BTR procedure was found to be successful in 25 (86.2%) of the eyelids with minor trichiasis and 74 (86.0%) of those with major trichiasis; the difference between patients who had had minor and major trichiasis (X2 = 0.08, P = 0.772) was not statistically significant. TTR was successful in 39 (95.1%) of the eyelids with minor trichiasis and 68 (84.0%) of those with major trichiasis, again no statistically significant difference was observed for minor and major trichiasis (X2 = 3.15, P = 0.379). There was no statistically significant difference in recurrence between BTR and TTR (X2 = 0.14, P = 0.711). Complications such as lid-notching, pyogenic granuloma, etc. were observed more in BTR than in TTR and this was statistically significant (X2 = 9.54, P = 0.002). In conclusion, the results show that TTR is equally successful in minor and major trichiasis and has fewer complications than BTR at three months of follow-up.