A Longitudinal Analysis of Chlamydial Infection and Trachomatous Inflammation Following Mass Azithromycin Distribution

Background: Mass azithromycin distributions are effective for clearing ocular strains of Chlamydia trachomatis, yet infection frequently returns in areas with hyperendemic trachoma. A better understanding of the factors associated with chlamydial reinfection could be helpful to plan trachoma elimination strategies.

Methods: This was a prospective cohort study conducted in a trachoma-hyperendemic region of Ethiopia in 2003. As part of a larger cluster-randomized trial, 21 villages were treated with a single mass azithromycin distribution and all children 5 years and younger were monitored for ocular chlamydia and clinically active trachoma at baseline and at 2 and 6 months following the treatment.

Results: In 20 villages with available data, azithromycin treatment coverage was 88.7% (95% confidence interval [CI] 85.7–91.8%). In total, 1005 children tested negative for ocular chlamydia at the 2-month visit, of whom 41 became infected by 6 months (1.0 incident chlamydia infections per 100 person-months, 95%CI 0.7–1.4). The presence of intense trachomatous inflammation (TI) at baseline was associated with incident infection at 6 months (incidence rate ratio 1.91, 95%CI 1.03–3.55). Ocular chlamydia infections clustered more within households than communities: (intraclass correlation coefficient 0.01 for communities and 0.29 for households six months posttreatment). Younger children were more likely to have persistent clinically active trachoma (P = 0.03).

Conclusions: More intensive antibiotic distributions may be warranted for younger children, for children with TI, and for households containing children with ocular chlamydia infections.     

Population-Based Trachoma Mapping in Six Evaluation Units of Papua New Guinea

ABSTRACT

Purpose: We sought to determine the prevalence of trachomatous inflammation – follicular (TF) in children aged 1–9 years, and trachomatous trichiasis (TT) in those aged ≥15 years, in suspected trachoma-endemic areas of Papua New Guinea (PNG).

Methods: We carried out six population-based prevalence surveys using the protocol developed as part of the Global Trachoma Mapping Project.

Results: A total of 19,013 individuals were sampled for inclusion, with 15,641 (82.3%) consenting to participate. Four evaluation units had prevalences of TF in children ≥10%, above which threshold the World Health Organization (WHO) recommends mass drug administration (MDA) of azithromycin for at least three years; Western Province (South Fly/Daru) 11.2% (95% confidence interval, CI, 6.9–17.0%), Southern Highlands (East) 12.2% (95% CI 9.6–15.0%), Southern Highlands (West) 11.7% (95% CI 8.5–15.3%), and West New Britain 11.4% (95% CI 8.7–13.9%). TF prevalence was 5.0–9.9% in Madang (9.4%, 95% CI 6.1–13.0%) and National Capital District (6.0%. 95% CI 3.2–9.1%) where consideration of a single round of MDA is warranted. Cases of TT were not found outside West New Britain, in which four cases were seen, generating an estimated population-level prevalence of TT in adults of 0.10% (95% CI 0.00–0.40%) for West New Britain, below the WHO elimination threshold of 0.2% of those aged ≥15 years.

Conclusion: Trachoma is a public health issue in PNG. However, other than in West New Britain, there are few data to support the idea that trachoma is a cause of blindness in PNG. Further research is needed to understand the stimulus for the active trachoma phenotype in these populations.     

Prevalence of Trachoma in Katsina State,Nigeria: Results of 34 District-Level Surveys

ABSTRACT

Purpose: To determine the local government area (LGA)-level prevalence of trachoma in all 34 LGAs of Katsina State.

Methods: A population-based prevalence survey was conducted in each LGA of Katsina State, using the Global Trachoma Mapping Project methodology. We used a 3-stage cluster random sampling strategy to select 25 households from each of 25 clusters. We examined all residents of selected households aged 1 year and older for the clinical signs of trachomatous inflammation–follicular (TF), trachomatous inflammation–intense and trichiasis, using the World Health Organization (WHO) simplified grading scheme.

Results: We examined 129,281 persons. Six LGAs had a TF prevalence ≥10%, and another six LGAs had a TF prevalence between 5% and 9.9%; all 12 require mass drug administration with azithromycin plus other interventions. The prevalence of trichiasis was ≥1.0% in 13 LGAs, and there is a need to perform trichiasis surgery in over 26,000 persons to reach targets set by the WHO for elimination of trichiasis.

Conclusion: The prevalence of TF is generally low in Katsina state, but urgent steps must be taken to implement the full SAFE strategy (surgery, antibiotics, facial cleanliness, environmental improvement) in at least 12 LGAs while also stepping up efforts to provide community-based trichiasis surgery throughout the whole state, in order to make trachoma elimination by 2020 a reality.     

Baseline Trachoma Mapping in Malawi with the Global Trachoma Mapping Project (GTMP)

ABSTRACT

Purpose: To determine the prevalence of trachoma in all suspected endemic districts in Malawi.

Methods: A population-based survey conducted in 16 evaluation units from 12 suspected endemic districts in Malawi (population 6,390,517), using the standardized Global Trachoma Mapping Project (GTMP) protocol. A 2-stage cluster-random sampling design selected 30 households from each of 30 clusters per evaluation unit; all residents aged 1 year and older in selected households were examined for evidence of follicular trachoma (TF), intense trachomatous inflammation (TI), and trachomatous trichiasis (TT).

Results: Four of the 16 evaluation units were found to be endemic for trachoma, with a prevalence range of 10.0–13.5% for TF and 0.2–0.6% for TT. Nine evaluation units had a TF prevalence between 5.0% and 9.9% while three evaluation units had a TF prevalence <5.0%.

Conclusion: The prevalence rates of active trachoma in Malawi were not uniform among suspected endemic evaluation units, with rates higher than the World Health Organization (WHO) threshold for implementation of community-based control measures (TF?≥?10.0%) in only 4 of the 16 evaluation units. Trachoma remains a disease of public health importance in some parts of Malawi and adjoining (unmapped) districts should be prioritized for mapping. According to the survey, an additional 3,169,362 people require intervention to reduce active disease and 1557 trichiasis surgeries are needed to reduce the prevalence of TT below WHO recommended thresholds.     

Mapping Trachoma in the Solomon Islands: Results of Three Baseline Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project

ABSTRACT

Purpose: We sought to complete the baseline trachoma map of the Solomon Islands by establishing prevalences of active trachoma and trichiasis in the provinces of Choiseul, Western, Rennell-Bellona, and Temotu.

Methods: Using the standardized methodology developed for the Global Trachoma Mapping Project, we conducted cross-sectional community-based surveys from September to November 2013. Choiseul and Western provinces were each mapped as separate evaluation units (EUs); Rennell-Bellona and Temotu were combined to form a third EU.

Results: A total of 9819 individuals were sampled for inclusion, with 9224 (93.3%) consenting to examination, of whom 4587 (46.3%) were female. Survey teams visited 82 villages, and surveyed 2448 households. Two EUs had prevalences of trachomatous inflammation – follicular (TF) in 1–9-year-olds over the 10% threshold at which WHO recommends mass distribution of azithromycin for at least 3 years (Western 20.4%, 95% confidence interval, CI 15.6–26.3%; Rennell-Bellona/Temotu 22.0%, 95% CI 18.5–26.0%). Choiseul had a TF prevalence of 6.1% (95% CI 4.1–8.6%), and met the criterion for a single round of mass antibiotic distribution before re-survey. The adjusted prevalences of trichiasis in those aged 15+ years were 0.0% (95% CI 0.0–0.2%) in Choiseul, 0.16% (95% CI 0.0–0.5%) in Western, and 0.10% (95% CI 0–0.3%) in Rennell-Bellona/Temotu provinces. All three EUs require implementation of the facial cleanliness and environmental improvement components of the trachoma elimination strategy.

Conclusion: Active trachoma is prevalent in the Solomon Islands. However, there is little evidence of the blinding complications of trachoma being a public health problem there. Further research into the explanation for this phenomenon is warranted.     

Evaluation of a Single Dose of Azithromycin for Trachoma in Low-Prevalence Communities

Purpose: Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, is the leading infectious cause of blindness worldwide and is targeted for elimination as a public health problem. We sought to determine whether a one-time azithromycin mass treatment would reduce trachomatous inflammation–follicular (TF) levels below the elimination threshold of 5% in communities with disease prevalence between 5 and 9.9%.

Methods: The study was conducted in 96 sub-village units (balozis) in the Kongwa district of Tanzania which were predicted from prior prevalence surveys to have TF between 5 and 9.9%. Balozis were randomly assigned to the intervention and control arms. The intervention arm received a single mass drug administration of azithromycin. At baseline and 12-month follow-up, ocular exams for trachoma, ocular swabs for detection of chlamydial DNA, and finger prick blood for analysis of anti-chlamydial antibody were taken.

Results: Comparison of baseline and 12-month follow-up showed no significant difference in the overall TF_1-9 prevalence by balozi between control and treatment arms. In the treatment arm there was a significant reduction of ocular infection 12 months after treatment (p = 0.004) but no change in the control arm. No change in Pgp3-specific antibody responses were observed after treatment in the control or treatment arms. Anti-CT694 responses increased in both study arms (p = 0.009 for control arm and p = 0.04 for treatment arm).

Conclusion: These data suggest that a single round of MDA may not be sufficient to decrease TF levels below 5% when TF_1-9 is between 5 and 9.9% at baseline.     

Prevalence of Trachoma in Kano State,Nigeria: Results of 44 Local Government Area-Level Surveys

Purpose: We sought to determine the prevalence of trachoma in 44 Local Government Areas (LGAs) of Kano State, Nigeria.

Methods: A population-based prevalence survey was conducted in each Kano LGA. We used a two-stage systematic and quasi-random sampling strategy to select 25 households from each of 25 clusters in each LGA. All consenting household residents aged 1 year and above were examined for trachomatous inflammation–follicular (TF), trachomatous inflammation–intense (TI) and trichiasis.

Results: State-wide crude prevalence of TF in persons aged 1–9 years was 3.4% (95% CI 3.3–3.5%), and of trichiasis in those aged ≥15 years was 2.3% (95% CI 2.1–2.4%). LGA-level age- and sex-adjusted trichiasis prevalence in those aged ≥15 years ranged from 0.1% to 2.9%. All but 4 (9%) of 44 LGAs had trichiasis prevalences in adults above the elimination threshold of 0.2%. State-wide prevalence of trichiasis in adult women was significantly higher than in adult men (2.6% vs 1.8%; OR = 1.5, 95% CI 1.3–1.7; p = 0.001). Four of 44 LGAs had TF prevalences in 1–9-year-olds between 10 and 15%, while another six LGAs had TF prevalences between 5 and 9.9%. In 37 LGAs, >80% of households had access to water within 30 minutes round-trip, but household latrine access was >80% in only 19 LGAs.

Conclusion: Trichiasis is a public health problem in most LGAs in Kano. Surgeons need to be trained and deployed to provide community-based trichiasis surgery, with emphasis on delivery of such services to women. Antibiotics, facial cleanliness and environmental improvement are needed in 10 LGAs.     

The Epidemiology of Trachoma in the Five Northern Districts of Sierra Leone

Purpose: In 2008, a trachoma prevalence survey was conducted in the five northern districts of Sierra Leone to determine if and where specific components of the SAFE strategy (Surgery, Antibiotics, Face washing, Environmental change) should be initiated.

Methods: A cross-sectional survey at district level was implemented using two-stage random cluster sampling: probability proportionate sampling was used to select villages in the first stage and compact segment sampling of households in the second stage. Both eyes of 16,780 individuals were examined using the World Health Organization simplified trachoma grading system. Data were also collected on village- and household-level behavior and environmental factors related to trachoma.

Results: Prevalence of trachomatous inflammation-follicular (TF) in children aged 1–9 years was highest in Kambia at 3.52% (95% Confidence Interval (CI): 2.28–4.75%), while the prevalence of trachomatous trichiasis (TT) in persons over 15 years of age was highest in Port Loko at 0.27% (95% CI: 0.03–0.50%). Across all districts, the percentage of households reporting washing children’s faces less than once per day was very low, while latrine coverage and accessible and safe water sources were not highly prevalent.

Conclusions: In all districts but Koinadugu, TT prevalence was greater than the WHO elimination threshold, indicating the need for 1,016 TT surgeries to prevent blindness. District TF prevalence rates did not warrant mass antibiotic distribution. Although not required given the low prevalence of TF, we recommend the construction of 35,941 household latrines and provision of water sources within a 30-minute walk roundtrip for 17,551 households to bring Sierra Leone closer to reaching Millennium Development Goal 7.     

Prevalence of Trachoma in Bauchi State,Nigeria: Results of 20 Local Government Area-Level Surveys

ABSTRACT

Purpose: To determine the prevalence of trachomatous inflammation – follicular (TF) and trichiasis in each of the 20 local government areas (LGAs) of Bauchi State, Nigeria.

Methods: We undertook a population-based prevalence survey in each LGA in Bauchi State, employing the Global Trachoma Mapping Project methodology. We used a 2-stage, systematic and quasi-random sampling strategy. Using probability proportional to size, we selected 25 clusters, in each of which 25 households were selected by random walk. All residents of selected households 1 year and older were examined for TF, trachomatous inflammation – intense, and trichiasis, using the World Health Organization simplified grading scheme.

Results: Only two LGAs in Bauchi State had TF prevalences in 1–9-year-olds over 5%, with none having TF prevalences of 10% or greater. Only one LGA had a trichiasis prevalence in adults below the elimination threshold; all the others had trichiasis at levels suggestive of public health significance. In all 20 LGAs, more than 60% of households were within 1 km of an improved source of water for hygiene.

Conclusion: Efforts need to be made in Bauchi State to provide trichiasis surgery in order to avert trachomatous blindness. Water supplies needs to be sustained and good personal hygiene practices assured so that elimination of trachoma as a public health problem will be achieved and sustained.     

Completion of Baseline Trachoma Mapping in Malawi: Results of Eight Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project

ABSTRACT

Purpose: Following a first phase of trachoma mapping in Malawi with the Global Trachoma Mapping Project, we identified and mapped trachoma districts previously suspected to be non-endemic, although adjacent to districts with estimated trachoma prevalences indicating a public health problem.

Methods: We conducted population-based surveys in eight evaluation units (EUs) comprising eight districts in Malawi (total population 3,230,272). A 2-stage cluster random sampling design allowed us to select 30 households from each of 30 clusters per EU; all residents aged 1 year and older in selected households were examined for evidence of trachomatous inflammation–follicular (TF) and trachomatous trichiasis (TT).

Results: None of the eight EUs had a TF prevalence in 1–9-year-olds ≥10%, one district (Dedza) had a TF prevalence between 5.0% and 9.9%, and only one district (Karonga) had a trichiasis prevalence in adults ≥0.2%.

Conclusion: The prevalence of TF and TT in six of eight EUs surveyed was consistent with an original categorization of trachoma being unlikely to be a public health problem. In the absence of formal surveys, health management information system data and other locally available information about trachoma is likely to be useful in predicting areas where public health interventions against trachoma are required.     

Prevalence and Risk Factors for Trachoma in Rural Areas of Sistan-va-Baluchestan Province,Iran: A Population-Based Study

ABSTRACT

Purpose: To determine the prevalence of trachoma and risk factors associated with the disease in rural areas of the Sistan-va-Baluchestan province in Iran from 2012–2013. Population-based prevalence data for trachoma is lacking in this region.

Methods: In this population-based cross-sectional study, 80 clusters were selected using a systematic and probability proportional to size method. All participants underwent clinical eye examinations according to the World Health Organization simplified trachoma grading system. The prevalence of follicular trachoma (TF) in children aged 1–9 years and the prevalence of trachomatous trichiasis (TT) in women aged over 15 years were the most important clinical indicators of trachoma.

Results: The study surveyed 8187 individuals and analyzed 7912 participants (96.6%) including 3737 children aged 1–9 years and 4175 females >15 years. The prevalence of TF and TT in the relevant indicator groups were 0.59% (95% confidence interval, CI, 0.36–0.89%) and 0.02% (95% CI 0.00–0.13%), respectively.

Conclusion: Previously, trachoma prevalence data for this region were lacking. This study confirms that the Sistan-va-Baluchestan region is not endemic for trachoma. This has important implications for national trachoma elimination activities.     

Rapid Assessment of Trachoma among Children Living in Rural Northern India

ABSTRACT

Purpose: Rapid assessment of active trachoma in children aged 1–9 years in a previously hyperendemic rural area in Haryana, India. Methods: Ten disadvantaged villages each with a population of 3000–5000 were chosen by cluster random sampling. One thousand children from 500 households in the most underdeveloped parts of the villages—identified by observation and consultation, between the ages of 1–9 years—were examined for signs of Trachomatous inflammation follicular (TF) and Trachomatous inflammation intense (TI). Assessment was done in a health care unit. Examination of both eyes for signs of trachoma and its complications was done with the aid of binocular loupe (2.5X magnification). Tarsal conjunctival swabs from patients of active trachoma were analyzed by direct immunoflourescence assay and polymerase chain reaction for Chlamydia trachomatis antigen. Results: Forty children (males 21, females 19) had signs of active trachoma that included TF (33) and TI (7). At least one ocular morbidity was present in 69% of all children that were examined. Unclean face carried a 2.70 (confidence interval [CI] = 1.30–5.37) times higher risk and poor ocular hygiene had 2.05 (CI = 1.02–4.11) times higher risk for trachoma infection. Among clinically positive cases, direct immunoflourescence assay and polymerase chain reaction assays were positive in 25% and 10%, respectively. Conclusions: Active trachoma is not a public health problem in previously hyperendemic areas of North India.     

Inter-Rater Agreement between Trachoma Graders: Comparison of Grades Given in Field Conditions versus Grades from Photographic Review

ABSTRACT

Purpose: Trachoma surveillance is most commonly performed by direct observation, usually by non-ophthalmologists using the World Health Organization (WHO) simplified grading system. However, conjunctival photographs may offer several benefits over direct clinical observation, including the potential for greater inter-rater agreement. This study assesses whether inter-rater agreement of trachoma grading differs when trained graders review conjunctival photographs compared to when they perform conjunctival examinations in the field.

Methods: Three trained trachoma graders each performed an independent examination of the everted right tarsal conjunctiva of 269 children aged 0–9 years, and then reviewed photographs of these same conjunctivae in a random order. For each eye, the grader documented the presence or absence of follicular trachoma (TF) and intense trachomatous inflammation (TI) according to the WHO simplified grading system.

Results: Inter-rater agreement for the grade of TF was significantly higher in the field (kappa coefficient, κ, 0.73, 95% confidence interval, CI 0.67–0.80) than by photographic review (κ?=?0.55, 95% CI 0.49–0.63; difference in κ between field grading and photo grading 0.18, 95% CI 0.09–0.26). When field and photographic grades were each assessed as the consensus grade from the three graders, agreement between in-field and photographic graders was high for TF (κ?=?0.75, 95% CI 0.68–0.84).

Conclusions: In an area with hyperendemic trachoma, inter-rater agreement was lower for photographic assessment of trachoma than for in-field assessment. However, the trachoma grade reached by a consensus of photographic graders agreed well with the grade given by a consensus of in-field graders.     

Estimating the Future Impact of a Multi-Pronged Intervention Strategy on Ocular Disease Sequelae Caused by Trachoma: A Modeling Study

Abstract

Purpose: Trachoma control programs are underway in endemic regions worldwide. They are based on the SAFE strategy (Surgery for trichiasis, Antibiotic distribution, Facial cleanliness, and Environmental improvement). Although much is known about the effect of community-wide treatment with antibiotics on the prevalence of Chlamydia trachomatis, the impact of the SAFE strategy on severe ocular disease sequelae (the main focus of the Global Elimination of blinding Trachoma by 2020 program) remains largely unknown.

Methods: We use a mathematical model to explore the impact of each of the components of the SAFE strategy, individually and together, on disease sequelae, arising from repeat infection and subsequent conjunctival scarring. We ask whether two elimination goals, to reduce the prevalence of trachomatous trichiasis to 1 per 1000 persons, and the incidence of corneal opacity to 1 per 10,000 persons per annum, are achievable, and which combinations of interventions have the greatest impact on these indicators.

Results: In high prevalence communities (here, >20% infection of children aged 1–9 years), a combination of efforts is needed to bring down sustainably the prevalence and incidence of ocular disease sequelae.

Conclusion: The mass delivery of antibiotics is highly beneficial for the clearance of infection, inflammation and prevention of subsequent scarring, but needs to be supplemented with sustained reductions in transmission and surgery to consider realistically the elimination of blindness by the year 2020.     

Assessment of Trachoma in Cambodia: Trachoma Is Not a Public Health Problem

ABSTRACT

Purpose: To determine whether trachoma is a public health problem requiring intervention in Cambodia.

Methods: Based on historical evidence and reports, 14 evaluation units (EUs) in Cambodia, judged to be most likely to harbor trachoma, were selected. The Global Trachoma Mapping Project methodology was used to carry out rigorous surveys to determine the prevalence of trachomatous inflammation–follicular (TF) and trichiasis in each EU.

Results: The EU-level prevalence of TF among 25,801 1–9-year-old children examined ranged from 0% to 0.2%. Among the 24,502 adults aged 15+ years examined, trichiasis was found in 59 people. Age- and sex-adjusted prevalences of trichiasis in all ages in the EUs studied ranged from 0% to 0.14%; five EUs had a prevalence of trichiasis ≥0.1%.

Conclusions: There appears to be no need nor justification at this time for implementing public health measures to control trachoma in Cambodia.     

A Community-Based Trachoma Survey: Prevalence and Risk Factors in the Tigray Region of Northern Ethiopia

Aim: Trachoma is a public health problem in Ethiopia accounting for 35–50% of cases of blindness. This study aims to determine the prevalence of trachoma in Tigray and to evaluate whether common risk factors are also risk factors in this region. Method: A cross sectional community-based survey was conducted. From six districts, a total of 48 villages were selected by a multistage cluster random sampling technique. A total of 3900 people who were selected randomly from 1200 households were assessed for signs of trachoma. Ophthalmic nurses used a simplified clinical grading system to assess stages of trachoma while environmentalists assessed risk factors for trachoma. Results: Of the 3900 people examined, 13% had trachomatous follicles (TF), 27% intense trachomatous inflammation (TI), 17.7% trachomatous scarring (TS), 3.4% trachomatous trichiasis (TT) and 0.3% had corneal opacity (CO). The presence of a kitchen with chimney had a protective effect on TS (Adjusted Odds Ratio [AOR] = 0.82; 95% Confidence Interval [CI]: 0.65–0.96) and TT (AOR = 0.80; 95% CI: 0.53; 0.97). Active trachoma was more prevalent among children (AOR = 0.97; 95% CI: 0.96–0.97), illiterates (AOR = 1.38; 95% CI: 1.13–1.69) and those who infrequently wash their face (AOR = 1.35; 95% CI: 1.18–1.54). Conclusions: Trachoma is hyperendemic in the Tigray region. Mass chemotherapy, the expansion of primary eye care services, and promotion of a regular face washing habit are recommended. We recommend further investigations on the effect of domestic use of biomass energy on trachoma.     

Trachoma among adults in Damot Gale District,South Ethiopia

PURPOSE To determine the prevalence of trachoma and its risk factors among adults in the Damot Gale District of south Ethiopia. METHODS A cross-sectional, community based survey was conducted in the Damot Gale District of south Ethiopia. A multi-stage sampling method was used to select subjects. RESULTS Out of 924 eligible subjects, 855 were examined, for a response rate of 92.5%. Active trachoma [follicles (TF), intense inflammation (TI) or TF/TI] was found in 20.6% (95% CI: 17.8–23.4%) of the subjects. The prevalence of trachomatous trichiasis (TT) and corneal opacity (CO) was 6.8% (95% CI: 5.1–8.5%) and 2.1% (95% CI: 1.0–3.1%), respectively. Females were affected by active trachoma twice as often as males [OR 2.13 (95% CI: 1.67–3.50, P &lt; 0.0001)]. The prevalence of blinding trachoma (TT and CO) was also significantly higher among females [OR 3.03 (95% CI: 1.58–5.89, P &lt; 0.001)]. Literacy and face washing were found to be significantly associated with less prevalence of active trachoma. CONCLUSION The prevalence of both active and cicatricial trachoma among adults residing in the Damot Gale District of south Ethiopia is very high. Although children are the main reservoirs of active trachoma, intervention strategies should address the fact that a high prevalence of active trachoma is also found among adults residing in hyperendemic areas.     

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

ABSTRACT

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).     

National Trachoma Assessment in the Lao People’s Democratic Republic in 2013–2014

ABSTRACT

Purpose: Population-based prevalence surveys were undertaken to determine whether trachoma is a public health problem in Laos requiring implementation of the SAFE strategy (surgery, antibiotics, facial cleanliness, environmental improvement).

Methods: The country was divided into 19 evaluation units (EUs), each containing a population of roughly 100,000–350,000 people. Of these, 16 were believed most likely to harbor trachoma (based on historical evidence), and were mapped using the Global Trachoma Mapping Project methods. A 2-stage cluster sampling was used to sample approximately 1222 children aged 1–9 years in each EU, as well as all adults aged 15 years and older resident in households with children. The presence or absence of trachomatous inflammation – follicular (TF) and of trichiasis was documented in each subject, and prevalences (adjusted for age and sex) estimated.

Results: The adjusted prevalence of TF in 1–9-year-olds ranged from 0.2% to 2.2% across the 16 EUs. Adjusted all-ages prevalence of trichiasis was 0.00% in 13 EUs, 0.06% in two EUs, and 0.12% in one EU. The trichiasis prevalence in adults in the last EU was 0.19%.

Conclusions: The assessment included all areas of Laos suspected of ever harboring trachoma and most of the rural population of the country. The low prevalence of TF and trichiasis do not warrant any special programs against trachoma at this time.     

Prevalence of Trachoma in Niger State,North Central Nigeria: Results of 25 Population-Based Prevalence Surveys Carried Out with the Global Trachoma Mapping Project

ABSTRACT

Purpose: To determine the prevalence of trachoma in each of the 25 local government areas (LGAs) of Niger State, Nigeria.

Methods: A population-based cross-sectional survey was conducted in each Niger State LGA between March and April 2014, as part of the Global Trachoma Mapping Project (GTMP). GTMP protocols were used in planning and conduct of the surveys. Using probability proportional to size, 25 clusters were selected; in each of these clusters, 25 households were enrolled for the survey. All residents aged 1 year and older were examined by GTMP-certified graders for trachomatous inflammation – follicular (TF) and trichiasis using the World Health Organization simplified grading scheme. Additionally, we collected data on household water and sanitation facilities.

Results: Only one LGA (Kontagora) had TF prevalence in 1–9-year-olds above 10%; one other LGA (Rafi) had TF prevalence between 5.0 and 9.9%. Six LGAs need trichiasis surgical services provided to achieve a prevalence of <1 case of trichiasis per 1000 total population. The proportion of households with access to improved water sources ranged from 23 to 100%, while household-level access to improved latrines ranged from 8 to 100% across the LGAs.

Conclusion: The prevalence of trachoma is relatively low in most of Niger State. There is a need for community-based trichiasis surgical services in a small number of LGAs. The trachoma elimination program could engage water and sanitation agencies to augment access to improved water and sanitation facilities, for human rights reasons. Kontagora and Rafi need community-based interventions to reduce the prevalence of active trachoma.