Elimination of blinding trachoma in oman

The Gambia Trachomatous Trichiasis Surveys: Results from Five Evaluation Units Confirm Attainment of Trachoma Elimination Thresholds

INTRODUCTION

Trichiasis is present when in-turned eyelashes touch the eyeball. It may result in permanent vision loss. Trachomatous trichiasis (TT) is caused by multiple rounds of inflammation associated with conjunctival Chlamydia trachomatis infection. Surveys have been designed to estimate the prevalence of TT in evaluation units (EUs) of trachoma-endemic countries in order to help develop appropriate programme-level plans. In this study, TT-only surveys were conducted in five EUs of The Gambia to determine whether further intensive programmatic action was required.

METHODS

Two-stage cluster sampling was used to select 27 villages per EU and ~25 households per village. Graders assessed the TT status of individuals aged ≥15 years in each selected household, including the presence or absence of conjunctival scarring in those with TT.

RESULTS

From February to March 2019, 11595 people aged ≥15 years were examined. A total of 34 cases of TT were identified. All five EUs had an age- and gender-adjusted prevalence of TT unknown to the health system <0.2%. Three of five EUs had a prevalence of 0.0%.

CONCLUSION

Using these and other previously collected data, in 2021, The Gambia was validated as having achieved national elimination of trachoma as a public health problem. Trachoma is still present in the population, but as its prevalence is low, it is unlikely that today's youth will experience the exposure to C. trachomatis required to precipitate TT. The Gambia demonstrates that with political will and consistent application of human and financial resources, trachoma can be eliminated as a public health problem.

Postoperative trachomatous trichiasis: a systematic review and meta-analysis study

BACKGROUND

Trachomatous trichiasis is the potential stage of trachoma in which the eyelashes scratch the surface of the globe, ultimately causing corneal opacity, visual impairment and blindness. The aim of this systematic review and meta-analysis is to obtain the pooled prevalence and associated factors of postoperative trachomatous trichiasis (PTT) in World Health Organization (WHO) trachoma-endemic regions.

METHODS

An inclusive literature search was undertaken using PubMed, Cochrane Library, Science Direct and Google Scholar databases from 30 May 2022 to 28 June 2022. I2 statistics and funnel plots were used to determine heterogeneity and publication bias among included studies. A random effects model was used to estimate pooled prevalence, incidence and odds ratios (ORs) with the respective 95% confidence intervals (CIs) using RevMan 5.4 software.

RESULTS

Eighteen articles were included in this meta-analysis and systematic review. The pooled prevalence of PTT was 19% (range 18-21). PTT was lower among young adults compared with old adults (OR 0.63 [95% CI 0.44 to 0.92]), single-dose oral azithromycin as compared with tetracycline eye ointment users (OR 0.82 [95% CI 0.69 to 0.99]) and minor trichiasis before surgery as compared with major trichiasis (OR 0.63 [95% CI 0.47 to 0.85]).

CONCLUSIONS

The incidence of PTT was higher than the WHO's recommendation. Prescribing single-dose oral azithromycin after surgery, periodic training for trichiasis surgeons, close follow-up and health education after surgery are crucial to minimize the recurrence.Study protocol registration on PROSPERO: CRD42022336003.

The World Health Organization Recommendations for Trachoma Surveillance, Experience in Nepal and Added Benefit of Testing for Antibodies to Chlamydia trachomatis pgp3 Protein: NESTS Study

BACKGROUND

The World Health Organization (WHO) now requires a second surveillance survey for trachoma after an impact assessment has found follicular trachoma (TF) <5% to determine if re-emergence has occurred. Using new WHO guidelines, we undertook surveillance surveys, and determined the prevalence of infection and antibody positivity, in two districts in Nepal.

METHODS

20 clusters were randomly selected within each district, 15 were randomly selected for antibody testing. In each cluster, we randomly selected 50 children ages 1-9 years and 100 adults ≥15 years. TF and trachomatous trichiasis (TT) were evaluated. Conjunctival swabs to test for chlamydial infection using GenXpert platform were obtained, and dried blood spots were collected to test for antibodies to Chlamydia Trachomatis pgp3 using the Luminex platform.

FINDINGS

3 cases of TF were found in the two districts, and one case of infection. Pgp3 antibody positivity was 2·4% (95% confidence interval: 1·4%, 3·7%), and did not increase with age (P = 0.24). No clustering of antibody positivity within communities was found. TT prevalence was <1/1,000 population.

INTERPRETATION

The surveillance surveys, as proposed by WHO, showed no evidence for re-emergence of trachoma in two districts of Nepal. The low level and no significant increase by age in seroprevalence of antibodies to C trachomatis pgp3 antigen deserve further investigation as a marker of interruption of transmission.