The long-term natural history of trachomatous trichiasis in the Gambia

Corneal pannus, Herbert's pits and conjunctival inflammation in older children in Papua New Guinea

PURPOSE

The prevalence of trachomatous inflammation-follicular (TF) in Papua New Guinea (PNG) suggests antibiotic mass drug administration (MDA) is needed to eliminate trachoma as a public health problem but the burden of trichiasis is low. As a result, WHO issued bespoke recommendations for the region. If ≥ 20% of 10-14-year-olds have both any conjunctival scarring (C1 or C2 or C3) and corneal pannus and/or Herbert's pits, MDA should be continued. Equally, if ≥ 5% of that group have both moderate/severe conjunctival scarring (C2 or C3) and corneal pannus and/or Herbert's pits, MDA should be continued.

METHODS

We identified 14 villages where > 20% of 1-9-year-olds had TF during baseline mapping undertaken 4 years and 1 month previously. Every child aged 10-14 years in those villages was eligible to be examined for clinical signs of corneal pannus, Herbert's pits and conjunctival scarring. A grading system that built on existing WHO grading systems was used.

RESULTS

Of 1,293 resident children, 1,181 (91%) were examined. Of 1,178 with complete examination data, only one (0.08%) individual had concurrent scarring and limbal signs.

CONCLUSIONS

The WHO-predefined criteria for continuation of MDA were not met. Ongoing behavioural and environmental improvement aspects of the SAFE strategy may contribute to integrated NTD control. Surveillance methods should be strengthened to enable PNG health authorities to identify future changes in disease prevalence.

Gender differences in trachomatous scarring prevalence in a formerly trachoma hyperendemic district in Tanzania

BACKGROUND

Trachoma is a chronic conjunctivitis caused by the bacterium Chlamydia trachomatis. Repeated infections lead to trachomatous conjunctival scarring which can progress to potentially blinding trachomatous trichiasis (TT). In trachoma hyperendemic conditions, women compared to men have an increased risk of scarring and TT, which can progress to blinding corneal opacification. This study determined if there were gender differences in scarring prevalence and severity when trachoma prevalence approaches elimination, in a formerly trachoma hyperendemic region.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional prevalence study was conducted amongst adults age 15 years and older in Kongwa district, Tanzania in 2019. 3168 persons over age 15 years agreed to be examined and had at least one eye with a gradable image. Ocular photographs were graded for scarring according to a published four-step severity scale. Overall, about half of all study participants had scarring. However, more females (52.3%) had any scarring compared to males (47.2%), OR = 1.22 (95% CI = 1.05-1.43). For every year increase in age, there was a 6.5% increase in the odds of having more severe scarring (95% CI: 5.8%, 7.2%). Women were more likely than men to have severe scarring, OR 2.36 (95% CI: 1.84-3.02). Residence in a community with TF≥10% was associated with a 1.6-fold increased odds of any scarring.

CONCLUSIONS/SIGNIFICANCE

Overall scarring prevalence and more severe scarring prevalence was higher in females compared to males, even adjusting for age and community TF prevalence. The data suggest that processes occur that lead to women preferentially progressing towards more severe scarring compared to men.

Prevalence of Trachomatous Trichiasis in Ten Evaluation Units of Embu and Kitui Counties, Kenya

BACKGROUND

Late-stage blinding sequalae of trachoma such as trachomatous trichiasis (TT) typically take decades to develop and often do so in the absence of ongoing ocular Chlamydia trachomatis infection. This suggests that most TT risk accumulates in early life; as a result, population-level TT incidence and prevalence can remain high years after C. trachomatis transmission among children has decreased. In Embu and Kitui counties, Kenya, the prevalence of trachomatous inflammation - follicular is low in children. In this survey, we set out to determine the prevalence of TT in ten evaluation units (EUs) in these counties.

METHODS

We undertook ten cross-sectional prevalence surveys for TT. In each EU, people aged ≥15 years were selected by a two-stage cluster sampling method and examined for TT. Those with TT were asked questions on whether they had been offered management for it. Prevalence was adjusted to the underlying age and gender structure of the population.

RESULTS

A total of 18,987 people aged ≥15 years were examined. Per EU, the median number of examined participants was 1,656 (range: 1,451 - 3,016) and median response rate was 86% (range: 81 - 95%). The prevalence of TT unknown to the health system in people aged ≥15 years was above the threshold for elimination (≥0.2%) in all ten EUs studied (range: 0.2-0.7%). TT was significantly more common in older than younger individuals and in women than in men.

DISCUSSION

Provision of surgical services should be strengthened in Embu and Kitui counties of Kenya to achieve the World Health Organization threshold for eliminating TT as a public health problem.

The Association Between the Severity of Trachomatous Scarring and Trachomatous Trichiasis Severity in Surgical Patients in Tanzania

PURPOSE

To determine the association between the severity of trachomatous conjunctival scarring (TS) of the upper eyelid conjunctiva and trachomatous trichiasis (TT) severity in TT surgical patients.

METHODS

A cross-sectional study was conducted amongst adults with TT who were referred to surgical camps in Bahi District, Tanzania, for TT surgery. Participants underwent ocular examination. The presence and severity of TS was evaluated in photographs of the everted upper eyelid. TT severity was assessed at the time of the ocular exam based on the number of lashes touching the globe and/or evidence and extent of epilation. Ordinal logistic models were used to examine the association between the severity of TS and TT severity.

RESULTS

A total of 627 eyes of 388 participants were included. Mean age was 65 years (ranging from 21-98), 81% were females, and 62% had bilateral TT. 93% of eyes with any TT had at least moderate TS; 62% of eyes had severe TS. An increase in TS severity was associated with an increase in the severity of TT. Using as a reference eyes with none to mild TS, in eyes with moderate TS the odds of increased severity of TT was 1.30 (95% CI 0.67-2.51), in eyes with severe TS the odds was 4.20 (95% CI 2.23-7.92).

CONCLUSION

In cases of trachomatous trichiasis presenting for surgery, the severity of TT was significantly associated with the severity of TS with almost all cases of TT having moderate or severe scarring.

Risk factors for the progression of trachomatous scarring in a cohort of women in a trachoma low endemic district in Tanzania

Background

Trachoma, a chronic conjunctivitis caused by Chlamydia trachomatis, is the leading infectious cause of blindness worldwide. Trachoma has been targeted for elimination as a public health problem which includes reducing trachomatous inflammation—follicular prevalence in children and reducing trachomatous trichiasis prevalence in adults. The rate of development of trachomatous trichiasis, the potentially blinding late-stage trachoma sequelae, depends on the rate of trachomatous scarring development and progression. Few studies to date have evaluated the progression of trachomatous scarring in communities that have recently transitioned to a low trachomatous inflammation—follicular prevalence.

Methodology/Principal findings

Women aged 15 and older were randomly selected from households in 48 communities within Kongwa district, Tanzania and followed over 3.5 years for this longitudinal study. Trachomatous inflammation—follicular prevalence was 5% at baseline and at follow-up in children aged 1–9 in Kongwa, Tanzania. 1018 women aged 15 and older had trachomatous scarring at baseline and were at risk for trachomatous scarring progression; 691 (68%) completed follow-up assessments. Photographs of the upper tarsal conjunctiva were obtained at baseline and follow-up and graded for trachomatous scarring using a previously published four-step severity scale. The overall cumulative 3.5-year progression rate of scarring was 35.3% (95% CI 31.6–39.1). The odds of TS progression increased with an increase in age in women younger than 50, (OR 1.03, 95% CI 1.01–1.05, p = 0.005) as well as an increase in the household poverty index (OR 1.29, 95% CI 1.13–1.48, p = 0.0002).

Conclusions/Significance

The 3.5-year progression of scarring among women in Kongwa, a formerly hyperendemic now turned hypoendemic district in central Tanzania, was high despite a low active trachoma prevalence. This suggests that the drivers of scarring progression are likely not related to on-going trachoma transmission in this district.

Trachoma, a chronic conjunctivitis caused by Chlamydia trachomatis, presents with follicles (trachomatous inflammation—follicular, TF) in children which leads to trachomatous conjunctival scarring (TS) in young adults. TS can progress to the in-turning of eyelashes, trachomatous trichiasis (TT) which places individuals at high risk of irreversible vision loss. Few studies to date have evaluated the progression of TS in communities that have recently transitioned to a low trachoma prevalence.

We studied the progression of TS in women in Kongwa, Tanzania a district that recently transitioned to a low prevalence of trachoma. We found that the overall cumulative progression of scarring was 35.3% over 3.5 years. The scarring progression rate observed is very similar to what we observed a decade prior in Kongwa when the trachoma prevalence was very high.

Our findings suggest that once scarring has developed it continues to progress irrespective of the current trachoma environment. This has potential ramifications for trachoma elimination efforts. An area could achieve the elimination of TF and still have to deal with scarring progression, which may lead to the development of TT. If this occurs: 1) elimination of TT will be delayed which will delay the overall elimination of trachoma as a public health problem, and 2) the limited resources available to elimination programs may need to be re-allocated.

Effect of repeated epilation for minor trachomatous trichiasis on lash burden, phenotype and surgical management willingness: A cohort study

Background

WHO endorsed the use of epilation as an alternative treatment to surgery for the management of both minor unoperated TT (UTT) and postoperative TT (PTT). However, some trachoma control programmes hesitated to implement epilation citing concerns that it would hamper TT surgical acceptance and result in larger numbers of and stiffer trichiatic eyelashes than the original TT lashes. We investigated the burden and phenotypes of post-epilation trichiatic eyelashes, and willingness to accept surgical management separately in unoperated and postoperative TT cases.

Methodology/Principal findings

We recruited cases with minor (≤5 eyelashes from the upper eyelid touching the eye or evidence of epilation in <1/3^rd of the upper eyelid) UTT (170) and PTT (169) from community-based screenings in Amhara Region, Ethiopia. Participants eyes were examined and data on present and future willingness to accept surgical management collected at baseline and every month for 6-months. Eyelashes touching the eye were counted and their phenotypes documented. Participants were trained on how to epilate. Epilation was done by the participants at home and by the examiner during follow-ups when requested by the participant. Follow-up rates were ≥97%. There was evidence of a significant reduction in the burden of trichiatic eyelashes in unoperated (mean difference = -0.90 [-1.11– -0.69]; RR = 0.50 [95% CI, 0.40–0.62]; p<0.0001), and postoperative (mean difference = -1.16 [-1.36– -0.95]; RR = 0.38 [95% CI, 0.31–0.48]; p<0.0001) cases 6-month after frequent epilation. Post-epilation trichiatic eyelashes at 6-months had higher odds of being thin (40.2% vs 55.8%, OR = 1.88 [95% CI, 1.21–2.93]; p = 0.0048), weak (39.8% vs 70.8%, OR = 3.68 [95%CI,2.30–5.88]; p<0.0001), and half-length (30.9% vs 43.3%, OR = 1.71 [1.09–2.68]; p = 0.020) than the pre-epilation trichiatic eyelashes in unoperated cases. There was a significant increase in the proportion of weak trichiatic eyelashes (OR = 1.99 [95% CI, 1.03–3.83; p = 0.039) in postoperative cases. In all 6 follow-up time points, 120/164 (73.2%) of unoperated and 134/163 (82.2%) of postoperative cases indicated that they would accept surgery if their trichiasis progressed.

Conclusions/Significance

In this study setting, frequent epilation neither hampers surgical acceptance nor results in more damaging trichiatic eyelashes than the pre-epilation lashes; and can be used as an alternative to the programmatic management of minor unoperated and postoperative TT cases.

Trachomatous Trichiasis (TT), the blinding stage of trachoma, ranges from few peripheral eyelashes touching the eye to all eyelashes scratching the cornea. TT is mainly treated with corrective eyelid surgery. However, not all TT cases require surgical correction, and some, particularly, those with few eyelashes decline surgery. Epilation, the repeated removal of eyelashes, is a very common clinical and traditional practice in many trachoma endemic settings. The World Health Organisation recommends that epilation can be offered as an alternative management strategy to surgery for patients with few eyelashes touching the eye or refusing surgery. However, some trachoma control programmes hesitated to implement epilation with the concern that it would hamper surgical acceptance and results in larger numbers of and stiffer eyelashes touching the eye than the original TT eyelashes. In this study, we explored if these concerns are true in epilating minor (≤5 eyelashes from the upper eyelid touching the eye or evidence of epilation in <1/3^rd of the upper eyelid) unoperated (170) and postoperative TT (169) cases. We found, in the contrary to these concerns, the post-epilation eyelashes touching the eye were less damaging being fewer in number, thinner, weaker and shorter than the pre-epilation eyelashes. In addition, the majority of both unoperated and postoperative cases indicated that they are willing to accept surgery if their trichiasis progressed.

Prevalence of Trachoma in Pakistan: Results of 42 Population-Based Prevalence Surveys from the Global Trachoma Mapping Project

Purpose: Previous phases of trachoma mapping in Pakistan completed baseline surveys in 38 districts. To help guide national trachoma elimination planning, we set out to estimate trachoma prevalence in 43 suspected-endemic evaluation units (EUs) of 15 further districts.

Methods: We planned a population-based trachoma prevalence survey in each EU. Two-stage cluster sampling was employed, using the systems and approaches of the Global Trachoma Mapping Project. In each EU, residents aged ≥1 year living in 30 households in each of 26 villages were invited to be examined by trained, certified trachoma graders. Questionnaires and direct observation were used to evaluate household-level access to water and sanitation.

Results: One EU was not completed due to insecurity. Of the remaining 42, three EUs had trichiasis prevalence estimates in ≥15-year-olds ≥0.2%, and six (different) EUs had prevalence estimates of trachomatous inflammation—follicular (TF) in 1–9-year-olds ≥5%; each EU requires trichiasis and TF prevalence estimates below these thresholds to achieve elimination of trachoma as a public health problem. All six EUs with TF prevalences ≥5% were in Khyber Pakhtunkhwa Province. Household-level access to improved sanitation ranged by EU from 6% to 100%. Household-level access to an improved source of water for face and hand washing ranged by EU from 37% to 100%.

Conclusion: Trachoma was a public health problem in 21% (9/42) of the EUs. Because the current outbreak of extremely drug-resistant typhoid in Pakistan limits domestic use of azithromycin mass drug administration, other interventions against active trachoma should be considered here.

Lamellar Tarsectomy Procedure In Major Trichiasis Of The Upper Lid

Aims

Evaluation of failure rate and outcomes between skin and muscle surgery and lamellar tarsectomy procedure in major trichiasis of the upper lid.

Design

Quasi-randomized clinical study.

Methods and subjects

One hundred individuals with major trichiasis of the upper lid were enrolled and assigned to either skin and muscle surgery (group A) or a lamellar tarsectomy procedure (group B). Participants were examined at 6 and 12 months. The primary outcome measure (failure rate) was the percentage of participants having five or more eyelashes touching the globe or having surgery performed at any follow-up time in both groups. The secondary outcomes included failure time and changes in both visual acuity and corneal opacity.

Results

Risk failure over 6 months was 40% in group A and 10% in group B. Absolute risk reduction was 30% (95% CI=14.08–45.92%). Cumulative risk failure over 12 months was 20% in group A and 0.00% in group B after the second intervention. Absolute risk reduction was 20% (95% CI=8.58–31.42%). The number needed to treat (NNT) was 3.3 patients (95% CI=2.2–7.1). The mean number of rubbing lashes was greater in the skin and muscle group than in the lamellar tarsectomy group for 6 and 12 month examinations (0.002, 0.005). The change in visual acuity between the two groups was not significant. Recurrent trichiasis was noticed earlier, 6 weeks after surgery, in the skin and muscle group participants, and later, 3 months after surgery, in the lamellar tarsectomy group participants.

Conclusion

The lamellar tarsectomy procedure is a good choice for management of major trichiasis of the upper lid. The subjective symptoms and lid margin conjunctivalization were improved in lamellar tarsectomy participants. Absence of new corneal opacity or a change in existing corneal opacification was noticed at the 12 months follow-up study.

The global burden of trichiasis in 2016

Background

Trichiasis is present when one or more eyelashes touches the eye. Uncorrected, it can cause blindness. Accurate estimates of numbers affected, and their geographical distribution, help guide resource allocation.

Methods

We obtained district-level trichiasis prevalence estimates in adults for 44 endemic and previously-endemic countries. We used (1) the most recent data for a district, if more than one estimate was available; (2) age- and sex-standardized corrections of historic estimates, where raw data were available; (3) historic estimates adjusted using a mean adjustment factor for districts where raw data were unavailable; and (4) expert assessment of available data for districts for which no prevalence estimates were available.

Findings

Internally age- and sex-standardized data represented 1,355 districts and contributed 662 thousand cases (95% confidence interval [CI] 324 thousand–1.1 million) to the global total. Age- and sex-standardized district-level prevalence estimates differed from raw estimates by a mean factor of 0.45 (range 0.03–2.28). Previously non- stratified estimates for 398 districts, adjusted by ×0.45, contributed a further 411 thousand cases (95% CI 283–557 thousand). Eight countries retained previous estimates, contributing 848 thousand cases (95% CI 225 thousand-1.7 million). New expert assessments in 14 countries contributed 862 thousand cases (95% CI 228 thousand–1.7 million). The global trichiasis burden in 2016 was 2.8 million cases (95% CI 1.1–5.2 million).

Interpretation

The 2016 estimate is lower than previous estimates, probably due to more and better data; scale-up of trichiasis management services; and reductions in incidence due to lower active trachoma prevalence.

As an individual with trichiasis blinks, the eyelashes abrade the cornea, which can lead to corneal opacity and blindness. Through high quality surgery, which involves altering the position of the eyelid margin, it is possible to reduce the number of people with trichiasis. Accurate estimates of the number of persons with trichiasis and their geographical distribution are needed in order to effectively align resources for surgery and other necessary services. We obtained district-level trichiasis prevalence estimates for 44 endemic and previously-endemic countries. We used the most recently available data and expert assessments to estimate the global burden of trichiasis. We estimated that in 2016 the global burden was 2.8 million cases (95% CI 1.1–5.2 million).

The 2016 estimate is lower than previous estimates, probably due to more and better data; scale-up of trichiasis management services; and reductions in incidence due to lower active trachoma prevalence.

Understanding the spatial distribution of trichiasis and its association with trachomatous inflammation-follicular

BACKGROUND

Whilst previous work has identified clustering of the active trachoma sign "trachomatous inflammation-follicular" (TF), there is limited understanding of the spatial structure of trachomatous trichiasis (TT), the rarer, end-stage, blinding form of disease. Here we use community-level TF prevalence, information on access to water and sanitation, and large-scale environmental and socio-economic indicators to model the spatial variation in community-level TT prevalence in Benin, Cote d'Ivoire, DRC, Guinea, Ethiopia, Malawi, Mozambique, Nigeria, Sudan and Uganda.

METHODS

We fit binomial mixed models, with community-level random effects, separately for each country. In countries where spatial correlation was detected through a semi-variogram diagnostic check we then fitted a geostatistical model to the TT prevalence data including TF prevalence as an explanatory variable.

RESULTS

The estimated regression relationship between community-level TF and TT was significant in eight countries. We estimate that a 10% increase in community-level TF prevalence leads to an increase in the odds for TT ranging from 20 to 86% when accounting for additional covariates.

CONCLUSION

We find evidence of an association between TF and TT in some parts of Africa. However, our results also suggest the presence of additional, country-specific, spatial risk factors which modulate the variation in TT risk.

Non-Chlamydial Bacterial Infection and Progression of Conjunctival Scarring in Trachoma

Purpose

The purpose of this study was to assess whether non-chlamydial bacterial infection is associated with progression of trachomatous scarring in adults.

Methods

This was a cohort study involving 800 participants in northern Tanzania who underwent clinical examination, photography, and conjunctival swab collection for microbiology over a 24-month period. Samples for microbiology were inoculated onto blood and chocolate agar, and Chlamydia trachomatis was detected by PCR. Progression was determined by comparison of baseline to 24-month photographs.

Results

C. trachomatis was detected in only four participants at baseline. At 24 months, 617 participants (77.1%) were followed up. Of those seen at 24 months, 452 could be reliably assessed. Definite scarring progression (progressors) was seen in 345 (55.9%); there was no progression (nonprogressors) in 107 (17.3%). Using combined baseline and 12-month microbiology results, progressors had significantly higher levels of commensal and pathogenic bacterial organisms detected compared with nonprogressors. After adjusting for age, baseline scarring, and ethnicity, there was weak evidence (P = 0.07) that the bacteria category was associated with scarring progression (commensal organisms only: odds ratio [OR] = 1.61; 95% confidence interval [CI]: 0.90 to 2.89; pathogenic organisms either with or without commensal: OR = 2.39; 95% CI: 1.10 to 5.16).

Conclusion

The findings were consistent with the possibility that trachomatous scarring in adults is associated with the presence of non-chlamydial bacterial organisms, particularly pathogenic organisms. C. trachomatis was detected very infrequently and may not be an important factor in the pathogenesis of scarring progression in adults. This has implications for trachoma control programs, which largely concentrate on reducing C. trachomatis levels and transmission.

Fluorometholone 0.1% as Ancillary Therapy for Trachomatous Trichiasis Surgery: Randomized Clinical Trial

PURPOSE

To assess the hypothesis that fluorometholone 0.1% eye drops are safe and effective as adjunctive therapy for trachomatous trichiasis (TT) surgery; determining the most promising dose.

DESIGN

Randomized, placebo-controlled, double-masked parallel dose-ranging clinical trial.

METHODS

Patients undergoing upper lid TT surgery at a rural Ethiopian hospital were randomized to fluorometholone 0.1% twice daily for 4 weeks, 4 times daily for 4 weeks, 4 times daily for 8 weeks, or matching frequency placebo in a 3:1:3:1:3:1 ratio for 1 eye. Randomization was stratified by TT severity (1-4 vs ≥5 lashes touching the globe). Safety outcomes (intraocular pressure [IOP] elevation, cataract, and other dose-limiting toxicities) and postoperative TT incidence were assessed over 1 year.

RESULTS

Subjects randomized were 39:13:39:13:38:13 in the respective groups, and 1 subject in the 8-weeks fluorometholone group was withdrawn. Of 154 subjects, 148 (96.1%) completed 1 year's follow-up. Among 76 eyes receiving fluorometholone 4 times daily, 1 developed IOP elevation ≥ 30 mm Hg (to 37 mm Hg) and 1 had an allergic reaction attributed to the study drug; each resolved upon drug cessation without sequelae. No cataract or other dose-limiting toxicity events occurred. Postoperative TT within 1 year occurred in 29.3% of placebo eyes vs 17.7%, 19.6%, and 23.2% among the respective fluorometholone groups (P = .29 comparing placebo vs all active treatments combined).

CONCLUSIONS

The results suggest fluorometholone 0.1% is likely to be safe and efficacious to reduce postoperative TT following TT surgery, and 1 drop twice daily for 4 weeks is the most promising dose. Confirmation in a full-scale clinical trial is needed before programmatic implementation.

Determinants for not utilizing trachomatous trichiasis surgery among trachomatous trichiasis patients in Mehalsayint District, North-East Ethiopia

Background

Globally, trachoma is the leading cause of infectious blindness. In Ethiopia, the overall Trachomatous Trichiasis (TT) surgical coverage is 41%. Identifying determinants for not utilizing TT surgery among TT patients is important to design and monitor effective intervention programs. Therefore, this study aimed to identify determinants for not utilizing TT surgery among TT patients in Mehalsayint District, North East Ethiopia.

Methodology/Principal findings

A community based unmatched case control study was employed from March 30, 2017 to April 13, 2017. A total of 482 study participants (241 cases and 241 controls) with age of ≥15 years were included in the study. The data were entered with Epi info version 7.2 software and exported to SPSS version 20 for analysis. Bivariate analysis was fitted to screen candidate variables with p<0.2 for the final model. Finally, multivariable logistic regression analysis was employed to identify significant factors (p<0.05) for not utilizing TT surgery. Respondents’ age of 16–30 years (AOR: 10.11; 95% CI: 2.72, 37.59) and widowed respondents (AOR: 0.40; 95% CI: 0.21, 0.77), time to reach the service (AOR: 0.46; 95% CI: 0.24, 0.87), unavailability of TT surgeon (AOR: 5.00; 95% CI: 1.16, 21.38), symptoms of trichiasis (AOR: 7.49; 95% CI: 2.41, 23.26), duration of the problem (AOR: 2.56; 95% CI: 1.44, 4.54), the affected eye (AOR: 2.16; 95% CI: 1.23, 3.80), epilation practice (AOR: 3.22; 95% CI: 1.84, 5.64), and place of TT surgery given (AOR: 4.21; 95% CI: 2.48, 7.14) were significant determinants for not utilizing TT surgical services.

Conclusions/Significance

In this study, TT surgery against trachoma is very low and TT remains public health problem in the district. Being younger age and widowed, time taken to reach the service, absence of TT surgeon, symptoms of trichiasis, duration of problem, the affected eye, epilation practice, and service place were determinants for the inability of TT surgical services. The findings of this study would help in designing effective interventions to reduce trachoma in that district.

Trachoma is the common ophthalmic infection and cause of blindness worldwide. It is caused by ocular infections with causative agent of Chlamydia trachomatis that might effect in chronic inflammation of the eyelids, which produces scarring of the conjunctiva that can consequently cause entropion trichiasis, resulting in interned eyelashes. The interned eyelashes as well as other changes of the eye, harm the cornea causing severe pain, corneal opacity and resulting vision loss. Over a million people in Ethiopia are estimated to have Trachomatous trichiasis (TT). Trachomatous trichiasis surgery is the backbone treatment option. Though the provision of free surgical services in the country exists, utilization rates are very low. Identifying the determinants for not utilizing the service is mandatory to take measures towards surgical uptake. A total of 482 study participants (241 cases and 241 controls) with age of ≥15 years were included in the study. The determinants for not use of surgical services were respondents in the younger age group (16–30 years) and widowed participants, lengthy distance from the service, unavailability of TT surgeon, no trichiasis symptoms, long time knowing the problem, right/left eye affected, no experience of epilation practice, and participants who knew place of service was given at health center.

Oral doxycycline for the prevention of postoperative trachomatous trichiasis in Ethiopia: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Trachomatous trichiasis is treated surgically to prevent sight loss. Unfavourable surgical outcomes remain a major challenge. We investigated the hypothesis that doxycycline might reduce the risk of postoperative trichiasis following surgery in patients with trachomatous trichiasis through anti-matrix metalloproteinase and anti-inflammatory activity.

METHODS

In this randomised, double-blind, placebo-controlled trial, adults (aged >18 years) with upper lid trachomatous trichiasis in association with tarsal conjunctive scarring were recruited through community-based screening and surgical outreach campaigns in Ethiopia. Individuals who had previously had eyelid surgery were excluded. Participants were randomly assigned (1:1), with random block sizes of four or six, to receive oral doxycycline (100 mg once a day) or placebo for 28 days immediately after trichiasis surgery. Randomisation was stratified by surgeon. Patients, investigators, surgeons, and all other study team members were masked to study group allocation and treatment. Participants were examined at 10 days, and 1, 6, and 12 months after surgery. The primary outcome was the cumulative proportion of individuals who developed postoperative trichiasis by 12 months. Primary analyses were done in all participants who attended at least one of the four follow-up assessments. Safety analyses were done in all participants who attended either the 10 day or 1 month follow-up assessments. This trial is registered with the Pan African Clinical Trials Registry, number PACTR201512001370307.

FINDINGS

Between Dec 21, 2015, and April 6, 2016, 1000 patients with trichiasis were enrolled and randomly assigned to treatment (499 patients to doxycycline, 501 patients to placebo). All but one participant attended at least one follow-up assessment. Thus, 999 participants were assessed for the primary outcome: 498 in the doxycycline group and 501 in the placebo group. By month 12, 58 (12%) of 498 patients in the doxycycline group and 62 (12%) of 501 patients in the placebo group had developed postoperative trichiasis (adjusted odds ratio 0·91, 95% CI 0·61 to 1·34, p=0·63), with a risk difference of -0·5% (-4·5% to 3·5%). Significantly more patients in the doxycycline group had an adverse event than in the placebo group (18 [4%] of 498 vs six [1%] of 501; odds ratio 3·09, 95% CI 1·21-7·84; p=0·02). The most frequent adverse events in the doxycycline group were gastritis symptoms (n=9), constipation (n=4), and diarrhoea (n=4).

INTERPRETATION

Doxycycline did not reduce the risk of postoperative trichiasis and is therefore not indicated for the improvement of outcomes following trachomatous trichiasis surgery. Surgical programmes should continue to make efforts to strengthen surgical training and supervision to improve outcomes.

FUNDING

The Wellcome Trust.

Profiling and validation of individual and patterns of Chlamydia trachomatis-specific antibody responses in trachomatous trichiasis

BACKGROUND

Ocular Chlamydia trachomatis (Ct) infection causes trachoma, the leading infectious cause of blindness. A Ct D/UW3 proteome microarray and sera from Gambian adults with trachomatous trichiasis (TT) or healthy matched controls previously identified several novel antigens, which suggested differential recognition in adults with TT.

METHODS

We re-analysed this serological microarray data using more robust microarray analysis techniques accounting for typical problems associated with highly dimensional data. We examined the Ct-specific antibody profile concerning the overall diversity of responses, antigen expression stage and cellular localisation of antigens. We tested differentially recognised antigens by further serological testing of the screened sera and used larger independent sample sets for validation.

RESULTS

Antibody responses identified High-Performance on antigens expressed early and late in the Ct developmental cycle and those secreted or localised to the outer membrane. Eight antigens were preferentially recognised by scarred individuals and one antigen by healthy individuals. Three of these antigens, two associated with scarring (CT667 and CT706) and one healthy-associated (CT442), were not associated with the presence or absence of scarring following specific serological testing of the arrayed sera and sera from larger, independent case-control cohorts.

CONCLUSIONS

This study identified focussed Ct-specific antibody profiles targeting proteins expressed during entry and exit from cells and localised to interact with the host. A small panel of antibody responses could discriminate between adults with and without TT in a trachoma-endemic community. Heterogenous responses in the independent validation of these antibody targets highlighted the need for large sample sizes, clearly defined clinical phenotypes and follow-up work.

Blinding Trachoma: Systematic Review of Rates and Risk Factors for Progressive Disease

BACKGROUND

Sight loss from trachoma is the end result of a scarring disease process starting in early childhood and characterised by repeated episodes of conjunctival inflammation (active trachoma). Subsequently, the conjunctiva becomes scarred, causing the eyelashes to turn inwards and scratch the cornea (trichiasis), damaging the corneal surface and leading to corneal opacification and visual impairment. It is thought that this process is initiated and driven by repeated infection with Chlamydia trachomatis. We review published longitudinal studies to re-examine the disease process, its progression rates and risk factors.

METHODOLOGY/PRINCIPAL FINDINGS

We searched PubMed for studies presenting incidence and progression data for the different stages of trachoma natural history. We only included studies reporting longitudinal data and identified 11 publications meeting this criterion. The studies were very heterogeneous in design, disease stage, duration, size and location, precluding meta-analysis. Severe conjunctival inflammation was consistently associated with incident and progressive scarring in five studies in which this was examined. One study reported an association between C. trachomatis infection and incident scarring. No studies have yet demonstrated an association between C. trachomatis infection and progressive scarring. Several studies conducted in regions with low prevalence active disease and C. trachomatis infection found evidence of on-going scarring progression.

CONCLUSIONS/SIGNIFICANCE

Overall, there are few longitudinal studies that provide estimates of progression rates and risk factors, reflecting the challenges of conducting such studies. Our understanding of this disease process and the long-term impact of control measures is partial. Intense conjunctival inflammation was consistently associated with scarring, however, direct evidence demonstrating an association between C. trachomatis and progression is limited. This suggests that on-going chlamydial reinfection may not be mandatory for progression of established scarring, indicating that sight threatening trichiasis may continue to evolve in older people in formerly endemic populations, that will require service provision for years after active disease is controlled.

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

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.

Immunohistochemical Analysis of Scarring Trachoma Indicates Infiltration by Natural Killer and Undefined CD45 Negative Cells

INTRODUCTION

The phenotype and function of immune cells infiltrating the conjunctiva in scarring trachoma have yet to be fully characterized. We assessed tissue morphology and immunophenotype of cellular infiltrates found in trachomatous scarring compared to control participants.

METHODOLOGY

Clinical assessments and conjunctival biopsy samples were obtained from 34 individuals with trachomatous scarring undergoing trichiasis surgery and 33 control subjects undergoing cataract or retinal detachment surgery. Biopsy samples were fixed in buffered formalin and embedded in paraffin wax. Hematoxylin and eosin (H&E) staining was performed for assessment of the inflammatory cell infiltrate. Immunohistochemical staining of single markers on individual sections was performed to identify cells expressing CD3 (T-cells), CD4 (helper T-cells), CD8 (suppressor/cytotoxic T-cells and Natural Killer, NK, cells), NCR1 (NK cells), CD20 (B-cells), CD45 (nucleated hematopoietic cells), CD56 (NK and T-cells), CD68 (macrophages/monocytes) and CD83 (mature dendritic cells). The degree of scarring was assessed histologically using cross-polarized light to visualize collagen fibres.

PRINCIPLE FINDINGS

Scarring, regardless of clinical inflammation, was associated with increased inflammatory cell infiltrates on H&E and CD45 staining. Scarring was also associated with increased CD8+ and CD56+ cells, but not CD3+ cells, suggestive of a NK cell infiltrate. This was supported by the presence of NCR1+ cells. There was some increase in CD20+ cells, but no evidence for increased CD4+, CD68+ or CD83+ cells. Numerous CD45 negative cells were also seen in the population of infiltrating inflammatory cells in scarred conjunctiva. Disorganization of the normal collagen architecture was strongly associated with clinical scarring.

CONCLUSIONS/SIGNIFICANCE

These data point to the infiltration of immune cells with a phenotype suggestive of NK cells in conjunctival trachomatous scarring. A large proportion of CD45 negative inflammatory cells were also present. Future work should seek to understand the stimuli leading to the recruitment of these cells and their role in progressive scarring.

Azithromycin, fluoroquinolone and chloramphenicol resistance of non-chlamydia conjunctival bacteria in rural community of Ethiopia

Aim:

To determine profiles of non-chlamydia conjunctival bacteria and their antimicrobial susceptibility from adults who underwent trachomatous trichiasis surgery in rural areas of Ethiopia.

Materials and Methods:

A cross-sectional study was conducted in rural districts in West Gojjam administrative zone. Conjunctival swabs were collected during surgery and transported using Stuart transport broth (Oxoid, UK). Antibiotic susceptibility of conjunctival isolates was determined using the Kirby-Bauer disc-diffusion method.

Results:

Non-chlamydia pathogenic bacteria were recovered from conjunctiva of 438 (31%) participants before treatment. The isolated conjunctival bacteria were Staphylococcus aureus, coagulase-negative Staphylococci, Streptococcus group (A, C, F and G), Enterococci, Streptococcus pneumoniae, Moraxella spp., Escherichia coli, Citrobacter spp., Proteus spp., Klebsiella spp., Pseudomonas spp. and Enterobacter spp. Overall, resistance rates of 57.8% to azithromycin and 68.5% to chloramphenicol were found. However, 86-94.4% sensitivity was demonstrated to ciprofloxacin and norfloxacin. Moderate sensitivity rates (61.8-78.4%) were observed to ceftriaxone, tetracycline and cotrimoxazole.

Conclusion:

Fluoroquinolones that have activity against the majority of bacterial isolates were potent at in vitro. However, unacceptably high levels of resistance to azithromycin and chloramphenicol in rural community indicated a need for further study and antimicrobial resistance surveillance.

Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease

The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT) and/or corneal opacity (CO) due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO) at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals) were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation), there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification) were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated with increased risk in this context and highlighting their potential use in improving estimates of disease burden at large scales.

Trichiasis (TT) and corneal opacity (CO) are chronic stages of trachoma, which remains an important cause of blindness. This study used multilevel spatial models to investigate risk factors for TT/CO in Nigeria, including data for more than 13,500 adults aged 40 years and above collected in the 2007 National Blindness and Visual Impairment survey. Individual-level risk factors were consistent with those identified in other studies, including a higher risk in females, older individuals and those with lower socioeconomic status. After controlling for these factors, there was evidence that a number of environmental and climatic factors are associated with the distribution of TT/CO in Nigeria. These findings establish for the Nigerian context the importance of risk factors at different scales for the later stages of trachoma, supporting anecdotal evidence that hotter, drier environmental conditions are associated with increased risk.

Epilation for minor trachomatous trichiasis: four-year results of a randomised controlled trial

Background

Trachomatous trichiasis (TT) needs to be managed to reduce the risk of vision loss. The long-term impact of epilation (a common traditional practice of repeated plucking of lashes touching the eye) in preventing visual impairment and corneal opacity from TT is unknown. We conducted a randomized controlled trial of epilation versus surgery for the management of minor TT (fewer than six lashes touching the eye) in Ethiopia. Here we report the four-year outcome and the effect on vision and corneal opacity.

Methodology/ Principal Findings

1300 individuals with minor TT were recruited and randomly assigned to quality trichiasis surgery or repeated epilation using high quality epilation forceps by a trained person with good near vision. Participants were examined six-monthly for two-years, and then at four-years after randomisation. At two-years all epilation arm participants were offered free surgery. At four-years 1151 (88.5%) were re-examined: 572 (88%) and 579 (89%) from epilation and surgery arms, respectively. At that time, 21.1% of the surgery arm participants had recurrent TT; 189/572 (33%) of the epilation arm had received surgery, while 383 (67%) declined surgery and had continued epilating (“epilation-only”). Among the epilation-only group, 207 (54.1%) fully controlled their TT, 166 (43.3%) had minor TT and 10 (2.6%) had major TT (&gt;5 lashes). There were no differences between participants in the epilation-only, epilation-to-surgery and surgery arm participants in changes in visual acuity and corneal opacity between baseline and four-years.

Conclusions/ Significance

Most minor TT participants randomised to the epilation arm continued epilating and controlled their TT. Change in vision and corneal opacity was comparable between surgery and epilation-only participants. This suggests that good quality epilation with regular follow-up is a reasonable second-line alternative to surgery for minor TT for individuals who either decline surgery or do not have immediate access to surgical treatment.

Trachoma causes visual impairment through the effect of in-turned eyelashes (trichiasis) on the surface of the eye. Epilation is a common traditional practice of intermittent plucking of lashes touching the eye, however, its long-term effectiveness in preventing visual impairment is unknown. We conducted a randomized controlled trial of epilation versus eyelid surgery (the main treatment option) in 1300 people with mild trichiasis in Ethiopia. We defined mild trichiasis as fewer than six lashes touching the eye. We have previously reported results to two years and have now re-assessed these individuals at four years. Overall, we found no difference between the epilation and surgery groups in terms of change in vision and corneal opacity between baseline and four years. Most mild trichiasis participants randomised to the epilation arm continued epilating and controlled their trichiasis. This suggests that good quality epilation is a reasonable second-line alternative to surgery for mild trichiasis for individuals who either decline surgery or do not have immediate access to surgical treatment.

Trachoma: protective and pathogenic ocular immune responses to Chlamydia trachomatis

Trachoma, caused by Chlamydia trachomatis (Ct), is the leading infectious blinding disease worldwide. Chronic conjunctival inflammation develops in childhood and leads to eyelid scarring and blindness in adulthood. The immune response to Ct provides only partial protection against re-infection, which can be frequent. Moreover, the immune response is central to the development of scarring pathology, leading to loss of vision. Here we review the current literature on both protective and pathological immune responses in trachoma. The resolution of Ct infection in animal models is IFNγ-dependent, involving Th1 cells, but whether this is the case in human ocular infection still needs to be confirmed. An increasing number of studies indicate that innate immune responses arising from the epithelium and other innate immune cells, along with changes in matrix metalloproteinase activity, are important in the development of tissue damage and scarring. Current trachoma control measures, which are centred on repeated mass antibiotic treatment of populations, are logistically challenging and have the potential to drive antimicrobial resistance. A trachoma vaccine would offer significant advantages. However, limited understanding of the mechanisms of both protective immunity and immunopathology to Ct remain barriers to vaccine development.

Association of conjunctival bacterial infection and female sex in cicatricial trachoma

PURPOSE

Conjunctival infection with non-chlamydial bacteria may play an important role in the progression of trachoma, especially with regard to the development of corneal opacity and blindness. To further characterize the microbiological profile of bacterial conjunctival infections in cicatricial trachoma, a conjunctival swabbing of adults in rural Ethiopia was performed.

METHODS

In a cross-sectional study conducted in nine Ethiopian villages with hyperendemic trachoma, persons 40 years of age or older with signs or symptoms consistent with trichiasis were recruited and conjunctival swabbing for bacterial pathogens was performed.

RESULTS

Conjunctival examination and swabbing on 112 females and 36 males were performed. Of the 148 study participants, 101 (68.2%) were confirmed to have trichiasis, and 118 (80%) had conjunctival swabs positive for bacteria. In multivariate analyses, growth of pathogenic conjunctival bacteria was independently associated with trichiasis (odds ratio [OR] 6.93; 95% confidence interval [CI] 2.71-17.7) and female sex (OR 5.90; 95% CI 2.09-16.7). Females were more likely to have swabs positive for Streptococcus pneumoniae or Haemophilus influenzae than were males (OR 9.09; 95% CI 1.17-70.8).

CONCLUSIONS

In a region of Ethiopia with endemic trachoma, conjunctival bacterial growth was more common in females than that in males. S. pneumoniae and H. influenzae, both of which frequently colonize the nasopharynx of children, were more common in females, suggesting that the preponderance of infection in females may be attributable to close contact with children. This finding is consistent with the theory that childcare activities may preferentially expose females to ocular chlamydial infection. (ClinicalTrials.gov number, NCT00221364.).

Surgery versus epilation for the treatment of minor trichiasis in Ethiopia: a randomised controlled noninferiority trial

BACKGROUND

Trachomatous trichiasis can cause corneal damage and visual impairment. WHO recommends surgery for all cases. However, in many regions surgical provision is inadequate and patients frequently decline. Self-epilation is common and was associated with comparable outcomes to surgery in nonrandomised studies for minor trichiasis (<six lashes touching eye). This trial investigated whether epilation is noninferior to surgery for managing minor trichiasis.

METHODS AND FINDINGS

1,300 individuals with minor trichiasis from Amhara Regional State, Ethiopia were recruited and randomly assigned (1:1) to receive trichiasis surgery or epilation. The epilation group were given new forceps and epilation training. The surgical group received trichiasis surgery. Participants were examined every 6 months for 2 years by clinicians masked to allocation, with 93.5% follow-up at 24 months. The primary outcome measure ("failure") was ≥five lashes touching the eye or receiving trichiasis surgery during 24 months of follow-up, and was assessed for noninferiority with a 10% prespecified noninferiority margin. Secondary outcomes included number of lashes touching, time to failure, and changes in visual acuity and corneal opacity. Cumulative risk of failure over 24 months was 13.2% in the epilation group and 2.2% in the surgical group (risk difference = 11%). The 95% confidence interval (8.1%-13.9%) includes the 10% noninferiority margin. Mean number of lashes touching the eye was greater in the epilation group than the surgery group (at 24 months 0.95 versus 0.09, respectively; p<0.001); there was no difference in change in visual acuity or corneal opacity between the two groups.

CONCLUSIONS

This trial was inconclusive regarding inferiority of epilation to surgery for the treatment of minor trichiasis, relative to the prespecified margin. Epilation had a comparable effect to surgery on visual acuity and corneal outcomes. We suggest that surgery be performed whenever possible but epilation be used for treatment of minor trichiasis patients without access to or declining surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00522912.

Innate immune responses and modified extracellular matrix regulation characterize bacterial infection and cellular/connective tissue changes in scarring trachoma

Trachoma is the most common infectious cause of blindness and a major public health problem in many developing countries. It is caused by recurrent ocular infection with Chlamydia trachomatis in childhood, with conjunctival scarring seen later in life. The pathogenesis of trachomatous scarring, however, is poorly understood, and this study was carried out to investigate the immunofibrogenic correlates of trachomatous conjunctival scarring. A case-control study of 363 cases with conjunctival scarring and 363 control participants was conducted. Investigations included in vivo confocal microscopy (IVCM) assessment, quantitative real-time PCR gene expression, C. trachomatis detection, and nonchlamydial bacterial culture. Trachomatous scarring was found to be strongly associated with a proinflammatory, innate immune response with increased expression of psoriasin, interleukin-1β, tumor necrosis factor alpha, defensin-β4A, chemokine ligand 5, and serum amyloid A1. There was also differential expression of various modifiers of the extracellular matrix, including metalloproteinases 7, 9, 10, and 12, tissue inhibitor of matrix metalloproteinase 1, and secreted protein acidic cystein-rich-like 1. The expression of many of these genes was also significantly associated with the presence of nonchlamydial bacterial infection. These infections had a marked effect on conjunctival immune processes, including an increased inflammatory infiltrate and edema seen with IVCM. This study supports the possibility that the immunofibrogenic response in scarring trachoma is partly stimulated by nonchlamydial bacterial infection, which is characterized by the expression of innate factors.

Epilation for trachomatous trichiasis and the risk of corneal opacification

Purpose

Eight million people have trachomatous trichiasis (TT). The World Health Organization (WHO) recommends entropion surgery for TT regardless of severity. However, epilation is widely practiced for treating minor TT (1–5 lashes touching the globe). We report the frequency and effectiveness of patient-initiated epilation and its relationship to corneal opacity.

Design

Cross-sectional baseline data of individuals recruited to 2 randomized, clinical trials.

Participants

We included 2556 individuals (4310 eyes) with previously unoperated TT in ≥1 eye.

Methods

A single ophthalmologist examined all participants for signs of trachoma using WHO grading systems with additional assessment of entropion grading, location and number of trichiatic lashes, and evidence of epilation. A questionnaire enquired about epilation practices.

Main Outcome Measures

The association between epilation and degree of corneal opacity. Epilation practices of TT patients.

Results

Central corneal scarring was present in 1436 (33%) eyes. Entropion was absent/mild in 2328 (54%) eyes, moderate in 1259 (29.2%), and severe in 723 (16.8%). The median number of lashes touching the eye was 2 (interquartile range, 1–5; range, 0–133). There was clinical evidence of epilation in 3018 (70%) eyes, of which 738 (24%) were successfully epilated (no lashes touching globe). Epilation was performed frequently (at least monthly in 3311 [76.8%] eyes), by someone other than the patient (92.8%), and using locally made forceps (88.9%). Controlling for age and degree of entropion, successful epilation was associated with less corneal opacity (odds ratio [OR], 0.61; 95% confidence interval [CI]. 0.43–0.88; P = 0.007). The association was only significant in patients with severe entropion (OR, 0.07; 95% CI, 0.02–0.25; P<0.005).

Conclusions

We found an association between successful epilation and less central corneal opacity. This indicates the importance of preventing eyelashes from touching the cornea, particularly in individuals with severe entropion. This is a cross-sectional study; therefore, a causative relationship cannot be concluded. However, the results suggest that among patients who decline or are unable to access surgery, and perhaps in minor TT where the management remains controversial, the provision of high-quality forceps and epilation training may be beneficial.

Financial Disclosure(s)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Rates and risk factors for unfavorable outcomes 6 weeks after trichiasis surgery

PURPOSE

Several studies of trichiasis recurrence suggest an association between surgical factors and long-term recurrence, yet data on short-term risk factors are limited. This study was conducted to evaluate risk factors for early trichiasis recurrence and other unfavorable short-term outcomes.

METHODS

Trichiasis patients presenting for surgery were evaluated for presence of active trachoma and signs of cicatricial outcomes of trachoma, including number of trichiatic lashes, epilation, and entropion. Surgical factors recorded included incision length, surgery duration, and the surgeon performing the operation. Participants were followed up for 6 weeks after surgery and evaluated for eyelid closure defect and trichiasis recurrence; in addition, in two thirds of the patients, eyelid contour abnormality and granuloma formation were evaluated.

RESULTS

First-time trichiasis surgery was performed on 2615 eyelids. Of these, 2601 eyelids without surgical failure were followed up 6 weeks after surgery. Of the eyelids treated, 2.3% had recurrent trichiasis and 1.3% had an eyelid closure defect. Data on eyelid contour abnormalities and granuloma formation were recorded for 1881 eyes, with rates of 1.2% and 10.5%, respectively. Associated risk factors differed by outcome. Surgeon was predictive of eyelid closure defect and granuloma formation. Eyelids with short incisions were nearly four times more likely to have recurrent trichiasis (95% confidence interval, 1.7-9.3). Baseline trichiasis severity was predictive of eyelid contour abnormalities and recurrent trichiasis. Epilation was associated with granuloma formation, but was protective against eyelid closure defect.

CONCLUSIONS

Surgical factors are important predictors of unfavorable outcomes in the weeks immediately after surgery. Although the overall rate of serious uncorrectable unfavorable outcomes was very low, the high rate of granuloma formation, which can be treated by removal, highlights the need for follow-up of patients after trichiasis surgery. (ClinicalTrials.gov number, NCT00347776.).

Bacterial infection in scarring trachoma

PURPOSE

To assess whether non-chlamydial bacterial infection is associated with trachomatous scarring in adults.

METHODS

This was a case-control study of 360 cases with trachomatous scarring but without trichiasis, and 360 controls without scarring. All participants underwent clinical examination, and a swab was taken from the inferior conjunctival fornix. Samples were inoculated onto blood and chocolate agar later that day.

RESULTS

Bacterial isolates were identified in 54.0% of cases compared with 34.6% of controls (P < 0.001). A multivariate logistic regression model adjusted for age and lack of education showed that scarring was associated with the presence of commensal organisms (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.01-2.09) and was strongly associated with the presence of pathogenic organisms (OR, 4.08; 95% CI, 1.59-10.45). There was an increasing prevalence of all bacterial isolates with increasing severity of scarring (P(trend) < 0.001).

CONCLUSIONS

Trachomatous scarring is strongly associated with non-chlamydial bacterial infection compared with controls. The role of such infection with regard to scarring progression should be investigated and may have important implications for trachoma control strategies and prevention of blindness.

Elimination of active trachoma after two topical mass treatments with azithromycin 1.5% eye drops

Background

Following an epidemiological study carried out in 2006 showing a high prevalence of blinding trachoma in the Far North Region of Cameroon, a trachoma elimination programme using the SAFE strategy was initiated: three yearly trachoma mass treatments were to be performed.

Methodology/Principal Findings

The entire district population (120,000 persons) was treated with azithromycin 1.5% eye drops in February 2008 and January 2009. To assess the effect of treatment on the prevalence of active trachoma, three epidemiological studies were conducted on a representative sample of children aged between 1 and 10 years. The first study was performed just prior to the first treatment, the second just prior to the 2nd treatment and the third one, one year later. The prevalence of active forms of trachoma (TF + TI) dropped from 31.5% (95%CI 26.4–37.5) before treatment to 6.3% (95%CI 4.1–9.6) one year after first treatment; a reduction of nearly 80%. One year after the second treatment, the prevalence decreased to 3.1% (95%CI 2.0–4.9), a total reduction of 90%. Furthermore, there were no more TI cases (only TF). There was no report of serious or systemic side effects. Tolerance was excellent.

Conclusions/Significance

Active trachoma mass treatment with azithromycin 1.5% eye drops is feasible, well tolerated, and effective.

Trachoma is the leading cause of infectious blindness worldwide, accounting for 1.3 million cases of blindness. Although it has disappeared in many regions of the world, trachoma is still endemic in Africa, Eastern Mediterranean, Latin America, Asia, and Australia. The WHO has currently set a target of 2020 for controlling trachoma to a low enough level that resulting blindness will not be a major public health concern. Topical tetracycline was for a long time the recommended treatment for active trachoma, but compliance to the regimen is extremely poor. Azithromycin has properties that make it an ideal treatment for Chlamydia trachomatis: high efficacy, intracellular accumulation, and a long tissue half-life. There is now a new mass treatment of trachoma by azithromycin 1.5% eye drops which is as effective as the oral route. In the test health district of Kolofata, Cameroon, the prevalence of trachoma among children dramatically decreased from 31% to less than 5% after 2 treatments. A third treatment was performed in January 2010. An epidemiological surveillance is implemented to see if this removal will be permanent. It also avoids misuse of oral azithromycin and the eye drops are directly treating the site of the infection.

Conjunctival expression of matrix metalloproteinase and proinflammatory cytokine genes after trichiasis surgery

PURPOSE. Trachoma, the leading infectious cause of blindness, is a chronic inflammatory scarring condition. Blindness follows the development of trichiasis, which is treated surgically. Unfortunately, it frequently recurs, compromising the treatment. In this study, gene expression analysis was used to examine factors that may be involved in the inflammation and tissue remodeling after surgery. METHODS. Subjects were examined before and at 1 and 4 years after surgery. Conjunctival swab samples were collected for bacterial culture, Chlamydia trachomatis PCR, and RNA isolation at 1 year. Quantitative real-time PCR was performed to measure the expression of tumor necrosis factor-alpha (TNF), interleukin-1beta (IL1B), matrix metalloproteinase-1 (MMP1), MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), TIMP-2, and hypoxanthine phosphoribosyl transferase-1 (HPRT1). RESULTS. Two hundred forty individuals with trachomatous trichiasis were recruited. One year after surgery, recurrent trichiasis was associated with a reduced MMP-1/TIMP-1 ratio (P = 0.029). IL1B expression was elevated in the presence of either conjunctival bacterial infection (P = 0.011) or inflammation (P = 0.002). TNF expression was greater in the Mandinka ethnic group (P < 0.0001), and it was increased when clinical inflammation was associated with nonchlamydial bacterial infection (P = 0.012). MMP-9 expression increased when conjunctival inflammation was associated with bacterial infection (P = 0.007). CONCLUSIONS. Recurrent trichiasis was associated with a reduced MMP-1 to TIMP-1 ratio, which may favor the accumulation of fibrotic tissue. Nonchlamydial bacterial infection may induce factors that contribute to conjunctival tissue remodeling and recurrent trichiasis in trachoma. Prospective studies are needed to assess the potential importance of these and other factors in progressive disease.

Epidemiology and control of trachoma: systematic review

Trachoma is the commonest infectious cause of blindness. Recurrent episodes of infection with serovars A-C of Chlamydia trachomatis cause conjunctival inflammation in children who go on to develop scarring and blindness as adults. It was estimated that in 2002 at least 1.3 million people were blind from trachoma, and currently 40 million people are thought to have active disease and 8.2 million to have trichiasis. The disease is largely found in poor, rural communities in developing countries, particularly in sub-Saharan Africa. The WHO promotes trachoma control through a multifaceted approach involving surgery, mass antibiotic distribution, encouraging facial cleanliness and environmental improvements. This has been associated with significant reductions in the prevalence of active disease over the past 20 years, but there remain a large number of people with trichiasis who are at risk of blindness.

Strategies to control trachoma

Trachoma is a significant public health problem that is endemic in 57 countries, affecting 40.6 million people and contributing to 4% of the global burden of blindness. Repeated episodes of infection from Chlamydia trachomatis lead to long-term inflammation, scarring of the tarsal conjunctiva and distortion of the upper eyelid with in-turning of eyelashes that abrade the surface of the globe. This constant abrasion, in turn, can cause irreversible corneal opacity and blindness. The Alliance for the Global Elimination of Trachoma by 2020 (GET2020) has adopted the SAFE (Surgery, Antibiotics, Facial cleanliness and Environmental improvement) strategy as the main action against trachoma. Trichiasis surgery reduces the risk of blindness by reversing the in-turning of eyelashes and also improves the quality of life from non-visual symptoms. However, future efforts need to aim at increasing accessibility to surgery and improving acceptance. Antibacterials are required to reduce the burden of infection. Oral azithromycin is as close to the perfect antibacterial as we will get for mass distribution: it is safe, requires only a single oral dose, treatment is usually repeated every 6-12 months, resistance is not seen as a problem, and cost is not a limiting factor with a large donation programme and newer generic versions of the drug. Future focus should be on the details of antibacterial distribution such as coverage, frequency of distribution and target population. The promotion of facial cleanliness through education may be the key to trachoma elimination as it will stop the frequent exchange of infected ocular secretions and thus reduce the transmission of infection. However, innovative methods are required to translate health education and promotion activities into sustainable changes in hygiene behaviour. Environmental improvements should focus on the barriers to achieving facial cleanliness and cost-effective means need to be identified. There are a number of countries already eligible for certification of trachoma elimination and if current momentum continues, blinding trachoma can be eliminated by the year 2020.

The development of an age-structured model for trachoma transmission dynamics, pathogenesis and control

BACKGROUND

Trachoma, the worldwide leading infectious cause of blindness, is due to repeated conjunctival infection with Chlamydia trachomatis. The effects of control interventions on population levels of infection and active disease can be promptly measured, but the effects on severe ocular sequelae require long-term monitoring. We present an age-structured mathematical model of trachoma transmission and disease to predict the impact of interventions on the prevalence of blinding trachoma.

METHODOLOGY/PRINCIPAL FINDINGS

The model is based on the concept of multiple reinfections leading to progressive conjunctival scarring, trichiasis, corneal opacity and blindness. It also includes aspects of trachoma natural history, such as an increasing rate of recovery from infection and a decreasing chlamydial load with subsequent infections that depend upon a (presumed) acquired immunity that clears infection with age more rapidly. Parameters were estimated using maximum likelihood by fitting the model to pre-control infection prevalence data from hypo-, meso- and hyperendemic communities from The Gambia and Tanzania. The model reproduces key features of trachoma epidemiology: 1) the age-profile of infection prevalence, which increases to a peak at very young ages and declines at older ages; 2) a shift in this prevalence peak, toward younger ages in higher force of infection environments; 3) a raised overall profile of infection prevalence with higher force of infection; and 4) a rising profile, with age, of the prevalence of the ensuing severe sequelae (trachomatous scarring, trichiasis), as well as estimates of the number of infections that need to occur before these sequelae appear.

CONCLUSIONS/SIGNIFICANCE

We present a framework that is sufficiently comprehensive to examine the outcomes of the A (antibiotic) component of the SAFE strategy on disease. The suitability of the model for representing population-level patterns of infection and disease sequelae is discussed in view of the individual processes leading to these patterns.

Estimating household and community transmission of ocular Chlamydia trachomatis

Introduction

Community-wide administration of antibiotics is one arm of a four-pronged strategy in the global initiative to eliminate blindness due to trachoma. The potential impact of more efficient, targeted treatment of infected households depends on the relative contribution of community and household transmission of infection, which have not previously been estimated.

Methods

A mathematical model of the household transmission of ocular Chlamydia trachomatis was fit to detailed demographic and prevalence data from four endemic populations in The Gambia and Tanzania. Maximum likelihood estimates of the household and community transmission coefficients were obtained.

Results

The estimated household transmission coefficient exceeded both the community transmission coefficient and the rate of clearance of infection by individuals in three of the four populations, allowing persistent transmission of infection within households. In all populations, individuals in larger households contributed more to the incidence of infection than those in smaller households.

Discussion

Transmission of ocular C. trachomatis infection within households is typically very efficient. Failure to treat all infected members of a household during mass administration of antibiotics is likely to result in rapid re-infection of that household, followed by more gradual spread across the community. The feasibility and effectiveness of household targeted strategies should be explored.

Trachoma is a major cause of blindness worldwide and results from ocular infection with the bacterium Chlamydia trachomatis. Mass distribution of antibiotics in communities is part of the strategy to eliminate blindness due to trachoma. Targeted treatment of infected households could be more efficient, but the success of such a strategy will depend on the extent of transmission of infection between members of the same household and between members of the community. In this work, we estimated the magnitude of household and community transmission in four populations, two from The Gambia and two from Tanzania. We found that, in general, transmission of the bacteria within households is very efficient. In three of the four populations, persistent infection within households was predicted by the high level of household transmission (a phenomenon observed in longitudinal studies of trachoma). In all of the studied populations, individuals who live in households with more individuals contribute more to the number of new infections in the community than those who live with fewer individuals. Further studies are required to identify and examine household-targeted approaches to treatment.

The natural history of trachoma infection and disease in a Gambian cohort with frequent follow-up

Background

The natural history of ocular Chlamydia trachomatis infections in endemic communities has not been well characterised and is an important determinant of the effectiveness of different mass treatment strategies to prevent blindness due to trachoma.

Methodology/Principal Findings

A multistate hidden Markov model was fitted to data on infection and active disease from 256 untreated villagers in The Gambia who were examined every 2 weeks over a 6-month period. Parameters defining the natural history of trachoma were estimated, and associations between these parameters, demographic and baseline immune measurements examined. The median incubation period following infection was estimated at 17 days (95% confidence interval: 11–28). Disease persisted for longer than infection (median 21 (15–32) weeks) versus 17 (12–24) weeks), with an estimated median duration of post-infection inflammation of 5 (3–8) weeks. The duration of active disease showed a significant decline with age even after accounting for lower rates of re-infection and disease at older ages (p = 0.004). Measurements of levels of baseline IgA to epitopes in the major outer membrane protein of Chlamydia trachomatis were not significantly correlated with protection or more rapid clearance of infection.

Conclusions

The average duration of infection with Chlamydia trachomatis especially at younger ages is long. This contributes to the persistence and gradual return of trachoma after community-wide treatment with antibiotics.

Trachoma is an infectious disease of the eye that causes blindness in many of the poorest parts of the world. In this paper, we use a novel statistical approach to estimate the characteristics of this disease among people living in The Gambia who were examined every 2 weeks over a 6-month period. We found that the typical duration of infection with Chlamydia trachomatis and of clinically active disease were significantly longer than previously estimated. We tested different hypotheses about the natural history of trachoma that explain the relationship between infection and disease observed in the field. We also confirmed that disease lasts significantly longer among young children under 5 years old compared with older children and adults, even after accounting for high rates of re-infection in this age group, consistent with the development of immunity with age. The long duration of infection, especially among younger children, contributes to the persistence and gradual return of trachoma after community-wide treatment with azithromycin. This implies the need for high treatment coverage if infection is to be eliminated from a community, even where the return of infection after treatment is seen to be slow.

Determinants of uptake of surgical treatment for trachomatous trichiasis in North Ethiopia

BACKGROUND

Surgery for trachomatous trichiasis prevents blindness. However people still decline surgery despite the availability of services in nearby health facilities.

OBJECTIVES

To assess what proportion of cases of trichiasis had surgical treatment and to investigate the determinants of uptake of surgery.

METHODS

Eight villages in Enebse Sarmidir district of Amhara Region-Ethiopia were randomly selected and all self-reported cases of trichiasis were approached. Both operated and un-operated trichiasis cases were interviewed using structured questionnaires.

RESULT

The study employed a case control study design with patients with untreated trichiasis being cases (135) and those operated, controls (141). The main reasons given for not having surgery were burden of household tasks, indirect cost of surgery, lack of companion and fear of surgery. Uptake of surgery was found to rise with duration of illness (Chi Square for trend = 26.62, P < 0.05). Longer walking distance (more than one hour) to the nearby health facility was a negative predictor of uptake of surgical treatment (adjusted odd ratio 0.31, 95% confidence interval 0.15-0.67).

CONCLUSION

Behavior change communication interventions targeted on early uptake of surgery are very important. Village-based surgical service provision may be worthwhile in settings of high blinding trachoma burden.

Integrating an NTD with one of "The big three": combined malaria and trachoma survey in Amhara Region of Ethiopia

Background

Amhara Regional State of Ethiopia has a population of approximately 19.6 million, is prone to unstable and epidemic malaria, and is severely affected by trachoma. An integrated malaria and trachoma control program is being implemented by the Regional Health Bureau. To provide baseline data, a survey was conducted during December 2006 to estimate malaria parasite prevalence, malaria indicators, prevalence of trachoma, and trachoma risk factors in households and people of all ages in each of the ten zones of the state, excluding three urban centers (0.4% of the population).

Methodology/Principal Findings

The study was designed to provide prevalence estimates at zone and state levels. Using multi-stage cluster random sampling, 16 clusters of 25 households were randomly selected in each of the ten zones. Household heads were interviewed for malaria indicators and trachoma risk factors (N = 4,101). All people were examined for trachoma signs (N = 17,242), and those in even-numbered households provided blood films for malaria parasite detection (N = 7,745); both thick and thin blood films were read.

Zonal malaria parasite prevalence ranged from 2.4% to 6.1%, with the overall state-wide prevalence being 4.6% (95% confidence interval (CI): 3.8%–5.6%). The Plasmodium falciparum: Plasmodium vivax ratio ranged from 0.9–2.1 with an overall regional ratio of 1.2. A total of 14.8% of households reported indoor residual spraying in the past year, 34.7% had at least one mosquito net, and 16.1% had one or more long-lasting insecticidal net. Zonal trachoma prevalence (trachomatous inflammation follicular [WHO grade TF] in children aged 1–9 years) ranged from 12.6% to 60.1%, with the overall state-wide prevalence being 32.7% (95% CI: 29.2%–36.5%). State-wide prevalence of trachomatous trichiasis (TT) in persons aged over fifteen was 6.2% (95% CI: 5.3–7.4), and 0.3% (95% CI: 0.2–0.5) in children aged 0–14 years. Overall, an estimated 643,904 persons (lower bound 419,274, upper bound 975,635) have TT and require immediate corrective surgery.

Conclusions/Significance

The results provide extensive baseline data to guide planning, implementation, and evaluation of the integrated malaria and trachoma control program in Amhara. The success of the integrated survey is the first step towards demonstration that control of priority neglected tropical diseases can be integrated with one of the “big three” killer diseases.

The “big three” killer diseases are malaria, HIV/AIDS, and tuberculosis; control programs for these diseases are usually well developed and financed. The neglected tropical diseases (NTDs) are a group of ancient afflictions that are frequently sidelined by planners and are under-resourced. Opportunities of integrating the big three with NTDs have been talked about but not widely acted upon. There is potential synergy for an integrated trachoma and malaria control program since control of both diseases is community-based. The first step in accessing these synergies has been an integrated malaria prevalence and indicator and trachoma prevalence and risk factor survey. This has been achieved at the incremental cost of one additional staff member per field team. The results give unprecedented precision for the calculation of intervention targets for the integrated program and demonstrate that it is possible to integrate NTDs with the “big three.”

Trichiasis and geoclimatic factors in Mali

Several trachoma surveys conducted in sub-Saharan countries showed different geographical distributions of active trachoma and trichiasis. Trichiasis is more common in southern regions. We analysed the role of geoclimatic factors in determining the distributions of active trachoma and trichiasis in Mali. In each region a random sample of 30 clusters was examined. The prevalence of active trachoma among children and of trichiasis among women was compared, and geographical, environmental and social risk factors were assessed. Logistic regression models were constructed. Multiple regression analysis was applied and models were used to map the probability of active trachoma and trichiasis. The highest prevalence rates of active trachoma (TF/TI) were found in the northern part of Mali reaching 41.1% among children living north of the 15th parallel. Surprisingly, prevalence rates of trichiasis (TT) among women regularly increased from north to south (1.0% north of the 15th parallel vs. 2.8% south; OR=2.91, 95% CI 2.01-4.24). The two related predictive maps showed a gradient SSE/NNW for TF/TI very different from the gradient NS/SW for TT. These opposite spatial distributions could be explained by differences in the pathogenic agent, the natural history of the disease, population susceptibility, grading process or vulnerable group behaviour.

Trachoma: transmission, infection, and control

Mass antibiotic treatment and facial cleanliness are central to WHO's strategy for the elimination of blindness caused by trachoma. Recent studies have highlighted the heterogeneous response of communities to mass treatment and the complex relation between infection with Chlamydia trachomatis and clinical disease. It is important to be able to explain these findings to predict and maximise the effect of treatment on active trachoma disease and blindness in the community. Here we review the immunobiology of trachoma and provide a simple conceptual model of disease pathogenesis. We show how incorporating this model into a mathematical framework leads to an explanation of the observed community distribution of infection, bacterial load, and disease with age. The predictions of the model and empirical data show some differences that underscore the importance of individual heterogeneity in response to infection. The implications of disease transmission and pathogenesis for trachoma control programmes are discussed.

Genetic variation at the TNF locus and the risk of severe sequelae of ocular Chlamydia trachomatis infection in Gambians

Tumor necrosis factor (TNF) is thought to be a key mediator of the inflammatory and fibrotic response to Chlamydia trachomatis (Ct) infection. A large matched-pair case-control study investigated putative functional single nucleotide polymorphisms (SNPs) across the major histocompatibility complex (MHC) class III region, including TNF and its immediate neighbors nuclear factor of kappa light polypeptide gene enhancer in B cells (IkappaBL), inhibitor like 1 and lymphotoxin alpha (LTA) in relation to the risk of scarring sequelae of ocular Ct infection. Haplotype and linkage disequilibrium analysis demonstrated two haplotypes, differing at position TNF-308, conferring an increased risk of trichiasis. The TNF-308A allele, and its bearing haplotype, correlated with increased TNF production in lymphocyte cultures stimulated with chlamydial elementary body antigen. Thus TNF-308A may determine directly, or be a marker of a high TNF producer phenotype associated with increased risk of sequelae of chlamydial infection. Multivariate analysis provided evidence for the presence of additional risk-associated variants near the TNF locus.