Risk factors for corneal abrasions in Nepal: a community-based study.

BACKGROUND: South Asia is experiencing rapid urbanization, which may be changing the risk factor profile for ocular trauma. The objective of this study was to compare risk factors for traumatic corneal abrasions in rural versus urban Nepal, and to assess if any risk factors were associated with a poor outcome. METHODS: In a prospective, cross-sectional, community-based study performed as part of a cluster-randomized trial, community health workers from Nepal were trained to diagnose and treat traumatic corneal abrasions. Participants with an abrasion were invited to complete a risk factor survey. The main exposure variable was the object of eye injury, stratified by rural-urban residence. The main outcome measure was a lack of corneal healing after a three-day course of antimicrobials. RESULTS: Of 3657 participants diagnosed with a corneal abrasion, 2265 completed a survey. Eye trauma occurred most frequently during agricultural activities. The most common object of injury was vegetative matter, accounting for approximately 40% of injuries in rural, peri-urban, and urban communities. Wood injuries were more common in rural communities (24%) compared with urban or peri-urban communities (13%). Eye injury from an animal was more likely to result in a non-healing corneal abrasion after 3 days of treatment compared with other types of trauma (prevalence ratio 2.59, 95%CI 1.16-5.76). CONCLUSIONS: Health promotion activities for prevention of corneal ulcers in Nepal should focus on agricultural trauma in both rural and urban areas. Community members experiencing eye trauma from an animal may benefit from early referral to an eye clinic.

Seasonal and Temporal Trends of Infectious Keratitis in Northern Vietnam.

The epidemiology of corneal ulcers in Vietnam has not been well characterized. In this report, we reviewed retrospectively the microbiological data of patients with a clinical diagnosis of corneal ulcer at the microbiology laboratory of Vietnam National Eye Hospital from January 1, 2010 to March 31, 2023. We observed a seasonal pattern for fungal and microsporidial keratitis, with an annual peak in November, and an inverse relationship between fungal keratitis and inclement weather. The November peak coincided with one of the major harvesting seasons in Vietnam. We also observed increasing numbers of microsporidial and Acanthamoeba keratitis cases in recent years. Knowledge of these trends are helpful in guiding empirical treatment of corneal infections and preventing corneal blindness.

Diagnostic accuracy of smartphone corneal photography for detection of corneal opacities in a resource-limited setting: a community-based study.

Purpose: To evaluate the diagnostic accuracy of smartphone corneal photography in detecting corneal opacities in a community-based setting. Methods: A case-control, diagnostic accuracy study was nested in a cluster-randomized trial of a corneal ulcer prevention intervention in Nepal. Smartphone corneal photography was performed annually on community members self-reporting a potential risk factor for a corneal infection. Corneal photographs were graded for the presence or absence of an opacity. All cases with an opacity on smartphone photography and an equal number of controls were invited for a comprehensive eye examination with a slit lamp biomicroscope at an eye hospital. A mobile team visited participants unable to come to the hospital, conducting a limited examination with a penlight. Results: Of 1332 study participants (666 cases and 666 controls), 1097 had a penlight examination (535 cases and 562 controls) and 191 had a slit lamp examination (120 cases and 71 controls). When penlight examination was considered the reference standard, smartphone diagnosis of a corneal opacity had a positive predictive value (PPV) of 47% (95% confidence interval 43-52%) and negative predictive value (NPV) of 95% (93-97%). When slit lamp examination was considered the reference standard, the overall PPV and NPV were 71% (62-78%) and 80% (70-88%), respectively. The NPV was greater for detection of opacities > 1mm, estimated at 95% (90-98%). Conclusions: Corneal photography performed in a resource-limited community-based setting using a smartphone coupled to an external attachment had acceptable diagnostic accuracy for detection of corneal opacities large enough to be clinically meaningful.

Risk factors for corneal ulcers: a population-based matched case-control study in Nepal.

BACKGROUND/AIMS: We aimed to examine risk factors for corneal ulcer in a rural and peri-urban setting in Nepal. METHODS: This population-based matched case-control study was nested in a cluster randomised trial in 24 village development committees in Nepal. Incidence density sampling was used to match incident corneal opacity cases to controls, matching on time of opacity, age, sex and location. Cases and controls were invited to participate in a survey of risk factors for corneal ulcer. Risk factors were evaluated using conditional logistic regression to account for matching. RESULTS: Of the 540 participants with incident opacities identified in the trial, 433 were willing to participate in this substudy and matched to a control. Compared with controls, cases had lower odds of having any education vs no education (adjusted OR, aOR 0.60, 95% CI 0.39 to 0.94), working in non-manual labour occupations vs manual labour occupations (aOR 0.64, 95% CI 0.42 to 0.95) and preferring medical shops for ocular trauma versus eye care system centres (aOR 0.58, 95% CI 0.37 to 0.92). Cases had higher odds of protective goggle use versus no protection (aOR 3.8, 95% CI 1.3 to 11.0) and having an ocular injury vs none (aOR 7.7, 95% CI 4.3 to 13.6) compared with controls. CONCLUSION: We found ocular injury, manual labour and lower education to be strongly associated with the development of corneal ulcer. Given the persistent burden of corneal blindness in this area, prevention efforts could target efforts to increase access to care in areas where these factors are common.

Village-integrated eye workers for prevention of corneal ulcers in Nepal (VIEW study): a cluster-randomised controlled trial.

BACKGROUND: Corneal ulcers are a common cause of blindness in low-income and middle-income countries, usually resulting from traumatic corneal abrasions during agricultural work. Antimicrobial prophylaxis of corneal abrasions can help prevent corneal ulcers, but delays in the initiation of therapy are frequent. We aimed to assess whether a community-based programme for corneal ulcer prevention would reduce the incidence of corneal ulceration. METHODS: A cluster-randomised trial was performed in village development committees (VDCs) in Nepal. VDCs in the catchment area of Bharatpur Eye Hospital, Nepal with less than 15 000 people were eligible for inclusion. We randomly assigned (1:1) VDCs to either an intervention group or a control group. In the intervention VDCs, existing female community health volunteers (FCHVs) were trained to diagnose corneal abrasions and provide a 3-day course of ophthalmic antimicrobials to their patients. In the control VDCs, FCHVs did not provide this intervention. Participants were not masked given the nature of the intervention. Both groups were followed up for 3 years for photographic evidence of corneal ulceration. The primary outcome was the incidence of corneal ulceration, determined by masked assessment of corneal photographs. The analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT01969786. FINDINGS: We assessed 112 VDCs, of which 24 were enrolled. The study was performed between Feb 4, 2014, and Oct 20, 2017. 12 VDCs were randomly assigned to the intervention group and 12 to the control group. 252 539 individuals were included in the study (130 579 in the intervention group and 121 960 in the control group). FCHVs diagnosed and provided antimicrobials for 4777 corneal abrasions. The census identified 289 corneal ulcers among 246 893 person-years in the intervention group (incidence 1·21 cases [95% CI 0·85-1·74] per 1000 person-years) and 262 corneal ulcers among 239 170 person-years in the control group (incidence 1·18 cases [0·82-1·70] per 1000 person-years; incidence rate ratio 1·03 [95% CI 0·63-1·67]; p=0·93). Medication allergy was self-reported in 0·2% of participants. INTERPRETATION: We did not detect a reduction in the incidence of corneal ulceration during the first 3 years of a community-based corneal ulcer prevention programme. Further study might be warranted in more rural areas where basic eye care facilities are not available. FUNDING: National Eye Institute.

Relationship Between Cooking Fuel and Lens Opacities in South India: A 15-Year Prospective Cohort Study.

PURPOSE: To determine whether exposure to unclean cooking fuels was associated with subsequent cataract progression as reported in previous cross-sectional studies. DESIGN: Prospective cohort study. METHODS: This is a secondary observational analysis of the community-based Antioxidants in Prevention of Cataracts trial (ClinicalTrials.gov ID NCT01664819). The exposure of interest was cooking fuel type, measured at baseline. Main outcome measures were baseline cataract severity and self-reported cataract surgery at a 15-year visit. RESULTS: Baseline and 15-year follow-up data were available for 798 and 579 participants, respectively. Wood or kerosene was used by 711 of 798 (89.1%) baseline participants, including 539 of 579 (93.1%) participants with complete follow-up. Cooking fuel type was not associated with cataract severity at baseline (P = .443). Of 8334 person-years of follow-up, 90 cataract surgeries were observed over 15 years (1.08 surgeries per 100 person-years; 95% CI = 0.87-1.32). Use of wood or kerosene was not associated with 15-year incidence of cataract surgery relative to use of propane (adjusted P = .154). Cataract surgery was more common in older individuals (HR = 1.1 per year, 95% CI = 1.1-1.2, P < .001), those with baseline myopia (HR = 2.1, 95% CI = 1.2-3.5, P = .009), and women (HR = 3.5, 95% CI = 1.2-10.1, P = .019). CONCLUSIONS: This study found no association between unclean cooking fuels and cataract progression over a 15-year period. No other modifiable risk factors were associated with incident self-reported cataract surgery.

Community Health Workers for Prevention of Corneal Ulcers in South India: A Cluster-Randomized Trial.

PURPOSE: To determine whether a community health worker (CHW) program increases referrals to local eye care providers and ultimately reduces the incidence of corneal ulcers. DESIGN: Cluster-randomized trial performed from 2014 to 2017 in rural South India. METHODS: This was a community-based study that included all inhabitants of 42 rural South Indian communities. CHWs were trained to diagnose corneal abrasions and assist participants in seeking care at a local vision center. Given the nature of the intervention, the trial was not masked. The main outcome measure was incident corneal ulcer, defined as an active infiltrate or evidence of a new opacity, as assessed by means of penlight examination during an annual door-to-door census. RESULTS: Twenty-one study clusters were randomized to the CHW intervention and 21 to no intervention. Vision centers diagnosed 195 corneal abrasions from the intervention clusters during the 2-year study (rate, 223 per 100,000 person-years; 95% CI, 28-1743) and 62 from the control clusters (rate, 62 per 100,000 person-years; 95% CI, 8-496; incidence rate ratio, 3.57; 95% CI, 2.01-6.35; P < .001). The estimated incidence of corneal ulceration during the study period was 60 per 100,000 person-years (95% CI, 25-141) in the intervention group and 32 per 100,000 person-years (95% CI, 13-80) in the control group (incidence rate ratio, 1.86; 95% CI, 0.5-6.4; P = .32). CONCLUSIONS: A CHW program resulted in 3.5 times more referrals to local eye care providers for corneal abrasions, but no difference could be detected in the incidence of corneal ulceration. CHW programs provide a mechanism for increasing referrals to eye hospitals. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02284698.

Assessment of herd protection against trachoma due to repeated mass antibiotic distributions: a cluster-randomised trial.

BACKGROUND: Trachoma-control programmes distribute oral azithromycin to treat the ocular strains of chlamydia that cause the disease and to control infection. Theoretically, elimination of infection is feasible if untreated individuals receive an indirect protective effect from living in repeatedly treated communities, which is similar to herd protection in vaccine programmes. We assessed indirect protection against trachoma with mass azithromycin distributions. METHODS: In a cluster randomised trial, 24 subkebeles (government-defined units) in Amhara, Ethiopia, were randomised, with use of a simple random sample, to distribution four times per year of single-dose oral azithromycin to children aged 1-10 years (12 subkebeles, 4764 children), or to delayed treatment until after the study (control; 12 subkebeles, 6014 children). We compared the prevalence of ocular chlamydial infection in untreated individuals 11 years and older between baseline and 12 months in the treated subkebeles, and at 12 months between the treated and control subkebeles. Health-care and laboratory personnel were blinded to study group. Analysis was intention to treat. The study is registered with clinicaltrials.gov, number NCT00322972. FINDINGS: At 12 months, 637 children aged 1-10 years and 561 adults and children aged 11 years and older were analysed in the children-treated group, and 618 and 550, respectively, in the control group. The mean prevalence of infection in children decreased from 48.4% (95% CI 42.9-53.9) to 3.6% (0.8-6.4) after four mass treatments. At 12 months, the mean prevalence of infection in the untreated age group (>/=11 years) was 47% (95% CI 33-57) less than baseline (p=0.002), and 35% (95% CI 1-57) less than that in untreated communities (p=0.04). INTERPRETATION: Frequent treatment of children, who are a core group for transmission of trachoma, could eventually eliminate infection from the entire community. Herd protection is offered by repeated mass antibiotic treatments, providing a strategy for elimination of a bacterial disease when an effective vaccine is unavailable. FUNDING: National Institutes of Health.

Complete elimination is a difficult goal for trachoma programs in severely affected communities.

The World Health Organization has distributed millions of doses of azithromycin to control the ocular chlamydial infection that causes trachoma. Theoretically, a loftier goal of elimination is feasible. Here, we demonstrate that, although local elimination of infection in the most severely affected communities is difficult, it is possible with biannual antibiotic distributions.

Does in vitro susceptibility predict clinical outcome in bacterial keratitis?

PURPOSE: To determine whether clinical outcomes in bacterial keratitis are associated with antibiotic susceptibility. DESIGN: Retrospective, ancillary study using data and samples from a completed randomized clinical trial. METHODS: Forty-two patients were enrolled with culture-confirmed bacterial keratitis at Aravind Eye Hospital in South India. All patients received topical moxifloxacin and were randomized to receive either topical prednisolone phosphate or placebo. Outcomes included time to epithelialization, best spectacle-corrected visual acuity (BSCVA), and infiltrate/scar size at three months. Bacterial isolates were cultured, and minimum inhibitory concentration (MIC) to moxifloxacin was measured using Etests. Multiple linear regression was used to assess the effect of MIC on outcome, adjusting for enrollment characteristics. RESULTS: MIC was associated with three-month infiltrate/scar size: each two-fold increase in MIC was associated with a 0.33-mm average diameter increase in scar size (P=.01). MIC was not associated with three-month BSCVA (P=.71) or time to epithelialization (P=.35). CONCLUSIONS: MIC was associated with infiltrate/scar size in bacterial keratitis. An ongoing larger, multicenter trial should provide further information on whether this association is maintained across subgroups of organisms.

Comparison of annual and biannual mass antibiotic administration for elimination of infectious trachoma.

CONTEXT: Treatment recommendations assume that repeated mass antibiotic distributions can control, but not eradicate or even locally eliminate, the ocular strains of chlamydia that cause trachoma. Elimination may be an important end point because of concern that infection will return to communities that have lost immunity to chlamydia after antibiotics are discontinued. OBJECTIVE: To determine whether biannual treatment can eliminate ocular chlamydial infection from preschool children and to compare results with the World Health Organization-recommended annual treatment. DESIGN, SETTING, AND PARTICIPANTS: A cluster-randomized clinical trial of biannual vs annual mass azithromycin administrations to all residents of 16 rural villages in the Gurage Zone, Ethiopia, from March 2003 to April 2005. INTERVENTIONS: At scheduled treatments, all individuals aged 1 year or older were offered a single dose of oral azithromycin either annually or biannually. MAIN OUTCOME MEASURE: Village prevalence of ocular chlamydial infection and presence of elimination at 24 months in preschool children determined by polymerase chain reaction, correcting for baseline prevalence. Antibiotic treatments were performed after sample collections. RESULTS: Overall, 14,897 of 16,403 eligible individuals (90.8%) received their scheduled treatment. In the villages in which residents were treated annually, the prevalence of infection in preschool children was reduced from a mean of 42.6% (range, 14.7%-56.4%) to 6.8% (range, 0.0%-22.0%) at 24 months. In the villages in which residents were treated biannually, infection was reduced from 31.6% pretreatment (range, 6.1%-48.6%) to 0.9% (range, 0.0%-4.8%) at 24 months. Biannual treatment was associated with a lower prevalence at 24 months (P = .03, adjusting for baseline prevalence). At 24 months, no infection could be identified in 6 of 8 of those treated biannually and in 1 of 8 of those treated annually (P = .049, adjusting for baseline prevalence). CONCLUSION: Local elimination of ocular chlamydial infection appears feasible even in the most severely affected areas, although it may require biannual mass antibiotic distributions at a high coverage level. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00221364.

Village-Integrated Eye Worker trial (VIEW): rationale and design of a cluster-randomised trial to prevent corneal ulcers in resource-limited settings.

INTRODUCTION: Corneal opacity is a leading cause of blindness worldwide. In resource-limited settings, untreated traumatic corneal abrasions may result in infection and ultimately, opacity. Although antimicrobial treatment of corneal ulcers may successfully cure infections, the scarring that accompanies the resolution of infection can still result in visual impairment. Prevention may be the optimal approach for reducing corneal blindness. Studies have employed community health workers to provide prompt administration of antimicrobials after corneal abrasions to prevent infections, but these studies were not designed to determine the effectiveness of such a programme. METHODS AND ANALYSIS: The Village-Integrated Eye Worker trial (VIEW) is a cluster-randomised trial designed to assess the effectiveness of a community health worker intervention to prevent corneal ulcers. Twenty-four Village Development Committees (VDCs) in Nepal were randomised to receive a corneal ulcer prevention programme or to no intervention. Female Community Health Volunteers (FCHVs) in intervention VDCs are trained to diagnose corneal abrasions, provide antimicrobials and to refer participants when needed. An annual census is conducted over 3 years in all study VDCs to assess the incidence of corneal ulceration via corneal photography (primary outcome). Masked outcome assessors grade corneal photographs to determine the presence or absence of incident corneal opacities. The primary analysis is negative binomial regression to compare the incidence of corneal ulceration by study arm. ETHICS AND DISSEMINATION: The University of California San Francisco Committee on Human Research, Nepal Netra Jyoti Sangh and the Nepal Health Research Council have given ethical approval for the trial. The results of this trial will be presented at local and international meetings and submitted to peer-reviewed journals for publication. TRIAL REGISTRATION NUMBER: NCT01969786; Pre-results.

Hookworm infestation as a risk factor for Mooren's ulcer in South India.

OBJECTIVE: To investigate the association between Mooren's ulcer and intestinal hookworm infestation in South India. DESIGN: Prospective observational case-control study. PARTICIPANTS: Fifteen patients with Mooren's ulcer and 30 age- and gender-matched controls seen at Aravind Eye Hospital. METHODS: Stool samples from the Mooren's ulcer patients and controls were collected and analyzed for presence of hookworm infestation. MAIN OUTCOME MEASURE: Prevalence of hookworm infestation in Mooren's ulcer patients and controls. RESULTS: There was a statistically significant correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer (P = 0.009). Retrospective exploratory subgroup analyses suggested that the correlation between intestinal hookworm infestation and the occurrence of Mooren's ulcer in men (P<0.0001) was stronger than the correlation in women, with no statistically significant difference being observed in the prevalence of hookworm infestation between women with Mooren's ulcer and female control subjects (P>0.99). Similarly, when both the Mooren's ulcer and the control subject groups were analyzed retrospectively by age > 50 years or age < 50, subjects with an age over 50 demonstrated a stronger correlation between hookworm infestation and Mooren's ulcer than controls (P = 0.017), whereas there was no statistically significant difference in the prevalence of hookworm infection between Mooren's ulcer subjects and control subjects < or = 50 (P = 0.31). CONCLUSION: Intestinal hookworm infestation appears to be associated with the development of Mooren's ulcer in South India. Although the power of our retrospective exploratory subgroup analyses was limited by multiple testing and small sample sizes, these data suggest further that the correlation between intestinal hookworm infestation and the development of Mooren's ulcer may be greatest in male patients with more advanced age.

Chlamydia on children and flies after mass antibiotic treatment for trachoma.

There are various approaches to control trachoma. These include the elimination of the ocular strains of Chlamydia trachomatis that cause the disease and to decrease the spread of infection by other measures such as fly control. Here, we examined how these two are related (i.e., how treating children with antibiotics affects carriage of Chlamydia by flies). Flies were collected in villages that had received mass oral azithromycin distribution and were compared with flies in untreated villages. Polymerase chain reaction (PCR) was performed to detect chlamydial DNA on the flies. Conjunctival swabs were also taken to assay for chlamydial prevalence in the children. Chlamydia was found on 23% of the flies in the untreated villages but only 0.3% in treated villages. Prevalence of trachoma in children proved to be an excellent predictor of the prevalence on flies (correlation coefficient, 0.89). Thus, treating children with antibiotics may drastically reduce the role of flies as a vector.

Spectrum of eye disease caused by methicillin-resistant Staphylococcus aureus.

PURPOSE: To compare the clinical features and antibiotic susceptibility of ocular methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). DESIGN: Cross-sectional study. METHODS: The Proctor clinical laboratory database was reviewed to identify all ocular isolates of S. aureus collected between July 1, 1998 and July 31, 2006. RESULTS: Of 915 S. aureus isolates, there were 88 MRSA isolates in 41 different patients. The proportion MRSA increased from 4.1% in 1998 to 1999 to 16.7% in 2005 to 2006. A total of 78.0% of patients with MRSA had blepharoconjunctivitis, 2.4% had cellulitis, 2.4% had dacryocystitis, 14.6% had keratitis, and 2.4% had endophthalmitis. The diagnoses associated with MSSA were not statistically different. A total of 63.6% of MRSA isolates were sensitive to bacitracin, 100% to vancomycin, 14.8% to ciprofloxacin, 14.8% to erythromycin, 97.7% to sulfisoxazole, and 93.2% to tetracycline. CONCLUSIONS: MRSA has become a more common ocular pathogen but, as with MSSA, causes mild disease. MRSA should be treated with vancomycin.

Clinical characteristics of Mooren's ulcer in South India.

AIM: To describe the clinical characteristics at presentation of a large cohort of patients with Mooren's ulcer in South India. METHODS: The medical records of patients with Mooren's ulcer examined in the cornea clinic at Aravind Eye Hospital Madurai, Tamil Nadu, India, over a 10-year period were reviewed in this retrospective observational case series. RESULTS: The cohort contained 242 eyes of 166 patients. All patients were from South India, and men outnumbered women by a ratio of 4.7:1. The median and mean ages at presentation were 65 and 61 years, respectively, with a range of 13-95 years. One eye was affected in 90 of 166 (54%) patients. Visual acuity in the affected eye at presentation ranged from 6/6 to light perception, and was 6/12 or better in 34 of 242 (14%) eyes, between 6/12 and 3/60 in 168 (69%) eyes, and worse than 3/60 in 40 (17%) eyes. Partial peripheral corneal ulceration was observed in 222 (92%) eyes, complete peripheral corneal ulceration was observed in 15 (6%) eyes and total corneal ulceration was observed in 5 (2%) eyes. For those 222 eyes with partial peripheral ulceration, 152 (68%) showed temporal involvement, 129 (58%) showed nasal involvement, 116 (52%) showed inferior involvement and 30 (14%) showed superior involvement. Perforation was observed in 26 (11%) eyes, and was more common in eyes with peripheral as compared with total ulceration (p<0.001). Identified risk factors in the cohort included evidence of prior corneal surgery (22%), corneal trauma (17%) and corneal infection (2%). CONCLUSIONS: Mooren's ulcer is a rare and potentially blinding eye condition observed not infrequently in the cornea clinic at Aravind Eye Hospital. Men are affected more often than women and may present with either unilateral or bilateral disease. Perforation is observed in approximately 1 in 10 affected eyes at presentation and occurs most often in the setting of peripheral ulceration. The occurrence of prior corneal surgery, trauma or infection in nearly one third of patients supports theories of exposure to corneal antigen in the pathogenesis of this disorder.

A rationale for continuing mass antibiotic distributions for trachoma.

BACKGROUND: The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. METHODS: We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. RESULTS: Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. CONCLUSION: Local elimination from a community is theoretically possible, even in the most severely infected communities. However, elimination from larger areas may require repeated biannual treatments and prevention of re-introduction from outside to treated areas.