Assessment of spillover of antimicrobial resistance to untreated children 7 to 12 years old after mass drug administration of azithromycin for child survival in Niger: a secondary analysis of the MORDOR cluster-randomized trial.

BACKGROUND: The risk of antibiotic resistance is complicated by the potential for spillover effects from one treated population to another. Azithromycin mass drug administration programs report higher rates of antibiotic resistance among treatment arms in targeted groups. This study aims to understand the risk of spillover of antibiotic resistance to non-target groups in these programs. METHODS: Data was used from a cluster-randomized trial comparing the effect of biannual azithromycin and placebo distribution to children 1-59 months on child mortality. Nasopharyngeal samples from untreated children 7-12 years old were tested for genetic determinants of macrolide resistance (primary outcome) and resistance to other antibiotic classes (secondary outcomes). Linear regression was used to compare the community-level mean difference in prevalence by arm at the 24-month timepoint adjusting for baseline prevalence. RESULTS: 1,103 children 7-12 years old in 30 communities were included in the analysis (15 azithromycin, 15 placebo). Adjusted mean differences in prevalence of resistance determinants for macrolides, beta-lactams and tetracyclines were 3.4% (95% CI -4.1% to 10.8%, P-value 0.37), -1.2% (95% CI -7.9% to 5.5%, P-value 0.72), and -3.3% (95% CI -9.5% to 2.8%, P-value 0.61), respectively. CONCLUSIONS: We were unable to demonstrate a statistically significant increase in macrolide resistance determinants in untreated groups in an azithromycin mass drug administration program. While the result might be consistent with a small spillover effect, this study was not powered to detect such a small difference. Larger studies are warranted to better understand the potential for spillover effects within these programs.

Preoperative Medical Testing and Falls in Medicare Beneficiaries Awaiting Cataract Surgery.

PURPOSE: Delaying cataract surgery is associated with an increased risk of falls, but whether routine preoperative testing delays cataract surgery long enough to cause clinical harm is unknown. We sought to determine whether the use of routine preoperative testing leads to harm in the form of delayed surgery and falls in Medicare beneficiaries awaiting cataract surgery. DESIGN: Retrospective, observational cohort study using 2006-2014 Medicare claims. PARTICIPANTS: Medicare beneficiaries 66+ years of age with a Current Procedural Terminology claim for ocular biometry. METHODS: We measured the mean and median number of days between biometry and cataract surgery, calculated the proportion of patients waiting ≥ 30 days or ≥ 90 days for surgery, and determined the odds of sustaining a fall within 90 days of biometry among patients of high-testing physicians (testing performed in ≥ 75% of their patients) compared with patients of low-testing physicians. We also estimated the number of days of delay attributable to high-testing physicians. MAIN OUTCOME MEASURES: Incidence of falls occurring between biometry and surgery, odds of falling within 90 days of biometry, and estimated delay associated with physician testing behavior. RESULTS: Of 248 345 beneficiaries, 16.4% were patients of high-testing physicians. More patients of high-testing physicians waited ≥ 30 days and ≥ 90 days to undergo surgery (31.4% and 8.2% vs. 25.0% and 5.5%, respectively; P < 0.0001 for both). Falls before surgery in patients of high-testing physicians increased by 43% within the 90 days after ocular biometry (1.0% vs. 0.7%; P < 0.0001). The adjusted odds ratio of falling within 90 days of biometry in patients of high-testing physicians versus low-testing physicians was 1.10 (95% confidence interval [CI], 1.03-1.19; P = 0.008). After adjusting for surgical wait time, the odds ratio decreased to 1.07 (95% CI, 1.00-1.15; P = 0.06). The delay associated with having a high-testing physician was approximately 8 days (estimate, 7.97 days; 95% CI, 6.40-9.55 days; P < 0.0001). Other factors associated with delayed surgery included patient race (non-White), Northeast region, ophthalmologist ≤ 40 years of age, and low surgical volume. CONCLUSIONS: Overuse of routine preoperative medical testing by high-testing physicians is associated with delayed surgery and increased falls in cataract patients awaiting surgery.

Cost-Effectiveness of Mass Treatment with Azithromycin for Reducing Child Mortality in Malawi: Secondary Analysis from the MORDOR Trial.

The recent Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance (MORDOR) trial reported a reduction in child mortality following biannual azithromycin mass drug administration (MDA). Here, we investigate the financial costs and cost-effectiveness from the health provider perspective of azithromycin MDA at the MORDOR-Malawi study site. During MORDOR, a cluster-randomized trial involving biannual azithromycin MDA or placebo to children aged 1-59 months, fieldwork-related costs were collected, including personnel, transport, consumables, overheads, training, and supervision. Mortality rates in azithromycin- and placebo-treated clusters were calculated overall and for the five health zones of Mangochi district. These were used to estimate the number needed to treat to avert one death and the costs per death and disability-adjusted life year (DALY) averted. The cost per dose of MDA was $0.74 overall, varying between $0.63 and $0.94 in the five zones. Overall, the number needed to treat to avert one death was 1,213 children; the cost per death averted was $898.47, and the cost per DALY averted was $9.98. In the three zones where mortality was lower in azithromycin-treated clusters, the number needed to treat to avert one death, cost per death averted, and cost per DALY averted, respectively, were as follows: 3,070, $2,899.24, and $32.31 in Monkey Bay zone; 1,530, $1,214.42, and $13.49 in Chilipa zone; and 344, $217.98, and $2.42 in Namwera zone. This study is a preliminary cost-effectiveness analysis that indicates azithromycin MDA for reducing child mortality has the potential to be highly cost-effective in some settings in Malawi, but the reasons for geographical variation in effectiveness require further investigation.

Insecticide-treated bed net access and use among preschool children in Nouna District, Burkina Faso.

BACKGROUND: We evaluated universal insecticide-treated bed net access and use in children <5 y of age in a rural area of Burkina Faso. METHODS: A door-to-door enumerative census was conducted in Nouna District, Burkina Faso in December 2018 through April 2019. The most recent mass bed net distribution campaign occurred in June 2016. Heads of households were interviewed about household bed net ownership and use by children <5 y of age. We evaluated the relationship between demographic and socio-economic factors and household universal bed net access and use by children. RESULTS: In 23 610 households with at least one child <5 y of age, 71 329 bed nets were reported (94.5% insecticide-treated). One-third (35.2%) of households had universal access and two-thirds (67.0%) of children slept under an insecticide-treated net the previous night. Children in households with universal access more often slept under a net the previous night (adjusted odds ratio 4.81 [95% confidence interval 4.39-5.26]). CONCLUSIONS: Bed net coverage was substantially less than the 80% World Health Organization target for universal coverage in Nouna District. Insecticide-treated nets were used preferentially for children, but important gaps remain in consistent bed net use in this population. Structural and behavioural interventions are needed to close these gaps.

Longer-Term Assessment of Azithromycin for Reducing Childhood Mortality in Africa.

BACKGROUND: The MORDOR I trial (Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance) showed that in Niger, mass administration of azithromycin twice a year for 2 years resulted in 18% lower postneonatal childhood mortality than administration of placebo. Whether this benefit could increase with each administration or wane owing to antibiotic resistance was unknown. METHODS: In the Niger component of the MORDOR I trial, we randomly assigned 594 communities to four twice-yearly distributions of either azithromycin or placebo to children 1 to 59 months of age. In MORDOR II, all these communities received two additional open-label azithromycin distributions. All-cause mortality was assessed twice yearly by census workers who were unaware of participants' original assignments. RESULTS: In the MORDOR II trial, the mean (±SD) azithromycin coverage was 91.3±7.2% in the communities that received twice-yearly azithromycin for the first time (i.e., had received placebo for 2 years in MORDOR I) and 92.0±6.6% in communities that received azithromycin for the third year (i.e., had received azithromycin for 2 years in MORDOR I). In MORDOR II, mortality was 24.0 per 1000 person-years (95% confidence interval [CI], 22.1 to 26.3) in communities that had originally received placebo in the first year and 23.3 per 1000 person-years (95% CI, 21.4 to 25.5) in those that had originally received azithromycin in the first year, with no significant difference between groups (P = 0.55). In communities that had originally received placebo, mortality decreased by 13.3% (95% CI, 5.8 to 20.2) when the communities received azithromycin (P = 0.007). In communities that had originally received azithromycin and continued receiving it for an additional year, the difference in mortality between the third year and the first 2 years was not significant (-3.6%; 95% CI, -12.3 to 4.5; P = 0.50). CONCLUSIONS: We found no evidence that the effect of mass administration of azithromycin on childhood mortality in Niger waned in the third year of treatment. Childhood mortality decreased when communities that had originally received placebo received azithromycin. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT02047981.).

Sensitivity and specificity of computer vision classification of eyelid photographs for programmatic trachoma assessment.

BACKGROUND/AIMS: Trachoma programs base treatment decisions on the community prevalence of the clinical signs of trachoma, assessed by direct examination of the conjunctiva. Automated assessment could be more standardized and more cost-effective. We tested the hypothesis that an automated algorithm could classify eyelid photographs better than chance. METHODS: A total of 1,656 field-collected conjunctival images were obtained from clinical trial participants in Niger and Ethiopia. Images were scored for trachomatous inflammation-follicular (TF) and trachomatous inflammation-intense (TI) according to the simplified World Health Organization grading system by expert raters. We developed an automated procedure for image enhancement followed by application of a convolutional neural net classifier for TF and separately for TI. One hundred images were selected for testing TF and TI, and these images were not used for training. RESULTS: The agreement score for TF and TI tasks for the automated algorithm relative to expert graders was κ = 0.44 (95% CI: 0.26 to 0.62, P < 0.001) and κ = 0.69 (95% CI: 0.55 to 0.84, P < 0.001), respectively. DISCUSSION: For assessing the clinical signs of trachoma, a convolutional neural net performed well above chance when tested against expert consensus. Further improvements in specificity may render this method suitable for field use.

Antibiotic Prescription Patterns among Children Younger than 5 Years in Nouna District, Burkina Faso.

Understanding antibiotic use may help predict emergence of antimicrobial resistance. We evaluated antibiotic prescription trends in rural Burkina Faso, where little is known about antibiotic consumption. Antibiotic prescription data for 20 communities were extracted through record review in six primary health-care facilities serving the communities. The number of antibiotic prescriptions per child-year was calculated using population-based census data from the communities. A total of 1,444 antibiotic prescriptions were made from March to June 2017 among 3,401 children in the communities. The frequency of antibiotic prescription was 1.70 prescriptions per child-year (95% CI: 1.61-1.79). Penicillins were the most common (1.04 prescriptions per child-year, 95% CI: 1.01-1.06), followed by sulfonamides (0.69 prescriptions per child-year, 95% CI: 0.67-0.71) and macrolides (0.38 prescriptions per child-year, 95% CI: 0.37-0.40). Continued monitoring of antibiotic consumption in diverse settings will be important to understand the potential for emergence of antibiotic resistance.

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.

Effectiveness of expanding annual mass azithromycin distribution treatment coverage for trachoma in Niger: a cluster randomised trial.

BACKGROUND/AIMS: The WHO recommends 3-5 years of annual mass azithromycin distribution with at least 80% treatment coverage to districts with active trachoma prevalence over 10% among children. Here, we assess the efficacy of expanding the coverage target to at least 90% for trachoma control in a mesoendemic region of Niger. METHODS: Twenty-four communities were randomised to a single day of azithromycin distribution with a coverage target of 80% of the community or up to 4 days of treatment, aiming for greater than 90% coverage. Distributions were annual and individuals above 6 months of age were treated. Children under 5 years of age were monitored for ocular chlamydia infection and active trachoma. RESULTS: At baseline, ocular chlamydia prevalence was 20.5% (95% CI 9.8% to 31.2%) in the standard coverage arm and 21.9% (95% CI 11.3% to 32.5%) in the enhanced coverage arm, which reduced to 4.6% (95% CI 0% to 9.5%, p=0.008) and 7.1% (95% CI 2.7% to 11.4%, p<0.001) at 36 months, respectively. There was no significant difference in 36-month ocular chlamydia prevalence between the two arms (p=0.21). There was no difference in the rate of decline in ocular chlamydia between the two arms in a repeated measures model (p=0.80). CONCLUSIONS: For annual mass azithromycin distribution programme to an entire community, there may be no additional benefit of increasing antibiotic coverage above the WHO's 80% target. TRIAL REGISTRATION NUMBER: NCT00792922, post-results.

Is Using a Latrine "A Strange Thing To Do"? A Mixed-Methods Study of Sanitation Preference and Behaviors in Rural Ethiopia.

Latrines are the most basic form of improved sanitation and are a common public health intervention. Understanding motivations for building and using latrines can help develop effective, sustainable latrine promotion programs. We conducted a mixed-methods study of latrine use in the Amhara region of Ethiopia. We held 15 focus group discussions and surveyed 278 households in five communities. We used the Integrated Behavioral Model for Water, Sanitation, and Hygiene interventions to guide our qualitative analysis. Seventy-one percent of households had a latrine, but coverage varied greatly across communities. Higher household income was not associated with latrine use (odds ratio [OR] = 1.9; 95% confidence interval [CI] = 0.5, 7.7); similarly, cost and availability of materials were not discussed as barriers to latrine use in the focus groups. Male-headed households were more likely to use latrines than households with female heads (OR = 3.5; 95% CI = 1.6, 7.7), and households with children in school were more likely to use latrines than households without children in school (OR = 2.3; 95% CI = 1.6, 3.3). These quantitative findings were confirmed in focus groups, where participants discussed how children relay health messages from school. Participants discussed how women prefer not to use latrines, often finding them strange or even scary. These findings are useful for public health implementation; they imply that community-level drivers are important predictors of household latrine use and that cost is not a significant barrier. These findings confirm that school-aged children may be effective conduits of health messages and suggest that latrines can be better marketed and designed for women.

Surgery Versus Interferon Alpha-2b Treatment Strategies for Ocular Surface Squamous Neoplasia: A Literature-Based Decision Analysis.

PURPOSE: To compare treatment strategies for ocular surface squamous neoplasia (OSSN), ranging from surgical excision to empiric topical interferon alpha-2b (IFN-α2b). METHODS: A decision model was constructed to determine which of 4 treatment strategies minimized expected persistence/recurrence of disease in patients with OSSN: excision followed by repeat excision for positive surgical margins, excision followed by IFN-α2b for positive margins, incisional biopsy followed by IFN-α2b for positive biopsies, and empiric treatment with IFN-α2b. Probabilities were estimated from literature published between 1983 and 2015. Expected values for the probability of recurrence could range from 0 (no persistence/recurrence) to 1 (persistence/recurrence). Sensitivity analyses were performed for each variable. RESULTS: Excision followed by IFN-α2b for positive margins was estimated to minimize persistence/recurrence of OSSN (expected value 0.13 versus 0.17 for empiric IFN-α2b, 0.22 for excision-only, and 0.30 for incisional biopsy-directed IFN-α2b). The optimal strategy was sensitive to 3 variables: efficacy of IFN-α2b, recurrence after negative surgical margins, and accuracy of excisional biopsy. CONCLUSIONS: In our decision analysis using studies published between 1983 and 2015, surgical excision followed by IFN-α2b for positive margins is the favored strategy for minimizing persistence/recurrence of OSSN. Future prospective studies would add to the certainty of these conclusions.

Assessment of transmission in trachoma programs over time suggests no short-term loss of immunity.

Trachoma programs have dramatically reduced the prevalence of the ocular chlamydia that cause the disease. Some have hypothesized that immunity to the infection may be reduced because of program success in reducing the incidence of infection, and transmission may then increase. Longitudinal studies of multiple communities would be necessary to test this hypothesis. Here, we quantify transmission using an estimated basic reproduction number based on 32 communities during the first, second, and third years of an antibiotic treatment program. We found that there is little to no increase in the basic reproduction number over time. The estimated linear trend in the basic reproduction number, [Formula: see text], was found to be -0.025 per year, 95% CI -0.167 to 0.117 per year. We are unable to find evidence supporting any loss of immunity over the course of a 3-year program. This is encouraging, as it allows the possibility that repeated mass antibiotic distributions may eliminate infection from even the most severely affected areas.

The fitness cost of antibiotic resistance in Streptococcus pneumoniae: insight from the field.

BACKGROUND: Laboratory studies have suggested that antibiotic resistance may result in decreased fitness in the bacteria that harbor it. Observational studies have supported this, but due to ethical and practical considerations, it is rare to have experimental control over antibiotic prescription rates. METHODS AND FINDINGS: We analyze data from a 54-month longitudinal trial that monitored pneumococcal drug resistance during and after biannual mass distribution of azithromycin for the elimination of the blinding eye disease, trachoma. Prescription of azithromycin and antibiotics that can create cross-resistance to it is rare in this part of the world. As a result, we were able to follow trends in resistance with minimal influence from unmeasured antibiotic use. Using these data, we fit a probabilistic disease transmission model that included two resistant strains, corresponding to the two dominant modes of resistance to macrolide antibiotics. We estimated the relative fitness of these two strains to be 0.86 (95% CI 0.80 to 0.90), and 0.88 (95% CI 0.82 to 0.93), relative to antibiotic-sensitive strains. We then used these estimates to predict that, within 5 years of the last antibiotic treatment, there would be a 95% chance of elimination of macrolide resistance by intra-species competition alone. CONCLUSIONS: Although it is quite possible that the fitness cost of macrolide resistance is sufficient to ensure its eventual elimination in the absence of antibiotic selection, this process takes time, and prevention is likely the best policy in the fight against resistance.

Latrine promotion for trachoma: assessment of mortality from a cluster-randomized trial in Ethiopia.

Trachoma control strategies, including latrine construction and antibiotic distribution, are directed at reducing ocular chlamydia, but may have additional benefits. In a cluster-randomized clinical trial, 24 subkebeles (administrative geographic units) in Ethiopia were offered a single mass azithromycin treatment, and half were randomized to receive an intensive latrine promotion. At a follow-up census 26 months after the baseline treatment, 320 persons had died. The mortality rate of children 1-5 years of age was 3.87 (95% confidence interval [CI] = 2.19-6.82) per 1,000 person-years in the latrine promotion arm, and 2.72 (95% CI = 1.37-5.42) per 1,000 person-years in the control arm. In a multi-level mixed effects logistic regression model controlling for age, there was no difference in mortality in persons randomized into the latrine or control arms (odds ratio = 1.18, 95% CI = 0.89-1.58). Latrine promotion provided no additional effect on mortality in the context of an azithromycin distribution program (clinicaltrials.gov, #NCT00322972).

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.

Atopic disease and herpes simplex eye disease: a population-based case-control study.

PURPOSE: To determine whether atopy is associated with herpes simplex virus (HSV) ocular disease. DESIGN: Retrospective, population-based, case-control study. SETTING: Large, regional health maintenance organization (Northern California Kaiser Permanente). STUDY POPULATION: 1,042,351 people over a one-year period. OBSERVATION PROCEDURES: Electronic database search for HSV ocular disease and subsequent chart review determined study eligibility. Two age-matched control groups (one population-based and one clinic-based) were randomly chosen. Medical record review determined the presence of atopy. Severe atopic disease was defined by diagnostic code or illness requiring an emergency room visit, hospitalization, or treatment with a systemic corticosteroid. MAIN OUTCOME MEASURES: Presence of HSV eye disease, presence of atopy, and characterization of atopy severity. RESULTS: HSV eye disease was found in 172 patients. HSV cases had a greater prevalence of atopy (34%, 58/172) than the clinic-based (25%, 43/172) or the population-based controls (21%, 36/172, odds ratio (OR) 1.5, 95% confidence interval (CI) 0.9 to 2.6 and OR 1.9, 95%, CI 1.1 to 3.3, respectively). The association of HSV ocular disease with severe atopy was even greater, with a history of severe atopic disease in 13% (22/172) of patients with HSV ocular disease as compared with 6% (11/172) of patients in the clinic control group and 3% (5/172) of patients in the population control group (OR 2.0, 95% CI 0.7 to 5.9 and OR 4.8, 95% CI 1.6 to 19.2, respectively). CONCLUSIONS: Patients with HSV ocular disease are more likely to have a history of atopic disease, especially severe atopic disease, than age-matched controls.

Trends in the etiology of infectious corneal ulcers at the F. I. Proctor Foundation.

OBJECTIVE: We analyzed laboratory results from corneal ulcers seen from 1976 to 1999 at the Francis I. Proctor Foundation, a referral center in San Francisco, to determine the relative frequencies of pathogens and to analyze for trends in frequencies of the most common pathogens. The results were compared with a previous study of corneal ulcers seen from 1948 to 1976 at the same institution. METHODS: Ulcers presenting to the Proctor Foundation were Gram stained and cultured using standard techniques. Herpetic corneal ulcers were excluded from the study. RESULTS: Organisms were isolated from 427 ulcers, 38% of all cases. Two hundred seventy-eight (59%) isolates were gram-positive bacteria, 145 (31%) gram-negative bacteria, 16 (3%) Acanthamoeba spp., and 36 (8%) fungi. Staphylococcus aureus was the most common organism, composing 20% of all isolates, followed by viridans group streptococci (12%), Streptococcus pneumoniae (11%), Pseudomonas aeruginosa (6%), Moraxella spp. (5%), and Serratia marcescens (4%). Over the 24-year study period the proportion of positive cultures decreased and the incidence of S. marcescens increased significantly. Comparing the period of 1948-1976 to 1976-1999, the frequency of S. pneumoniae and P. aeruginosa decreased, and that of S. marcescens increased significantly. CONCLUSION: The common pathogens associated with corneal ulcers have changed over the past 50 years in Northern California, with S. pneumoniae and P. aeruginosa being isolated relatively less often and S. marcescens being isolated with increasing frequency. The decrease in isolation of organisms over the 1976-1999 period may have resulted from increasing empiric antibiotic treatment by referring ophthalmologists.

Rapid assessment of trachoma in Hainan Province, China: validation of the new World Health Organization methodology.

This study was undertaken to validate a WHO methodology for the rapid assessment of trachoma. Fourteen villages were chosen by random sampling in two counties in Hainan Province, China. For the rapid assessment, trichiasis patients were identified, 50 children ages 1-10 years were examined for active trachoma, and information was collected on community access to services and community risk factors. To validate the methodology, a prevalence survey was undertaken simultaneously in the same villages. For the prevalence survey, 2428 people from 1606 households in the 14 villages were chosen by random sampling. Very little active trachoma was found by either method, although the rates of trichiasis were more substantial. Ranking of the villages by the two methods for trichiasis was highly correlated (Spearman's correlation coefficient = 0.60, p = 0.02). For active trachoma, the Spearman's correlation coefficient for the ranking of villages by the two methods was 0.40 and not significant (p = 0.14), suggesting that a correlation this close may have been seen by chance alone. The observational data showed all the villages to be at risk of active trachoma (due to poor environmental hygiene conditions), suggesting that this aspect of the WHO methodology overestimates the risk for active trachoma. We conclude that, with the exception of the community assessment of risk, this rapid assessment methodology is a valid tool for the assessment of trichiasis and possibly of active trachoma in rural communities, although the level of active trachoma in this study was too low to effectively validate that aspect of the methodology.