Pilot Audit of Trichiasis Surgery Outcomes Using a Mobile App in the Republic of Chad.

PURPOSE: The purpose of the study was to assess the feasibility of a mobile data collection app for use in trichiasis surgical audits in the Melfi and Mangalme districts of the Guera region of the Republic of Chad and to perform a cost analysis to determine if the auditing mechanism could be implemented nationally. MATERIALS AND METHODS: Patients who underwent trichiasis surgery 6 months prior and who had follow-up 7-14 days after surgery were included in the study. Each surgeon had a sample of 20% of operated eyelids; nine surgeons with data for ≥20 eyelids were included. A trichiasis recurrence rate of ≥25% suggested that the surgeon needed retraining. Smartphones captured data using the data collection app, which transmitted data to an online server. Direct costs and supervision costs were collated and summed. RESULTS: There were 916 eyelids operated on; 170 patients (269 eyelids, 29% follow-up rate) participated in the audit. Twenty participants (11.8%) had recurrence. The mean recurrence rate among surgeons was 8.3% (standard deviation: 0.07%; range: 0%-17.9%). None had a recurrence rate of ≥25%; thus, no retraining was necessary. The total cost of the audit was US$15,111.25 ($12,882.28 in direct costs and $2,228.97 in supervision costs). CONCLUSIONS: The simple, easy-to-use, and low-cost mobile auditing mechanism is a practical solution for conducting surgical audits in remote and resource-limited settings and is undergoing national scale-up by the Chadian trachoma elimination program.

A Population-Based Trachoma Prevalence Survey Covering Seven Districts of Sangha and Likouala Departments, Republic of the Congo.

PURPOSE: We set out to estimate the prevalence of trachoma and access to water and sanitation in seven suspected-trachoma-endemic districts of northern Congo, surveyed as a single evaluation unit. METHODS: From a complete list of rural villages in the seven districts, we systematically selected 22 with probability proportional to village size. In selected villages, we included all households where there were fewer than 25 in total, or used compact segment sampling to select a group of approximately 20 households by random draw. In each selected household, all consenting residents aged ≥1 year were examined by Global Trachoma Mapping Project-certified trachoma graders, and data collected on household-level access to water and sanitation. RESULTS: In November and December 2015, 466 households were visited in 22 villages, and 2081 (88%) of 2377 residents of those households were examined. No examined individual had trichiasis. The age-adjusted prevalence of the active trachoma sign trachomatous inflammation-follicular (TF) in 1-9-year-olds was 2.5% (95%CI 0.9-4.5%). Only 39% (95%CI 35-44%) of households had access to an improved source of drinking water. Only 10% (95%CI 7-13%) of households had access to an improved sanitation facility. CONCLUSION: Trachoma is not a public health problem in this part of Congo. Access to water and sanitation is inadequate.

Prevalence of trachoma in the Republic of Chad: results of 41 population-based surveys.

PURPOSE: To estimate the prevalence of trachoma in suspected-endemic areas of Chad, and thereby determine whether trachoma is a public health problem requiring intervention. METHODS: We divided the suspected-endemic population living in secure districts into 46 evaluation units (EUs), and used the standardized methodologies of the Global Trachoma Mapping Project. A two-stage cluster-sampling procedure was adopted. In each EU, the goal was to examine at least 1019 children aged 1-9 years by recruiting 649 households; all consenting residents aged ≥ 1 year living in those households were examined. Each participant was examined for trachomatous inflammation-follicular (TF), trachomatous inflammation-intense (TI), and trichiasis. RESULTS: Two EUs had data that could not be validated, and were excluded from the analysis. GPS data for three other pairs of EUs suggested that EU divisions were inaccurate; data for each pair were combined within the pair. In the 41 resulting EUs, 29,924 households in 967 clusters were visited, and 104,584 people were examined. The age-adjusted EU-level prevalence of TF in 1-9-year-olds ranged from 0.0% to 23.3%, and the age- and gender-adjusted EU-level prevalence of trichiasis in ≥ 15-year-olds ranged from 0.02% to 1.3%. TF was above the WHO elimination threshold in 16 EUs (39%) and trichiasis was above the WHO elimination threshold in 29 EUs (71%). Women had a higher prevalence of trichiasis than did men in 31 EUs (76%). A higher ratio of trichiasis prevalence in women to trichiasis prevalence in men was associated (p = 0.03) with a higher prevalence of trichiasis at EU level. CONCLUSION: Public health-level interventions against trachoma are needed in Chad. Over 10,000 people need management of their trichiasis; women account for about two-thirds of this total. The association between a higher ratio of trichiasis prevalence in women to that in men with higher overall trichiasis prevalence needs further investigation.

Predicting organic loading in natural water using spectral fluorescent signatures.

Spectral fluorescent signature (SFS) is a rapid, reagent free and inexpensive technique, which has great potential for environmental monitoring of aqueous systems, especially for predicting dissolved organic carbon (DOC) along natural waters. This technical note aimed to examine the possibility to use SFS associated with partial least squares regression (PLS) to assess the organic loading in natural water. A model was built using samples of water collected between October 1999 and February 2002 on the Passaic River at Little Falls, NJ, USA. A correlation was established between measured DOC, SFS, and the corresponding daily registered flow from United States Geological Survey (USGS) New Jersey's streamflow database. The methodology presented herein looks promising in making use of the significant organic characteristics information contained in a SFS for application and use in spatial and temporal water quality management and treatment.

Modified dissolved organic matter fractionation technique for natural water.

A technique to fractionate dissolved organic materials (DOMs) from low DOM water (<5mg/l) was developed by using triple columns of DAX-8 adsorption resin, one column of AG-MP-50 cationic resin, and another column of WA 10 weak anionic resin in sequence. The procedure was then applied to fractionate water samples obtained at various sampling locations throughout two surface water treatment plants (WTPs) in central New Jersey to study its effectiveness, DOM occurrence, and variation along treatment units. The treatment plants utilize different treatment methods, hence producing variability in DOM fractions suitable for examining the procedure's effectiveness. This procedure was compared with current fractionation protocols and proved to be accurate in fractionation of low DOM water.

Comparison of spectral fluorescent signatures-based models to characterize DOM in treated water samples.

Statistical procedures enable a multivariate analysis of the measurements to identify specific characteristics of the dissolved organic matter (DOM) fractions in raw natural water, including the concentrations. In this work, three already established models were used to predict the concentrations of fractions of DOM from spectral fluorescent signatures (SFSs): a general linear regression (GLR), loadings and scores of a principal components analysis (PCA), and a partial least squares regression (PLS). Details about the method undertaken to prepare the fractions were given. Water samples from surface water treatment plants in New Jersey were used for the testing. In all cases, PLS have shown much better biases and accuracies than GLR and PCA models. Hydrophilic neutral, however, showed poor performances (bias 33%) due to the isolation technique used. Recommendations were provided in order to improve the DOM characterization through SFS, which linked to PLS make a powerful and cost-effective surrogate parameter to characterize DOM.

Using principal component analysis to monitor spatial and temporal changes in water quality.

Chemical, biological and physical data monitored at 12 locations along the Passaic River, New Jersey, during the year 1998 are analyzed. Principal component analysis (PCA) was used: (i) to extract the factors associated with the hydrochemistry variability; (ii) to obtain the spatial and temporal changes in the water quality. Solute content, temperature, nutrients and organics were the main patterns extracted. The spatial analysis isolated two stations showing a possible point or non-point source of pollution. This study shows the importance of environmental monitoring associated with simple but powerful statistics to better understand a complex water system.

Spectral fluorescence signatures and partial least squares regression: model to predict dissolved organic carbon in water.

Spectro-fluorescence signature (SFS) of water samples contains information that may be used to quantify dissolved organic carbon (DOC) if combined with multivariate analyses. A model was built through SFS and partial least squared (PLS) regression. The SFSs of 219 samples of natural water along the Raritan River and Millstone River watersheds located in central New Jersey, and their corresponding DOC concentrations were used to build the model. Calibration, full cross-validation, and prediction performances of various models were statistically compared before optimal model selection. The final selected model, tested on the Passaic River watershed in northern New Jersey, provided a bias of 0.028 mg/l and a root mean squared error of prediction (RMSEP) of 0.35 mg/l. Linked to PLS, SFS can be a quality and cost effective method to perform on-line rapid DOC measurements.