Success of active tuberculosis case detection among high-risk groups in urban slums in Pakistan

BACKGROUND

In Pakistan, patients with symptoms suggestive of tuberculosis (TB) seek care from a wide array of health care providers, many of whom do not notify cases to the National TB Programme (NTP).

SETTING

We evaluated an active case detection intervention in five randomly selected districts in urban slums of Sindh Province, Pakistan.

OBJECTIVE

To evaluate the increase in case notification of smear-positive TB by active case finding at community-based chest camps by engaging the private providers.

DESIGN

A cross-sectional study of TB case detection associated with a project using integrated intervention and chest camps.

RESULTS

From April 2011 to September 2012, the total number of clients seen in the camps was 165 280. Of all the attendees, 13 481 (12.7%) were examined by sputum smear microscopy. The proportion of smear-positive results was significantly higher among those from engaged private providers than among those referred from camps (OR 1.54, 95%CI 1.42-1.66). During the project, the total number of smear-positive TB notifications increased over the intervention period from 5158 to 8275.

CONCLUSION

Active case detection by engaging private providers and chest camps can significantly increase the number of smear-positive TB case notifications.

In situ tryptophan-like fluorometers: assessing turbidity and temperature effects for freshwater applications

Tryptophan-like fluorescence (TLF) is an indicator of human influence on water quality as TLF peaks are associated with the input of labile organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time measurement of TLF could be particularly useful for monitoring water quality at a higher temporal resolution than available hitherto. However, current understanding of TLF quenching/interference is limited for field deployable sensors. We present results from a rigorous test of two commercially available submersible tryptophan fluorometers (ex ∼ 285, em ∼ 350). Temperature quenching and turbidity interference were quantified in the laboratory and compensation algorithms developed. Field trials were then undertaken involving: (i) an extended deployment (28 days) in a small urban stream; and, (ii) depth profiling of an urban multi-level borehole. TLF was inversely related to water temperature (regression slope range: -1.57 to -2.50). Sediment particle size was identified as an important control on the turbidity specific TLF response, with signal amplification apparent <150 NTU for clay particles and <650 NTU for silt particles. Signal attenuation was only observed >200 NTU for clay particles. Compensation algorithms significantly improved agreement between in situ and laboratory readings for baseflow and storm conditions in the stream. For the groundwater trial, there was an excellent agreement between laboratory and raw in situ TLF; temperature compensation provided only a marginal improvement, and turbidity corrections were unnecessary. These findings highlight the potential utility of real time TLF monitoring for a range of environmental applications (e.g. tracing polluting sources and monitoring groundwater contamination). However, in situations where high/variable suspended sediment loads or rapid changes in temperature are anticipated concurrent monitoring of turbidity and temperature is required and site specific calibration is recommended for long term, surface water monitoring.

Prioritising lexical patterns to increase axiomatisation in biomedical ontologies. The role of localisation and modularity

INTRODUCTION

This article is part of the Focus Theme of METHODS of Information in Medicine on "Managing Interoperability and Complexity in Health Systems".

OBJECTIVES

In previous work, we have defined methods for the extraction of lexical patterns from labels as an initial step towards semi-automatic ontology enrichment methods. Our previous findings revealed that many biomedical ontologies could benefit from enrichment methods using lexical patterns as a starting point.Here, we aim to identify which lexical patterns are appropriate for ontology enrichment, driving its analysis by metrics to prioritised the patterns.

METHODS

We propose metrics for suggesting which lexical regularities should be the starting point to enrich complex ontologies. Our method determines the relevance of a lexical pattern by measuring its locality in the ontology, that is, the distance between the classes associated with the pattern, and the distribution of the pattern in a certain module of the ontology. The methods have been applied to four significant biomedical ontologies including the Gene Ontology and SNOMED CT.

RESULTS

The metrics provide information about the engineering of the ontologies and the relevance of the patterns. Our method enables the suggestion of links between classes that are not made explicit in the ontology. We propose a prioritisation of the lexical patterns found in the analysed ontologies.

CONCLUSIONS

The locality and distribution of lexical patterns offer insights into the further engineering of the ontology. Developers can use this information to improve the axiomatisation of their ontologies.