Fecal Indicator Bacteria Data to Characterize Drinking Water Quality in Low-Resource Settings: Summary of Current Practices and Recommendations for Improving Validity.

Mustafa Sikder,Anthonia O Ogudipe,Mateo Gomez,Elena N Naumova,Daniele Lantagne

doi:10.3390/ijerph18052353

Abstract

Fecal indicator bacteria (FIB) values are widely used to assess microbial contamination in drinking water and to advance the modeling of infectious disease risks. The membrane filtration (MF) testing technique for FIB is widely adapted for use in low- and middle-income countries (LMICs). We conducted a systematic literature review on the use of MF-based FIB data in LMICs and summarized statistical methods from 172 articles. We then applied the commonly used statistical methods from the review on publicly available datasets to illustrate how data analysis methods affect FIB results and interpretation. Our findings indicate that standard methods for processing samples are not widely reported, the selection of statistical tests is rarely justified, and, depending on the application, statistical methods can change risk perception and present misleading results. These results raise concerns about the validity of FIB data collection, analysis, and presentation in LMICs. To improve evidence quality, we propose a FIB data reporting checklist to use as a reminder for researchers and practitioners.

Highlights

Assessing microbial contamination in drinking water is crucial to verify water safety, understand baseline conditions, validate preventive interventions, and investigate disease outbreaks [1]
2251 manuscripts with Fecal indicator bacteria (FIB) data in low- and middle-income countries (LMICs) were identified in the initial and follow-up searches, 1850 unique articles remained after removing duplicates, 1107 were included after title screening, 301 were included after abstract screening, and 171 were included for data extraction after full-text review (Figure 2)
Membrane filtration methods are commonly used in LMICs to assess drinking water quality risk

Summary

Introduction

Assessing microbial contamination in drinking water is crucial to verify water safety, understand baseline conditions, validate preventive interventions, and investigate disease outbreaks [1]. Fecal indicator bacteria (FIB) values are widely used to characterize microbial contamination [2,3], and there are multiple ways to assess FIB presence and concentration. These include presence/absence, most probable number (MPN), and colony count methods (e.g., membrane filtration, plating, or gel) [2,4,5]. To ensure the validity and reproducibility (i.e., replicable sampling and testing protocol) of the membrane filtration test results, step-by-step instructions are available, in Standard Methods and other guidelines [4,6,7]. The instructions focus primarily on sample collection steps and precautions, preservation and storage, laboratory quality control (e.g., personnel, facility, equipment, supply), media preparation, analytical quality control (e.g., plate counts comparison, control culture, duplicate analysis, sterility checks), data handling, and documentation and record-keeping

Methods

Results

Conclusion