Maite Muniesa1, Hiroyuki Katayama2, Cristophe Gantzer3, Anicet Blanch1, James Ebdon4

1University of Barcelona, Barcelona, Spain. 2University of Tokyo, Tokyo, Japan. 3University of Lorraine, Villers-lès-Nancy, France. 4University of Brighton, Brighton, United Kingdom

Introduction

The use of new human viral fecal indicators represents a significant advancement in environmental monitoring and public health. Traditionally, bacterial indicators have been used to assess water quality and detect fecal contamination. However, bacteria often fail to accurately identify human-specific pollution, and their survival in the environment doesn’t always match that of human pathogens.

Bacteriophages are non-pathogenic viruses that have gained attention as effective viral fecal indicators in water quality monitoring. Phages offer great specificity, high resistance to environmental conditions and some are human specific. Somatic coliphages and F-specific RNA bacteriophages have been extensively studied as fecal indicators signaling the presence of pathogens linked to human waste. 

New viral markers for fecal detection have appeared in the recent years. Among them crAssphage, a Bacteroides-infecting phage discovered in silico, very specific and abundant in human wastes, and Pepper Mild Mottle Virus (PMMoV), a plant virus that passes through the human digestive and is abundant in wastewater. 

Advances in detection techniques, make the identification of these viral indicators more rapid and sensitive, streamlining the process for routine environmental monitoring.

To explore these advancements, Maite Muniesa and Hiroyuki Katayama will present the side event “Viral Clues: Innovative Indicators for Detecting Fecal Pollution in Water”. 

Side event objective

The side event aims to establish the current context of viral indicators in water management. Participants will examine the state of the science and potential application of the newest and most promising viral indicators. In a third talk, participants will be introduced to one of the most effective methodologies aiming to the detection of viral markers and, finally, the side event will conduct the audience through practical applications of viral markers, in a developing country and one in a high-income country. The final objective is to provide insights of the newest advances in the use of viral fecal indicators and to generate discussion that will encourage their use and the adoption of new methodologies that helps in preventing waterborne disease outbreaks, by offering earlier and more accurate warnings of human fecal pollution.

Methodology/format

Presentations (40’)

      Dr. Hiroyuki Katayama. PMMoV as treatment performance indicators

     PMMoVs, abundant in human feces, are found in higher concentrations than other viruses in water environments. This talk will discuss its potential as a viral indicator for assessing treatment processes like drinking water treatment, potable water reuse, and membrane bioreactors.

     Dr. Maite Muniesa. crAssphage as human viral indicator

     CrAss-like phages (including p-crAssphage), a recently discovered group of human gut bacteriophages, show promise as fecal indicators for MST. However, their human specificity and global distribution are still unclear. Dr. Muniesa will present the latest research and their potential as fecal indicators

     Dr. Anicet Blanch. Rapid coliphage quantification: from research to market-ready solution

     Dr. Blanch developed Bluephage, a method for coliphage quantification using a color change to indicate the presence of coliphages in one working day. This presentation will trace its development from research to a market-ready tool

    Dr. James Ebdon. Coliphages and Bacteroides phages application in low-income and humanitarian settlings

   Dr.. Ebdon will discuss phage-based testing in low-resource areas, including megaslums in India and the Cox’s Bazar refugee camp in Bangladesh, emphasizing the challenges and benefits of a phage-based laboratory testing capacity established in these settings

    Dr. Christophe Gantzer. Application of F-specific RNA coliphages as viral fecal indicators for oysters

    Evaluating the infectivity of norovirus, the most significant pathogenic enteric virus, in environmental samples is challenging. Dr. Gantzer demonstrates the benefits of F-specific RNA phages for norovirus risk management and to assess treatment efficiency during oyster depuratio

Round table+discussion (50’)

Expected outcome

After the five key talks presented by the contributors, a roundtable discussion will be moderated by the facilitators to highlight the different perspectives presented. The audience will be able to participate by asking questions, using interactive platforms such as Mentimeter.

 The following discussion points will be enhanced in the roundtable:

– The benefits and limitations of the newly proposed viral indicators, PPMoV and crAssphages.

– Key challenges faced and solutions that enabled the development of practical, fast, and economical tools for quantifying viral indicators in water quality monitoring.

– Practical application of phage indicators in low-income areas to understand human-to-human disease exposure in slum communities and the efficacy of lime-based faecal sludge treatments.

– Potential use of phage markers on a larger scale in the shellfish industry of developed countries, such as France.

Questions and opinions obtained with Mentimeter will be discussed at the end of the discussion.