Bio-Rad and GT Molecular announce a joint whitepaper on hMPXV (human monkeypox) surveillance and testing for wastewater-based epidemiology (WBE)

Abstract

The 2022 spike in human-to-human transmission of the human monkeypox virus (hMPXV) resulted in a public health emergency declaration, with cases increasing and symptoms causing increased morbidity and mortality worldwide. Yet, there is a lack of highly sensitive, specific, and rapid testing methods for detecting hMPXV.

Wastewater-based epidemiology (WBE) can help fill the current hMPXV testing gap as a passive and proactive way to monitor the presence and community spread of emerging infectious diseases regardless of symptomology or access to healthcare. In partnership with GT Molecular, we have developed a highly sensitive and specific Droplet Digital PCR (ddPCR™) assay and kit for detection of hMPXV in liquid and solid wastewater samples. This advancement equips WBE testing laboratories with a proven, validated workflow to combat the international spread of hMPXV.

GT Molecular and Bio-Rad’s Partnership:

Overcoming Hurdles in hMPXV WBE Many regional and city WBE programs and infrastructure were established during the COVID-19 pandemic. Now that they are available, these systems can also be used address other emerging or continued public health concerns, such as hMPXV. As the first reports of hMPXV cases were publicized, GT Molecular initiated collaborations with wastewater facilities and research partners to design an assay and testing service that could provide much-needed, actionable data for public health officials, supporting the global effort to track hMPXV in wastewater.

GT Molecular developed a workflow to recover hMPXV from suspended solids or liquid components of raw influent wastewater. The process is optimized for quick and easy processing and analysis using GT Molecular designed assays for hMPXV with the Bio-Rad QX200™ ddPCR system.

To validate the hMPXV kit created by GT Molecular, sample processing workflow, and data analysis, we collected wastewater influent at a wastewater treatment facility serving ~45,000 people, spiked in known quantities of parapoxvirus internal process control, and adjusted the sample to a 1% (v/v) with a proprietary anionic surfactant.

Particulates were removed via filtration, and samples were concentrated via dead-end filtration. Nucleic acids were extracted using QIAGEN extraction buffers, and the resulting DNA was then subjected to ddPCR analysis. Levels of hMPXV, internal process control, and fecal indicators were quantified using QX Manager Software. Longitudinal plots were generated using GraphPad Prism. The Bio-Rad and GT Molecular kit and workflow were able to detect hMPXV in the wastewater samples, and longitudinal tracking starting in July of 2022 indicated initial spikes in late-August and September, and a large spike in October of 2022, which correlated with global increase in hMPXV cases.

This high sensitivity and precise quantification of hMPXV in wastewater empowers WBE programs worldwide to track the continued spread of hMPXV through high-risk communities. With increased adaptation, WBE testing programs can rapidly respond to growing hMPXV cases and proactively implement public health programs to limit the spread. Download a copy here!