Fighting Disease Through Wastewater Monitoring in World’s Largest Refugee Settlement

It is clear, even without a robust disease surveillance system in place, that outbreaks of waterborne diseases prevail in the camp—including diarrhea, one of the leading causes of child mortality across the globe, and cholera, which can also kill within hours if left untreated.

Add to the mix natural disasters such as cyclones and heavy rain that causes regular flooding, and it is clear this is a complex environment for disease surveillance.

Wastewater monitoring, which doesn’t rely on data from a healthcare system or individual diagnostic testing, may prove to be an important contributor to helping public health authorities understand the current SARS CoV-2 infection rate, as well as identify other key infectious diseases circulating in the community.

The information provided by this surveillance will supplement scarce diagnostic testing, and can help guide decisions about where to prioritize limited resources, including vaccine campaigns and behavioral changes to fight Covid-19, cholera, typhoid, and rotavirus, all of which have been seen in Cox’s Bazar.

The proof-of-concept project funded by the Pandemic Prevention Institute focuses on standing up and evaluating wastewater monitoring in four to five camps. As a first step, the team will conduct an assessment of the local sanitation infrastructure to understand where fecal waste accumulates and flows, and use this to inform their sampling strategy. Wastewater samples will be tested for SARS-CoV-2, Salmonella Typhi, Vibrio cholerae, and Human rotavirus. A subset of the samples that contain SARS-CoV-2 will be analyzed for genomic variants circulating among Rohingya community.

The team will initially transport all wastewater samples to the icddr,b laboratory in Dhaka for analysis, but may eventually work toward analyzing directly in the field.

“I work closely with the majhis, and each majhi is influential to about 100 or so households. So if they are convinced, the way is cleared,” says Dr. Amin.

The community was cautious at first, though, and did not even want to accept treated drinking water from officials. Given historical state-based violence, they feared the water would be unsafe, Dr. Amin said. “It was very challenging in the beginning,” he said. “It took more than a year to build this bridge.”

But it was time well-spent, he says.

“We believe the wastewater surveillance at Cox’s Bazar should be able to generate evidence for the causes of viral and diarrheal diseases. We should also be able to spot signs of an outbreak—SARS CoV-2 or cholera or something else. And this will help determine where to apply therapeutics—or even where to encourage even simple behavioral changes.”

To help achieve this mission, the Institute is a leading voice in highlighting how wastewater monitoring is a vital tool for early pathogen detection, especially in places with limited disease surveillance infrastructure.

In addition to Bangladesh, the Institute has supported multiple wastewater surveillance programs in low-and-middle-income countries, including Ghana, India and Malawi. Together with grantees in the United States, they are refining protocols for wastewater sampling and testing, developing metrics to inform risks thresholds, and exploring novel approaches for sampling in non-sewered environments.

More recently, the Institute brought together over 150 wastewater surveillance experts representing more than 40 countries, including 25 percent from low-and-medium-income countries. The goal of the gathering, organized in collaboration with the UK Health Security Agency, was to create a forum for future evidence generation and cross-country collaboration.

“There is a clear desire and need for leadership and investment in wastewater surveillance as an efficient means to keep people safe from existing and novel pathogens,” Diamond said. “The work at Cox’s Bazar represents an important step forward in creating a disease containment strategy that is designed to operate within the context of a vulnerable community.”