A study conducted at a hospital in Ireland highlights the potential for hospital wastewater systems to serve as a reservoir for clinically relevant antibiotic-resistant pathogens, researchers reported last week in the Journal of Hospital Infection.

In the study, which was conducted at University Hospital Limerick, researchers performed a large-scale metagenomic analysis of wastewater pipes from a soon-to-be refurbished ward that has experienced multiple multidrug-resistant healthcare-associated infection outbreaks. For the analysis, they processed biofilm and extracted DNA from 20 pipe samples from patient rooms, including toilet u-bends and sink and shower drains. They also analyzed clinical isolates from patients who had been on the ward prior to refurbishment and were known to be colonized with antibiotic-resistant bacteria.

if we can stop these reservoirs from being established by improved infection control practices, we can hopefully stop patients from acquiring difficult-to-treat infections.

Sequencing of DNA from the pipe samples revealed a diverse reservoir of antibiotic-resistance genes (ARGs), and the most ARGs observed were those encoding resistant to commonly used antibiotics, including tetracyclines, fluoroquinolones, beta-lactams, and macrolides. Similarly, a diverse range of ARGs was identified in the clinical isolates, and a comparison of the clinical isolates with DNA from the wastewater pipes revealed a considerable number of identical ARGs.

"Whilst these data do not enable us to determine if resistance genes were transferred from patient to the wastewater system or indeed vice versa, they do allow us to confirm crossover in the resistome of clinically-relevant pathogens and the microbiome of the wastewater environment," the study authors wrote.

Wastewater highway

Since all pipes and drains from the hospital's wastewater system connect to the same sewage system, the authors say the findings suggest the system forms a "wastewater highway" that could spread the resistant bacteria from sinks, shower drains, and toilets throughout the hospital—a finding they believe could influence the hospital's infection control and cleaning strategies going forward.

"Such sites pose a risk for healthcare-associated infections, and if we can stop these reservoirs from being established by improved infection control practices, we can hopefully stop patients from acquiring difficult-to-treat infections," study co-author Nuala O'Connell, MD, of the University of Limerick said in a university press release.

Penn State researchers will use a $4.5 million grant from the US Department of Agriculture (USDA) to test for SARS-CoV-2 in 58 wildlife species, with the goal of tracking potential human spillback.

In a news release yesterday, Penn State said the researchers will collect more than 20,000 samples from wildlife such as eastern chipmunks, gray squirrels, raccoons, coyotes, white-footed mice, moose, wolverines, three species of deer, and several bat species. SARS-CoV-2 has already been found in 29 species, such as white-tailed deer, but most species haven't been tested.

Kurt Vandegrift, PhD, principal investigator and associate research professor of biology, cited recent evidence from deer in New York that showed the continued circulation of SARS-CoV-2 variants long absent from humans. "Viral persistence is important because it not only poses a looming risk of spillback to humans, but also allows for viral evolution and the emergence of highly divergent variants for which our diagnostics, therapeutics, and vaccines could be ill prepared," he said in the release.

The presence of the virus in wild animals also carries a risk of spillover to agricultural animals, which could threaten the food supply, he added.

Repeat sampling surveillance

The researchers will sample the same animals in the same region multiple times to determine whether and how transmission is occurring. They will then use a model-informed process to distinguish between dead-end hosts (which don't spread the virus) and those that do spread it, within and between species.

A 39-year-old man has tested positive for Nipah virus in India's Kerala state, raising the outbreak today to six cases, India Today reported today.

Kerala Health Minister Veena George's office said the man, who is from the affected district of Kozhikode, is hospitalized under observation. He had first sought treatment at a private hospital where other Nipah patients were being treated.

In good news, tests on 11 other patients who possibly had Nipah, which had been pending, came back negative for the virus, according to The Indian Express.

List of high-risk contacts expands to 213

Also today, the list of people who have come into contact with any of the patients grew to 950 people. Of those, 213 are in the high-risk category, including 21 who have been hospitalized and 287 healthcare workers. Fifteen samples from those in the high-risk category have been sent for testing.

Of the six people with confirmed Nipah, two have died. One of the surviving patients is a 9-year-old boy on a ventilator. Officials have ordered monoclonal antibody treatment for him. Though the antiviral therapy is unproven, George said it is the only option. Today, the Times of India reported that the Indian Council of Medical Research has decided to obtain 20 more doses of the monoclonal antibody treatment from Australia.

Schools will remain closed until tomorrow, and all public gatherings have been banned till September 24. Public Friday prayers today were also canceled.