COVID-19 infection surge detected in wastewater, signals potential new wave

US, Netherlands, Germany all show spikes while UK no longer collects data

US President Joe Biden declared the pandemic over in September 2022. Weeks into 2024, however, global data points to a surge in infections.

While vaccine programs have stabilized the number of hospitalizations, experts warn that authorities may be slow to react to the significant dangers that lie ahead.

Sounding the most recent alarm is Lucky Tran, a Columbia University science communicator who notes that the US ended 2023 with a steep increase in national and regional trends of SARS-COV-2 viral activity levels in wastewater.

According to the US Centers for Disease Control and Prevention (CDC), the national measure of wastewater viral activity stood at 12.85 for the week ending December 30, compared to 5.45 a month earlier.

The metrics are based on the number of standard deviations above the baseline, transformed to the linear scale. The regions with the highest figures were the US Midwest and the South at 16.57 and 13.86, respectively.

The CDC reckons wastewater monitoring can detect the spread of the virus before clinical testing and before people get ill. It can also point to asymptomatic transmission. Nationally, the wastewater viral activity level for COVID-19 is in the "very high" range.

Tran said: "We are currently in the second-biggest surge of the pandemic. It will peak in the next week, with ~2 million infections per day. During this surge, ~100 million people total (~1 in 3 people in the US) will likely get COVID."

He was not alone in his concerns. The new data was among the evidence prompting Eric Topol, professor of molecular medicine and executive vice-president of nonprofit Scripps Research, to warn in the LA Times about new COVID variant JN.1.

"By wastewater levels, JN.1 is now associated with the second biggest wave of infections in the United States in the pandemic, after Omicron," he said late last week. "We have lost the ability to track the actual number of infections since most people either test at home or don't even test at all but the very high wastewater levels of the virus indicate about two million Americans are getting infected each day."

Topol warned that only 19 percent of eligible Americans received the updated booster and the problem of waning immunity four to six months after vaccination remains.

"We continue to make-believe that the pandemic is over, that infections have been transformed to common cold status by prior exposure(s), and that life has returned to normal," he said. "Sadly, none of this is true. The massive number of infections in the current wave will undoubtedly lead to more people suffering from long COVID. For a high proportion of people, especially those of advanced age, immunocompromised or with coexisting conditions, getting COVID is nothing close to a straightforward respiratory infection."

He went on to criticize Biden's response to the climbing figures, lack of backing for nasal vaccines, and failure to back research into long COVID. According to a Whitehouse statement, the US administration has built a "robust emergency response infrastructure" to address further threats from COVID.

In May 2023, World Health Organization director general Tedros Adhanom Ghebreyesus said COVID-19 represented an "ongoing pandemic" and was an established health issue, though it no longer constituted a public health emergency of international concern (PHEIC).

"While the global risk assessment remains high, there is evidence of reducing risks to human health driven mainly by high population-level immunity from infection, vaccination, or both; consistent virulence of currently circulating Omicron sub-lineages compared to previously circulating Omicron sub-lineages; and improved clinical case management," he said.

"These factors have contributed to a significant global decline in the weekly number of COVID-19 related deaths, hospitalizations, and admissions to intensive care units since the beginning of the pandemic. While SARS-CoV-2 continues to evolve, the currently circulating variants do not appear to be associated with increased severity."

Matthew Fox, professor in the Epidemiology and Global Health department at Boston University, told The Register that the evidence emerging from wastewater data was a concern, but it remained to be seen how much vaccines and immunity built through exposure to the virus would keep hospitalizations down.

"The data suggests large increases in cases and that's concerning," he said. "But since we don't know much about actual case numbers given that so many people are testing at home, we don't learn much from things like wastewater data about severity, we need hospitalization data for that. There too we've seen surges here in the US and abroad but nothing like what we saw pre-vaccines. There is so much built-up immunity and the vaccine is still working against these new variants that so far we are doing OK, though not as well as we were. What would be concerning would be if we had a variant that was better at escaping immunity and to know that early we need good monitoring systems."

In December, the World Health Organization promoted JN.1, a variant of Omicron, to a "variant of interest" second only to the "variant of concern" classification awarded to Omicron, Delta, and Alpha at their peak. Its decision was based partly on wastewater data.

The US is not alone in recording concerning evidence of rising COVID in wastewater. In the Netherlands, the number of people hospitalized increased rapidly in mid-December, while the measure of the virus in wastewater climbed 57 percent in a week to 4,438 virus particles per 100,000 inhabitants. The number fell to 2,966 by the end of the month, although it is well above 57 reported in July.

Speaking to a Dutch news site, Harald Wychgel, a spokesman for the public health institute RIVM, said: "We have built up resistance through vaccinations and there is a lower likelihood of ending up in hospital, but COVID can still make people seriously ill."

French, German, and Danish data also shows a strong increase in evidence of COVID in wastewater.

The UK, however, elected to end its wastewater testing for COVID in March 2022. A spokesperson for the UK Health Security Agency (UKHSA) told The Register the decision was made "when The Living with COVID plan was set out by the government early in 2022 following the success of the vaccination program, which has heavily reduced the numbers of people getting severely ill and dying from the virus.

"At the time, UKHSA committed to maintaining critical surveillance capabilities, and that can still be seen through our Winter COVID Infection Survey with the ONS and our Weekly Winter Flu and COVID-19 surveillance reports. This surveillance captures data on levels of COVID-19 prevalence and also hospital admission rates."

Late last week, White House spokeswoman Karine Jean-Pierre said policy on masking would be devolved to a state and regional level, at least in a hospital setting. Only time will tell how much the data has to change for national governments to lead on public health policy once more. ®

More about


Send us news

Other stories you might like