COVID reinfections, sneezing hamsters and huge methane emissions


People walk past a COVID-19 testing sign on the street, during the COVID-19 pandemic in New York City, New York, U.S.

Instances of coronavirus reinfection are growing all over the world.Credit score: Carlo Allegri/Reuters

COVID reinfections surge throughout Omicron wave

For the reason that Omicron variant of SARS-CoV-2 was first detected, the variety of individuals reinfected with the coronavirus has been rising sharply — a pattern that was not noticed with earlier variants. Researchers say that Omicron might be driving the surge as a result of it will probably evade the physique’s immune defences.

In England, greater than 650,000 individuals have in all probability been contaminated twice; most of them had been reinfected prior to now two months, in accordance with knowledge collected by the UK Well being Safety Company. The company considers an an infection a ‘attainable reinfection’ if it occurred at the least three months after a earlier one. Earlier than mid-November, reinfections accounted for about 1% of reported instances of COVID-19, however the charge has now elevated to round 10%.

“The power of Omicron to contaminate individuals with both vaccine- or infection-derived immunity is a key a part of what made the latest surge so giant,” says Marm Kilpatrick, an infectious-disease researcher on the College of California, Santa Cruz.

Measuring reinfection charges helps to evaluate “how infections may surge”, says Catherine Bennett, an epidemiologist at Deakin College in Melbourne, Australia.

‘Dangerously quick’ progress in atmospheric methane

Methane concentrations within the ambiance raced previous 1,900 elements per billion final 12 months, almost triple pre-industrial ranges, in accordance with knowledge launched in January by the US Nationwide Oceanic and Atmospheric Administration. Scientists say the grim milestone underscores the significance of a pledge made ultimately 12 months’s COP26 local weather summit to curb emissions of methane, a greenhouse fuel at the least 28 instances as potent as carbon dioxide.

The expansion of methane emissions slowed across the flip of the millennium, however started a speedy and mysterious uptick round 2007. The spike has induced many researchers to fret that international warming is making a suggestions mechanism that may trigger ever extra methane to be launched, making it even tougher to rein in rising temperatures.

A worrying trend: Line chart showing the rise in atmospheric methane levels since 1985.

Supply: NOAA

“Methane ranges are rising dangerously quick,” says Euan Nisbet, an Earth scientist at Royal Holloway, College of London, in Egham, UK.

Some researchers assume that a lot of the rise prior to now 15 years could be attributable to microbial sources, somewhat than the extraction of fossil fuels. The emissions are a significant menace to the world’s aim of limiting international warming to 1.5–2 °C over pre-industrial temperatures.

Workers in full PPE at the Little Boss pet store in Hong Kong

A suspected outbreak at a pet store in January led to a cull of hamsters in Hong Kong.Credit score: Chan Lengthy Hei/Bloomberg/Getty

Sneezing hamsters sparked Hong Kong COVID outbreak

Pet hamsters in all probability carried the Delta variant of SARS-CoV-2 into Hong Kong and sparked a human COVID-19 outbreak, in accordance with a genomic evaluation of viral samples from the rodents. The analysis confirms earlier fears {that a} pet store was the supply of the outbreak, which had, by early February, contaminated about 50 individuals and led to the culling of some 2,000 hamsters throughout the town.

Hamsters are extremely prone to SARS-CoV-2 and so are a preferred mannequin for finding out the virus. However the Hong Kong research — posted on-line as a preprint and but to be peer reviewed — is the primary to point out that hamsters can change into contaminated exterior the laboratory, and that they’ll cross the virus on, each to different hamsters and to people (H.-L. Yen et al. Preprint at Social Science Analysis Community https://doi.org/hh9r; 2022). Hamsters are solely the second animal identified to have the ability to infect individuals, after mink. In late 2020, small outbreaks of COVID-19 in individuals in Denmark and the Netherlands had been linked to farmed mink, sparking panic and mass culls.

The most recent research factors to the pet commerce as a route for viral unfold, says co-author Leo Poon, a virologist on the College of Hong Kong. However “to be honest to the hamsters”, persons are nonetheless more likely to be contaminated by one another than by pets, he says.

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