Takeaways:

• A sudden rise in respiratory ailments in China, particularly among children, has raised global concern. The Chinese Center for Disease Control and Prevention reported over 3,500 cases of respiratory infection, with Chinese media attributing the outbreak to mycoplasma pneumonia.

• The World Health Organization has been monitoring the situation since mid-October 2023 and has requested more information from China. As of November 24, no unusual or novel pathogens have been reported in the clusters of pneumonia cases.

WASHINGTON, Dec 5 (Reuters) — Hundreds of thousands of people worldwide are killed annually by malaria and other diseases spread through the bite of mosquitoes, insects that date back to the age of dinosaurs. All of these bites are inflicted by females, which possess specialized mouth anatomy that their male counterparts lack.

But it has not always been that way. Researchers said they have discovered the oldest-known fossils of mosquitoes — two males entombed in pieces of amber dating to 130 million years ago during the Cretaceous Period and found near the town of Hammana in Lebanon. To their surprise, the male mosquitoes possessed elongated piercing-sucking mouthparts seen now only in females.

“Clearly they were hematophagous,” meaning blood-eaters, said paleontologist Dany Azar of the Chinese Academy of Sciences’ Nanjing Institute of Geology and Paleontology and Lebanese University, lead author of the study published this week in the journal Current Biology. “So this discovery is a major one in the evolutionary history of mosquitoes.”

Nearly four years into the pandemic, hundreds of Americans are still dying every day from Covid, according to the Centers for Disease Control and Prevention ( CDC).

The virus is responsible for around 1,000 deaths and 15,000 hospitalisations each week, CDC Director Mandy Cohen said during a media briefing on 2 December.

Death rates briefly dipped below 500 per week in July, the lowest rates since the pandemic began, before steadily increasing to as high as 1,400 in September.

Long-term data from a study implemented by the # NIH-funded International Maternal Pediatric Adolescent AIDS Clinical Trials Network showed very early antiretroviral therapy (ART) for infants who acquired HIV in utero enabled some infants to sustain viral suppression for more than two years.

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Very early ART for in-utero HIV-1 can achieve sustained virological suppression in association with biomarkers indicating restricted HIV-1 reservoirs by age 2 years, which might enable potential ART-free remission.

However, when major genome rearrangements occur — like the ones that the team was seeing in the skate’s DNA — boundaries can be lost, and the relative positions of genes on chromosomes can change. As a result, “some enhancers can provide instructions to the wrong gene,” explained Dario Lupiáñez, an evolutionary biologist at the Max Delbrück Center in Berlin and one of the senior authors of the study.

It seemed possible that the changes in the 3D architecture of the skate genome might have disrupted the ancient blocks of genes the skates inherited from their sharklike ancestors, affecting the genes’ function. “We were trying to look at whether some genome rearrangements in the little skate actually break these blocks,” said Ferdinand Marlétaz, a genomicist at University College London and co-first author of the study.