Factbox: Latest on the worldwide spread of the coronavirus

(Reuters) - Daily COVID-19 infections hit record highs in the United States, parts of Europe and in Australia as the Omicron variant of the coronavirus races out of control, keeping workers at home and overwhelming testing centres.

AMERICAS

* The average number of daily cases in the United States hit a record high of 258,312 over the last seven days, a Reuters tally found.

* U.S carriers Delta Air Lines and Alaska Air Group cancelled hundreds of flights on Tuesday because of adverse weather conditions and rising Omicron cases.

* Mexico on Tuesday reported 125 more confirmed fatalities, bringing the official death toll in the country since the pandemic began to 298,944.

* Brazil reported 171 deaths on Tuesday and 8,430 additional cases.

ASIA-PACIFIC

* Thai authorities warned residents should brace for a potential jump in coronavirus cases after classifying the country's first cluster of the Omicron variant as a "super-spreader" incident.

* Japan feared a rebound in infections as the highways and airports filled with travellers at the start of New Year holidays.

* New Zealand said a person who tested positive for the Omicron variant had briefly been active in the community in Auckland.

* A lockdown of 13 million people in the Chinese city of Xian entered its seventh day, with many unable to leave their residential compounds and relying on deliveries of necessities as new infections persisted.

* Australia will seek to make urgent changes to COVID-19 testing rules to ease pressure on test sites as infections surged and the country's most populous state reported a near doubling in daily cases.

EUROPE

* British Prime Minister Boris Johnson said the overwhelming majority of patients ending up in intensive care with COVID-19 had not received their booster vaccine.

* Poland reported 794 COVID-related deaths on Wednesday, the highest number in the fourth wave of the pandemic, with more than 75% of those who died unvaccinated.

AFRICA AND MIDDLE EAST

* Daily infections in the United Arab Emirates, the Gulf region's tourism and commercial hub, rose above 2,000 for the first time since June.

MEDICAL DEVELOPMENTS

* Tunisia's Ministry of Health approved the Russian one-shot Sputnik Light vaccine as a booster shot, Russia's RDIF sovereign fund said.

* Israel's Oramed Pharmaceuticals said its Oravax Medical unit had signed a deal with Vietnam's Tan Thanh Holdings for the pre-order of 10 million doses of its oral COVID-19 vaccine that is in clinical trials.

ECONOMIC IMPACT

* A Christmas rally in European shares paused near five-week highs, as investors exercised some caution as the number of Omicron cases surges globally. [MKTS/GLOB]

* Oil prices edged towards $80 per barrel as global supply outages and declining U.S. inventories offset worries that rising coronavirus cases might reduce demand.

* Asia's cash premiums for jet fuel slid to their lowest in nearly six weeks, weighed down by sluggish aviation demand as Omicron cases forced airlines to cancel flights.

* Financial institutions in India have remained resilient and stable financial markets are cushioned by policy and regulatory support, a central bank report said.

(Compiled by Marta Frackowiak and Devika Syamnath; Edited by Milla Nissi and Barbara Lewis)

People wait in long lines for coronavirus disease (COVID-19) testing, as the Omicron variant continues to spread in Memphis, Tennessee, U.S., December 28, 2021. REUTERS/Karen Pulfer Focht

A medical worker in protective suit collects a swab sample from a man for nucleic acid testing at a residential compound, during another round of mass testing following the coronavirus disease (COVID-19) outbreak in Xian, Shaanxi province, China December 27, 2021. cnsphoto via REUTERS

British Prime Minister Boris Johnson visits COVID-19 vaccination centre, amidst the spread of the coronavirus disease (COVID-19) pandemic, at the Rainbow Pharmacy in the Open University Campus, Walton Hall, Milton Keynes, Britain, December 29, 2021. Geoff Pugh/Pool via REUTERS

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