The Centers for Disease Control and Prevention announced on Wednesday night that a person in California who tested positive for coronavirus may be the first case of community spread in the United States.

This person did not recently travel out of the country or come into contact with anyone infected with the coronavirus, known as COVID-19. The case was "detected through the U.S. public health system," the CDC said, and "picked up by astute clinicians." The CDC said this could be an "instance of community spread of COVID-19," which means the source of infection is unknown, but also acknowledged that "the patient may have been exposed to a returned traveler who was infected."

Lawrence Gostin, director of the World Health Organization Collaborating Center on National and Global Health Law, told the Los Angeles Times this is "the first signal that we could be having silent transmission in the community. It probably means there are many more cases out there and it probably means this individual has infected others and now it's a race to try to find out who that person has infected." There are 60 cases of COVID-19 in the United States. Catherine Garcia

They've made full recoveries, and now it's time for koalas rescued during last year's devastating Australian bushfires to go back into the wild.

Science for Wildlife, a conservation organization in Sydney, released the first 12 koalas back into the Blue Mountains on March 25 and 27. Those koalas were saved in December and spent the last few months recovering at Sydney's Taronga Zoo. Dr. Kellie Leigh, Science for Wildlife's executive director, said in a statement that her team made sure conditions had improved enough to sustain the koalas.

"The recent rains have helped and there is now plenty of new growth for them to eat, so the time is right," Leigh said. "We will be radio-tracking them and keeping a close eye on them to make sure that they settle in okay."

On April 2, Port Macquarie Koala Hospital released a koala it rescued in October, and has plans to set 25 more koalas free in the next few days, The Independent reports. Sue Ashton, the hospital's president, said not only will the koalas go back to their home habitats, but in some cases, they will be returned "to their original tree." Catherine Garcia

U.S. officials and intelligence agencies started warning the White House in mid-January that the coronavirus outbreak in China could spread through the U.S. and around the world, but "the Trump administration squandered nearly two months that could have been used to bolster the federal stockpile of critically needed medical supplies and equipment," The Associated Press reported Sunday night. "A review of federal purchasing contracts by The Associated Press shows federal agencies largely waited until mid-March to begin placing bulk orders of N95 respirator masks, mechanical ventilators, and other equipment needed by front-line health care workers."

By mid-March, U.S. hospitals in hard-hit areas were treating a rising number of COVID-19 patients without adequate equipment, states were bidding against each other for masks and ventilators on the open market, and Trump was telling states the role of the U.S. stockpile was supplier of last resort. "The notion of the federal stockpile was it's supposed to be our stockpile," Jared Kushner, Trump's son-in-law and senior adviser in charge of coronavirus supply chains, said Thursday. "It's not supposed to be state stockpiles that they then use."

An AP reporter asked Trump about the federal supply shortfall at Sunday night's briefing, Trump dismissed the question and ended the briefing.

The federal emergency stockpile was created in 1999 to prepare for the Y2K issue, then was expanded after the Sept. 11, 2001, attacks and stocked up with pandemic response supplies in 2006. Greg Burel, director of the federal stockpile from 2007 until his retirement in January, told AP that based on budget allocations, it was intended only as a "bridge stock."

"States do not have the purchasing power of the federal government," said former Health and Human Services Secretary Kathleen Sebelius, who also served as governor of Kansas. "They do not have the ability to run a deficit like the federal government. They do not have the logistical power of the federal government." Now, she added, "we basically wasted two months." Read more at The Associated Press. Peter Weber

Public health experts and government officials agree that the U.S. government's coronavirus death toll almost certainly understates how many Americans have actually died from the virus.

The Centers for Disease Control and Prevention only counts deaths where the presence of the coronavirus is confirmed in a lab test, The Washington Post reports, and "we know that it is an underestimation," CDC spokeswoman Kristen Nordlund said.

There are many reasons why the numbers are underreported. Strict criteria in the beginning of the outbreak kept many people from getting tested for coronavirus, and it's still difficult to get tested in some areas, for example. There's also the matter of false positives, and not all medical examiners have tests or believe they should conduct postmortem testing, even on people who died at home or in nursing homes where there were outbreaks. Experts also believe some February and early March deaths that were attributed to influenza or pneumonia were likely due to coronavirus.

The official death count is based on reports sent by states, and as of Sunday night, the CDC reports 304,826 confirmed U.S. cases and 7,616 deaths. The Post, other media outlets, and university researchers update their numbers more frequently, with the Post reporting on Sunday night that 9,633 people have died from coronavirus in the U.S., and at least 337,000 cases have been confirmed. Catherine Garcia

A fight broke out in the White House Situation Room on Saturday, after President Trump's economic adviser Peter Navarro clashed with Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, over an unproven COVID-19 coronavirus treatment, Axios reports.

Four people with knowledge of the matter told Axios' Jonathan Swan the argument took place near the end of a White House coronavirus task force meeting, after Food and Drug Administration Commissioner Stephen Hahn brought up hydroxychloroquine, an antimalarial drug Trump has touted as a possible "game-changer" in the fight against coronavirus. When Hahn was finished giving updates on drug trials, Navarro put folders down on the table where Hahn, Fauci, Vice President Mike Pence, and others were sitting.

One person familiar with the conversation told Swan the "first words out of his mouth are that the studies that he's seen, I believe they're mostly overseas, show 'clear therapeutic efficacy.' Those are the exact words out of his mouth." Fauci responded that this was anecdotal evidence, and this "just set Peter off," Swan reports. Navarro pointed to the folders and said, "That's science, not anecdote," a source said, and as his voice continued to get louder, Pence tried to intervene. "It was pretty clear that everyone was just trying to get Peter to sit down and stop being so confrontational," another person told Swan.

Fauci and other public health officials have said more data is needed before anyone can say the drug is effective against COVID-19, but based on things he's read, Navarro is convinced it works, Swan reports. The task force ultimately decided that publicly, the White House needs to say that use of hydroxychloroquine is between doctors and patients. Read more at Axios. Catherine Garcia

Queen Elizabeth II delivered a rare televised address on Sunday, calling on the British people to keep doing their part to stop the spread of the COVID-19 coronavirus, reminding them that "while we may have more still to endure, better days will return."

On Sunday, the death toll from COVID-19 hit 4,934 in Britain. The queen declared that "together we are tackling this disease, and I want to reassure you that if we remain united and resolute, then we will overcome it. While we have faced challenges before, this one is different. This time we join with all nations across the globe in a common endeavor, using the great advances of science and our instinctive compassion to heal. We will succeed, and that success will belong to every one of us."

Queen Elizabeth thanked health care workers for their tireless efforts to save lives, as well as everyone staying at home, and said she was reminded of the 1940 address she made with her late sister Margaret. They spoke to children who were evacuated during the German bombing raids in World War II, and "today, once again, many will feel a painful sense of separation from their loved ones," she said. "But now, as then, we know, deep down, that it is the right thing to do."

The 93-year-old queen and her 98-year-old husband, Prince Philip, are at Windsor Castle. Their 71-year-old son Prince Charles tested positive for the COVID-19 coronavirus and has recovered. The queen's address was recorded in a large room, where the only other person was the cameraman, Reuters reports; he wore gloves and a mask. The queen delivers a Christmas message every year, but otherwise has only made a handful of televised addresses during her 68-year reign. Catherine Garcia

Nadia, a 4-year-old Malayan tiger at the Bronx Zoo in New York, has tested positive for the COVID-19 coronavirus.

She is the first of her kind to test positive for the virus, CNN reports. In a statement, the Bronx Zoo on Sunday said Nadia, her sister Azul, two Amur tigers, and three African lions recently developed dry coughs, but no other animals are showing symptoms of COVID-19. Nadia was tested "out of an abundance of caution," and the zoo said it "will ensure any knowledge we gain about COVID-19 will contribute to the world's continuing understanding of this novel coronavirus."

The cats have all "experienced some decrease in appetite," but otherwise are "doing well under veterinary care and are bright, alert, and interactive with their keepers." All are expected to make full recoveries. The zoo also said the cats were "infected by a person caring for them who was asymptomatically infected with the virus or before that person developed symptoms," and there are now "appropriate preventative measures" in place for staffers taking care of the animals. Catherine Garcia