July 7 coronavirus news

Silent transmission could be responsible for half of coronavirus cases in the US, according to a study published Monday in the Proceedings of the National Academy of Sciences.

The term "silent transmission" means the virus is transmitted through asymptomatic or pre-symptomatic patients, who are harder to find and trace.

How the study worked: The study, led by Alison Galvani of Yale University and colleagues, used coronavirus transmission models and existing research, which already indicated that asymptomatic infections account for 17.9% to 30.8% of all infections.

Based on these existing figures, the team found that presymptomatic people would account for 47% to 48% of transmission, and asymptomatic people would account for 3.4% to 6.6% of transmission. 

What this means: The team found that even immediate isolation of all symptomatic cases would not be enough to get the spread under control. Authorities would need to identify and isolate more than one-third of silent transmitters, as well as all symptomatic cases, to prevent an outbreak.

Researchers emphasized the need for both testing and contact tracing to safely lift the current social distancing and stay-at-home restrictions.

The California State Assembly has adjourned until further notice after several lawmakers tested positive for coronavirus, a state assembly staff member told CNN on Monday.

The historic Capitol building temporarily closed its doors to allow for deep cleaning, state speaker Anthony Rendon said in an internal email obtained by CNN. There is currently no date set for assembly members to return.

Democratic assembly member Autumn Burke was one of several lawmakers who tested positive, said a spokesperson.

"On July 3rd I received a call from the Assembly Human Resources Department that I had a 'mask to mask' exposure to COVID-19 on June 26th," Burke said in a statement. "I was tested on the morning of July 4th and received my results in the evening that I had tested positive for the coronavirus."

Nearly all employees in the building have been instructed to work from home for the foreseeable future, said Burke's chief of staff, Tish Rylander. 

California now has at least 271,013 cases and 6,440 deaths, the second highest figures nationwide after New York state, according to Johns Hopkins University.

The US military announced Monday it is sending about 50 medical and support personnel to the San Antonio area of Texas, a sign of rising concern that medical systems may be overwhelmed by the rise in coronavirus cases.

The extra personnel will "provide medical assistance by embedding in medical care facilities in the San Antonio, Texas area. The medical personnel include emergency room and critical care nurses, respiratory specialists and support personnel," the Northern Command said in a statement.

Earlier in the pandemic, the military had dispatched hundreds of medical personnel to assist in hospitals elsewhere, primarily in the New York City area.

Texas reported 5,318 new cases on Monday, bringing the state's total to 200,557 cases and 2,655 deaths.

Mexico's health ministry reported 480 more Covid-19 deaths on Monday, bringing the country's death toll to 31,119.

The ministry also recorded 4,902 newly confirmed cases in the past 24 hours, bringing the nationwide total to 261,750 cases.

On Saturday, Mexico surpassed France's death toll from the virus, and now has the 5th highest number of deaths worldwide.

Arizona now has more than 100,000 coronavirus cases as the virus continues to rise throughout America’s sun belt, according to the Arizona Department of Health Services.

The state now has 101,441 reported cases. Of this total, about 62,000 patients are younger than 44 years old, the department said in a statement on Monday.

There are 1,810 related deaths statewide, with more than 3,200 patients hospitalized and over 800 ICU patients currently in Arizona hospitals.

Atlanta Mayor Keisha Lance Bottoms said she is “still in a state of shock” and “stunned” after she and members of her family tested positive for coronavirus.

Bottoms, her husband, and one of her children have all tested positive. She has “no idea” how the family was exposed, she told CNN on Monday. 

The Atlanta mayor, who has suffered from a headache over the past few days, also said another of her children tested negative and two others still need to be tested.

Before she tested positive, the mayor said she was with her mother, who will get tested again.

Brazilian President Jair Bolsonaro attended a July 4th celebration event with Todd Chapman, the US Ambassador to Brazil, shortly before getting tested for coronavirus.

The event took place on Saturday, according to a photo posted that day to the President’s official Facebook page. In the photo, Bolsonaro is standing in close proximity to several US and Brazilian officials, in what Bolsonaro said was Chapman's residence.

No one in the photo is wearing a mask. Chapman is seen with his arm around the President; he also shared a photo of the event on Twitter, saying he was “honored” to host Bolsonaro on July 4th.

Bolsonaro was tested for coronavirus on Monday evening, and expects to receive the results on Tuesday, according to a statement from the president’s communication team.

"The President is, at the moment, in good health and at his residence," the statement added.

Chapman will also be tested for coronavirus. The US Embassy in Brasilia wrote on Twitter late Monday that Chapman will take Covid-19 tests and follow CDC protocols.

Other top US and Brazilian officials were at the event, including the US Defense Attache, Bolsonaro’s secretary of government, and Bolsonaro’s chief of staff. 

Dr. Anthony Fauci, the top US expert on infectious disease and member of the White House Coronavirus Task Force, warned on Monday that the country was facing a "serious situation" in part due to reopening too quickly.

"We were averaging about 20,000 new cases a day," he told National Institutes of Health Director Dr. Francis Collins during a livestreamed talk.

"And then a series of circumstances associated with various states and cities trying to open up, in the sense of getting back to some form of normality, has led to a situation where we now have record breaking cases. Two days ago it was at 57,500.”

Even the term "wave" is misleading because the number of cases has never dipped back down, only rose to new and alarming levels, he said.

Places like the European Union saw its cases go up, then come back down to a baseline, marking the possible end of a first wave, he said. "We went up, never came down to baseline, and now it's surging back up. So it's a serious situation that we have to address immediately.”

On Monday, Brazil reported 620 new deaths from coronavirus, raising the country's death toll to 65,487.

Brazil's health ministry also recorded 20,229 new cases in the past 24 hours, bringing the country's total to 1,623,284 cases.

The new figures come as cities around the country start to reopen.

Rio de Janeiro, where more than 10,000 people have died of coronavirus, opened its bars and restaurants over the weekend.

In Sao Paulo, bars, restaurants, and beauty salons also reopened with restrictions on Monday after been closed since March 24. Dining establishments will now have seating areas after previously being restricted to delivery and takeout services.

But new rules and restrictions apply: for example, Sao Paulo bars and restaurants can only operate for 6 hours a day and with a maximum occupancy of 40% capacity.

Brazil continues to follow the US in leading the world’s highest numbers of infections and deaths from the coronavirus.