All eyes on San Francisco Bay Area as nation's social distance bellwether

Los Angeles residents receive a test for Covid-19 while in their vehicles at the Crenshaw Christian Center in South Los Angeles. Wednesday, March 25, 2020. | AP photo

OAKLAND – The nation’s major social distance experiment began 10 days ago in the San Francisco Bay Area, where health officials issued the first protective orders to slow the spread of the coronavirus.

California Governor Gavin Newsom followed days later, triggering a cascade of states that imposed home stay policies from New York to Louisiana.


The big question now: How do health experts know when the Covid 19 infections weaken – and when do they feel safe enough to thaw restrictions? The lack of extensive testing and the novel biology of the virus will pose challenges for deciphering the growth curve in the coming weeks.

The Bay Area will serve as a guide to when cities and states across the country can hibernate – and to what extent they can return to normal life. The region of 7 million people is not only the tech capital of the world and home to the latest biomedical research, it also offers everything from the cosmopolitan city of San Francisco to high density to sprawling suburbs and rural enclaves, all in relative proximity.

But even in a region that prides itself on being one step ahead, health authorities are still forced to rely on insufficient data, experience from other countries, and anecdotes to determine if and when the contagion levels off .

Large health organizations such as Kaiser Permanente sometimes rely on call center data to measure how many people report potential coronavirus symptoms. A company for geodata analysis is Acquisition of smartphone data to see if people are reducing their movements. A reduction in hospital stays in the Bay Area could show when the disease flattens out.

But none are fail-safe measures to contain the virus.

“At this point, you can only track the number of cases,” said Jeffrey Martin, epidemiologist at the University of California, San Francisco. “It’s actually an incredible situation that the public sees exactly what academics see.”

The Bay Area was a leader in identifying outbreaks of coronavirus, with Santa Clara County in Silicon Valley particularly badly affected. As of Wednesday, the county has almost 2 million residents had confirmed 459 cases and 17 deaths – most in the Bay Area. Nationwide, 2,535 Californians tested positive for the virus and 53 people died. according to the health report on Wednesdaya late settlement of the actual number of cases.

Bay Area public health officials are frustrated that they may not be able to test the volume of residents they need to accurately assess when the region has peaked and the number of cases is decreasing – the trend commonly referred to as “flattening the curve”. ”

With limited testing capacity, federal health officials advise clinicians to use their judgment, but to test patients based on symptoms – fever, difficulty breathing, cough – as well as epidemiological factors, such as: B. How widespread the transmission is in the community in the region.

If they cannot test extensively, including those who are symptom-free, they simply cannot assess exactly how widespread the transmission is and how many people may develop immunity to the virus. Early signs indicate that many people can have Covid-19 without symptoms.

How health officials interpret the data will affect all 40 million Californians. Newsom suggested this week that it will take 8 to 12 weeks to determine whether government measures have been effective. President Donald Trump said Tuesday that he hoped the nation could emerge from hibernation by Easter, which he described as “a good time” to open up the economy.

“I would not talk about relaxing this now, but we have to think about when we will know,” said Martin. “Whenever you lift your foot from the breaks, there is the option of a second round. If there is no vaccine, this is possible. “

Newsom is confident that California’s efforts have already paid off. “We know that this has affected the curve bend and the amount of time spent,” said the governor on Wednesday.

Kaiser Permanente, which has 4.4 million members in Northern California and approximately 12.2 million system-wide, began testing coronavirus last week, but was hampered by the lack of test smears. Testing in the Southern California region is slated to begin this week.

Kaiser, academic medical centers, and hospitals work with state health agencies to provide data on how many patients have been hospitalized and how many are in ventilators – another important data point in the persecution.

Meanwhile, Kaiser officials are monitoring calls for cold and cough symptoms to determine the potential trajectory of the virus.

Typically, the call center receives around 4,000 calls a day when the flu season begins. On March 16, the day the six districts of the Bay Area announced the accommodation, Kaiser’s call center in Northern California received 14,000 calls – an unprecedented number – about cold and cough symptoms. A week later, that number dropped to around 8,500 calls.

Stephen Parodi, an infectious disease specialist at Permanente Medical Group in Northern California, hoped this number suggested that social distancing worked. The decline could also suggest that more people are turning to home care to treat their diseases. Primary care visits have decreased by 60 percent as Kaiser patients have been advised to avoid doctor visits and seek remote help via email, phone, and telemedicine.

“The ability to take a clearer approach to social distancing will be very important in the future,” said Parodi, chief physician for Kaiser’s national coronavirus response. “If you can test large sections of the population, you can determine who is positive, who is negative, who is socially distant, and who does not need to be socially distant.”

Matt Willis, Marin County’s public health officer, said that bias testing is also a factor in trying to track the effectiveness of social distancing. Experts may not be able to tell whether trends are a function of additional testing or a change in the spread of the disease.

“The number of cases reported in a county or municipality is strongly predicted from the number of tests performed in that municipality. It makes it very difficult to understand the actual scale of the epidemic, ”Willis told POLITICO before being diagnosed with the virus on Monday, making it the 39th Covid-19 case in his county.

While many Bay Area residents seem to obey the order – streets are clear and business districts are ghost towns – some don’t. Numerous residents flocked to regional parks and beaches over the weekend, causing many to close and Newsom to order the closing of state car parks in three dozen parks and beaches on Monday.

Confirmed coronavirus cases in California have doubled every three to four days, said Mark Ghaly, secretary of the California Health and Social Service, on Wednesday. However, he noted that the number of tests is increasing and wrote that it is important to stay at home and maintain physical distance to mitigate the expected increase in cases.

“We have early signs that some of these efforts are making a difference, and we believe that this is the case in some parts of the state,” said Ghaly.

Some early signals suggest that Bay Area efforts may begin to work.

UCSF epidemiologist George Rutherford said he saw significantly fewer Bay Area residents on the streets, indicating that most people follow the order and stay at home. He believes estimates that predict up to 80 percent of Americans will be infected are too high.

In addition, he said that he saw a smaller increase in the number of cases in some counties than before.

“What you’re really starting to see is dulling new cases,” said Rutherford. “The phenomenon is there. We just don’t see how the cases are loaded.”

Leave a Comment