Contact tracing is key to running down the chains of infection to get ahead of viral transmission, contain it, and kill it. Without new people to infect, the epidemic dies. Testing and contact tracing should be major priorities of local and state governments, especially since the federal government has abandoned any coherent policy toward the epidemic.
I have been following closely the Ducey Administration’s response to the epidemic, and thus far, I am not very impressed. Specifically: we are not testing enough (we have ‘blitzed’ testing from the very worst state, to almost the worst state); we have not been pro-actively testing the most vulnerable populations (even to the point inviting of lawsuits, which it seemed to me only protect the business interests of the long term care industry, and which DHS now openly admits!) until very recently; we are not providing any isolation services for those unable to do so themselves; they are muddying the epidemiological analysis of the epidemic in Arizona with widespread and non-random anti-body testing (which has been used, in part, to misleadingly justify re-opening prematurely); and they are not taking seriously the state’s obligation to ensure public safety when we do re-open the economy.
But today, I will focus on the Ducey Administration’s failures in rapidly expanding contact tracing to get the epidemic tracked down and contained. There are many reasons for that failure, the main ones being the lack of testing capacity (we simply can’t identify who to do contact tracing on), and a lack of contact tracing capacity (the county governments who normally do the work are simply overwhelmed by the sheer numbers of infected, and can’t follow every case).
AZ DHS Director Dr. Christ announced a plan to “enhance” contact tracing at the last press conference on Tuesday [discussion of contact tracing ends at time 19:45] :
Dr. Christ also announced an “enhanced” contact tracing program but gave very little detail as to what the “enhanced” part might entail. She says the State will provide “additional resources” to the county health departments, with few details available that I can find, which doesn’t mean much.
There is some good news. Maricopa County has announced its intention to expand contact tracing personnel by up to ten times. The current staff is 25, which is double the pre-epidemic staff size, and 5 of which are devoted solely to long term care facilities, which is sensible in that over half of Arizona’s COVID19 fatalities to date are among the residents of such facilities. Twenty-five current staff implies the hiring of up to 250 more contact tracers in the coming weeks or months, although the timeline is not clear at this point and will depending upon funding from the CARES Act, expanded training, and expanded COVID19 testing. So far, Maricopa has hired an additional 33 tracing staff. So we now have potentially 58 staff doing contact tracing in Maricopa County. That’s a start.
So just how many contact tracing staff are needed per capita during an epidemic according to epidemiological experts? As many as 30 tracers for every 100k population is needed to contain an epidemic that is as far advanced as America’s has become. In Maricopa, that means 1350 staff would be needed for Maricopa County’s 4.5 million residents. The big expansion in staff the County is talking about now is MAYBE 275-300 staff. That is far short of what we may ultimately need to stop this epidemic. We aren’t even being semi-serious about addressing the needed capacity to actually contain and eliminate this epidemic.
1350 contact tracers might seem an impossible number to reach, but in well-administered states that are being successful in controlling the epidemic, it is achievable. Look at Washington State: Governor Inslee has stood up an army of 1371 contact tracers. It is not a coincidence that their population is almost the same as Arizona’s.
Dr. Rebecca Sunenshine, Maricopa County’s medical director of public health, said that early on in the pandemic the county was doing “traditional public health contact tracing,”, with investigators talking to each and every contact. But as case numbers began to rapidly increase, the county modified its process to “mediated contact tracing.” That means each positive case the county identifies is interviewed, but public health officials have to rely on the individuals themselves to reach out to all of their contacts and provide information on potential exposure. That is not going to be very effective, as many contacts simply haven’t the ability, information, or resources to contact everyone they may have exposed, or simply be unwilling to do so.
“As the testing increases, we need to be able to enhance our investigators and the number of people that we have doing the contact investigations to keep up with the testing,” Dr. Sunenshine said.
In Pima County, testing is still not adequate, according to interim health director Dr. Bob England (former Assistant Surgeon General, Dr. Theresa Cullen was recently hired as permanent director). The situation has improved, but facilities are still having to prioritize who to test, he said.
For contact tracing, Pima county has focused mostly on notifying and tracking household and other ‘close’ contacts, rather than the traditional contact tracing of reaching everyone who might have been infected.
Dr. England says for infection as common and widespread as the new coronavirus now is, traditional complete contact tracing doesn’t make sense, given the county’s resources. If one assumes that COVID-19 is infecting up to 5% of the population, truly aggressive contact tracing would mean most of the population would be under some sort of quarantine or surveillance, England said. Which is exactly where we find ourselves, and why.
“At some point, it just doesn’t make sense because so many people have been exposed to this,” he said.
To summarize, the two Arizona counties with most of the population and most of the cases have effectively given up doing regular contact tracing because they are overwhelmed by the sheer number of cases, the lack of testing for those potential contacts and because so much of the population is potentially already exposed it just makes sense to shift to a public communication strategy and quarantining as much of the population as possible.
One would hope that once the current initial wave of infection has receded that we will be able to build out the staff for real contact tracing of new cases, the testing capacity to actually have an accurate picture of current infections and to test all contacts of the known infected, instead of just waiting for them to present with symptoms at the hospital or testing sites.
Being able to trace and contain new outbreaks is the key to returning to normal. Until we can effectively test and contact trace at least high-risk populations and those presenting with symptoms, we have no hope at all of actually containing and managing outbreaks. Given the prevalence of asymptomatic infections, even that may not be enough to get the job done. We may require the ability to randomly and regularly test a statistically significant sample of the population to catch outbreaks early enough to contain them.
There will be no return to anything like normal life until we can reach at least such minimal benchmarks, which we are now far short of. Instead, we will just see cases explode at exponential rates again as soon as people start interacting in any way like normal, and especially if an appreciable percentage of the population refuses to wear masks.
Thus far, I see little action toward reaching required benchmarks by the Arizona state government. There are hopeful signs that testing capacity and contact tracing capacity can be expanded in the future to take up the challenge we face, but no immediate and concrete plans or benchmarks that ensure progress is being made. Arizona’s government seems to be relying on hope, prayer, and corporate crisis-communication-style public relations bullshit to get our economy back on track, not solid epidemiological science.