Our local public health authorities haven’t skimped on sharing data tied to the novel coronavirus. Visit the dashboards on the Department of Health and Public Health—Seattle and King County websites and you’re liable to get dizzy from all the curves outlining the changes in cases, hospitalizations, and tests since the start of the pandemic.
But until recently, Washington officials had held out on publicly quantifying one area of our response to Covid-19: contact tracing, or the effort to identify and isolate people who have crossed paths with infectious hosts to curb the virus's spread. Though we knew the state had struggled, both initially and later on, to reach cases and their close contacts, we couldn’t point to any numbers assessing the current state of our disease containment effort.
Now we know why officials weren’t exactly in a rush to divulge the details. On Wednesday, the DOH released a report that showed the department had fallen well short of its case investigation and contact tracing goals despite mobilizing an army of sleuths. The department had sought to reach 90 percent of cases within one day of a positive test result. During the weeks between August 2 and September 5, the state never topped 51 percent in that area. The DOH had also targeted an 80-percent connection rate with contacts 48 hours post-case confirmation. It hasn’t yet met that mark. “While we expect our outcomes to improve over time, this initial data shows we have work to do,” state secretary of health John Wiesman said in a press release.
Are those goals too lofty? Hard to say. Many states still haven’t published their contact tracing stats, and those that have often use slightly different metrics. Public Health—Seattle and King County’s latest dashboard doesn’t lend itself to an apples-to-apples comparison with the broader state data, either, but it does provide some more interesting bits. For example, 60 Covid-19 contact tracers currently work for the authority. In mid-July, when cases were rising again, the number was half that.
Since the local headcount bump, the county’s case interview performance has stabilized. Roughly 60 percent of positive cases get interviewed (not just reached) on the same day they’re assigned to a contact tracer. Still, thanks to the pre-symptomatic period and lags between symptom onset and testing, nearly nine days of viral shedding have typically passed by the time tracers speak with infected individuals. Not ideal.
In addition to missing contact info, unanswered calls have significantly contributed to delays in reaching cases and contacts, according to the state. That isn't surprising in an era of robocalls. Thankfully, the department does send texts and even letters. But a call is a much quicker way to exchange vital information, which means the state's contact tracing numbers won't pick up until we do.