Health officials: US far short on virus tests

States across the US have performed millions of novel coronavirus tests, but several million more a week will be needed to curb spread of the virus, health officials said.

And the total number tests needed to prevent the disease from spreading at work and when schools reopen in the fall are beyond current capabilities, they said.

"While testing has doubled in the nation since May – from around 250,000 to 550,000 daily tests – we are nowhere near where we need to be," the Harvard University Global Health Institute said in a research report.

"We need to build capacity to test millions of people every day – around 4 million based on our latest modeling. That's an ambitious goal, but it's how we can suppress the virus, revive our economy and return to a new normal."

The COVID Tracking Project, a volunteer organization launched by The Atlantic magazine, said the number of daily tests on July 3 totaled 719,000 – an all-time high – and averaged about 640,000 a day last week as new cases spiked in the South and West.

Accurate numbers are hard to develop, but it's clear there isn't enough lab capacity to process all current tests in a timely fashion, health officials said.

Long turnaround times undercut the value of the tests by making it harder to trace and isolate those who may have come in contact with an infected individual, they warned.

Major commercial labs said increased testing has lengthened turnaround times. Quest Diagnostics said results typically take three to five days while LabCorp said it generally makes results available in four to six days. Others take longer.

About 40 million tests have been conducted in the last four months. But shortages of test kits and logistical delays in getting the samples to the labs and returning the results to clinics compounds the problem, officials said.

In a statement, Brett Giroir, assistant US secretary for health, said some testing problems stemmed from "mismanagement or miscommunication at the state level, and lack of flexibility to use resources".

He said he expects labs will be able to handle 1 million tests a day this fall.

The World Health Organization said the number of positive results should total no more than 10 percent of all tests. In the US, the positive rate is about 9 percent, but varies by state.

Only Alaska, Hawaii and Vermont are meeting suppression level targets. Montana, New Jersey and West Virginia are close behind, researchers said.

In addition, health officials believe the nation needs 100,000 "contact tracers" to get in touch with infected people and advise those they met at work or school to get tested and maintain steps to avoid spreading the coronavirus, including wearing a mask, frequent hand washing and, if needed, self-quarantine.

So far, 137,000 people in the US have died from COVID-19.

But the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle forecasts 208,255 COVID-19-related deaths in the US by Nov 1. The projection ranges from low of 186,087 to a high of 244,541.

The numbers drop to 162,808 with a range of 157,217 to 171,193 if at least 95 percent of people wear masks while in public, IHME said.

However, the projected deaths may increase if the current surge of infections increases among high-risk populations – especially the elderly or those with chronic underlying conditions that make them more vulnerable.

Despite an increase in the daily number of new cases, deaths totaled 482 Sunday, or about 18 percent of the 2,701 who succumbed to the virus at the peak in May.

Data from states reporting the ages of those recently infected suggest that new infections have increased sharply among young people who apparently take fewer precautions. But they are at a lower risk of death, the researchers said.

"The US didn't experience a true end to the first wave of the pandemic," IHME Director Christopher Murray said in a statement.

"This will not spare us from a second surge in the fall, which will hit particularly hard in states currently seeing high levels of infections."

States hardest-hit this fall are expected to be California, Florida, Georgia, Illinois, Massachusetts, Michigan, New Jersey, New York, Pennsylvania and Texas, IHME said.

"We have to be judicious about testing," Nam Tran, an associate clinical professor in the Department of Pathology and Laboratory Medicine at the Davis campus of the University of California and a member of Governor Gavin Newsom's COVID-19 Testing Task Force, said in a statement.

"If you test someone at the wrong time, just before symptoms develop, the viral load may be too low to register and they'll be the person who spreads the disease because they think they're safe."

That might be misunderstood as an "immunity passport" and that could lead to further spread of the virus, the researcher warned.

Antibody tests will eventually become a key tool for tracking infection rates and help researchers develop a COVID-19 vaccine. But scientists haven't determined which antibody neutralizes the virus.