As passengers return to the United States from a cruise during which a scarce hantavirus outbreak occurred, much of the country lacks a basic public health tool: a test that can diagnose the disease in the earliest stages of infection. Nebraska may be the first state to be able to do this.
In just a few days, the laboratory at the University of Nebraska Medical Center in Omaha developed its own diagnostic test for the Andean virus in anticipation of receiving 16 American passengers from the ship.
“I believe we may be the only lab in the country that currently has this test,” Peter Iwen, director of the Nebraska Public Health Laboratory, tells WIRED, referring to polymerase chain reaction (PCR) tests that have been essential during the Covid-19 pandemic. Its ability to detect tiny amounts of the virus before a patient develops full symptoms is key to quickly identifying cases, ensuring patients are treated quickly and preventing the spread of the disease.
The university medical center houses a highly specialized biocontainment unit tasked with caring for patients with solemn infectious diseases who lack vaccines and treatments. Staff members previously treated patients during the 2014 Ebola outbreak and cared for some of the first Americans diagnosed with Covid in 2020.
When Nebraska was notified that it would accept some of the passengers, Iwen contacted the U.S. Centers for Disease Control and Prevention to see if it had tests. He learned that the CDC has the ability to conduct a serological test that checks for hantavirus antibodies. But people don’t produce antibodies until they are actively ailing and their body has had time to mount an immune response.
Andrew Nixon, a spokesman for the U.S. Department of Health and Human Services, told WIRED that the CDC has a PCR test for Andes virus, but it is an investigational test that cannot be used to treat patients. Research tests are used in scientific experiments, while diagnostic tests that are used to confirm or rule out disease in patients must be rigorously tested or validated to ensure they can produce consistent results. Nixon said the agency is working to validate its PCR test.
Iwen’s lab quickly mobilized to find the materials needed to build and test the PCR test from scratch. They called a lab in California – a state that had previously reported cases of hantavirus – but their test was for a specific strain found in the US. So far, the Andes virus has only been detected in South America and has not occurred in rodents living in the USA.
“The tests we have available in the U.S. will not detect the virus found in South America,” he says, noting that the Andean virus is very different genetically from the original strain of hantavirus found in the U.S., known as the Sin Nombre virus.
The Nebraska team contacted Steven Bradfut, a hantavirus scientist at the University of Novel Mexico. Frannie Twohig, a graduate student in Bradfute’s lab, developed an Andes virus PCR test for research purposes as part of her doctoral thesis. Bradfute’s lab also has genetic material from the Andean virus, which is unable to cause disease and which the Nebraska lab would need to validate its test.
On Friday, Bradfute overnight sent genetic material and a box of chemical reagents needed to detect the virus in blood samples to Nebraska. On Saturday morning, Iwen’s team had everything they needed to start assembling and validating the test.
It was enough to conduct about 300 tests, which took all of Saturday and Sunday, says Iwen. His team added Andean genetic material in various concentrations to samples of hearty human blood to see if the test could detect it. They then compared the results with control samples. The team has used approximately one-third of the tests in the validation process and is currently able to perform several hundred tests on patient samples.