U.S. testing for monkeypox is insufficient to determine how widespread the virus is and where new cases are emerging, according to infectious disease experts and advocates concerned about a slow response to the outbreak that has already affected 32 countries.
While government labs have the capacity to test up to 8,000 samples a week, they only use 2% of that capacity, suggesting there are about 23 monkeypox tests being done a day, said James Krellenstein, co-founder of PrEP4All. , an organization dedicated to HIV. advocacy group that broadened its focus during the pandemic. Much more testing is needed to find out where the pathogen is and how fast it is moving, he said.
Normally seen in African countries where most human cases are caused by contagion from infected animals, monkeypox has been spreading through close contact. Although it doesn’t move as fast as COVID-19, more than 1,600 cases have been reported worldwide since health officials began tracking it last month, including 72 in the US as of Tuesday. The situation echoes the early days of COVID-19, when faulty tests by the Centers for Disease Control and Prevention allowed the pandemic to spread undetected in the US, Krellenstein said.
“It is concerning that the CDC is not pushing this, especially after COVID-19,” he said in an interview. “This is a critical period – outbreaks get harder to control as time goes on.”
How many viruses?
Monkeypox is diagnosed in designated public health laboratories with a type of molecular test approved by the Food and Drug Administration, called PCR, which recognizes viral genetic material. Currently, all testing is done through the government’s network of labs, which experts say is cumbersome, leading to potential delays in identifying new cases and risking missing out on wider community spread.
Testing is so limited that it’s impossible to know how much of the virus circulating in the US is being detected, said Ranu Dhillon, an infectious disease physician at Harvard Medical School and Brigham and Women’s Hospital in Boston. It could be 90% or just 10%, he said.
“This challenge of expanding and decentralizing testing in response to an outbreak with unknown and widespread chains of transmission is not new,” said Dhillon. “It’s been a common theme in multiple recent outbreaks,” including Ebola, Zika virus, and of course COVID.
Experts urged decentralizing testing and supporting an expansion to laboratories and hospitals capable of performing PCR tests, especially in places like sexual health clinics where many monkeypox patients present.
“We absolutely need to make sure that every hospital with a lab, a molecular virology lab, can test their patients for monkeypox,” said Michael Mina, a former Harvard epidemiologist who is now chief scientific officer of eMed, which sells a- covid home tests.
Raj Panjabi, the White House’s senior director for biodefense and global health security, said on Friday that more than 300 PCR tests for monkeypox had been conducted and that there had been a 45% increase week over week. The CDC said that, as of Monday, 556 specimens have been tested.
US health officials say they are working to expand testing to companies and other government labs. The CDC has posted online instructions for making primers (DNA sequences used in PCR tests) so that labs can start creating their own monkeypox assays.
“We have posted a guide on our website with our assay information that anyone could replicate if they wanted to develop their own test,” said Jennifer McQuiston, deputy director of the CDC’s Division of Pathology and High Consequence Pathogens. “We also know that some people just want to lift the CDC assay and set it up in a commercial lab, and we’re exploring ways to help them do that.”
On Friday, the Association of Public Health Laboratories said that if the outbreak continues to grow, it supports a “phased expansion” of monkeypox testing in the US The FDA says it is preparing to make available a molecular emergency use authorization template in the event the outbreak is declared a public health emergency.
Medical technology company Becton Dickinson and Co. and CerTest Biotec, based in Zaragosa, Spain, said they are teaming up to develop a PCR assay for monkeypox. Swiss pharmaceutical giant Roche Holding AG said it has already developed three different tests for monkeypox, while Abbott Laboratories said in late May that it is working on a test.
Testing giant Labcorp said it is “evaluating all available options to support increased monkeypox testing,” including partnerships with the CDC, other government entities and groups such as the American Association of Clinical Laboratories. Quest Diagnostics Inc. said it is not offering a monkeypox test but is exploring options.
Bottlenecks in the system could become a bigger problem as the outbreak spreads. High demand can lead to delays in the turnaround time for tests at public health labs, said Bryon Backenson, director of communicable diseases at the New York State Department of Health. A Washington-based doctor said on Twitter that it took him six hours to get a call to his public health lab about a suspected case of monkeypox.
“One thing we have learned from COVID is that the availability of tests is very important,” Backenson said. “Having more labs and more people capable of testing is a good thing.”
US health agencies began planning for a smallpox outbreak after the attacks of September 11, 2001, and mailed anthrax spores raised bioterrorism concerns. That helped bolster the health system against emerging diseases like monkeypox, but there are still major gaps that appeared in the early days of the pandemic.
Early COVID control efforts were marred by flawed test kits and the centralized approach of the US, along with regulatory hurdles. CDC testing may have missed one of the earliest infections in the US, leading to additional community exposure, experts said. Little testing was done in February or March 2020, even though the virus was already spreading across the US at the time.
Other practices may limit recognition of the spread of monkeypox. Most tests are currently reserved for people with a characteristic rash and who are men who have sex with men or have recently traveled abroad, according to Paul Sax, an infectious disease physician at Harvard and Brigham and Women’s Hospital. Most of the people tested by the New York health department have been men, Backenson said. Some people told PrEP4All that their own doctors had turned them down for monkeypox testing, Krellenstein said.
Monkeypox can also be confused with some sexually transmitted infections, such as herpes or syphilis, health officials said. Some patients in New York who might have had monkeypox were not tested because they tested positive for other pathogens, Backenson said. The CDC warned doctors this week that patients with rashes typically characteristic of other infections should be carefully evaluated for monkeypox, and that coinfections are possible.
Restrictive testing could create blind spots as the virus spreads to other populations. The focus on men could lead to missed infections in women or children, Harvard’s Dhillon said. The United States should do more testing for monkeypox to ensure the full extent of the outbreak is known, she said.
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