Dozens of public health labs across the country are now using a more generalized test for orthopoxvirus, a broader category that includes monkeypox, smallpox and other viruses. Two biotech companies, Roche and Abbott, have announced plans to roll out monkeypox PCR tests, although at this time their test kits are for research use only.
The US Centers for Disease Control and Prevention said it was exploring ways to get monkeypox-specific testing to the states.
There are already 74 labs in 46 states — part of a network known as the Laboratory Response Network — that are “using an FDA-approved test for orthopoxviruses,” CDC Director Dr. Rochelle Walensky said Thursday. .
Current capacity is around 7,000 of these tests per week, with potential for expansion if needed.
Dr. Amesh Adalja, a senior fellow at the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health, said much of this capability “has been put in place in response to the threat of biological weapons, and smallpox. is the most worrisome orthopoxvirus.”
The tests performed by the CDC are more specific to the monkeypox virus, and the agency can also genetically sequence samples. For example, it was by examining the viral genetic code of the first American patient – a man from Massachusetts who had recently traveled to Canada – that the researchers were able to see that his case of monkeypox closely matched that of a case in Portugal. .
However, Dr. Jennifer McQuiston, a veterinarian and deputy director of the CDC’s Division of High-Consequence Pathogens and Pathologies, pointed out that the tests that take place at the CDC aren’t really necessary for patient care.
“The orthopox test that is in place is a workable test,” she said.
Experts say action may include isolating patients, making treatments and vaccines available, and contact tracing to determine who else may have been exposed to the virus.
Because other orthopoxviruses do not spread in countries where they are not endemic like the United States, it can be assumed that a positive orthopox test here is indeed monkeypox, according to Adalja.
“I think more diagnostic testing closer to patients is better. Commercial testing is even better,” Adalja said. “But the thing is, there are no other orthopoxviruses right now.”
He does not believe that a lack of monkeypox-specific testing is hampering the public health response “because an orthopox-positive [case] going to be monkeypox until proven otherwise in this scenario we find ourselves in right now.”
He added that this is a very different situation from the Covid-19 testing stumbles of 2020, when the world was dealing with a new coronavirus without a major testing alternative, meaning it was often difficult to distinguish Covid-19 from other respiratory viruses such as influenza. Monkeypox, on the other hand, we’ve known about for decades, and there’s a plan in place.
“It’s not the same as Covid,” Adalja said.
Identify monkey pox
Symptoms of monkeypox can include fever, headache, muscle aches, and swollen lymph nodes. A hallmark of the disease is a rash that results in lesions or pustules. It can happen anywhere on the body, often on places like the face, hands, and feet. In the current outbreak, some cases have caused lesions in the genital area or groin, according to health officials.
The process of identifying a case of monkeypox in the United States begins with a person noticing possible symptoms and seeking medical attention. Their provider can contact a local or state health department to collect a sample for orthopox testing, said Chris Mangal, director of public health preparedness and response at the Association of Public Health Laboratories.
Currently, the CDC recommends the collection of two specimens – swabs from lesions.
“When they do that test, and if that test comes back positive, they’ll report a presumptive positive result for non-variola orthopoxvirus. And that presumptive positive result is actually quite good – that, combined with what you’re seeing in terms of patient presentation – to make them feel that “we should take public health measures here,” Mangal said.
The second sample and test result are sent to the CDC for its own testing.
“The CDC and public health labs are working very closely, hand in hand, on these tests,” Mangal said.
During the monkeypox outbreak, the confirmatory testing process was “pretty good for the phase we’re in right now” because there weren’t high numbers of cases, she said. .
“If we go into the scenario where we see a significantly higher number of monkeypox cases, I think the CDC will then work with the [US Food and Drug Administration] and public health labs to make sure they have that confirmatory capability,” she said, adding that a few scenarios could occur if that happened.
“We can have public health labs developing their own lab-developed tests,” Mangal said. “If this becomes an emergency scenario, similar to Covid, labs could go through the FDA to get emergency use authorization for confirmatory testing.”
But overall, Mangal said, she doesn’t see the current outbreak turning into a major emergency. For the general public, “it’s my opinion that they shouldn’t be too worried,” she said.
Current monkeypox testing capacity is “not a major public health concern” in general, Adalja said, but there is still room for it to move faster or be more widely available.
“It would be great if Quest and LabCorp could do that. It would be great if there were kits that people could put in sexually transmitted infection clinics to get a definitive diagnosis,” he said. “But I don’t think right now you’re hampering the public health response, just because there’s no other orthopoxvirus circulating.”
Even if the CDC transfers monkeypox-specific testing to state public health labs, getting confirmatory results could take time, Adalja added.
“Even though we’re talking about state public health labs and CDC lab response network members who can do orthodox PCR, that’s still one step — it still involves paperwork, it still involves making phone calls, which deters people from doing that, it has a built-in lag,” Adalja said.
“If you work in an STD clinic in a city and you have this kit there, or if you have a lab in your city that does it, that makes it so much easier,” he said. .
Plans for monkeypox PCR testing
The monkeypox PCR tests planned by Roche and Abbott are separate from the CDC plans.
None have been given the green light by the FDA, and the two companies said last week that their tests were for “research use” – although they left the door open to meet future testing needs. tests.
Even if it does not become necessary to expand testing in countries like the United States, these measures could benefit other countries, including those in West and Central Africa where the monkeypox virus is endemic for a long time.
“Some of the resource-poor countries where these diseases are endemic sometimes have a clearer path to get these tests into the hands of people than in the United States, where there are so many regulations and it is so difficult to get a test. at the point of service,” says Adalja.
“I think there’s a benefit to having these tests in endemic countries so people can get a diagnosis quickly,” he added. “You can find outbreaks much faster. You can deploy the smallpox vaccine faster for monkeypox.”