Dozens of public health labs across the country now use a more general test for orthopoxviruses, a larger category that includes monkeypox, smallpox and other viruses. Two biotechnology companies, Roche and Abbott, have announced plans to introduce monkeypox PCR testing, although their test kits are currently for research use only.
The U.S. Centers for Disease Control and Prevention say they are exploring ways to roll out monkeypox-specific testing across the states.
There are already 74 labs in 46 states — part of a network known as the Laboratory Response Network — that “use an FDA-approved test for orthopoxviruses,” said CDC director Dr. Rochelle Walensky on Thursday.
Current capacity is around 7,000 of these tests per week, with the ability to expand as needed.
dr Amesh Adalja, senior scientist at the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health, said much of this capacity “was established in response to the biological weapons threat, and smallpox is the orthopoxvirus of greatest concern. “
The tests that CDC runs are more specific for the monkeypox virus, and the agency can also genetically sequence samples. For example, using the viral genetic code of the first US patient — a Massachusetts man who recently traveled to Canada — the researchers were able to determine that his case of monkeypox exactly matched a case in Portugal.
dr However, Jennifer McQuiston, veterinarian and associate director of the CDC’s Division of Pathogens and Serious Consequence Pathology, emphasized that the tests that are performed at CDC are not really necessary for patient care.
“The existing Orthopox test is an actionable test,” she said.
Experts say measures may include isolating patients, providing treatments and vaccines, and contact tracing to determine who else may have been exposed to the virus.
Because other orthopoxviruses don’t spread to countries where they’re not endemic like the US, Adalja says it’s safe to assume that a positive orthopox test here is actually monkeypox.
“I think that more diagnostic testing closer to the patient is better. Commercial assays are even better,” said Adalja. “But the fact is that there are currently no other orthopoxviruses.”
He doesn’t think a lack of monkeypox-specific testing will hamper the public health response “because an orthopox-positive [case] will be monkeypox in the scenario we are in right now until proven otherwise.
He added that this is a very different situation from the stumbling blocks in Covid-19 testing in 2020, when the world was dealing with a novel coronavirus without a major testing alternative, meaning it was often difficult to identify Covid-19. 19 to distinguish from other respiratory viruses like the flu. We’ve known about monkeypox for decades, and there’s a plan.
“It’s not the same as Covid,” Adalja said.
Monkeypox symptoms can include fever, headache, muscle pain, and swollen lymph nodes. A feature of the disease is a rash that leads to lesions or pustules. This can happen anywhere on the body, often in places like the face, hands, and feet. In the current outbreak, some cases have caused genital or groin lesions, 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 help. Your provider may 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 collecting two samples—swabs from lesions.
“If they do this test and this test comes back positive, they will report presumptive positive for non-variola orthopoxvirus. And that putative positive is actually good enough — that, combined with what you’re seeing in terms of the patient’s presentation — to make them feel like ‘we should be taking public health action here,'” Mangal said.
The second sample and test result will be sent to the CDC for their own review.
“The CDC and public health labs actually work closely hand-in-hand on these tests,” Mangal said.
During the monkeypox outbreak, the confirmatory testing process was “good enough for the phase we’re in right now” because there wasn’t a high number of cases, she said.
“If we get into that scenario where we see a significantly higher number of monkeypox cases, I have no doubt the CDC will work with that [US Food and Drug Administration] and the public health labs to make sure they have that confirmatory capability,” she said, adding that there are a few scenarios that could play out in this case.
“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 work together through the FDA to obtain an emergency authorization for confirmatory testing.”
But overall, Mangal said, she doesn’t see the current outbreak evolving into a major emergency. For the general public, “my opinion is that they shouldn’t be overly concerned,” she said.
Current monkeypox testing capacity is generally “not a major public health concern,” Adalja said, but there is still room for faster progress or wider availability.
“It would be great if Quest and LabCorp could do this. It would be great if there were kits that people could take to sexually transmitted infection clinics to get a definitive diagnosis,” he said. “But I don’t think you’re hampering the public health response right now just because there’s no other orthopoxvirus out there.”
Even if the CDC moves monkeypox-specific testing to state health labs, it could take time to get confirmatory results, Adalja added.
“Even though we’re talking about state public health laboratories and members of the CDC’s Laboratory Response Network being able to do orthodox PCR, it’s still a step — it still involves paperwork, it still involves phone calls, which puts people off doing it.” , which has a built-in delay,” Adalja said.
“If you work at an STD clinic in a city and you have this kit there, or if you have a lab right in your city that does it, that makes it so much easier,” he said.
Monkeypox PCR test plans
Roche and Abbott’s planned monkeypox PCR tests are separate from the CDC’s plans.
Neither has received the green light from the FDA, and both companies said last week that their tests are for “research use” — although they leave the door open to meeting future testing needs.
While it doesn’t become necessary to expand testing in countries like the US, these moves could benefit other countries, including those in west and central Africa, where the monkeypox virus has long been endemic.
“Some of the resource-poor countries where these diseases are endemic sometimes have a clearer way of getting these tests into people’s hands than in the United States, where there is so much regulation and it’s so difficult to get a point- to carry out an of-care test. ‘ said Adalia.
“I think there’s an advantage in doing these tests in endemic countries so people can get diagnoses quickly,” he added. “They can find breakouts much faster. You can use the smallpox vaccine against monkeypox faster.”