A human case of New World screwworm was reported by the Centers for Disease Control after being discovered earlier this month. Colin Woodall, CEO of the National Cattlemen’s Beef Association, says while it’s something the cattle industry needs to monitor, this isn’t a risk to the U.S. livestock industry.
“From what we understand, it was an individual who had made a trip to one of the countries in Central America that has New World screwworm, which are all the countries in Central America right now, came back, had some pain, went to seek treatment, and discovered that they were infested with New World screwworm larvae. I think the key is that the CDC protocols work. They identified it. CDC is not a PR agency. I can’t speak as to why they make the decisions about what they announce or don’t announce, but we do know that the protocol worked in that individual, who was treated, and the larvae were destroyed. And while, yes, it’s surprising to see that particular story, it’s not shocking.”
There have been cases in the last couple of years in the U.S.
“There was a human case in the United States last year in 2024. There was one in 2023. We also know of one that happened in 2014, and all of them were very similar. These were individuals who traveled to a country that had New World screwworm, brought the larvae back with them, and then, when the pain got unbearable, went to seek treatment, and the CDC was engaged. It was identified, and those larvae were destroyed. So, in the NCBA, we’re not shocked to see that there is a human case.”
Woodall said the protocols for protecting humans and livestock from NWS worked as intended.
I think, for us, as we are taking a serious approach to protecting ourselves from New World screwworm, the things that we’re looking at are, one, did the protocols work? And it’s obvious that the protocols worked. Let’s think about this for a minute from a human standpoint. If you go traveling, and somehow the New World screwworm female lays its eggs somewhere in your body, you come back to the United States, and you’re going to have excruciating pain because these larvae, these maggots, are going to be eating you alive. So, you’re going to go seek some sort of treatment.”
The human infection had no chance to spread because of how quickly the person went to the doctor.
“This is not a situation where it’s a tick bite or a mosquito bite, and you might scratch it, and not necessarily think twice about seeking treatment until further down the line. This is not a situation where those larvae are going to then exit the human, pupate, and become the fly, because that pain is just so excruciating. So, the CDC approach, CDC protocols, and the information that they have out there in the medical community obviously works. So, that is probably the biggest takeaway we need to understand.”