CHICAGO/WASHINGTON — The individual who was infected with the first human case of travel-associated New World screwworm in the United States has successfully recovered from the flesh-eating parasite, as confirmed by the Maryland Department of Health on Monday (Aug 25). There have been no reports of transmission to other individuals or animals.

Concerns over the potential impact of the pest on livestock caused a decline in US cattle futures. Ranchers criticized the lack of transparency surrounding the case, especially after exclusive reporting by Reuters.

New World screwworms are parasitic flies whose females deposit eggs in wounds on warm-blooded animals. An outbreak could result in an estimated economic loss of about US$1.8 billion (S$2.3 billion) in Texas, the largest cattle-producing state in the US.

The Centres for Disease Control and Prevention (CDC) identified the human case as screwworm on Aug 4 in an individual who had recently returned from El Salvador, according to the US Department of Health and Human Services.

The confirmation of the case on Aug 4 was followed by a nearly three-week delay in the US government's public announcement, which has undermined trust in public agencies' ability to detect and combat potential screwworm outbreaks, according to Neal Wilkins, CEO of the conservation and cattle group East Foundation.

Maryland's health department disclosed that the infected individual was a resident of the state but did not provide further details about the travel destination or the timeline of the case. An HHS spokesperson did not clarify the discrepancy in the information source during Sunday's announcement.

Feeder cattle futures experienced a decline at the Chicago Mercantile Exchange, following record-setting cattle and beef prices this year due to a significant reduction in the nation's cattle herd size.

Screwworms have advanced northward into Mexico from Central America, leading the US Department of Agriculture to suspend imports of Mexican cattle in July.

During a visit to Texas on Aug 15, USDA Secretary Brooke Rollins did not mention the human case but announced a plan to allocate up to US$750 million to establish a facility in Texas for producing sterile flies to combat screwworm. The USDA has not reported any animal cases this year and has not responded to inquiries regarding the human case or communications with the CDC.

Last week, an executive from the industry group Beef Alliance informed about two dozen individuals via email that the CDC had confirmed a case in Maryland involving an individual who had traveled from Guatemala to the US. Beef Alliance has not yet commented on the matter.

R-CALF USA, a US cattle producers' association, called for an investigation on Monday to determine if government officials selectively shared information about the case with certain industry members.

"Transparency and equal distribution of information to all industry participants are essential for fostering trust between industry members and the government," stated Bill Bullard, CEO of the association.