Maryland screwworm case has US officials bracing for return of an old foe

Rise in cases south of the border prompts concern over US livestock as Trump budget cuts hit research and foreign aid

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patient in Maryland was diagnosed in August with New World screwworm, a parasitic fly, after traveling to El Salvador. Doctors and veterinarians say the case poses very low risks for human health in the US, but it comes after an increase of cases in South and Central America and the Caribbean in recent years. It also highlights the importance of international cooperation on research and prevention.

For decades, the fight against the screwworm was a success story of scientific innovation and collaboration with other countries. There were devastating outbreaks of the parasite in the US in the first half of the 20th century until an ambitious program pushed it south, all the way to Panama.

But now, that progress has been threatened, with resurgences reported almost to the US border. And recent budget cuts to scientific research and foreign aid could further imperil the fight against the screwworm.