New World screwworm, the flesh-eating fly larva the United States eradicated in the 1950s, has reached Texas and New Mexico, and researchers at the University of California San Diego, working with the County of San Diego's public health services, have built a dashboard to estimate where the threat could emerge next, ScienceDaily reports from materials provided by UC San Diego. The tool estimates risk for individual counties across the country from confirmed detections, environmental conditions that favour the fly and its larvae, and reports in the news media.

'Our County public health partners alerted us to the need for better situational awareness of New World screwworm,' said Eliah Aronoff-Spencer, professor of medicine at UC San Diego School of Medicine. Including news coverage is one of the dashboard's innovations, said Seema Shah, medical director of the county's epidemiology branch: 'Lab confirmation can take days or weeks. By incorporating media reports, we can identify potential threats sooner and stay one step ahead.' Access is limited to public health officials and partners for now, with a public version hoped for later.

Unlike most maggots, screwworm larvae feed on healthy living flesh: females lay eggs in wounds or body openings, the larvae burrow in, and untreated infestations can badly injure or kill livestock and wildlife; humans are occasionally infected. Adult flies travel miles seeking hosts, and infected livestock, pets, birds and wildlife can carry the parasite into new areas. 'We knew in 2023 that New World screwworm was going to move northward, but I wasn't expecting it to move as fast as it has,' said Mark Beatty, the county's assistant medical director. 'Once it entered Texas, we quickly saw an increase in detections.'

The US Department of Agriculture is leading the latest eradication campaign, reviving the sterile insect technique of the 1950s — irradiated male flies released in huge numbers so that wild females produce no viable offspring — combined with pesticides and quarantines on animal movement, and is seeking Environmental Protection Agency approval for a genetically modified all-male strain now in field tests; UC San Diego researchers are developing next-generation genetic tools for future control.

The dashboard came out of Resilient Shield, a UC San Diego centre funded by the US Centers for Disease Control and one of 13 core facilities in the CDC's Insight Net outbreak-modelling network, which builds tools to the priorities public health agencies submit; it draws on livestock, environmental, weather, health-record and social-listening data with technology partners including Google and MITRE. Emily Trumbull, the county's One Health veterinarian, said the team is working with the California Department of Food and Agriculture to connect local vets with screwworm surveillance resources.

Source: ScienceDaily (University of California San Diego)