US plans to fight flesh-eating screwworm outbreak with flies and dogs

Here is the latest breaking news from around the world: US plans to fight flesh-eating screwworm outbreak with flies and dogsJust now Share Save Add as preferred on GoogleMax MatzaReutersUS agriculture and health officials have outlined a plan to combat a flesh-eating parasite that has been detected in the US for the first time since 1966. The plan to prevent a US outbreak of the New World Screwworm focuses on deploying hundreds of millions of genetically-altered sterile flies. Experts, though, say the supply of sterile flies is too low to immediately impact and halt the growing screwworm population.

Other measures include establishing a containment zone around the site of the first US infection along the southern US border, and using sniffer dogs to detect the insects. The threat to humans is low, but cattle ranchers fear an outbreak could have a large impact on beef markets. Screwworms are parasitic flies whose females lay eggs in open wounds and mucous membranes of living warm-blooded animals and people.

The Details

When the eggs hatch, hundreds of larvae burrow through living flesh with sharp mouths, eventually killing their host if left untreated. On Wednesday, US officials announced that the first case in 60 years was detected in a three-week-old calf, with the larvae found in its umbilical area. The discovery was made in the town of La Pryor, Texas, about 30 miles (48km) from the Mexico border.

Officials have set up a 20km-wide "control zone", and are "implementing quarantines, movement controls, and surveillance in this area," according to the US Department of Agriculture (USDA). Screwworm larvae grow into flies which can travel short distances. The primary way that they have travelled long distances is by being brought by humans.

There have been a handful of US cases since 1966, when travellers brought the pest back, but no larger outbreaks. Officials in the US and in Latin America have been combating the problem of screwworms for much of the past six decades, with limited success. Getty ImagesScrewworms grow after hatching from flesh, and can grow to be twice as large as the size of regular houseflies One way to fight back is by releasing hundreds of millions of sterile screwworm flies, as the females only mate once in their lifetime, and any eggs they lay will be unfertilised and will not hatch.

What Experts Say

This method, known as the Sterile Insect Technique, has been in use for many years to control a variety of insect populations, including fruit flies and mosquitos. It works by hatching flies in an enclosed space, and then exposing them to radiation to make them sterile before releasing them into the wild. However, officials say that they will need to breed up to 600 million sterile screwworms flies each week in order to fight back the outbreak.

Currently, facilities in the US and Mexico are only capable of producing about 100 million sterile flies per week.

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