The US Department of Agriculture announced on 24 July a phased reopening of southern cattle ports that have been closed for a year to keep New World screwworm out of the United States.

The Douglas port of entry in Arizona opens to cattle trade on 24 August. The department said it would simultaneously begin the operational steps needed to reopen the Santa Teresa and Columbus ports in New Mexico, with each stage contingent on Mexico meeting milestones in a Joint Action Plan on the pest.

Every animal entering through these ports will undergo a full USDA inspection for signs of screwworm, a parasitic fly whose larvae feed on the living tissue of warm-blooded animals and which can kill untreated cattle within days.

"The closure of the Southern ports of entry for the last year has been a tough but necessary action to control the spread of NWS in Mexico and protect the American livestock industry," said Agriculture Secretary Brooke L. Rollins, who described the reopening as resuming a cattle trade that is hundreds of years old.

The department singled out the Mexican states of Sonora and Chihuahua, saying both have maintained animal health infrastructure and a record of successful disease control while the spread continued elsewhere in the country.

Closing a livestock border is an expensive instrument — it cuts feeder cattle supply to American feedlots and removes a market from Mexican producers — which is why the reopening is staged and reversible rather than complete.

The department publishes its screwworm response through the Animal and Plant Health Inspection Service.

Source: USDA