New World Screwworm moves beyond containment threshold NWS is a serious health and economic threat that could cost the US billions. This market intel analyzes the re-emergence of NWS and the danger it poses to animal health, human health and food security. NWS flies are able to travel as far as 12 miles to find suitable hosts. Since the female NWS flies only mate once, the wild population shrinks until the pest is eradicated. ConclusionsNWS ranks among the top animal health and food security concerns in 2025.