By Michele F. Mihaljevich

Indiana Correspondent

INDIANAPOLIS – Indiana and Tennessee are taking steps to prevent the spread of New World screwworm (NWS) after cases were reported recently in Texas and New Mexico.

NWS is a serious pest that threatens livestock, pets, wildlife, and, in rare cases, people, USDA said. The larvae burrow into the living tissue of animals, causing severe wounds, animal suffering and significant economic losses. The U.S. food supply is safe, the agency added, saying NWS does not infest meat, fruits, vegetables or other food products.

The insect hadn’t been found in Indiana as of June 9, according to the Indiana State Board of Animal Health (BOAH). However, the latest findings have triggered movement restrictions for animals traveling to the Hoosier state from NWS-infested areas, the agency noted.

BOAH has adopted movement restrictions consistent with USDA’s NWS playbook to prevent entry of the parasite into the state, the agency said in a release. The restrictions apply to all livestock and companion animals coming from an NWS-infested zone.

In addition to any requirements for leaving an infested zone imposed by USDA or the origin state, BOAH said animals entering Indiana that originate in an NWS-infested zone must meet the following enhanced entry requirements unless specifically exempted:

- Be accompanied by an animal movement certificate (provided by state of origin) approved by the state of origin and BOAH prior to shipment.

- Be inspected by a USDA-accredited veterinarian within five days of departure and obtain a certificate of veterinary inspection (CVI) issued within five days of movement to Indiana.

- Be accompanied by a CVI documenting application of an effective treatment for NWS. For livestock and poultry species, the treatment must be applied within 14 days of movement unless going directly to slaughter. For cats and dogs, within five days of movement.

Exceptions will be made for certain hatching and table eggs, and chicks, poults and ducklings, BOAH said. Other exceptions are for certain small mammals, exotic birds and swine. A list of exceptions and more information on Indiana’s response to NWS may be found on BOAH’s website, www.in.gov/boah/.

As of press time, BOAH had not changed exhibition requirements for fairs or open shows. All out-of-state entries must meet applicable interstate requirements, the agency said.

The signs of NWS in livestock, poultry and pets include the presence of unusual flies or maggots in or around open wounds/sores or body openings (nose, ears, navel, genitalia) of animals, BOAH said. NWS flies have orange eyes, a metallic blue or green body, and three dark stripes along their backs. Owners should also look for wounds that continue to drain or grow larger, often with the smell of decay; and animals showing discomfort, including head-shaking or irritated behavior.

Owners should contact their veterinarian if any of these signs are observed, BOAH said.

The Tennessee Department of Agriculture (TDA) said no cases of NWS had been detected in the state as of June 5.

“Livestock, pets and even wildlife are vulnerable,” State Veterinarian Samantha Beaty said in a release. “This parasite can have a tremendous negative impact on our animal populations and associated industries. Early detection is our best defense. Our priority now is to prepare – to ensure surveillance, movement controls and response plans are in place so that if we do detect NWS, we can act swiftly to protect the health of Tennessee’s animals and our agricultural industries.”

Beaty has temporarily implemented more stringent requirements for warm-blooded animals moving out of an infested area into Tennessee. These stricter requirements ensure that animals are thoroughly inspected and prophylactically treated prior to movement and allow officials to effectively implement other control measures, the release said.

In addition, the State Veterinarian’s Office is focused on implementing enhanced surveillance measures and providing outreach and education related to prevention, management and treatment, TDA said.

The TDA’s Animal Health field staff and Foreign Animal Disease diagnosticians are ready with materials to collect and submit larvae and fly specimens should a suspected case arise, the release said.

The USDA said the spread of NWS outside the main cluster in Texas demonstrates the difficulty of stopping a resurgent pest that could devastate the nation’s cattle industry.

On June 8, the Associated Press (AP) reported five confirmed cases of NWS: three calves and a goat in Texas, and a dog from Lea County, N.M. In each case, officials have set up a 12-mile quarantine zone to try to slow the parasite’s advance.

The U.S. cattle industry is valued at $113 billion, and Texas (at $17 billion) is the industry’s No. 1 state, AP said.

To help combat NWS, the USDA has been dropping sterile screwworm flies in south Texas since February, when it opened a center for dispersing them, according to AP. Releasing sterile flies is both time-tested and highly effective, the news agency reported. While males are “promiscuous,” in the scientific sense, females are not, and if their one mating hookup is with a sterile male, no eggs from that female will hatch.

Once sterile males are prevalent enough, the fly’s population declines and then dies out. USDA has invested $750 million to build a fly factory in southern Texas that can produce up to 300 million sterile flies a week, AP said. The facility is expected to begin operating next fall.

Veterinarians across the country are monitoring for potential cases, reporting to state and federal authorities, and educating their clients, according to the American Veterinary Medical Association.

“Veterinarians are trusted experts on the ground who possess the medical expertise required to limit animal suffering and prevent further spread of this parasite,” Dr. Michael Q. Bailey, the association’s president, was quoted as saying by the AP. “The (association) is committed to equipping our members with the up-to-date resources and guidance they need to remain proactively vigilant, protect their clients’ animals, and effectively combat NWS.”