The New World screwworm has now been detected in 30 of Mexico’s 32 states, after the first case in Sonora was confirmed on Wednesday, August 19. With this new detection, Baja California and Baja California Sur are the only states that remain without confirmed cases of the pest.
The report corresponding to epidemiological week 33 records 1,969 active screwworm cases in Mexico, according to an update attributed to the National Service for Agro-Alimentary Public Health, Safety and Quality (Senasica). The addition of Sonora to the national registry is particularly significant because of the state’s importance to cattle production and its location along the border with the United States.
The first case in Sonora was identified in a bovine in the community of Munihuasa, in the municipality of Álamos, approximately 17 kilometers from the border with Chihuahua. Following the detection, state and federal authorities activated surveillance, containment, and control measures to prevent the pest from spreading.
Which States Remain Free of New World Screwworm?
Following the confirmation in Sonora, only two states remain without reported cases:
- Baja California
- Baja California Sur
This means the pest has now reached 30 states, covering virtually the entire country, while the Baja California peninsula remains the only region of Mexico without confirmed detections in the latest report.
The situation in northwestern Mexico has changed rapidly. At the end of July, Sonora was still considered free of the pest, and state authorities had intensified inspections and prevention campaigns because of cases reported in neighboring states. The Government of Sonora had reported more than 1.4 million inspections as part of efforts to prevent the pest from entering the state.
What Happened With Sonora’s First Case?
The state government reported that the discovery occurred after a producer detected the problem in an animal and filed the corresponding report. Following confirmation, specialized personnel were deployed and sanitary containment measures were strengthened in the area.
Among the initial actions reported was the release of 360,000 sterile flies around the detection site. Authorities also established treatment and surveillance measures within a 20-kilometer radius of the location.
The sterile insect technique seeks to reduce the reproductive capacity of the insect responsible for screwworm and is part of the strategy used by Mexico and the United States to contain the spread of the pest.
Detection Comes Before Planned Reopening of Douglas Border Crossing
The Sonora case is particularly significant because it was confirmed five days before August 24, the date planned by the United States to reopen the Douglas, Arizona, port to Mexican cattle trade.
The situation page of the U.S. Department of Agriculture (USDA), consulted on August 19, still listed that date and indicated that the reopening is part of a gradual process subject to health evaluations. The agency warns that the schedule could change if an increased risk is detected in Sonora or Chihuahua.
As of Wednesday afternoon, no official change to the planned reopening date had been announced as a result of the case detected in Álamos.
What Is New World Screwworm and Why Is It a Concern?
New World screwworm is the larval stage of the fly Cochliomyia hominivorax. The fly lays its eggs in wounds on warm-blooded animals. After hatching, the larvae feed on living tissue, causing lesions that can worsen without treatment. The pest can also affect pets, wildlife, and, less frequently, humans.
Senasica urges people to immediately report wounds containing larvae or any suspected infestation. Early detection makes it possible to treat affected animals and reduce the risk of the pest spreading to other herds or regions.
The confirmation in Sonora therefore changes the national health map: 30 states now have reported cases, while only Baja California and Baja California Sur remain without confirmed detections, according to the epidemiological report available on August 19.
Key Facts
- New World screwworm has been confirmed in 30 of Mexico’s 32 states.
- Baja California and Baja California Sur are the only states without confirmed cases.
- Mexico has 1,969 active cases as of epidemiological week 33.
- Sonora confirmed its first case in a bovine from Munihuasa, Álamos, near the Chihuahua border.
- The detection occurred before the planned reopening of the Douglas, Arizona, cattle crossing on August 24, a date that remains subject to health evaluations.
Source: msn
