During the 1960's, screwworm cases were overwhelmingly concentrated in Texas with 12 other states experiencing screwworm cases.
During the 1960's, screwworm cases were overwhelmingly concentrated in Texas, which reported thousands of cases weekly in 1962. However, as the suppression program took effect, cases dropped significantly by 1967.
In 1967, only two other states reported screwworm cases alongside Texas:
- Arizona: 23 cases
- California: 14 cases
- New Mexico recorded zero cases during that specific year, as populations were already being pushed back.
During the 1960s, 13 states experienced New World screwworm cases or were actively involved in the eradication programs fighting infestations.
The presence of cases by region during this decade unfolded in two distinct phases:
The Southeastern States (Early 1960s)
The southeastern eradication campaign officially cleared the region by 1959, but intensive quarantine tracking and minor reinfestation flare-ups from imported livestock continued into the early 1960s. This impacted:
- Florida
- Georgia
- Alabama
- Mississippi
- South Carolinas
The Southwestern & Plains States (1962–1969)
When the Southwestern Eradication Program officially launched in 1962, the pest was highly active across the southern border and central plains. Driven by livestock transport and fly migration, cases and official monitoring spanned:
- Texas (The epicenter, reporting thousands of cases weekly in 1962)
- Arizona
- California
- New Mexico
- Oklahoma
- Arkansas
- Louisiana
Isolated cases linked to cattle shipments were also documented as far north as Iowa and North Dakota during the height of the 1960s program records. By 1966, self-sustaining indigenous populations were declared eradicated from the U.S., though seasonal migrations from Mexico caused smaller, recurring border state outbreaks through the end of the decade.
Source: USDA Data
