MOUNT VERNON, Wash. — Whooping cough, or pertussis, a highly infectious respiratory disease once considered doomed by science, has struck Washington State this spring with a severity that health officials say could surpass the toll of any year since the 1940s, before a vaccine went into wide use.

Although no deaths have been reported so far this year, the state has declared an epidemic and public health officials say the numbers are staggering: 1,284 cases through early May, the most in at least three decades and 10 times last year’s total at this time, 128.

The response to the epidemic has been hampered by the recession, which has left state and local health departments on the front lines of defense weakened by years of sustained budget cuts.

Here in Skagit County, about an hour’s drive north of Seattle — the hardest-hit corner of the state, based on pertussis cases per capita — the local Public Health Department has half the staff it did in 2008. Preventive care programs, intended to keep people healthy, are mostly gone.