MOUNT VERNON, WASH. - Whooping cough, or pertussis, an infectious respiratory disease once considered doomed by science, has struck Washington 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.

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.

The county's top medical officer, Dr. Howard Leibrand, who is also a full-time emergency room physician, said that in the crushing triage of a combined health crisis and budget crisis, he had gone so far as to urge local physicians to stop testing patients to confirm a whooping cough diagnosis.

If the signs are there, he said -- especially a persistent, deep cough and indication of contact with a confirmed victim -- doctors should simply treat patients with antibiotics. The pertussis test can cost up to $400 and delay treatment by days. About 14.6 percent of county residents have no health insurance, said a state study, up from 11.6 percent in 2008.

State health officials estimate that because of incomplete testing and the assumption that many people with mild cases are not seeking medical treatment, perhaps as few as one in five pertussis cases is being recorded.

Pertussis was once a dreaded disease of childhood -- killing 5,000 to 10,000 Americans a year from the 1920s through the 1940s -- but is now a risk mostly to infants, to whom it is fatal in about 1 percent of cases. Most of the victims in Washington, as in previous outbreaks in other states, are between ages 8 and 12.

The pertussis vaccine is commonly given in childhood, and many states require it for children of school age. But Washington, said a federal study last year, had the highest percentage of parents in the nation who voluntarily exempted children from one or more vaccines. Federal health officials said the number of pertussis cases had been rising gradually nationwide for decades.