Federal officials have long required doctors to report cases of many kinds of infectious diseases. However, the government has never required similar tracking of patients afflicted by chronic diseases such as asthma and autism -- lifelong disorders thought to be caused by a dance between people's genes and their exposure to particular substances in their diet or environment.

Washington's neglect of chronic-disease monitoring may have been a tragic mistake. A study released by UC Davis researchers last week showed a dramatic tripling of autism rates in California in the last decade and a half. The increase cannot be explained away merely by statistical glitches. For example, the researchers have ruled out the possibility that today's doctors are diagnosing anomalies that their predecessors missed.

The new study of autism -- a severe brain disorder that often leaves its victims unable to speak or form long-term social relationships -- should prompt Congress to develop an effective and comprehensive way to track the outbreak of chronic diseases.

The good news is that California legislators have been ahead nationally in recognizing the danger that chronic diseases present. They, in fact, commissioned the UC Davis report. But California's initiative does little to help people in other states, most of which have no chronic-disease monitoring systems.

Moreover, even California's autism reporting system is flawed. It does not, for example, require doctors in all state agencies, from the Department of Education to the Department of Developmental Disabilities, to use a uniform standard for diagnosing autism.

Creating a national chronic-disease database won't be easy. Epidemiologists will have to be careful to protect patients' privacy by using record-keeping safeguards, like computer encryption. And consumer privacy groups that have reflexively opposed any new reporting systems should accept that improved disease-rate monitoring will require patients to give scientists some limited access to their medical records.

What's clear is that continued indifference will be deadly. Political leaders have to give epidemiologists the money and moral support they need to overturn all the rocks in their search for answers to rising autism rates.