Despite the false positive, the recall is still on due to possible contamination.
Already large clinical trials are testing if certain drugs could prevent or at least delay the disease - and if any of those pan out, doctors will need an easy way to tell who should try them.
Despite the surge elsewhere, California is not among the states currently experiencing an increase in cyclosporiasis cases, health officials say.
Dr. Erica Schwartz, a formal deputy surgeon general, was nominated by President Donald Trump in April.
Officials also said they anticipate cases of cyclosporiasis to continue increasing in the U.S., possibly through the end of August.
The Senate passed a bill four years ago to make daylight saving time permanent, but it stalled in the House.