When will the coronavirus crisis end?

That's a critical question being asked by people around the world and facing health care experts and global leaders. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said Sunday only that the outbreak will get worse before it gets better.

Walter Ricciardi, a member of the World Health Organization's executive council and Italian health ministry consultant on the coronavirus, provided a modest timeline last week. Ricciardi suggested life could return to "normal" this summer.

Ricciardi compared the coronavirus pandemic to the SARS outbreak almost two decades ago, which he said ended in May or June.

"I have the impression that, if we are lucky and all work together, we should get through to the summer," he said. "That's when we should be able to return to normal life."

We asked some experts about that timeline. "Hopeful" was a recurring theme.

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Dennis Carroll, former director of the U.S. Agency for International Development's Global Health Security and Development Unit, called Ricciardi's statement "a hopeful political statement, not one supported by any available evidence." He described comparisons to SARS as "dubious" at best.

"A more reasonable reference point would be the duration in Wuhan," Carroll told USA TODAY. "With its comprehensive approach to slowing the spread, the outbreak is three months on."

The outbreak in China has passed its peak, but new infections continue to be reported, Carroll said. Still, he acknowledged the possibility that a “seasonal” decline might kick in.

"By May we could be returning to some state of normalcy," he said. "But, again, what we don’t know about this virus is epic. Holding a May date as a beacon of hope may soothe some of the angst but who knows?"

Ogbonnaya Omenka, an assistant professor and public health specialist at Butler University's College of Pharmacy and Health Sciences, told USA TODAY because the flu and colds occur mostly in the winter and retreat in the summer, there is an expectation that COVID-19 would follow similar trends.

But he noted that Australia, in spite of the summer season and warmer temperatures, is also dealing with the COVID-19 illness.

"That might be an indication of the need for cautious optimism regarding expectations for the influence of warmer temperatures," he said. "Especially since we (don't) know much about what this novel coronavirus will do across seasons."

Melissa Nolan, a physician and professor of epidemiology at the University of South Carolina’s Arnold School of Public Health, did not dispute Ricciardi's outlook.

"Estimates suggest that cases will peak in late April/early May, and experts are hopeful that the current stringent measures will ensure mitigation of continued spread," she said. She noted the "unprecedented" actions being taken by governments, schools and businesses around the globe.

"As we have never before seen measures like this, it is unclear as to the full extent they will have in lowering transmission," she said. "But experts are hopeful that enhanced mitigation of community spread will lower overall disease burden."

All the experts stressed the importance of behavior on any coronavirus timeline. The less people interact with one another and are mobile, the quicker we exit the crisis, they agreed.

"Regardless of how many interventions are implemented, a great deal of their success depends on the willingness of the public to adjust their behaviors accordingly," Omenka said.