(CBS) — In Illinois, two pregnant women are among the three cases of Zika virus in the state. The third case is an adult male and all have traveled to Latin America, according to the state health department.

Geographically, Chicago is not at great risk for the type of mosquito that typically carries Zika, says Dr. Mitchell Weinstein of Presence St. Joseph Hospital.

He says the cases Illinois is likely to see will be in people who have traveled to Latin America and have been bitten by mosquitoes there. Potentially not a small number, given Chicago’s strong ties to that part of the Americas.

“We’re not looking at something like Ebola, but if you’re going to be looking at numbers of cases, you’re probably going to be looking at a magnitude of cases larger than Ebola.”

Dr. Weinstein says 80 percent of infected people will have no symptoms. The other 20 percent will probably not have severe symptoms.

The real worry is for pregnant women. He says it’s unclear how many infected pregnant women will have babies with microcephaly.