Some of the current cases involve individuals who recently traveled to Europe, CDPH said. One city resident with the virus said they attended the International Mr. Leather (IML) conference in Chicago that took place from May 26-30.
In addition, individuals from another state who were confirmed to have monkeypox also reported attending the IML conference.
The cases in Chicago are made up of both men and women, officials said.
"While the risk in Chicago remains low, CDPH wants the public to be able to make informed choices about gathering in spaces or participating in events where monkeypox could be spread through close or intimate contact," said Chicago's top doctor, Allison Arwady.
Individuals attending festivals or other summer events should consider how much close, personal, skin-to-skin contact is likely to occur at the events they plan to attend, CDPH said.
The first two probable cases of monkeypox in Illinois were reported in early June.
The United States confirms 49 cases of monkeypox in 16 states and Washington DC. No deaths have been reported, with individuals suffering from just mild symptoms.
Globally, 33 countries have reported more than 1,450 confirmed monkeypox cases, CDPH said.
Monkeypox is caused by a virus that is in the same genus of viruses that causes smallpox, according to the CDC.
Symptoms of the virus include fever, headache, muscle aches, backache, swollen lymph nodes, chills, exhaustion and a noticeable rash.
People usually recover within two to four weeks without needing to be hospitalized, but the disease is occasionally deadly.
"The risk to the general public remains low," IDPH said in a tweet.
Anyone can get monkeypox, but a number of cases involve gay and bisexual men, according to the CDC.
Dr. Anew Hazra of Howard Brown Health has been following the outbreak.
"It’s really important for us to approach this in a non-stigma way and realize the virus is out there," he said.
From exposure to the onset of sickness can occur within one to two weeks.
CDC officials say anyone with a rash that looks like monkeypox should talk to their healthcare provider immediately.
"Knowledge empowers people. We wanted to make people aware what’s really going on," Hazra said.
Monkeypox is ordinarily found in countries in West and Central Africa with tropical rainforests.
The monkeypox virus was first discovered in colonies of lab monkeys in 1958.
Associated Press and Sun-Times Media Wire contributed to this report.