CHICAGO (WGN) Chicago health officials are sounding the alarm over multiple recent cases of leptospirosis, a disease blamed for roughly 60,000 annual deaths globally.

The Chicago Department of Public Health said a total of six cases of leptospirosis have been reported to the department so far this year, which is more than expected. Officials said median case numbers historically have been two per year.

Brought on by the Leptospira bacterium, which can survive in water or soil for months, leptospirosis can be serious if left untreated. According to the Centers for Disease Control and Prevention, people with leptospirosis can experience damage to their kidneys, meningitis, liver failure, breathing problems, and, in some cases, death. About 10% of cases become severe and life-threatening, including hepatic and renal failure, and pulmonary hemorrhage.

You may be most at risk for contracting the bacteria while swimming or boating in freshwater or floodwater that has been contaminated with animal urine, or while spending time outside gardening, completing yard work, hiking, or otherwise interacting with animals, their urine, or their bodily fluids.

Roughly 100 to 150 cases of leptospirosis are reported in the U.S. each year, with outbreaks more likely to occur after heavy rain and flooding.

The incubation period after exposure is usually 5-14 days, but may range from two days to a month. Most common symptoms include fever, chills, body aches (especially in the calves and lower back), nausea, vomiting, diarrhea, abdominal pain, cough, red and swollen eyes, and sometimes skin rash.

Officials said illnesses may come with two phases, where a patient may briefly recover only to develop severe symptoms afterwards. Leptospirosis can also cause complications in pregnancy, including spontaneous abortion or fetal death.

As for the cases reported in Chicago, officials said the majority are mild.

Of the six cases reported on Chicago’s northwest side, four of them were identified as having experienced symptoms between July 16 to Aug. 28. The cases in July and August all reported either direct exposure to animal waste, particularly from rats, or indirect exposure to rodent waste through gardening or yard work.

The CDC says leptospirosis can be treated with antibiotics.

Livestock, pets, marine mammals, and wild animals can also become infected. Some animals may show no signs or symptoms, the CDC explains, which means they may also be able to spread the bacteria “for several months or years.”

Over the last 10 years, Chicago officials said 28 cases of leptospirosis have been reported in the city. Within the U.S., Puerto Rico and Hawaii report the most cases annually, according to health officials.