Deadly Bacterial Infection From Rats Is on the Rise—These Are the Flu-Like Symptoms

brown rat on the street — Andi111 / Shutterstock

With news about bird flu making headlines this month, it's disconcerting to hear about yet another illness that could be transmitted to humans from animals. But in New York City, cases of leptospirosis, a bacterial disease caused by rat urine, are on the rise.

According to NBC New York, six cases of leptospirosis have been reported so far in 2024. (In 2023, 24 total cases were reported, which set a new record.) Infections are mainly caused when people or pets are exposed to items and materials that may be contaminated with rat pee. But while cases are still somewhat limited—and officials are working to address the issue in New York—there is cause for concern.

Leptospirosis can have serious complications like kidney damage, meningitis, liver failure, respiratory distress, and death, if left untreated, per the U.S. Centers for Disease Control and Prevention (CDC). With that in mind, you'll want to know what to keep an eye out for. Read on for the 10 symptoms of infection.

1 High fever

woman sick checking temperature — Shutterstock

According to the CDC, a high fever is a telltale sign of leptospirosis. Per Harvard Health, a high fever in adults is somewhere between 102.4 to 105.8 Fahrenheit.

2 Red eyes

Senior man is holding eyeglasses and rubbing his tired eyes while reading e-book in tablet. — iStock

Red eyes are another leptospirosis symptom.

3 Yellow skin or eyes

yellow jaundice in the eye — Shutterstock

If you notice your skin has a yellow tint and your eyes appear more yellow than red, it should put you on alert. Also known as jaundice, this condition occurs when your skin, the whites of your eyes, and mucus membranes turn yellow, according to the Cleveland Clinic.

4 Nausea and vomiting

young woman with nausea covering her mouth — Shutterstock

Feeling sick to your stomach or throwing up can signal several different illnesses, but it can point to leptospirosis, the CDC says.

5 Chills

Ill man covered with blanket holding thermometer, having fever. — Prostock-Studio / iStock

Another flu-like symptom of leptospirosis is chills.

6 Abdominal pain

man with abdominal pain suffering at home — staras / Shutterstock

Even if you aren't throwing up, you might feel some discomfort in your stomach area with a leptospirosis infection.

7 Diarrhea

person opening bathroom door — suriyachan / Shutterstock

Unpleasant or irregular bowel movements like diarrhea also typically accompany this type of illness.

8 Rash

man checking for rash on arm — Andrey_Popov / Shutterstock

With a more severe case of leptospirosis, you could also develop flat, red spots on your skin that resemble a rash, according to the Cleveland Clinic.

9 Headache

Close up image woman holding round pill and glass of still water taking painkiller to relieve painful feelings migraine headache, antidepressant or antibiotic medication, emergency treatment concept — Shutterstock

If you have a headache combined with these other symptoms, it might be worth seeing a doctor.

10 Muscle aches

Man suffering from muscle aches and a headache. — iStock

Another flu-like symptom of leptospirosis is muscle aches, so don't dismiss them if you start to feel sore.

Symptoms can appear in two phases.

girl calling doctor using video conference — Gorodenkoff / Shutterstock

The CDC warns that these symptoms can easily be confused with other diseases, and you may not even show symptoms at all.

If you do, signs normally appear between two days and four weeks after "exposure to a contaminated source," the agency says.

The first phase typically includes fever, chills, headache, muscle aches, vomiting, or diarrhea—and patients sometimes recover before feeling sick again. If you do progress to the second phase of symptoms, that's when the infection becomes more severe, and poses the risk of kidney failure, liver failure, or meningitis.

People who contract leptospirosis can be sick for anywhere from a few days to three weeks. Without treatment, the illness can span even longer.

According to the CDC, leptospirosis is treated with antibiotics like doxycycline or penicillin. More severe cases may require intravenous antibiotics, so anyone with symptoms of the condition is urged to contact their healthcare provider.

Best Life offers the most up-to-date information from top experts, new research, and health agencies, but our content is not meant to be a substitute for professional guidance. When it comes to the medication you're taking or any other health questions you have, always consult your healthcare provider directly.

Abby Reinhard Abby Reinhard is a Senior Editor at Best Life, covering daily news and keeping readers up to date on the latest style advice, travel destinations, and Hollywood happenings. Read more Filed UnderHealth Advice • News Sources referenced in this article