Three sea lions in San Luis Obispo County have been diagnosed with leptospirosis, a highly contagious bacterial infection, the Marine Mammal Center confirmed on Wednesday.

Since July, the center has confirmed 24 cases of leptospirosis and says an active outbreak is occurring.

The center said it sees a surge in the number of sea lions admitted with symptoms of leptospirosis every four to five years. Before the 2017 outbreak, the most recent ones occurred in 2011 and 2008. During the 2008 outbreak, about 200 sea lions infected with leptospirosis were admitted to the center.

About 12 of the 2017 cases were found in Monterey County sea lions, the Monterey Herald reported. Leptospirosis is caused by a spiral-shaped bacteria called leptospira. Two of the cases were in Santa Cruz County.

If leptospirosis is not caught and treated in time, the infection can result in kidney damage and renal failure.

Symptoms of the infection in sea lions include drinking water and folding their flippers over their abdomen. Generally, sea lions don’t need to drink water because they receive all the moisture they need from food, the Marine Mammal Center said. When they’re infected with leptospira bacteria, their kidneys stop functioning properly and can’t filter out toxins or regulate hydration.

“We have not seen an outbreak in several years, so this is definitely something we’re watching,” said Giancarlo Rulli, spokesman for the Marine Mammal Center.

Because leptospirosis is spread through urine, dogs and humans are also at risk for the infection through contact with contaminated urine, water or soil, according to the Marine Mammal Center.

To report a sea lion infected with leptospirosis, call the Marine Mammal Center’s 24-hour hotline at 415-289-7325. The center also reminds the public to stay at least 50 feet away and to keep dogs away as well.