Health officials in New York City issued a new warning this week regarding an increase in a transmitted bacterial illness that is spread in rat urine.
In 2023, there were 24 cases of this disease being spread, which is the highest recorded number on record, according to officials.
The city’s Department of Health said that in 2024, “only” six cases of what’s known as leptospirosis have thus far been reported, though the numbers are starting to trend upward.
The New York City cases largely are associated with people being exposed to materials that are contaminated by rat urine from the Norway rat.
In a memo sent on April 12, Celia Quinn, the city’s deputy commissioner for the Division of Disease Control, said the disease can cause humans to experience rash, jaundice, conjunctival suffusion, cough, diarrhea, vomiting, muscle aches, chills, headache and fever.
If it’s not treated properly and quickly, it can also lead to respiratory distress, liver damage, meningitis and kidney failure.
As the memo reads:
“Transmission occurs through direct contact with infectious urine or urine contaminated water, soil or food, entering the body through open wounds or mucous membranes.”
Between 2001 and 2023, there were 37 recorded cases of leptospirosis in the Bronx, which was the most of any boroughs in New York City. Manhattan was next with 28, according to the memo.
There were also six people who died as a result of these infections in that time period.
City health officials added that it’s very rare for leptospirosis to transmit from one person to another.
In addition, Quinn said that the Leptospira bacteria, which causes leptospirosis, often dies in only a few minutes in the freezing cold or dry heat.
As she explained:
“The cold winters of New York City likely limit the extent to which leptospires can survive in the environment. However, excessive rain and unseasonably warm temperatures, factors associated with climate change, may support the persistence of leptospires in more temperate areas like New York City.”
Of the 24 reported cases in 2023, more than half of them happened from June through October. That’s a period of time in New York City where there is typically warmer weather, with an overall wetter climate that brings excessive rain and “unseasonably” warm days.
According to the city, the total number of cases of leptospirosis that were reported recently raised alarms because there were only three such reported cases every year between 2001 and 2020. Then, between 2021 and 2023, New York City received 15 reports of leptospirosis.
A pest company conducted a study recently that found that there are about 3 million rats in New York City.
Eric Adams, the city’s mayor, said at the end of last year that the infestation of rats was a main reason why many people were leaving the city.
As he said at the time in response to a report that showed the city’s population was plunging:
“Some people who have children and families decide they want to go to a place where their children can play outdoors, larger green spaces, you want to see animals — you don’t see animals except for rats in New York.”
