The number of leptospirosis cases has tripled in the past year in New York City, and four people have died from the bacterial infection that is transmitted through urine.
The bugs that carry the bacteria — cobras, capybaras, skunks, etc. — are common animals that are present in New York.
While leptospirosis can be fatal, people who are sick enough to develop symptoms often recover within a week.
How does it spread?
Leptospirosis has three possible routes of transmission: mosquito bites, rodents and horses.
The bacteria thrive in warm weather months such as the summer months in our region, says Dr. Matt Barnes, the director of epidemiology in the department of infectious diseases at New York University Langone Medical Center.
Conditions where they thrive include certain areas, such as the southern Bronx, the Westchester area north of Yonkers, and the Delaware area. But in New York City, leptospirosis is most common around the UES, Lower Manhattan and upper Manhattan.
What causes it?
The organism first appears as a mild illness that can go for a week without symptoms, but when left untreated, infection can cause severe symptoms.
Leptospirosis can cause back pain, a fever, swelling of muscles, swollen lymph nodes and even death, Barnes says.
“In the majority of cases, it goes away on its own after the fever subsides, but some people will have a severe case of the disease.”
What can be done?
Barnes recommends that you see a physician if you experience any of the symptoms of leptospirosis, including fever, back pain, muscle swelling and muscle aches, although he says it’s best to see a physician for treatment if symptoms are less severe.
Barnes also recommends that your physician treat leptospirosis with antibiotics. He says that antibiotics work best when taken before symptoms appear, but that they can be effective on their own and that anyone in the hospital should be treated with antibiotics for three days after being treated.
Is it uncommon?
Leptospirosis is rare in the United States. In 2012, there were only 483 cases reported to the Centers for Disease Control and Prevention in the U.S. and 2,781 confirmed cases worldwide.
Symptoms range from mild illnesses lasting one to three days to deadly infections with fatalities in only one in 10,000 cases, according to the CDC.
Who is most likely to be infected?
Leptospirosis, also known as Leptospira, is spread through urine and stool of infected people.
Barnes says that while it can be spread to humans, mosquitoes are the most likely source of infection.
“You can get it from a mosquito, but most of the time it is only from infected people,” he says.
How the cold virus spreadr mosquitoes
Wendy Tumelty and J.M. Crain contributed to this report.