Rail construction in Tel Aviv may be behind a surge in rat-related disease cases

Hospitals in the greater Tel Aviv area have reported a significant rise in murine (flea-borne) typhus and leptospirosis cases in the last several years. Both diseases are spread by rats, with patients reporting seeing more of the rodents in neighborhoods, playgrounds, gardens, and even homes.

Physicians speaking to The Times of Israel have expressed concern about sanitation problems and the likely possibility that the above-ground rat population has surged as a result of the digging and construction of new mass transportation systems in Tel Aviv and surrounding cities.

Prof. Yasmin Maor, head of the infection diseases unit at Wolfson Medical Center in Holon, just south of Tel Aviv, said that her hospital treated 16 cases of murine typhus in 2022 and 2023 as compared to just one in the five years prior.

“This is a very high increase. There is something definitely going on epidemiologically,” she said.

The Health Ministry told The Times of Israel that in Bnei Brak, an ultra-Orthodox city east of Tel Aviv, there were nine reported cases of murine typhus in 2023 and two in 2022.

Prof. Galia Grisaru-Soen is the director of the pediatric infectious diseases service at Dana-Dwek Children’s Hospital, which is part of Tel Aviv Sourasky Medical Center-Ichilov Hospital. She told The Times of Israel that she is aware of one adult case of murine typhus, two adult cases of leptospirosis, and three cases of children with leptospirosis in recent years at the medical center.

“I suspect that this is just the tip of the iceberg because these diseases need specific diagnostic testing. If somebody has a milder case and they don’t see an infectious disease specialist, the diagnosis will most probably be missed,” Maor said.

Maor, who treats adults, said the 16 cases of murine typhus at Wolfson involved patients in their late teens up to their 70s.

Murine typhus is caused by the bacteria Rickettsia typhi and is spread to people when they come in contact with fleas that have bitten rats or other animals that are infected with the bacteria.

Human infection happens when the infected flea bites a person. As the flea feeds, it also excretes waste, which is known as “flea dirt.” The flea dirt containing the bacteria can enter the open bite or another wound on the body. A person can also breathe in flea dirt or rub it into their eyes and become infected.

Leptospirosis, caused by a bacteria of the genus Leptospira, is spread through the urine of infected animals, including rats. Humans become infected when they come in contact with water, soil, or food contaminated with the urine of these animals. The bacteria can enter a person’s body through contact with broken skin and mucous membranes in the eyes, nose and mouth. A person can also become infected if they drink affected water.

Neither disease can be communicated from one person to another. However, there have been spurts of murine typhus in Israeli cities in the past, as well as outbreaks of leptospirosis in northern Israel’s waterways.

While some people infected with the Rickettsia typhi bacteria may not be symptomatic, many develop symptoms generally associated with the flu, such as a high fever, body aches, nausea, vomiting, loss of appetite, and coughing. Some people also develop a rash. Although murine typhus is not usually fatal and can be treated with antibiotics, some cases can be serious and land patients in the intensive care unit.

“Sometimes we can see complications like encephalitis, or the involvement of the lungs or heart, or multi-organ failure,” Maor said.

The symptoms of leptospirosis are similar to those of murine typhus. The one major difference is that those infected with the Leptospira bacteria may have jaundice (yellow eyes and skin).

Grisaru-Soen said that one of her pediatric patients needed intensive care for an extreme version of leptospirosis called Weil disease, which involves renal insufficiency, hemorrhage, and respiratory distress.

“Fortunately, all the children who were hospitalized, including that one, recovered,” she said.

Both Maor and Grisaru-Soen suspect that the increase in cases of these two diseases is due to changes in the urban environment that would bring rats closer in contact with humans and their environs.

“It reflects a lack of control of the rat population, whatever the reason. The rats have shifted from one place to another and the situation is not well controlled,” Maor said.

Grisaru-Soen reported that the children with leptospirosis all lived in south Tel Aviv, an area known for suboptimal public sanitation.

“These are young children between the ages of three to 10 who play outside in the yard or street. Their parents reported to us that they saw a lot of rats around the buildings where they live,” she said.

“In our region, you see many more rats in the streets than before. About half of the patients told us that they had some contact with rats in their vicinity. Either they saw rats in their house, in the garden around the house, or when they were walking in the street,” Maor said.

Maor added that although she has no direct proof, she said that it is plausible that the increase in rat sightings is a result of the subway and light rail construction projects that have been going on in the metropolitan Tel Aviv area in recent years.

“We saw in our data that patients with the typhus infection lived closer to the train lines compared to patients who didn’t have the diagnosis but had similar symptoms. But this is just an association and I’m not sure if this is an explanation, but it’s possible,” Maor said.

“We are sharing the statistics we have now to raise awareness among primary care physicians who may not recognize that patients with these non-specific symptoms may have these diseases and need specialized testing. We plan on publishing the data at some point soon,” she said.

The Health Ministry, which receives reports of every case of an infectious disease, said that since these are rat-borne, it is up to municipal sanitation departments to control the infestations. The Tel Aviv-Yafo municipality insisted that it has effective systems in place.

“The Sanitation Department of the Municipality of Tel Aviv-Yafo has maintained an innovative model for years, where a monitor is employed on behalf of the Construction Supervision Unit. This monitor visits various construction sites and enforces regulations concerning pests, primarily rats and mosquitoes,” a spokesperson said.

“The municipality’s extermination unit conducts proactive measures in public spaces and collaborates with the inspectorate to issue requirements for cleaning yards of debris and objects that serve as hiding places for rats. Proactive and targeted extermination efforts are also undertaken in areas suspected of rat infestation, such as burrows, sewers, markets, and beaches,” he added.

While the responsibility for controlling the rat population belongs to local governments, individuals can try to avoid being infected by staying away from the rats they see, as well as the areas where they are spotted.

“This is admittedly hard if rats end up in your home, which raises your exposure risk,” Maor said.

She also warned that with murine typhus, the issue is the fleas rather than the rats.

“You don’t need to actually see the rat near you. You just need to be in direct contact with a flea that bit the infected rat, fell off, and then jumped on you. Wearing insect repellent can help,” she said.