The number of leptospirosis cases reported in Petaling Jaya until a fortnight ago is 121 cases, out of 382 in the entire Petaling district.
In 2014, the city area only reported 171 leptospirosis cases for the whole year.
Petaling Jaya mayor Mohd Azizi Mohd Zain said this was a worrying development.
"Rats are a major health problem, as they can cause food poisoning and infect people with leptospirosis through their urine, which carries the Leptospira bacteria," the mayor said at the launch of the first Mass Rat Reduction Action Task Force or "Mr Rat" initiative at Section 21 in Seapark.
According to Petaling Jaya City Council Environmental Health director Dr Chitradevi N. Vadivellu, who was also present at the launch, a person infected with leptospirosis would show symptoms such as fever, muscle pain and bleeding in the lungs, which could lead to death.
Seapark is the first place in Petaling Jaya where the initiative has been implemented, focusing on its commercial areas.
During the launch, Mohd Azizi, accompanied by several councillors and Seapark Rukun Tetangga chairman Gan Keng, went on a walkabout to check and place rat poison along the back lanes.
For Seapark's commercial area, council workers used 25kg worth of rat poison in sachets.
Besides placing sachets in the back lanes, the contents of some sachets were sprinkled into the drains.
After a few days, the workers would return to check for dead rats, while placing poison sachets in the residential areas where the rats are expected to move to.
"We also placed our own traps and will forward pest-control complaints to the council when it gets out of hand," said Gan.
He added that the rat issue was a long-running problem in Seapark's commercial area, as there were many restaurants and hawkers, resulting in a lot of food waste.
"This area has just been cleaned two or three days ago, and you could see how dirty the area has come to be, so it is not really a surprise that rats come around," said Gan.