A 24-year-old man died of dengue in a city hospital on Thursday, taking the toll in the Calcutta municipal area this year to six.

Li Seong Kwong died of “septic shock and multi-organ failure in dengue fever, with hepatitis B-related chronic liver disease”, an official of AMRI Hospital-Salt Lake said.

Kwong, a resident of Matheshwartala Road in Tangra’s China Town, was admitted to the hospital on October 31. He died at 6.30pm on Thursday, the official said.

Kwong’s death takes the dengue toll in the Calcutta municipal area to six this year. All the deaths were reported after September.

There has been a sudden spurt in the number of dengue patients in the city and neighbouring areas over the past month and a half, officials of Calcutta, Howrah and Bidhannagar municipal corporations said.

At least 2,500 cases have been reported in Calcutta since January, of which 1,700 were reported in the past 45 days. In Howrah, more than half of the 1,500 cases were reported during this period.

In Bidhannagar, too, nearly half of the 800 cases have been reported since late September.

“The number, 2,500, in a city as big as Calcutta is not worrying. But the sudden spurt and the deaths have us worried,” a Calcutta Municipal Corporation doctor said.

A cop from the city’s northern outskirts who delivered a baby last month and a homemaker from Howrah died of dengue on Wednesday and Tuesday, civic officials from Howrah and Bidhannagar said.

Runu Biswas, 28, a Calcutta police constable posted at Amherst Street police station, died at a private hospital off the Bypass around 6am on Wednesday.

She had been admitted to a New Town hospital on October 25 with fever, a relative said.

Keya Goswami, 26, died at a private hospital in Howrah on Tuesday. A resident of Chatterjee Haat, Goswami had been down with fever since October 29.

She had been admitted to a nursing home in Santragachhi and shifted to a private hospital along Andul Road on Monday after her condition worsened.