Dengue cases in Bangladesh have crossed the 300,000 mark as the nation grapples with its worst outbreak of the vector-borne disease, media reports said on Monday.

Bangladesh’s overall tally of dengue infections stood at 301,255, with the country logging 1,549 deaths by the viral disease this year, the bdnews24.com news portal reported, citing data from the Directorate General of Health Services.

On Sunday alone, 1,291 new cases of the viral fever were reported, according to the report. A total of 4,949 patients, including 1,127 in Dhaka, are receiving treatment at hospitals across the country.

After August saw 71,976 cases and 342 deaths, a record 79,598 dengue cases and 396 deaths were recorded in September amid the worst outbreak of the disease, while 67,769 cases and 359 deaths were reported in October.

The death toll in the first 19 days of November was 201, while 30,080 new dengue cases were recorded during this period. According to the report, experts blamed a prolonged monsoon, rising temperatures and a lack of effective measures to kill the Aedes aegypti mosquito, the known carrier of the dengue virus, for the outbreak.

It said an alarming surge of the Aedes aegypti mosquito was recorded in a government-funded pre-monsoon survey of Dhaka, fuelling the worst spread of the disease over the past five years. Last year, hospitals in Bangladesh reported 62,382 patients who took medical care for the disease.