More and more dengue patients are experiencing diarrhoea this year, which is causing severe complications.

"Diarrhoea has emerged as a highly prevalent characteristic among dengue patients, which we did not see the previous year -- the condition of the patients with diarrhoea is turning worse fast," said Tariqul Matin, assistant director at the emergency unit at Bangabandhu Sheikh Mujib Medical University (BSMMU).

Roughly 40 percent of the dengue patients at BSMMU suffer from diarrhoea along with vomiting.

At noon yesterday, around 28 patients were undergoing treatment at the BSMMU, including the emergency unit and the dedicated dengue unit at the hospital, according to Matin.

BSMMU has around 50 beds dedicated to dengue patients.

Doctors at the capital's Shaheed Suhrawardy Medical College Hospital said the same as Matin.

About 30 percent of dengue patients suffer from diarrhoea, said Khalilur Rahman, director of Shaheed Suhrawardy Medical College Hospital.

"This has become a very common feature of dengue infection this year."

Another common feature among the hospitalised patients is vomiting.

"Dengue patients should take adequate fluid such as oral saline. It will prevent vomiting and the patient's condition will remain stable," Rahman said.

He also advised going to the hospital as the patient will show severe signs of dengue.

Blood in vomit or stool, extreme thirst, and pale and cold skin constitute some other symptoms of severe dengue infection, according to the World Health Organisation.

According to virologists, the observed symptoms such as diarrhoea could potentially be linked to DEN-2 (Dengue serotype-2), which is considered the most severe among all the dengue virus types.

This year, DEN-2 has become the most prevalent serotype, marking a shift from the previous four years when DENV-3 was predominant.

Last week, a government study on 200 patients revealed that three in every four dengue patients were infected with DENV-2.

WHO earlier warned that the DENV-2 predomination may result in higher numbers of severe cases as a result of a second infection with a different serotype.

In the 24 hours preceding 8:00am yesterday, the health directorate reported another nine deaths from dengue. Of the deceased, five were in Dhaka city.

In the same 24-hour period, at least 1,960 dengue patients were hospitalised, according to data from the Directorate General of Health Services.

Dengue has so far claimed at least 537 lives this year and nearly 112,184 were hospitalised, making this the deadliest year since the first recorded epidemic in 2000.

According to DGHS figures, a total of 8,236 dengue patients are undergoing treatment at different hospitals across the country.