The Institute of Epidemiology, Disease Control and Research (IEDCR) has recently confirmed the presence of the virus commonly known as bird flu in the capital's different kitchen markets after three workers were reported positive with H5N1.

They informed the authorities concerned to start cleaning drive to wipe out the virus from the environment.

The detection also prompted health experts to call for a change in what they term 'dangerous' practice of selling and slaughtering poultry just anywhere in the market or open spaces without taking any sanitary measures.

Visiting different markets on Thursday and Friday, it is learnt that Dhaka City Corporation that collects tax from those markets do not disinfect the market.

Workers have been seen working in the filthy environment strewn with chicken giblets and wings in the blood and mud-strained floor.

Hemayet Uddin, a worker of Gulistan Kaptan Bazar market, said he had not seen anyone from City Corporation.

"We clean on our own," he said.

Employees said they never used gloves while cleaning chickens, though experts have repeatedly advised that direct contact with poultry could increase the possibility of infection.

"We just wash our hands (after slaughtering and processing)," said Hemayet Uddin, a worker of a poultry slaughterhouse at a kitchen market in Jatrabari.

He said their slaughterhouse had not undertaken any precautions against the threat of bird flu.

"My sir (owner) did not instruct me to prepare anything," he said.

The chief technical adviser for the Food and Agriculture Organisation Mat Yamage told Bdnews24.com that they always advised through Department of Livestock to disinfect the wet markets.

"It (disinfecting) is very important to arrest the virus transmission," he said adding that that they can clean at least once a week.

He suggested steps to improve sanitation of slaughterhouses as it will be difficult to change the tradition of selling live-birds in Bangladesh.

Coordinator of One Health Bangladesh Nitish Chandra Debnath said there should have been a collaborative approach among all relevant departments.

"The local government ministry should take up the issue seriously at this moment."

Chief health officer of Dhaka South City Corporation Brig Gen Md Abdullah-Al-Harun said they would start the cleaning drive from Sunday.

"We have decided it in a ministry meeting on Thursday," he told bdnews24.com.

He said their staff on the ground had been told to monitor live-bird markets from now on.

He, however, would not comment on why they were delaying the start of the drive.

The first human case in Bangladesh was detected in May 2008 after an outbreak in a poultry farm in March 2007.

But the latest detection is worrying experts as four strains of flu virus – H5N1, H1N1, H3N2 and H9N2 – are circulating in the air and the UN Food and Agriculture Organisation in Aug last year warned of a possible major resurgence of bird flu as a mutant strain of the H5N1 virus is spreading in Asia including Bangladesh.

World Health Organisation's (WHO) influenza expert Dr ASM Alamgir said they still consider H5N1 as pandemic potential virus.

"So, countries should focus on preventive measures," he said adding that slaughterhouse workers should use mask and gloves while slaughtering and processing chickens.

"There should have been a separate room for slaughtering."

He said these issues have been discussed in several meetings, but none of it has been implemented.

"The government could pilot the practice in one or two markets," he said.

IEDCR senior scientist Dr M Mushtuq Husain termed the live-bird market a 'dangerous' place for spreading the deadly virus in the country.

"We should stop it," he said.

"Slaughterhouses should be isolated from public and those involve in slaughtering must wear protective gears like masks, gloves, and apron to prevent the infection.

Due to lack of biosecurity measures such as using solid fences and nets to quarantine infected flocks, and disinfecting footwear, experts say H5N1 is widespread in Bangladesh's poultry farms.

Over two million chickens have been culled since the first outbreak in 2007.

IEDCR that oversees human infections advises people wash egg shells and suggests consuming well-cooked poultry products.

It also urged not to litter giblets and dead birds just anywhere and maintain personal hygiene – cough into the crook of elbow and wash hands with soap often.

The IEDCR director Prof Mahmudur Rahman said we are lucky enough as the strain of H5N1 that circulates in Bangladesh is less virulent, but it can change into another class, which is highly infectious to human.

"You cannot predict anything about the virus circulation," he warned.

According to WHO, the first human infection from H5N1 was detected in 1997 in Hong Kong.

So far 349 people died from the virus.