Body pain and asthma compel me to stay at home several days in a month. Though I use a mask and sanitizer I have to take medicines,” said Didarul Alam, 35, owner of a poultry named Bhai Bhai Store at Chawkbazar in Chattogram.  

Antibiotics provide only temporary cure – he suffers again and again.

Many of the poultry dealers in the city’s markets are suffering the same health problems. Some think it is a seasonal sickness.

I have had fever and cough for a couple of months and have painkiller type medicines to get relief, said Jamal Uddin, 55, another poultry dealer in the same market, who has been involved with the business from childhood with his father. I cough all the time, but there is not much fever or headache, he said, adding that the sickness has not affected him much.

Researchers said, fever and cough are common symptoms of the highly pathogenic avian influenza known as A (H5N1) virus, which causes sporadic infection in humans. Chicken is the commonest host of this zoonotic disease. The World Health Organization says avian influenza has a high fatality rate and can lead to a pandemic.

Researchers at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) have conducted a year round study in Dhaka and identified three human cases during 2012-2016 while they had influenza-like symptoms.

The virus spread

Bangladesh reported the first HPAI (H5N1) outbreak in poultry in March 2007 and by 2022 more than 560 outbreaks were reported. Commercial chicken farms were mostly the worst affected. The virus mainly attacked chicken but humans suffered sporadic infections.

A research paper titled Association of Biosecurity and Hygiene Practices with Environmental Contamination with Influenza A Viruses in live Bird Markets, Bangladesh

surveyed 800 poultry shops all over the country in 2015 to describe biosecurity practices and collect environmental samples. They found that shops that slaughtered poultry, kept poultry overnight, remained open without rest days, had uneven muddy floors, held poultry on the floor, and housed sick and healthy poultry together were more frequently positive for influenza A viruses. The result was environmental specimens from 205 shops were positive for influenza A viral RNA, 108 were positive for the H9 subtype and 60 were positive for H5 subtype. Meanwhile, 37 influenza A positive shops had samples that were not subtype with H5, H7 and H9 primers.  

Assuming Bangladesh can be a hotspot country of Avian Influenza virus and transmission from poultry to humans, Dr. Sukanta Chowdhury, one of the scientists from icddr,b - a partner at STOP Spillover - a global project focused on preventing the spillover of viral zoonotic pathogens and author of the paper, said unplanned live poultry markets with poor bio-security and personal hygiene where both consumers and sellers come close to the birds create a, high risk virus transmission. “We have to emphasize the biosecurity of poultry farms to reduce infection in poultry at farm level which might spread infection to the poultry market,” he added.     

Dr. Chowdhury also said that regular surveillance both poultry and humans using the one health approach could help understand the present situation including detection of novel avian influenza strains and reduce its casualty.

More research studies are needed to develop and design interventions, he added.

Risk to public health

Nipah and avian influenza are two zoonotic diseases whose epidemiologists have been documented in Bangladesh.

There is limited information about other potential zoonotic diseases and it has been difficult to develop and design locally accepted and effective interventions to control zoonotic disease transmission.

A research paper called Major zoonotic diseases of public health importance in Bangladesh said wild birds including shore birds, gulls and domestic ducks act as a reservoir for HPAI. Since 2001, Bangladesh has experienced zoonotic disease outbreaks including Nipah, avian influenza, pandemic H1N1 and Covid-19.

The study also said that some other zoonotic pathogens may emerge including Ebola virus, Coronavirus, Middle East Respiratory Syndrome, Kyasanur forest disease virus and Crimean-Congo hemorrhaegic fever. Close interaction of people with domestic and peri-domestic animals makes them prone to zoonotic pathogens which need to be considered a public health threat.

Prof Dr Sharmin Chowdhury, Director of One health institute of Chittagong Veterinary and Animal Science University said the intensification of animal-human and ecosystem interfaces increases the risk of zoonotic diseases spreading. The application of a one-health approach is essential for addressing this health threat in Bangladesh. It is also important for public health policymakers to know the risks and emergence of zoonotic diseases.

According to WHO, In order to achieve better outcomes in public health, One Health as an approach to designing and implementing programmes, policies, legislation, and research that involves multiple sectors communicating and working together.

Emphasizing on regular surveillance in villages and peri-urban areas, she also said that it is high time to pay attention on zoonotic diseases especially avian influenza and its subtypes including H5N1, H5N2, H7N9, and H9N2, because of having possibility of community transmission.

Prof Dr Sharmin a Veterinary Epidemiologist and Zoonotic Disease Specialist said a few molecular and immunologic studies have been conducted on zoonotic diseases. More studies are needed to understand the burden of zoonotic diseases and its impact on public health and to develop interventions..

According to World Health Organization, in the last three decades, more than 30 new human pathogens that attack humans have been detected, 75% of which come from animals. Zoonotic diseases, pose a growing public health threat.

The World Organisation for Animal Health (OIE) said that more than 40 countries reported high pathogenicity avian influenza subtypes in 2021. A high level of surveillance is needed during the high-risk period of the disease, especially October to April, to ensure strict biosecurity measures are in place and outbreaks are reported in a timely manner, it added. At present in Africa, Asia and Europe, avian influenza is a threat to food security and livelihoods as well as economic stability.

More poultry shops are opening, which results in more infections of poultry workers. Photo/ Shehenoor Akther Urmi

Bangladesh reported the highest number of H5N1 outbreaks in poultry and wild birds from 2007 to 2019. In a report The Pattern of Highly Pathogenic Avian Influenza H5N1 outbreak in South Asia Dr Sukanta Chowdhury and other experts explain the present evolution of the avian influenza virus with potential to become of public health interest. They emphasize the need for strong regional collaboration and cooperation for pandemic influenza preparedness planning and response in South Asia.

Government initiative

"We do surveillance in the big cities and fix the slaughter place which is not abided by the poultry businessmen and workers,’ said one Deputy Director in the Department of Livestock under the Ministry of Fisheries and Livestock.

Speaking on the condition of anonymity, he added “The ministry is aware about the avian influenza virus but sometimes it becomes impossible to continue the surveillance of the outskirts of the cities.”

The official also said that the number of poultry shops are increasing and the virus infected more poultry labour which had an impact on public health. But this was not being identified adequately due to lack of knowledge about the virus.

(This story was produced with the support of Internews’ Earth Journalism Network.)