Poultry farming is contributing to the growth of the national economy and it is now considered as an important sector in creating both direct and indirect employment opportunities, improving food security and nutrition, as well as contributing to the country’s economic growth and reducing poverty in this country. The total investment in the poultry sector is about BDT 35,000 crore (USD 4.12 billion) and it has created employment opportunities for over 6.0 million people, most of them being youth and women (BPICC, 2020). There are about 70,000 commercial farms, 100 breeder farms & hatcheries, 8 grandparent stock farm and over 200 feed mills in this country (http://wpsa-bb.com/poultry-at-a-glance/, BAB). The breeder farms and hatcheries produce about 16 million and 1 million Layer day-old chicks per week. However, the recent COVID-19 pandemic situation has seriously affected the entire poultry value chain and one estimation found that it resulted in about 35% drop in day-old chicks (DOC), eggs and meat production in our country (BPICC,2020). Therefore, private poultry sectors, service providers, government and other stakeholders are applying suitable coping mechanisms to overcome the situation.
Although poultry farming has become attractive income sources for the people, especially the unemployed youth and women in our country, they are facing the problem of disease outbreaks in broiler farms that cause high mortality, lower growth and higher FCR. Among the diseases, poultry practitioners and consultants are suspecting about the incidence of Inclusion Body Hepatitis (IBH) disease as an emerging disease in this country. Therefore, ACI Animal Health conducted a quick assessment to know about the prevalence of the Inclusion Body Hepatitis (IBH) disease and its economic impact. Nine experienced and qualified technical experts were selected as participants of this quick assessment study who are directly associated and involved in the poultry farming of Bangladesh. They were selected from different geographical locations and different organizations. The respondents are from universities, private sectors, private practitioners and the Department of Livestock Services (DLS). This report can be a good source of information to understand the current situation of IBH disease in Bangladesh.
About Inclusion Body Hepatitis (IBH)
In poultry, Inclusion Body Hepatitis (IBH) principally affects broilers up to five weeks of age but it has also been reported sporadically in layers and broiler breeders. IBH is a very much pronounced and important disease in broiler especially sensitive to high growth broilers. IBH is very important for broiler farmers and it causes tremendous financial losses because there is no corrective measure that can be taken if the symptoms are exposed. IBH is an acute disease of young chickens caused by fowl adenoviruses (FAdVs). It was first described in 1963 in the USA (Helmboldt and Frazier, 1963). Then, the disease has been reported in many countries worldwide. It is a sporadic disease condition caused by several serotypes of fowl adenoviruses (Franco et al., 1974; Ferran, 2000; Fitzgerald, 2008; 2006; Dar et al., 2012). Horizontal and vertical transmission plays an important role in IBH (Noormohammadi,.2019). It is an emerging poultry disease in recent times characterized by sudden onset with a high death rate (Memon et al.,2006). The disease was first described in young broilers in Angara Goth, Pakistan, during the year 1987. Thereafter, it spread throughout Pakistan (Anjum et al.,1989) as neighboring countries in Asia like India (Dahiya et al., 2001). During the last decade, several novel diseases, which affect the poultry with variable consequences, have emerged. Among these, IBH has a significant position (Fernandez,2003; Kataria et al.,). Several different serotypes have been isolated from disease outbreaks, but they may also be isolated from healthy chickens. In chickens less than 6 weeks of age, the mortality usually varies from 2–40 percent. Under certain conditions, however, mortality up to 80 percent has been recorded based on the pathogenicity of the virus. Peak mortality usually observed within 3–4 days is followed by cessation within 9–14 days. The feed conversion ratio may be affected in addition to the reduction in weight gain (Cowen, 1992). In our country, sudden mortality is usually seen in chickens <6 weeks old and as young as 4 days of age. In recent years in Bangladesh, it’s assumed that IBH prevails in poultry.
Status of IBH in Bangladesh – Field observation
Over the last two decades, an increasing number of IBH outbreaks have been reported in different geographic locations stressing the worldwide spread of the disease. It is now suspecting that there is a prevalence of IBH, and it is an emerging disease of poultry in Bangladesh. A result of quick assessment study from the field found that 100% of respondents believe that there is a prevalence of IBH in this country and the disease affects young birds (<6 weeks old) especially broilers and as young as 4 days of age. About 75% of our respondents believe that the age at which poultry is most affected by IBH is between 16-30 days. The other 25% says that it’s between 1-15 days. No one reported the incidence of this disease found in layers or breeders. It is economically important due to significant high mortality in young broiler birds that may reach up to 40%. Mortality normally ranges between 2% and 40% in IBH. Mortality rates also vary depending on the pathogenicity of the virus and infection with other viral or bacterial agents. Signs associated with diseases caused by other pathogens (e.g. bacteria, fungi, or viruses) commonly occur if birds are immunosuppressed. Flocks affected with IBH virus often have an abrupt onset of mortality, and individual chickens may show non-specific clinical signs such as lethargy, huddling, ruffled feathers and yellow, mucoid drippings due to excess bile acids.
According to the respondents, clinical lesions in the suspected cases of IBH are Hydro pericardium (67%), Hepatitis or enlarged liver (67%), Yellow or pale liver (44%), Necrotic foci on the liver (33%), Pale & inflamed kidney (33%), Regression of lumen/ Hemorrhages (11%), Hemorrhage on muscle & gizzard erosion (11%), Water accumulation in the head (11%) and Sudden mortality (22%). 50% of our respondents think that the percentage of farms affected by IBH in our country is 1-5%, while 25% think it is 6-10%. 12.5% of the respondents think it’s below 1% and the others think it ranges from 11-20%. The intensity of economic impact caused by IBH is considered “moderate” by 50% of the respondents and “negligible” by the other half. The interesting finding of the study is that none of the participants mention the confirmed case by any laboratory test (by molecular or histopathological examination). Most of the respondents (75%) think that this is an addressable concern. Therefore, further investigation is needed for the confirmation of IBH disease. Considering it as an emerging disease in the poultry industry, controlling the disease should be done rapid diagnostics along with proper vaccination.
It has been suspected from the observations that IBH disease has been prevailing in Bangladesh. But there hasn’t been any confirmation on the matter yet. Therefore, further investigation is needed urgently to confirm the prevalence of IBH and its effects in the poultry industry in this country. Currently, IBH is considered an emerging disease of poultry. Concurrent infections of other immunosuppressive viruses like Infectious Bursa Disease Virus (IBDV) and Marek’s Disease Virus (MDV) significantly increase the severity of infection in field conditions. Good hygiene, management practices, strict biosecurity and effective vaccination program are of paramount importance in preventing the disease. We should consider the autogenous vaccines prepared from the prevalent serotype of FAdV and it is practical and financially justifiable for the prevention and control of this disease.
Dr. Md. A. Saleque
Chief Technical Advisor, ACI Animal Health