Vaccination: A key way to prevent Newcastle disease in poultry of Nepal

Abstract

Nepal is a country with variation in topography and diverse climatic zones. Agriculture is a major occupation for majority of Nepalese engaging 66% of total population in farming and Poultry farming is integral part of the agriculture in Nepal. Nepal has long history of traditional poultry keeping. Poultry are the important source of valuable dietary proteins and rural cash income. In recent data, about 72 million chickens and 400 thousand ducks are present which include commercial, small holder and backyard type of farm. Poultry sector is an emerging industry engaging and employing 70,000 people directly contributing about 4% in National GDP. In present days, the traditional poultry farming is replaced by commercial farming. But the challenge and constraints on poultry sector are increasing day by day. Outbreak and spread of emerging infectious disease is headache in poultry farming. Various disease like Avian influenza, Newcastle disease, IBD, IB, ILT, coccidiosis, Avian Mycoplasmosis, Fowl typhoid, Fowl pox etc. cause serious economic loss in poultry industry. Newcastle disease is common and spread throughout the country having higher incidence in the summer which is caused by avian paramyxovirus type-1 of Paramyxoviridae. Vaccines are important tool for prophylactic measures. In many countries, vaccination against ND is routinely practiced for prevention and control of disease and types of vaccines and vaccination schedule vary according to potential threat and virulence property of the field challenge virus. There is big challenge for vaccine researchers, manufacturers and scientists for development of effective vaccine against Newcastle disease. In this paper, we will discuss about present status of Newcastle disease and Vaccine produced in Nepal and Vaccination protocol to prevent spread of Newcastle Disease in Nepal.

Newcastle disease burden in Nepal and efficacy of Tablet I-2 vaccine in commercial and backyard poultry production

“…Vaccines were tested at 4°C and 37°C. Infectivity titers (EID 50 ) were measured at various time intervals [(4, 7, 10, 14, 28) day, (2-6) month] to assess efficacy and stability of the vaccines. The EID 50 was measured in SPF egg with the procedure described by OIE guidelines (42).…”

“…Damage is more profound in backyard poultry production in a developing countries like Nepal, where it accounts for 45% of total poultry production and most of the people live under poverty line (5). There were more than 90 reported cases of ND outbreaks in Nepal in 2018, with over 74,986 birds being affected (6). ND might be responsible for over 7% of total poultry mortality in the country (7, 8).…”

Newcastle disease burden in Nepal and efficacy of Tablet I2 vaccine in commercial and backyard poultry production

“…A single dose of Ranigoldunga™ at day 7 will be enough to protect short cycle broiler breed such as Cobb 500 that have turnovers in 45 days. Currently, general practice is to give three different doses of ND vaccine(s) at day 7, 18, and 22 [6], considerably increasing the cost of immunization. Differences in vaccine efficacies observed between the two field trial sites could be due to inefficiencies in vaccine delivery (such as eye dropper inaccuracies) and/or immune-compromised chickens with morbidity caused by other infections (S9 Table in S1 File).…”

“…The live ND vaccines are also mostly of lentogenic and mesogenic strains that require cold chain transportation, and currently only one I-2 strain based vaccine produced by the National Vaccine Production Lab (NVPL) is used for the vaccinating backyard poultry [6]. We believe vaccines like Ranigoldunga™ can be used for commercial and backyard poultry and increase the accessibility of immunization against NDV in places where maintaining cold chain for transportation and storage is a challenge.…”

“…In a developing country like Nepal, backyard poultry accounts for more than 45% of the total poultry production, and ND is one of the major diseases impacting this sector [5]. There were more than 90 reported ND outbreaks in Nepal in 2018 with over 74,986 birds being affected [6]. Overall ND is responsible for more than 7% of total poultry mortality in the country [7,8].…”