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Newcastle Disease Suspected in Sri Lanka

by 5m Editor
22 November 2010, at 10:07am

SRI LANKA - It is suspected that Newcastle disease has hit the country.

Recent, well illustrated reports in the media appear to suggest a resurgence of Ranikhet disease (Newcastle disease) in poultry, according to The Island of Sri Lanka. This is indeed a disturbing revelation. Could the current resurgence of Newcastle disease be attributed to certain weaknesses now in the administrative and extension services, which had prevailed for so long?

In the backdrop of other unresolved disease problems such as salmonellosis to contend with and the prevailing shortfall in production with the consequent escalation in price of eggs and poultry meat, the industry cannot take another blow of a devastating but yet preventable disease. It must not be forgotten that today, chicken meat is not a rich man's dish, being the cheapest of all meats, and the egg is the cheapest source of protein of high biological value.

More than half a century ago, Newcastle disease devastated entire flocks of poultry. It is a disease caused by a virus. There is no treatment and mortality rate is high, often nearing 100 per cent. It can be effectively prevented by vaccination. Newcastle disease is not communicable to man.

In Sri Lanka, the disease was effectively controlled by vaccination, and its control is considered to be a major factor that contributed to the transformation of the backyard and small farmer poultry systems that prevailed then to the large scale commercial poultry industry today.

Newcastle disease then became a part of history.

A vaccine against Newcastle disease was first produced in Sri Lanka in 1953. It was in liquid form and being a live virus vaccine using a chick embryo propagated seed virus had a short shelf life. To overcome this problem, in 1960 the vaccine was presented in solid form by freeze-drying and distributed together with a diluent, to be dissolved before use. This made the vaccine very popular and its use widespread. Later, with the growth of the broiler industry, a milder vaccine was developed which could be given even to day-old broiler chicks.

A considerable amount of research was done at the Veterinary Research Institute Peradeniya on the efficacy of the vaccine by various routes (injection, oral-in drinking water, eye drops) and the stability of the vaccine, both in the freeze dried form and after dissolving, at various temperatures was ensured.

Thus during the past half century, billions of birds have been saved from Newcastle disease as a result of vaccination.

The Island reports that originally, the vaccine was made using an Indian seed virus, described by poultry scientists as a 'hot strain' – meaning that whilst conferring good immunity it also caused some casualties. Later a 'less hot' strain was substituted with satisfactory safety and immunity.

In 1986, Newcastle disease vaccine produced at the VRI was subjected to a rigorous testing. Excellent results were obtained. Rigid protocols were developed for the quality control of every batch of vaccine prior to release. The vaccines were provided to poultry farmers directly or through veterinary surgeons, free of charge. The locally produced vaccines were recommended for commercial layers and broilers only, which constituted the bulk of our poultry population. Breeder flocks, on the other hand need a vaccine prepared using SPF (specific pathogen-free) eggs.

Having established the usefulness of the vaccine for commercial layer and broilers, which constituted the bulk of Sri Lankan poultry, steps were taken to increase production with the vision of an expanding ;poultry industry. In 1992, with assistance from the Asian Development Bank funded Livestock Development Project, personnel engaged in Newcastle disease vaccine production were provided further short term training in Malaysia to update their skills. New freeze-drying equipment with double the production capacity was procured under this project and an officer was trained at the manufacturing company on its use and maintenance.

With the success story of control of Newcastle disease using vaccines produced in Sri Lanka for nearly four decades in the background, a bright idea suddenly emerged, from above, that the Newcastle disease vaccines produced in Sri Lanka were not up to 'international standards'. Sri Lanka never had export in mind, nor was the vaccine used in the microscopic minority of breeder (parent and grandparent) stock. As an outcome, a committee was appointed to report on the vaccine. Without subjecting the vaccine to any further tests and no consultation with the actual users or the field staff, in a rapidly churned out report it was recommended that production be discontinued. This was readily implemented.

Thus the investment on training personnel and the purchase of equipment were all rendered useless. This was followed by the influx of Ranikhet vaccines imported by the private sector from several countries. The control of Newcastle disease continued effectively for the past over 15 years or so, with imported vaccines, which of course the farmers had to buy at a price. The current price ranges between three and six rupees (LKR) per dose, depending on the type of vaccine.

If Newcastle disease raises its head again, it could be disastrous to the poultry industry, continues The Island report. The Department of Animal Production and Health should therefore view the media reports seriously and take such steps as necessary to avoid disaster.

  1. Are the reports merely isolated instances blown up, or is it widespread – an assessment of magnitude?

  2. Since Newcastle disease was only a thing of the past, have farmers reached a state of complacency and skipped vaccination? The fact that farmers have to purchase the vaccine at the current price may be a discouragement.

  3. The two vaccines produced locally were able to provide immunity to broiler chicks as well as to layers through their productive life. Do the imported vaccines that use milder strains provide immunity of similar duration?

  4. Are the imported vaccines properly stored and do the users (farmers themselves) understand and follow the proper instructions?

  5. Are random samples of imported vaccines tested on arrival?

  6. At the time of writing, none of the authorised importers had any stocks of Newcastle disease vaccine, presumably due to panic buying following media reports. What mechanisms are in place to ensure that vaccines are always available to ensure that every bird is immunised at the correct age?

  7. Diseases of cattle and buffaloes considered to be of economic importance are controlled by national programmes where vaccines, locally made or imported by the department, are supplied free of charge. The economic gains have become evident. It is suggested that among the poultry diseases Newcastle disease be placed on the same footing, and a locally made vaccine be supplied to the vulnerable segment of the industry – the small and medium scale farmer. Their contribution (around 40 per cent) is significant and their survival deserves support from the self-employment point of view. Their products are more likely to be consumed in the rural sector. The poultry giants on the other hand could continue to use imported vaccines.

  8. With the poultry in private hands and the Department's role being purely regulatory, an officer should be assigned the task of monitoring the industry. There was in fact, such a person, but unfortunately due to the prevailing scheme of promotions this officer had to lay aside decades of experience and switch to an administrative position or else, be denied the promotion. Now, there appears to be a vacuum.

Complacency on the part of authorities could spell danger to the poultry industry, concludes The Island.

Further Reading

- Find out more information on Newcastle disease by clicking here.