Aquatic health in the new millennium - An Intervet Editorial

Intervet editorial, translated and reprinted from Industrial South America (ISA), Vol. 1, No. 5, Oct 2001, p.65-68

During the last two decades, aquaculture has been one of the fastest expanding sectors of the agrifood industry. To date, this area has achieved a 1998 world production of about 40 million metric tons, valued at over US$50 billion and with average annual growth rates of 10 to 20%.

Latin America has had a very small portion of global production, about 2% by weight, 5% by value. However, it is a very important region as it tends to produce highly valued species, like salmon and shrimp, and is growing at a rate faster than any other region.

The rapid increase in aquaculture worldwide, particularly in finfish and shellfish culture, is a result of both area expansion and production intensification. Under these conditions, the prevalence and spread of infectious diseases have increased as a result of higher infection pressure and decreased resistance of the aquatic animals. Accordingly, the effective control of infectious diseases has become more and more important.

Today, vaccination has become the dominant strategy for effective disease control in commercial fish farming and Intervet plays a significant role in this research and development (R&D) effort, as well as in the subsequent commercialisation of fish vaccines and vaccination strategies.

Aquatic animal health

Intervet International, the Dutch multinational animal health company, is currently ranked number three in the world. The corporation is dedicated to the R&D, production and marketing of innovative, high quality animal health products and feed additives for all farm and companion animal species, including vaccines, antiparasitics, anti-infectives and endocrine products. 

Intervet is also a pioneer in state-of-the-art aquatic animal health (AAH) products. It has consistently been at the forefront of technology in AAH vaccines and disease prevention, and has grown hand in hand with the rapidly developing aquaculture industry. Intervet has three specialised AAH R&D centres, each located in a major aquaculture production area. Each centre brings together multi-disciplinary teams in biotechnology, microbiology, immunology and aquatic veterinary science.

All this makes Intervet ideally placed to act when a new pathogen is discovered or when vaccine development and tests are required for any aquaculture species. Intervet is fully committed to the development of new preventive measures to tackle the most devastating diseases, in ways that are safe for the environment.

Diseases in aquaculture

From the time man started to culture fish, fish diseases changed from being an interesting phenomenon to an important socio-economic problem. Infectious disease is considered to be the industry's single most important cause of mass mortalities and economic losses. Therefore, effective disease control is consequently regarded as the single most important cost factor after feed. A range of infectious organisms including bacteria, viruses, protozoan and metazoan parasites, and fungi causes disease in fish.

Most economic losses related to diseases are caused by mortality and reduced growth. Estimates from various organisations have indicated that approximately 50% of all fish and shrimp put into cages and ponds are lost due to disease before they reach market size. The actual economic losses in the aquaculture industry worldwide are estimated to be about US$8 billion per year, which is roughly 15% of the world's farmed fish and shellfish value.

Prevention better than cure

While under certain circumstances antibiotics can provide a useful means of helping to control some bacterial diseases, there are many problems associated with their use. An important side effect of the use of antibacterial drugs in aquaculture, apart from residue problems and increasing customer concerns, is the development of drug resistance among the bacterial fish and shellfish pathogens. Furthermore, there is no effective chemotherapy for the control of viral diseases. It is against this background that vaccination, based on effective vaccines and vaccination strategies, can and will play a most important and increasing role in aquaculture.

Achievements of vaccination

Although fish vaccinology is still in its infancy, the achievements that have been reached and to which Intervet has significantly contributed are noteworthy, both scientifically and economically. Years after the first attempts to vaccinate fish, successful immunisation programmes against viral and bacterial diseases leave little need for chemotherapy, and provide evidence as to how aquatic animal diseases can be effectively controlled without the use of anti-microbials. Nowadays, virtually all salmon and rainbow trout are vaccinated against all major diseases before being transferred to the sea. Indeed, the growth in salmonid production over the last five years would not have been possible without the use of effective vaccines.

A growing market

Aquaculture is an increasingly significant and growing market for life-science products. With a combination of improved AAH management, better sector planning, increased investment in marketing and product development, the introduction of new species and production technologies, and the greater use of breeding programmes, the aquaculture sector is expected to double or triple in size by 2015. A much greater range of authorised, ecologically sound, effective and preventive AAH products will be essential if this is to be achieved.

In conjunction with improved management methods, vaccines will become the most dominant disease control strategy in industrial fish farming, along with diagnostic kits, hygiene chemicals, anti-parasitics, reproduction enhancers and anaesthetics. In contrast, the use of other therapeutics is likely to continue to decline.

Intervet is a dominant player in the world aquaculture vaccine market. With the company's R&D centres, vision and commitment in place, the future looks bright.