Enhancing proactive prevention of avian influenza

Posted at: WEDnesday - 15/02/2017 15:47 - post name: Cộng tác viên

Dr. Nguyen Van Cam - The Vietnam Union of Science and Technology Associations

Dr. Nguyen Van Cam - The Vietnam Union of Science and Technology Associations

Not being subjective and neglectful of avian flu before, during and after the Lunar New Year is an urgent requirement implemented by Veterinary and localities to control the spread of the disease. To be able to comprehend the situation as well as the scientific approach in order to prevent effectively, reporter of vusta.vn had an interview with Dr. Nguyen Van Cam - a member of The Vietnam Union of Science and Technology Associations.

Avian influenza occurring every year has a great influence on the economy, daily life, and public consumption. Could you share the cause, speed and movement of avian flu in our country in recent years?

Avian influenza has occurred in our country since 2003, resulted from the influenza virus A/H5N1. The influenza virus in general and influenza A/H5N1, in particular, are constantly changing. First, influenza A/H5N1 clade 1 appears, later are the appearance of many other clades such as clade 2.3.4; a, b, c; even clade 7, etc. Each clade has certain antigenic changes, thus if there is no vaccine having antigen suitable for a certain type of virus, it will be little or ineffective. Vietnam has imported and used many types of vaccines, including Re-1 vaccines initially being very effective, and then importing Re-5 and now Re-6 due to the virus mutation.


About the speed and development of avian flu in our country in recent years: Since 2003, highly pathogenic avian influenza (HPAI) has appeared in Vietnam, starting in the North and then spreading to the central and the South. 2004 was the peak of bird flu owing to the new HPAI and the hyper susceptibility of our poultry (we did not have any antibody for this disease). Furthermore, we did not have any experience for disease prevention so the culling of tens of millions of poultry causes severe damages to the poultry industry. To make it even worse, the disease is contagious and fatal, getting the public confused. In 2005, after OIE recommended using vaccines together with properly adjustments, the whole country had almost no outbreak in 2006. It should be emphasized that the vaccines, the participation, and direction of the political system helped fulfill both technical and monitoring process. Therefore it ended up with the aforementioned results of 2006. The next years, as pathogens still exist, especially among waterfowl, the annual flu continues to happen. However, we have the vaccination (the rate is not high), with antiseptic disinfection eliminating germs (not thoroughly), hence, in a narrow scope, the outbreak only occurred in small-scale farms or ducks raised in paddy fields. The livestock biosecurity methods are apparently not applied in such places. It can be demonstrated that from early 2014 till now, though happening in many provinces and cities all over the country, quite a few outbreaks were found and the poultry cull is not high.

In your viewpoint, what is the most effective and scientific approach to prevent the spread?

The prevention of infectious diseases in general and influenza A/H5N1, in particular, must be persistent, synchronous and scientific. The best method is safely biological farming. It should be based on 3 factors forming the epidemic, namely pathogens, mediation factors, and receptors. If they are separated or one of three factors is eliminated, the disease will not occur. Specifically, sick or dead poultry with pathogens must be culled with proper technical (burying, burning ...) to destroy pathogens and disallow transportation of sick poultry from the infected area to a safe area. In terms of mediation factors with pathogens (transportation, destruction tools, pants, shirts, shoes and human, etc.), poultry should not be exposed to these factors and be frequently disinfected. As for the susceptible animals (poultry), they should be vaccinated (vaccine matching antigens of the pathogen) to generate antibodies against the pathogens (if any germs get into the body they will be neutralized by the antibodies). Nevertheless, each farming methods would be applied by different approaches. For example, regarding industrial methods, livestock biosecurity should be focused on; regarding small-scale farming, attention should be paid on vaccination.

As a scientist in the field of animal health, how do you evaluate the disease prevention of state agencies today?

H5N1 avian influenza has occurred for many years in our country, the authorities have had a lot of experience in prevention. Regarding prevention, in addition to continuous propaganda on the mass media, the authorities have developed short, medium and long-term programmes for prevention. With the backward farming of our country, vaccination is concentrated by state agencies through vaccination periods, supervision of annual circulating virus to alert the community. Nonetheless, as the Department of Animal Health evaluation towards the provinces: "One of the reasons leading to outbreaks in many provinces today is that periodic vaccinations are not implemented in round 2 of 2013, and round 1 of 2014, making the poultry have no immune protection against influenza virus A/H5N1".

About anti-epidemic, the Government has established the National Steering Committee since 2004 (including all ministries managed by the Department of Agriculture and Rural Development) to fight against this disease and uphold till today, working very effective. The provinces and districts also have their own steering committee; however, the activities of the committee are irregular. Thus, it is not surprising that not until the situation has occurred on a large scale that the disease is recognized in quite a few provinces, so the prevention faced difficulties and prolonged, even spread to other provinces.

Managers should also know that the risk of avian flu is relatively high. Through supervising, especially the ducks, apart from H5N1, the proportion of pathogens of H5N6 is high. Although virus H7N9 has not been detected in Vietnam, the risk of intrusion and causing fatal risk for people is also quite huge. Foot and mouth disease, Type A distribute on a large scale, therefore the strategy of vaccination does not only limit on Type O but includes dichotomous vaccines Type O and Type A.

Currently, do you have any advice for consumers of poultry products?

Poultry is an indispensable part of daily meals. However, during outbreaks of avian influenza, when buying alive poultry, consumers should pay attention to their origin and quarantined poultry, avoid sick or dead poultry and birds from disease areas. For poultry products, consumers should not eat duck blood or purchase poultry products without quarantine accented by veterinary authorities.

   Thank you!

Author: L.H
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