Written by Dr Dorcas Fadugba and Dr Kikiope Oluwarore
Bird Flu is also known as Avian Influenza (AI) and it is a disease of birds feared by owners of poultry farms with good reasons. This is because the disease kills birds suddenly, fast and in large numbers and spread quickly to other neighboring farms and the whole. Also, as expected, it is a deadly zoonotic disease!
The two types of virus that affect both poultry and humans include A(H5N1) virus subtype, a (highly pathogenic AI virus, HPAI) and A(H7N9) virus subtype, (a low pathogenic AI virus).
H5NI first infected humans in 1997 during a poultry outbreak in Hong Kong SAR, China. It re-emerged again in 2003 and 2004, and has since spread from Asia to Europe, resulting in millions of poultry infections, several hundred human cases, and many human deaths. In European Union only, more than 50 million birds died or were depopulated after H5NI epidemics between December 1999 to April 2003. Outbreaks in poultry have seriously impacted livelihoods, the economy and international trade in affected countries. This happens especially when large amounts of birds either die while other birds in the area that are vulnerable to the disease get destroyed so as to stop its spread to human and animals. Presence of A(H5N1) and A(H7N9) viruses in poultry, continues to pose threats to public health and in the past few months, there have been outbreaks of the disease in poultry farms in Nigeria. Chickens, ducks, geese, turkeys, guinea fowl, quail, pheasants, pigeons and numerous wild birds may all be affected by these viruses.
The disease can enter your farm or affect a human being through contact with an infected bird, animal, manure, water or feed. Note that the person or animal does not necessarily have to be obviously sick before infecting other birds or animals.
Clinical signs of birds infected with Bird Flu virus
Avian Flu is very similar to Newcastle disease. You must suspect Avian Flu when you see important & rapid death in poultry! A lot of birds die without showing any clinical signs. However, some may show weakness, stop laying eggs or lay soft-shelled eggs, have ruffles feathers or have watery diarrhea. Mortality ranges from 50-100%, meaning that at least half of the poultry on the farm die.
How do you protect yourself from Bird Flu?
To reduce your risk of catching bird flu, you should take these general precautions, especially if you live and/or work around a poultry farm;
- Wash your hands regularly, particularly before and after handling food or birds (live or dead)
- Do not go near sick birds. If you do, wash your hands regularly
- If you’re traveling in a country that’s had an outbreak of bird flu, don’t go to live animal markets or poultry farms. Don’t go near bird droppings or dead birds, and don’t bring live birds or poultry products
- As a precaution, always ensure good hygiene standards when preparing and cooking chicken (and meat).
- If you’re ill, avoid public places. Turn away from other people and cover your mouth with tissues when you cough or sneeze. Also, dispose of tissues immediately after use and wash your hands with soap and warm water. Tell your doctor about your symptoms so you can given a surgical mask if necessary
- Make sure you maintain a good level of general health
How do you prevent and control Bird Flu on your Poultry Farm?
In the past few months, there have been outbreaks of the disease in poultry farms in Nigeria. So, because of its fast spread, it is important that you take measures on preventing Avian Influenza in your farm. Bird flu is not easily differentiated from other disease so it is best to start implementing control measures as soon as you can. There is not treatment for bird flu and though vaccines are available, prevention and control methods must still be applied effectively.
- Contact a qualified veterinarian to intervene in effective prevention and control process against Bird Flu.
- Vaccination: if you are in an area where the disease is widespread, you could vaccinate your birds from potential infection and as an emergency effort. Through this, you can thereby reducing the incidence or the severity of disease. Contact a qualified veterinarian for more information.
- Biosecurity: This is basically carrying out common-sense day-to-day preventive activities in the management of your farm so as to reduce the risk of transmission of infectious diseases on your farm. They are generally based on simple activities that cost little or nothing but keep poultry away from microbes and vice versa. If biosecurity measures are not followed, we spend more time and more money on treatment when the disease does appear. Biosecurity can take care of all diseases, not only bird flu and it would be discussed in full later in the week.
Guess what! AI is no respecter of large or small scale poultry farms. If the basic principles to attaining a disease-free farm are not meticulously followed, outbreak is very possible. First, you must work to prevent an outbreak on your farm. However, if an outbreak occurs, protect yourself first by intensifying on practicing standard hygiene and wearing full protective clothing (masks, boots, overalls etc). Also, in case of an outbreak, the most effective (but sad) solution and best practice would be to close down the farm and all dead birds gathered into a pit and burned. This is because the disease is transmitted very rapidly making it dangerous to human and animal health in the environment.
References; WHO Avian Infuenza, NHS UK, Capua and Marangon (2006)
Compiled and written by Dr. Dorcas Fadugba and K.O
Dr Dorcas Fadugba is a graduate of Veterinary Medicine from the University of Ibadan. She completed her Masters in Veterinary Public Health and Preventive Medicine where she worked on Lassa fever through the MacArthur Foundation Scholarship of the Control and Prevention of Zoonoses (CCPZ) department, University of Ibadan, Nigeria
She currently undertakes a PhD research on Epidemiology of Avian Influenza in Oyo State.