Introduction:
Considering the enormity of the epidemics afflicting the world in the course of the 20th century, ending up of colossal death tolls, and in light of the current world circumstances, which are quite ready for the appearance of a new epidemic, giving way, according to health experts, to the death of 2 to 4.7 million people, there has been an global response, under the auspices of the World Health Organization (WHO), aiming to make good use of the local, regional and international capacities in face of the epidemic. Such early preparation, based upon the statistics recorded in some Asian and European countries, would enable us to avoid and control the epidemic, as well as setting the proper plans to do so.
What is Bird Flu?
Bird Flu, more properly called avian influenza, historically dubbed "fowl plague", is an infectious disease that primarily affects birds but can also infect several kinds of mammal, including humans. Characterized by rapid prevalence, avian influenza has a variety of symptoms, ranging from simple to lethal.
The avian influenza A encompasses numerous subclasses and strains (15 strains so far), undergoing several genetic mutations and leading up to the appearance of several avian epidemics in South East Asia, the Americas, and, recently, Russia. These viral strains have been reduced to one stain (H5N1), which can affect several mammals, including humans. All bird species are prone to the H5N1 infection, but at varying degrees. At present, several spots around the world are hit by H5N1 outbreaks, leading up to the death and culling of millions of birds.
Besides, a number of humans, those in contact with infected birds, have been detected to be carriers of the virus. The contact with the live infected birds, either direct or indirect, is considered the main cause of infection. The virus could be transmitted through the birds' mouth secretions and excretion. Human infection could also caused by the contamination of the tools or clothes of the workers at poultry farms with the virus included in the birds' secretions and wastes. The virus can live for relatively long time in low-temperature environments.
To what extent is avian influenza (H5N1) similar to human influenza?
They are completely different, since the human influenza virus is genetically distinct from avian influenza, which usually infects birds only (and sometimes pigs). It had been very unlikely for avian influenza to infect humans, until 1997, when the first bird flu human case was recorded. This is because the bird-to-human transmission is very rare, and difficult. The infection takes place as a result of direct contact with the infected birds. Human-to-human transmission is not yet proved to be true, even though scientists are very much skeptic about it.
What are the birds vulnerable to H5N1?
Many species of wild bird – particularly migratory waterfowl, and, especially, ducks - seem able to carry bird flu without coming to any apparent harm, but infection with avian influenza causes other species, including domestic chickens, turkeys and geese, to become seriously ill. In poultry, the sickness caused by bird flu comes in two different types, one mild, widespread and barely noticeable, the other uncommon, deadly and very difficult to overlook. The incubation period of avian influenza ranges from 1 to 7 days. It is worth mentioning that the recent Bird Flu outbreaks in South East Asia and some European countries (like Turkey), as well as Iraq, are basically attributed to the direct contact with domestic, migratory and water birds.
Viral transmission among birds:
Infection among birds takes place by touching the contaminated secretions of the infected birds, such as blood, saliva, excretion and respiratory secretions.
Symptoms in birds:
Bird flu infection among birds is usually collective. Some of the symptoms are:
- Severe bloody diarrhea.
- Low productivity of eggs.
- Inactivity, and ruffled feathers.
- Loss of appetite.
- Runny nose.
- Difficulty in breathing.
- Eye inflammation.
- Soreness of the crest, and swelling of the face.
Infection Transmission:
Infection is mainly transmitted through direct contact with the live infected birds, either direct or indirect. So it is considered the main cause of infection. The virus could be transmitted also through the birds' mouth secretions and excretion. Therefore most bird flu cases have been detected in rural areas. The possibility of infection transmission becomes even higher in during slaughtering and cleansing the infected birds. The virus cannot be transmitted to humans when eating infected birds, or their eggs, in case they are well cooked at a temperature of at least 70° C.
Human infection could also caused by the contamination of the tools or clothes of the workers at poultry farms with the virus included in the birds' secretions and wastes. The virus can live for relatively long time in low-temperature environments.
It should be noted that the possibility of infection transmission to humans is still very low, considering the hundreds of millions of culled birds, if compared to only 70 deaths among humans so far.
What is the possibility of bird flu infection among humans? Does bird flu pose a health predicament for humans?
The possibility of infection transmission to humans is still very low, especially in cities and urban communities, considering the hundreds of millions of culled birds, if compared to only 70 deaths among humans so far. Consequently, bird Flu (avian influenza) is still a veterinary problem in the first place. However, all the necessary measures should be taken, and the public awareness of the disease should be raised, in a pursuit to fight the disease in a proper manner.
Symptoms of Avian Influenza (H5N1) among Humans:
The symptoms of avian influenza are quite similar to the symptoms of severe human influenza. Some of these symptoms are:
- High temperature (38° C, or more)
- Throat pains
- Fatigue
- Eye inflammation
- Cough
- Dyspnea
- Vomiting and diarrhea
Then, these symptoms grow severer quickly, causing pneumonia and failure in several organs. The possibility of death amounts to 50% of cases.
Number of Bird Flu Cases and Deaths (according to WHO, since its appearance in 1997 till 1/11/2005):
| 1 |
Indonesia |
As of 2003 |
7 |
4 |
| 2 |
Thailand |
As of 2003 |
20 |
13 |
| 3 |
Vietnam |
As of 2003 |
91 |
41 |
| 4 |
Cambodia |
As of 2003 |
4 |
4 |
| 5 |
Hong Kong |
1997 |
18 |
6 |
| 6 |
Hong Kong |
2003 |
2 |
1 |
| Total |
|
Since the appearance of the disease |
142 |
69 |
Is there an avian influenza antiviral at present?
There are no vaccinations against H5N1 throughout the world so far. Many countries around the world, however, are currently working on the production of the vaccine. The primary phases of the vaccine production have already been successful. Nevertheless, a problem seems to be still persistent; as the vaccine production cannot be completed before months from the infection prevalence, so as to ascertain the safety and validity of the vaccine.
Does vaccination against human influenza protect from avian influenza?
Although many leading health organizations, including the WHO, recommend vaccination against human influenza, it actually has nothing to do with the protection from avian influenza, as they are two distinct viruses.
Are there any medicines effective in the treatment of bird flu?
Although there are no medical studies affirming that the medicines used for human influenza could be used for the treatment of avian influenza, because of the novelty of the virus, and its resistance to the available vaccines, as well as our inability to foresee the viral mutations that might take place, some laboratory studies showed that using some medicines (e.g. "Tamiflu" and "Relenza"), provided that the medicine is taken during the first 48 hours from the appearance of symptoms.
How could humanity be affected by bird flu?
The Bird Flu virus, in itself, could be not that dangerous. The danger essentially lies in the virus mutation, causing it to be transmitted from human to human, thus leading up rapid prevalence amongst people, from one place to another. Even though the number of infected cases throughout the world is only 140 cases, it should be acknowledged that they were very severe cases, to the effect that 70 cases ended up dead. The World Health Organization (WHO) is afraid that the infection prevalence will take place more quickly.
Expected estimates of the death toll in case of pandemic prevalence:
The WHO's preliminary estimates show that the number of deaths might range from 2 to 7.5 million persons. These are not but theoretical estimates, based on the viral severity and the countries' capability of early detection, and the prevention of the transmission of the virus to other countries.
Most devastating influenza pandemics in the history:
| Spanish Influenza |
1918 |
40-50 million |
| Asian Influenza |
1957 |
2 million |
| Hong Kong Influenza |
1968 |
1 million |
Phases of global pandemic:
In order for the avian influenza (H5N1) to be a global pandemic, threatening humanity, it should undergo these three phases:
- The appearance of a viral strain affecting humans.
- The virus becomes able to reproduce in human bodies, thus developing into a pathological form.
- The transmission of the virus among humans (becoming highly contagious, through a regular series of viral transmission, ending up with a pandemic outbreak.)
How could the global pandemic sweep the entire world:
As a matter of fact, no country could be said to be immune against the pandemic. The virus might develop into a global pandemic if it undergoes mutations changing its genetic components, to the effect that it becomes capable of transmission from birds to very easily, or, even more dangerous, from human to human.
Mechanism of viral mutation:
The avian influenza virus is very likely to undergo genetic mutation, from a weak to strong virus, in a short period. Mutations could also make up a completely new virus out of the old one, genetically distinct from the original virus. Scientists opine that such a mutation could take place through one of the following methods:
- The avian influenza virus (H5N1) undergoes a mutation when combined with the human influenza virus.
- The avian influenza virus (H5N1) undergoes a mutation progressively, as it enhances its ability to live and reproduce in human bodies with every new human infection.
Indications of speed of pandemic prevalence:
The World Health Organization (WHO) emphasizes that the timing of the avian influenza global outbreak, as well as the speed of prevalence and the readiness of the countries to fight it, cannot be predicted. From this, we can infer that there are certain indications of the speed of pandemic prevalence, summed up as follows:
- Unreadiness of most countries to fight the pandemic.
- The increase of the opaque danger posed by migratory birds in the transmission of contagious viruses.
- Domestic duck function as a "silent store" for the virus, as they contain large quantities of the virus, spread out through their excretions and secretions, without any palpable symptoms; what makes it even harder to combat.
- The current pandemic outbreak of H5N1is more dangerous than those taking place between 1997 and 2004.
How could the pandemic be early predicted?
The occurrence of a number of infections in one place, during a close time, is considered the most evident warning sign towards the occurrence of a pandemic.
How to prevent the pandemic:
So far, this question cannot be answered soundly, in a confirmed and scientific way, owing to a variety of considerations relevant to the pandemic. The pandemic, however, could be evaded, Allah willing, once the following procedures are taken:
- Veterinary care is the corner stone of combating avian influenza infection prevalence.
- Taking serious steps towards joint cooperation among all countries in isolating the virus and preventing it from transmission from one area to another.
- Maintaining strong preventive health systems, capable of quickly predicting the pandemic in due time.
To what extent is the world ready for fighting the disease?
WHO reports show that the world still has much to do to be able to combat the pandemic. It is for this reason that the WHO is quite skeptic about the world's ability to combat this pandemic soundly, proceeding from the fact that only 40 countries in the whole world have clear and effective plans concerning the potential avian influenza outbreak, whereas only 30 countries are in possession of antiviral supplies, let alone the fact that pharmaceutical companies do not produce quantities of the vaccine adequate for addressing the requirement in case of the occurrence of pandemic outbreaks soon.
Steps towards optimism:
Notwithstanding the tragic quagmire that we might find ourselves in, Allah forbid, still there are a bunch of optimistic remarks to be clarified with regard to the pandemic:
- Relentless world endeavors are now made, under the auspices of the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the International Organization for Animal Health (OIE).
- The greater bulk of countries are getting ready for avian influenza outbreak infection, under the pressure posed by the world public opinion on the governments to exert more effort in handling this issue.
- Allocating big budgets for the disease control.
- There are some medicines (such as Tamiflu and Relenza), which are somehow effective in the treatment of avian influenza.
- A breakthrough has been made in the vaccine production. Hungary has announced that it managed to produce the vaccine, and tested it on humans.
Summary:
- Human-to-human infection of avian influenza virus (H5N1) is not ascertained to be possible. It is basically transmitted from infected birds to humans, rarely and with difficulty, through direct contact.
- The disease, so far, is considered a veterinary problem.
- There are no scientific recommendations to abstain from eating chicken meat, or traveling to any of the affected countries.
- Chicken and eggs are recommended to be cooked at a temperature of at least 70° C; taking into consideration that medical studies almost unanimously agree that the disease cannot be transmitted through eating.
- Tamiflu (and the like medicines) cannot be stored. Also, such medicines shall be taken also under the doctor's observation.
How to best protect ourselves from bird flu:
- Abstention from traveling to the affected countries; only when absolutely necessary.
- Cooking chicken meat and eggs at a temperature of 70° C or more, and avoiding mayonnaise and ice-cream.
- Immunization against human influenza, especially children, elderly persons, diabetics, cardiac patients and patients with asthma.
- Being cautious when dealing with birds, by putting on protective facemasks for nose and eyes, along with gloves.
- Banning the import of all types of hawks.
- Proceeding on raising health awareness, and coordinating with all the relevant health authorities.
How to protect ourselves while traveling:
Keeping away from sources of infection (poultry farms, bird markets, etc.)
Washing hands every now and then.
Avoiding contact with those suffering from respiratory diseases.
Cooking chicken meat and eggs at a temperature of 70° C, or more.
Being cautious of eggs and the products of which eggs are an ingredient (mayonnaise and ice-cream), as well as the dishes which are not very well cooked.
Permanently keeping an eye on children.
Taking the human influenza vaccination, even though it does not protect from avian influenza, as it reduces the probability of joint infection.
Keeping away from any infected environment, or any birds suspected to be infected, in addition to taking the necessary actions, such as putting on personal protective equipment (PPE) when handling laboratory specimen, or other secretions; including gloves, high-quality facemask (N95), or a surgical facemask, in addition to an apron with long sleeves, a head cover and glasses.
To download (available only in Arabic), click here.
