Committee: World
Health Organization
Topic: Avian influenza and its potential effects on
human populations
Author: Heather
Tarnowski B.Sc.H., M.Sc.
Committee
Background
The World Health Organization
(WHO) was established on April 7, 1948, as a United Nations body to ensure “the
attainment by all peoples of the highest possible level of health”, where
health is defined by the WHO constitution as “a state of complete physical,
mental and social well-being and not merely the absence of disease or
infirmity”.
The World Health Organization is
governed through the World Health Assembly, which is composed of 192 member states. The Assembly
serves to approve the WHO program, the budget and to make decisions on
questions of policy.
The WHO coordinates many
efforts internationally to advocate the highest attainable standard of
well-being as a fundamental human right. For this reason, WHO supports
the development and maintenance of health care systems within member nations
that are of adequate quality, affordable for the population, and cover
populations inhabiting both cities and rural areas, equally.
The World Health Organization serves many
functions, a few listed here. To know more about the work of the WHO,
several resources are listed at the end of the paper.
Perhaps the best-known
function of the WHO is the coordination of international efforts to eradicate
infectious diseases. Not only do the efforts save lives, but it also
helps to keep public health funds available for other purposes. In 1980,
the WHO certified the global elimination of smallpox. The disease
affected up to 15 million and killed approximately 2 million people each year
internationally.
On an annual basis, WHO makes
recommendations on the best, and most cost-effective training for health care
providers (especially doctors and nurses), using both traditional and
contemporary education techniques.
Ensuring internationally
acceptable standards and developing recommendations on the quality,
effectiveness and safety of drugs is another important aspect of the duties of
the organization. The WHO provides a model list of essential drugs, which
aids national authorities in ensuring that the drugs are affordable and
accessible to the individuals requiring them.
Prevention and control of chronic
non-communicable diseases is another facet of the organization. Long-term
studies within several nations involve monitoring of trends and
risk factors in cardiovascular diseases, and also serve to monitor the public
health interventions. Recommendations are also developed in regards to
the most effective approaches to control hereditary diseases, diabetes, cancer,
and asthma.
The last function to mention
is the mandate for the WHO to prepare recommendations
and guidelines on acceptable levels of various chemicals in the air, drinking
water and food products. The organization also examines the safety of
chemical products used internationally in everyday life.
Statement of the Problem
“The conditions of our
highly mobile interconnected and economically interdependent world have made
these diseases a much larger menace than in the past. This menace is likely to grow in the
future. And it is a menace that can
directly threaten every country in the world, not just developing nations.
“
- Dr. Margaret Chan, Director General of WHO
Avian influenza refers to a
group of influenza viruses that primarily affect bird populations. Most avian influenza viruses do not infect
humans. However, in rare cases, these
bird viruses have infected other species, such as pigs and humans. Avian influenza H5N1 is a virus subtype that
has pandemic potential, as it may mutate and adapt into a strain that is
contagious among humans. Influenza
pandemics occur because influenza viruses have adapted to infect and be passed
between humans.
Currently, the world may be on
the brink of another influenza pandemic.
Health experts have been monitoring the H5N1 strain of influenza viruses
for many years. The H5N1 strain first
infected humans in 1997 in
Once a contagious virus
materializes, global spread is considered inevitable. Measures such as border closures and travel
restrictions will delay arrival of the virus in a nation, but will not stop it
all together. The influenza pandemics
of the previous century circled the globe in six to nine months, even when most
international travel was by boat. Given
the speed and volume of air travel at this point in time, the virus could
possibly reach all continents within a three month time period.
Infection and illness rates
are expected to be higher than that observed during seasonal epidemics of
influenza, since most individuals will have no immunity to the new virus. Current projections for the next pandemic
estimate that a substantial percentage of the world’s population will require
some form of medical care. Few nations
have the staff, facilities, equipment, and space that will be required to
manage the large numbers of people who may become ill.
The most important medical interventions
for reducing illness and deaths during an influenza pandemic are vaccines and
anti viral drugs. Supplies of both will
be inadequate to meet the demand in all nations at the start of a pandemic, and
potentially for many months afterward.
Insufficient vaccine supplies are of particular concern, given that
vaccines are considered the first line of defense for protecting
populations. Based upon present trends,
many developing nations will have little to no access to vaccines for the
duration of a potential influenza pandemic.
In an address to the Pacific
Health Summit on June 13th 2007, the Director-General of the World
Health Organization, Dr. Margaret Chan stated that another influenza pandemic
could cost the world economy anywhere between 800 billion and 2 trillion
dollars, depending on the virulence of the virus. The greatest source of
economic loss will most likely occur due to uncoordinated efforts of the public
to avoid infection.
While economic loss is an
important factor, the primary concern would be the loss of human life that
could occur if there is influenza pandemic.
Three pandemics have occurred in the previous century, all having great
death tolls. The “Spanish Influenza”
pandemic that occurred in 1918 was the most severe pandemic, as it killed
between 40 and 50 million people. It was
considered one of the deadliest disease events in human history. Subsequent pandemics such as the “Asian
Influenza” in 1957 and the “
The World Health Organization
has acknowledged that every nation must be prepared for a potential influenza
pandemic. WHO is working closely with
various public health organizations to support surveillance of circulating H5N1
influenza viruses and rapid detection of potential pandemic viruses. The principal tasks facing the international
community are two-fold: 1)Reduce the opportunities for H5N1 to mutate and improve its
pandemic potential and 2) be prepared for a pandemic should these efforts fail.
Table 1: Human cases have been confirmed by WHO sanctioned laboratories in the following nations.
History of the Problem
Avian influenza is an
influenza type A virus that appears in many different sub-types classified
according to the nature of the two components that make up the virus –
haemagglutinin (H) and neuraminidase (N).
Haemagglutinin is a protein found on the surface of the virus that is
responsible for binding the virus to red blood cells, causing cell
clumping. Neuraminidase is an enzyme
found on the viral surface that dissolves the cellular mucous thus allowing
release of newly formed virus particles.
There are 16 haemagglutinin and 9 neuraminidase subtypes of influenza A virus, which give rise to hundreds of different
viruses. All combinations may be found
in wild aquatic birds, while H1, H2, and H3 subtypes have been circulating in
human populations for at least a century.
Avian influenza in wild and
domestic birds can exist in two forms.
One form has a low capacity for causing disease (low pathogenic avian
influenza) and the other form causes disease easily in birds (highly pathogenic
avian influenza). The latter form is of
the greatest concern, specifically the H5N1 subtype. This highly pathogenic form of avian
influenza has killed tens of millions of domestic birds and probably tens of
thousands of wild birds.
Migratory waterfowl, most
notably wild ducks, constitute the naturally existing reservoir of the
virus. Chicken, ducks, turkeys, and
geese are susceptible to illness because the virus spreads easily via contact
between infected and healthy birds. Wild
birds may carry H5N1 from one area to another via migration. However, conditions in domestic bird
production environments on farms and in rice paddy fields play a major role in
secondary spread of the disease, as does the carrying of poultry from one point
to another and to live bird markets.
The H5N1 virus is highly
contagious among birds and infection results in a high mortality rate. If an outbreak occurs, both infected and
healthy birds are exterminated to prevent spread of the virus. Between 1996 (when the virus was first isolated
in a farmed goose in
The H5N1 virus can also affect
humans. The first documented human
infections with H5N1 occurred in
To date, all evidence
indicates that close contact with dead or sick birds is the principal source of
human infection. Behaviours associated
with human infection include slaughtering, de-feathering, butchering, and
preparation for consumption of infected birds.
In a few cases, exposure to chicken feces when children played in an
area frequented by free-range poultry is thought to be the source of
infection. Swimming in bodies of water
where carcasses and feces of infected birds may be another source of
exposure. Most cases have occurred in
rural households where small flocks of poultry are kept. Very few cases have been detected in assumed
high-risk groups, such as commercial poultry workers, cullers, veterinarians,
and health staff caring for patients without adequate protective
equipment. Currently, the H5N1
influenza virus does not cross easily from birds to humans, but through the
process of genetic re-assortment, a fully transmissible pandemic virus could
come into existence.
In humans, influenza
caused by the H5N1 virus follows an aggressive clinical course, with rapid
deterioration and high fatality. The
progression of viral infection is poorly understood, but clinical data from new
cases is beginning to clarify the clinical features of the disease, but there
is still much to learn. The incubation
period of the virus is thought to range anywhere from 2 to 17 days. WHO is currently recommending that an
incubation period of seven days be used for field investigations and the
monitoring of patient contacts. The
initial symptoms observed include high fever (temperature higher than 38ºC or
100.4ºF), diarrhea, vomiting, abdominal pain, chest pain, difficulty breathing,
and bleeding from the gums and/or nose.
Eventually, almost all patients develop pneumonia, which is does not
respond to antibiotic treatment.
Deterioration of infected patients is rapid with the time of onset to
pneumonia symptoms ranging from four to 13 days. In many cases, multi-organ dysfunction is observed,
which will eventually lead to mortality.
Some studies suggest that
anti-viral drugs (i.e.: oseltamivir or Tamiflu) can reduce the duration of
viral replication and improve the chance of survival, if they are administered
within 48 hours of symptom onset.
However, oseltamivir and other anti-viral drugs were developed for
treatment of seasonal influenzas, which are less severe than H5N1. WHO has undertaken the review of optimum
dosage and duration of treatment for H5N1 influenza using oseltamivir in both
adults and children.
Past
UN Actions
In November 2005, a meeting
was convened by the World Health Organization, the Food and Agriculture
Organization, the World Organization for Animal Health, and the World Bank to
review the current status of the H5N1 avian influenza in animals and to assess
the risks it posed to humans including the likelihood of the virus developing
pandemic potential. In early 2006, WHO
developed and issued a Strategic Action Plan for Pandemic Influenza. The plan outlines the key interventions
required in each of the five priority areas and has a budget of $99.4 million
(USD).
The five priority areas of the strategic action plan are as follows:
1) Reduce human exposure to the H5N1 influenza virus – Reduce opportunities for human infection and, in so doing, reduce opportunities for a pandemic virus to emerge;
2) Strengthen the early warning system – Ensure that affected countries, WHO, and the international community have all data and clinical specimens needed for an accurate risk assessment;
3) Intensify rapid containment operations – Prevent the H5N1 virus from further increasing its transmissibility among humans or delay its international spread;
4) Build capacity to cope with a pandemic – Ensure that all countries have formulated and tested pandemic response plans and that WHO is fully able to perform its leadership role during a pandemic;
5) Coordinate global scientific research and development – Ensure that pandemic vaccines and antiviral drugs are rapidly and widely available shortly after the start of a pandemic and that scientific understanding of the virus evolves quickly.
Since the Action Plan was
issued, WHO headquarters, regional offices and country offices have been
initiating and undertaking activities within the framework of the strategic
objectives. The Global Influenza
Programme within the Department for Epidemic and Pandemic Alert and Response at
WHO headquarters has overall responsibility for providing technical leadership
as well as coordinating the activities taking place across the
organization. WHO is working closely
with partners in ministries of health and agriculture of
Bloc Positions
Currently, there is
one united position to prevent a human H5N1 influenza pandemic. Most developed
nations are working towards stockpiling avian influenza vaccines and completing
research about the spread of the virus.
However, the immediate focus of the individual blocks becomes slightly
different at this point. The Asian and
African blocs are currently focusing on containing both avian and human cases
of the influenza, via public education of hygiene issues and culling of
potentially infected bird populations.
All other blocs (North and
Questions a Resolution Must Answer
These are just a few questions,
but they cover a wide range and are important to keep in mind when writing a
resolution.
1) How can a pandemic be prevented using resources from all nations?
2) How will educational prevention be implemented in each nation?
3) How will vaccine stocks and anti-viral drugs be allocated internationally?
4) What research can be done to prevent an influenza pandemic?
5) How can bird culls be kept to a minimum, while minimizing infection?
6) What other organizations will be involved to deal with the economic issues presented by avian influenza and the potential for a pandemic?
Some
questions and suggestions to guide your research
1) How does your nation feel it is best to control the spread of avian influenza?
2) How will your nation prioritize the important goals related to combating avian influenza? Ie: education, pandemic preparedness, production or attainment of vaccine stocks, etc.
3) What elements need to be included in public education?
4) What funding or equipment does your nation need?
5) What funding or equipment is your nation willing to provide?
6) What role does your nation play in the WHO strategic action plan for pandemic influenza?
Resources for your research
1) WHO Constitution - http://www.who.int/about/en/
2) International Health Regulations - http://www.who.int/csr/ihr/en/
3) Ten Things You Need to Know About Pandemic Influenza – www.who.int/csr/disease/influenza/pandemic10things/en/index.html
4) Pandemics: Working together for an effective and equitable response. Speech by Dr. Margaret Chan. www.who.int/dg/speeches/2007/20070613_seattle/en/print.html.
5) Antigenic and genetic characteristics of H5N1 viruses and candidate H5N1 vaccine viruses developed for potential use as pre-pandemic vaccines http://www.who.int/csr/disease/avian_influenza/guidelines/summaryH520070403.pdf
6) H5N1 avian influenza: Timeline of major events. http://www.who.int/csr/disease/avian_influenza/Timeline_07_Aug27.pdf
7) Bird Flu – The Chronology of a Disease. www.fao.org/avianflu/en/chronology/html
8) Avian influenza (“bird flu”) – Fact Sheet www.who.int/mediacentre/factsheets/avian_influenza/en/index.html
9) Avian Influenza – Background www.fao.org/avianflu/en/background.html
10) Avian influenza – Food safety issues www.who.int/foodsafety/micro/avian/en/print.html
11) Avian Influenza Glossary www.fao.org/avianflu/en/glossary.html
12) WHO Activities in Avian Influenza and Pandemic Influenza Preparedness. January – December 2006. http://www.who.int/csr/disease/avian_influenza/WHOactivitiesavianinfluenza/en/index.html
13) The Role of National Influenza Centres (NICs) during Interpandemic, Pandemic Alert and Pandemic Periods http://www.who.int/csr/disease/avian_influenza/guidelines/RoleNICsMay07/en/index.html
14) Avian Influenza, Including Influenza A (H5N1), in Humans: WHO Interim Infection Control Guideline for Health Care Facilities http://www.who.int/csr/disease/avian_influenza/guidelines/infectioncontrol1/en/index.html