Monday, January 21, 2008

The HIV/AIDS pandemic

The HIV/AIDS pandemic is one of the most important and urgent public health challenges facing governments and civil societies around the world. Adolescents are at the centre of the pandemic in terms of transmission, impact, and potential for changing the attitudes and behaviours that underlie this disease.
It is estimated that 50% of all new HIV infections are among young people (about 7,000 young people become infected every day), and that 30% of the 40 million people living with HIV/AIDS are in the 15-24 year age group. The vast majority of young people who are HIV positive do not know that they are infected, and few young people who are engaging in sex know the HIV status of their partners.
The importance of focusing on young people has been recognised at a global level by the 2001 UN General Assembly Special Session on HIV/AIDS, which endorsed a number of goals for young people, including:
"By 2003, establish time-bound national targets to achieve the internationally agreed global prevention goal [adopted during the ICPD+5 Conference] to reduce by 2005 HIV prevalence among young men and women aged 15-24 in the most affected countries by 25% and by 25% globally by 2010"
"By 2005, ensure that at least 90%, and by 2010 at least 95% of young men and women have access to the information, education, including peer education and youth-specific education, and services necessary to develop the life skills required to reduce their vulnerability to HIV infection; in full partnership with youth, parents, families, educators and health care providers."
Fortunately, most young people are not infected. In fact, during early adolescence HIV rates are the lowest of any period during the life cycle. The challenge is to keep them this way. Focusing on young people is likely to be the most effective approach to confronting the epidemic, particularly in high prevalence countries.

Thursday, January 17, 2008

The health impact of Indoor air pollution

Indoor air pollution and health

Scope
of the problem

More than half of the world’s population rely on dung, wood,
crop waste or coal to meet their most basic energy needs. Cooking and heating
with such solid fuels on open fires or stoves without chimneys leads to indoor
air pollution. This indoor smoke contains a range of health-damaging pollutants
including small soot or dust particles that are able to penetrate deep into the
lungs. In poorly ventilated dwellings, indoor smoke can exceed acceptable levels
for small particles in outdoor air 100-fold. Exposure is particularly high among
women and children, who spend the most time near the domestic hearth. Every year,
indoor air pollution is responsible for the death of 1.6 million people - that's
one death every 20 seconds.

The use of polluting fuels thus poses a major
burden on the health of poor families in developing countries. The dependence
on such fuels is both a cause and a result of poverty as poor households often
do not have the resources to obtain cleaner, more efficient fuels and appliances.
Reliance on simple household fuels and appliances can compromise health and thus
hold back economic development, creating a vicious cycle of poverty.

According
to the 2004 assessment of the International Energy Agency, the number of people
relying on biomass fuels such as wood, dung and agricultural residues, for cooking
and heating will continue to rise. In sub-Saharan Africa, the reliance on biomass
fuels appears to be growing as a result of population growth and the unavailability
of, or increases in the price of, alternatives such as kerosene and liquid petroleum
gas. Despite the magnitude of this growing problem, the health impacts of exposure
to indoor air pollution have yet to become a central focus of research, development
aid and policy-making.

The health impact: A major killer

The
World Health Organization (WHO) has assessed the contribution of a range of risk
factors to the burden of disease and revealed indoor air pollution as the 8th
most important risk factor and responsible for 2.7% of the global burden of disease
. Globally, indoor air pollution from solid fuel use is responsible for 1.6 million
deaths due to pneumonia, chronic respiratory disease and lung cancer, with the
overall disease burden (in Disability-Adjusted Life Years or DALYs, a measure
combining years of life lost due to disability and death) exceeding the burden
from outdoor air pollution five fold. In high-mortality developing countries,
indoor smoke is responsible for an estimated 3.7% of the overall disease burden,
making it the most lethal killer after malnutrition, unsafe sex and lack of safe
water and sanitation.

Indoor air pollution has been associated with a wide
range of health outcomes, and the evidence for these associations has been classified
as strong, moderate or tentative in a recent systematic review. Included in the
above assessment were only those health outcomes for which the evidence for indoor
air pollution as a cause was classified as strong. There is consistent evidence
that exposure to indoor air pollution increases the risk of pneumonia among children
under five years, and chronic respiratory disease and lung cancer (in relation
to coal use) among adults over 30 years old. The evidence for a link with lung
cancer from exposure to biomass smoke, and for a link with asthma, cataracts and
tuberculosis was considered moderate. On the basis of the limited available studies,
there is tentative evidence for an association between indoor air pollution and
adverse pregnancy outcomes, in particular low birth weight, or ischaemic heart
disease and nasopharyngeal and laryngeal cancers.

While the precise mechanism
of how exposure causes disease is still unclear, it is known that small particles
and several of the other pollutants contained in indoor smoke cause inflammation
of the airways and lungs and impair the immune response. Carbon monoxide also
results in systemic effects by reducing the oxygen-carrying capacity of the blood.

Pneumonia
and other acute lower respiratory infections

Globally, pneumonia and other
acute lower respiratory infections represent the single most important cause of
death in children under five years. Exposure to indoor air pollution more than
doubles the risk of pneumonia and is thus responsible for more than 900 000 of
the 2 million annual deaths from pneumonia.

Chronic
obstructive pulmonary disease

Women exposed to indoor smoke are three times
as likely to suffer from chronic obstructive pulmonary disease (COPD), such as
chronic bronchitis, than women who cook and heat with electricity, gas and other
cleaner fuels. Among men, exposure to this neglected risk factor nearly doubles
the risk of chronic respiratory disease. Consequently, indoor air pollution is
responsible for approximately 700 000 out of the 2.7 million global deaths due
to COPD.

Lung cancer

Coal use is widespread in
China and cooking on open fires or simple stoves can cause lung cancer in women.
Exposure to smoke from coal fires doubles the risk of lung cancer, in particular
among women who tend to smoke less than men in most developing countries. Every
year, more than one million people die from lung cancer globally, and indoor air
pollution is responsible for approximately 1.5% of these deaths.

Disproportionate
impacts on children and women

Household energy practices vary widely around
the world, as does the resultant death toll due to indoor air pollution. While
more than two-thirds of indoor smoke deaths from acute lower respiratory infections
in children occur in WHO's African and South East Asian Regions, over 50% of the
COPD deaths due to indoor air pollution occur in the Western Pacific region.

In
most societies, women are in charge of cooking and - depending on the demands
of the local cuisine - they spend between three and seven hours per day near the
stove, preparing food. 59% of all indoor air pollution-attributable deaths thus
fall on females. Young children are often carried on their mother's back or kept
close to the warm hearth. Consequently, infants spend many hours breathing indoor
smoke during their first year of life when their developing airways make them
particularly vulnerable to hazardous pollutants. As a result, 56% of all indoor
air pollution-attributable deaths occur in children under five years of age.

In
addition to the health burden, fuel collection can impose a serious time burden
on women and children. Alleviating this work will free women's time for productive
endeavours and child care, and can boost children's school attendance and time
for homework.

Millennium Development Goals are guiding
international action

Tackling indoor air pollution in the context of household
energy is linked to achieving the Millennium Development Goals, in particular
to reducing child mortality (Goal 4), to promoting gender equality and empowering
women (Goal 3), to opening up opportunities for income generation and eradicating
extreme poverty (Goal 1), and to ensuring environmental sustainability (Goal 7).
WHO reports the "proportion of the population using solid fuels for cooking" as
an indicator for assessing progress towards the integration of the principles
of sustainable development into country policies and programmes. Yet, the central
role of household energy is not currently reflected in the political responses
to achieve the Millennium Development Goals.

Measures to reduce indoor air
pollution and associated health effects range from switching to cleaner alternatives,
such as gas, electricity or solar energy, to improved stoves or hoods that vent
health-damaging pollutants to the outside, to behavioural changes. There is an
urgent need to investigate which interventions work and how they can be implemented
in a successful, sustainable and financially viable way.

What
WHO is doing

WHO, as the global public health agency, is advocating for
the integration of health in international and national energy policies and programmes.
WHO collects and evaluates the evidence for the impact of household energy on
health and for the effectiveness of interventions in reducing the health burden
on children, women and other vulnerable groups. WHO's programme on household energy
and health rests on four pillars:

  • Documenting the
    health burden of indoor air pollution and household energy:
    WHO will
    provide a regular update of the links between household energy and health and,
    where feasible, offer support to key research undertakings.
  • Evaluating
    the effectiveness of technical solutions and their implementation:
    Developing
    simple tools for monitoring the effectiveness of interventions in improving health
    and building the capacity to conduct such evaluations will help generate much
    needed information from ongoing small- and large-scale projects. This information
    will provide the basis for the development of a catalogue of options that review
    both the effectiveness of interventions, and lessons learnt in relation to their
    implementation.
  • Acting as the global advocate for health as a central
    component of international and national energy policies:
    Ultimately,
    policy-makers will want to know whether it pays off to invest in large-scale operations
    to reduce indoor air pollution. In terms of health, a recent cost-effectiveness
    analysis of different interventions suggests that improved stoves and switching
    to kerosene and gas represent cost-effective solutions. In addition, WHO is working
    on a cost-benefit analysis of interventions that - beyond health - will take into
    account all the benefits associated with improved household energy practices.
  • Monitoring changes in household energy habits over time:
    Information about the energy habits of poor, mostly rural households is scarce
    and WHO has the responsibility to work towards progress in this area and to report,
    on a yearly basis, the Millennium Development Goal Indicator 29 "percentage of
    population using solid fuels".

Key partners include the Partnership
for Clean Indoor Air, the United Nations Environment Programme, the United Nations
Development Programme and the World Bank as well as many research institutions
and non-governmental agencies around the world. WHO is already actively taking
part in projects in several developing countries, including the most sophisticated
scientific indoor air pollution study to date undertaken in Guatemala, and work
in China, Lao People's Democratic Republic, Mongolia, Nepal, Kenya and Sudan.
In the future, work will focus even more on those countries and populations most
in need.

Health effects of sun exposure

Protecting children from ultraviolet radiation

Children
are in a dynamic state of growth, and are therefore more susceptible to environmental
threats than adults. Many vital functions such as the immune system are not fully
developed at birth, and unsafe environments may interfere with their normal development.
But most environmental hazards are preventable: reducing exposure is the most
effective way of protecting children's health.

Ultraviolet
radiation and ozone depletion

Ultraviolet (UV) radiation is one component
of solar radiation. It is progressively filtered as sunlight passes through the
atmosphere, in particular by the ozone layer.

As the ozone layer is depleted,
the protective filter activity of the atmosphere is reduced and more UV radiation,
in particular the more harmful UVB, reaches the Earth's surface. In the year 2000,
the ozone hole over the Antarctic reached its biggest size ever covering 11.4
million square miles - an area more than three times the size of the United States.
For the first time it also stretched over populated areas exposing local residents
to extreme levels of solar UV radiation. Local authorities warned residents in
Southern Chile that they could sunburn in less than seven minutes and should avoid
spending time outdoors in the middle of the day.

Sustained ozone depletion
and enhanced levels of UV radiation on Earth will aggravate UV effects on the
human skin, eyes and immune system. Children are at especially high risk of suffering
damage from exposure to UV radiation.

Health effects
of sun exposure: a global concern

UV radiation causes sunburn and skin
cancer and accelerates skin ageing. Overexposure to UV radiation can lead to inflammations
of the cornea and the conjunctiva in the eye, and causes or accelerates cataract
development. A health issue of growing concern is that UV radiation can reduce
the effectiveness of the human immune system. Consequently, sun exposure may enhance
the risk of infection and could limit the efficacy of immunization against disease.
Both of these act against the health of poor and vulnerable groups, especially
children of the developing world, as many developing countries are located close
to the equator and hence exposed to very high levels of UV radiation.

Skin
cancer has become the focus of intervention campaigns in Australia, Europe and
North America. Many believe that only fair-skinned people need to be concerned
about overexposure to the sun. Although it is true that darker skin has more protective
pigment, the skin is still susceptible to the damaging effects of UV radiation.
The incidence of skin cancers is lower in dark-skinned people, nevertheless skin
cancers occur and are often detected at a later, more dangerous stage. The risk
of other UV-related health effects, such as eye damage, premature ageing of the
skin, and immunosuppression is independent of skin type. For example, a 10% decrease
in total stratospheric ozone is predicted to result in between 1.6 and 1.75 million
additional cases of cataract per year worldwide.

Skin
cancer incidence on the rise

Between 2 and 3 million non-melanoma skin
cancers and approximately 132,000 malignant melanomas occur globally each year.
With a sustained 10% decrease in stratospheric ozone, an additional 300,000 non-melanoma
and 4,500 melanoma skin cancers could be expected world-wide, according to UNEP
estimates. Currently, one in five North Americans and one in two Australians will
develop some form of skin cancer in their lifetime.

People's behaviour in
the sun is the main cause for the rise in skin cancer rates in recent decades.
An increase in popular outdoor activities and changed sunbathing habits often
result in excessive UV exposure. Many people consider intensive sunbathing to
be normal and unfortunately, even many children and their parents perceive a suntan
as a symbol of attractiveness and good health. However, a suntan is merely a sign
of UV damage and represents the skin's defence to prevent further harm.

Children
require special protection

The United Nations Convention on the Rights
of the Child states that children, including all developmental stages from conception
to age 18, have the right to enjoyment of the highest attainable standard of health
and to a safe environment. Children require special protection as they are at
a higher risk of suffering damage from exposure to UV radiation than adults, in
particular:

  • A child's skin is thinner and more sensitive
    and even a short time outdoors in the midday sun can result in serious burns.
  • Epidemiological studies demonstrate that frequent sun exposure and sunburn
    in childhood set the stage for high rates of melanoma later in life.
  • Children
    have more time to develop diseases with long latency, more years of life to be
    lost and more suffering to be endured as a result of impaired health. Increased
    life expectancy further adds to people's risk of developing skin cancers and cataracts.
  • Children are more exposed to the sun. Estimates suggest that up to 80 per
    cent of a person's lifetime exposure to UV is received before the age of 18 .
  • Children love playing outdoors but usually are not aware of the harmful effects
    of UV radiation.

Caring for children in the sun

According
to an Australian study, four out of five cases of skin cancer are preventable
by sensible behaviour. Encouraging children to take simple precautions will prevent
both short-term and long-term damage while still allowing them to enjoy the time
they spend outdoors. Parents should serve as role models, and it is their responsibility
to ensure that their children are protected adequately. Always keep infants of
less than 12 months in the shade and make sure your children:


  • Cover up with protective clothing, a hat and sunglasses.
  • Apply broad-spectrum
    sunscreen of SPF 15+.
  • Limit their time in the midday sun.
  • Seek shade.
  • Avoid sunlamps and tanning parlours.

Shade, clothing and hats
provide the best protection for children -- applying sunscreen becomes necessary
on those parts of the body that remain exposed like the face and hands. Sunscreen
should never be used to prolong the duration of sun exposure.

Sun
protection is relevant in all settings

Sun protection is not only necessary
on the beach or at the swimming pool but applies to all outdoor settings. In many
situations sunburn arises because people do not realize the need for protection.
Children can be exposed to intense sunlight on the balcony at home, on weekend
trips or a visit to the zoo, during breaks at kindergarten or school, and during
outdoor sporting activities.

Particular attention should be paid in the
mountains, as UV levels increase by approximately 8 per cent with every 1000 meters
altitude. Although UV radiation is most intense under cloudless skies it may be
high even on an overcast day. Many surfaces such as snow, sand and water reflect
the sun's rays and add to the overall UV exposure.

Sun
protection programmes can make a difference

Sun protection programmes to
raise awareness and achieve changes in life-style is urgently needed to slow down
and eventually reverse the trend towards more and more skin cancers. An effective
campaign can have an enormous impact on public health: the regular use of sunscreen
with sun protection factor 15 or higher up to the age of 18 could decrease the
frequency of skin cancer in Australia by more than 70 per cent. Beyond the health
benefits, effective education programmes can significantly decrease costs in the
health system and strengthen the economy. Current prevention campaigns in Australia
invest approximately US$ 0.08 per person per year, while the direct costs of skin
cancer treatment have been estimated at US$ 5.70 per head of the population during
the same period of time.

WHO's Activities to promote
children's sun protection

INTERSUN Project

INTERSUN, WHO's
Global UV Project aims to reduce the burden of disease resulting from exposure
to UV radiation. The programme encourages and evaluates research to fill gaps
in scientific knowledge, assesses and quantifies health risks, and develops an
appropriate response through guidelines, recommendations and information dissemination.
Beyond its scientific objectives, INTERSUN provides guidance to national authorities
and other agencies about effective sun awareness programmes. These address different
target audiences such as occupationally exposed people, tourists, school children
and the general public. The programme is working towards the development of a
framework for children's sun protection education that comprises an educational
package as well as recommendations on best practices.

Global Solar UV
Index

The UV Index (UVI) was developed by WHO, the United Nations Environment
Programme, and the World Meteorological Organization as part of an international
effort to raise public awareness of the risks of sun exposure. It is a simple
measure of the intensity of the sun's ultraviolet rays at the earth's surface,
and in many countries is presented as part of the weather forecast. INTERSUN promotes
the harmonized use of the UVI, and advises governments to employ this educational
tool in their health promotion programmes. WHO encourages dissemination channels
such as the media and tourism industry to publish the UVI forecast and promote
sun protection messages.

Global School Health Initiative

WHO's
Global School Health Initiative seeks to mobilize and strengthen health promotion
and education activities to improve the health of students, school personnel,
families and other members of the community. Schools are vitally important settings
to promote sun protection, and play a significant role in increasing awareness
and changing behaviour among children and the people taking care of them. As part
of the WHO Information Series on School Health, INTERSUN is preparing a document
that will describe the essential steps in setting up a school initiative on sun
protection.

Task Force for the Protection of Children's Environmental
Health

In response to new knowledge about the special vulnerability
of children and to growing concerns about the health impact of unsafe environments,
WHO set up a Task Force for the Protection of Children's Environmental Health
in July 1999. Its objectives are to raise the awareness of member states and the
general public, to assist countries in mitigating the effects of environmental
threats and to develop methodologies for risk assessment and the dissemination
of information. Protecting children from harmful ultraviolet radiation is one
of the topics covered by the Task Force's activities.

Traditional Medicine


Traditional
medicine

What
is traditional medicine?

Traditional
medicine refers to health practices, approaches, knowledge and beliefs incorporating
plant, animal and mineral based medicines, spiritual therapies, manual techniques
and exercises, applied singularly or in combination to treat, diagnose and prevent
illnesses or maintain well-being.

Countries
in Africa, Asia and Latin America use traditional medicine (TM) to help meet some
of their primary health care needs. In Africa, up to 80% of the population uses
traditional medicine for primary health care. In industralized countries, adaptations
of traditional medicine are termed “Complementary“ or “Alternative” (CAM).

Increasing
use and popularity

TM
has maintained its popularity in all regions of the developing world and its use
is rapidly spreading in industrialized countries.

  • In
    China, traditional herbal preparations account for 30%-50% of the total medicinal
    consumption.
  • In Ghana, Mali,
    Nigeria and Zambia, the first line of treatment for 60% of children with high
    fever resulting from malaria is the use of herbal medicines at home.
  • WHO
    estimates that in several African countries traditional birth attendants assist
    in the majority of births.
  • In
    Europe, North America and other industrialized regions, over 50% of the population
    have used complementary or alternative medicine at least once.
  • In
    San Francisco, London and South Africa, 75% of people living with HIV/AIDS use
    TM/CAM.
  • 70% of the population
    in Canada have used complementary medicine at least once.
  • In
    Germany, 90% of the population have used a natural remedy at some point in their
    life. Between 1995 and 2000, the number of doctors who had undergone special training
    in natural remedy medicine had almost doubled to 10 800.
  • In
    the United States, 158 million of the adult population use complementary medicines
    and according to the USA Commission for Alternative and Complementary medicines,
    US $17 billion was spent on traditional remedies in 2000.
  • In
    the United Kingdom, annual expenditure on alternative medicine is US$ 230 million.
  • The global market for herbal
    medicines currently stands at over US $ 60 billion annually and is growing steadily.

Safety
and efficacy issues

Scientific
evidence from randomized clinical trials is only strong for many uses of acupuncture,
some herbal medicines and for some of the manual therapies. Further research is
needed to ascertain the efficacy and safety of several other practices and medicinal
plants.

Unregulated or
inappropriate use of traditional medicines and practices can have negative or
dangerous effects.

For
instance, the herb “Ma Huang” (Ephedra) is traditionally used in China to treat
respiratory congestion. In the United States, the herb was marketed as a dietary
aid, whose over dosage led to at least a dozen deaths, heart attacks and strokes.

In
Belgium, at least 70 people required renal transplant or dialysis for interstitial
fibrosis of the kidney after taking a herbal preparation made from the wrong species
of plant as slimming treatment.

Biodiversity
and sustainability

In
addition to patient safety issues, there is the risk that a growing herbal market
and its great commercial benefit might pose a threat to biodiversity through the
over harvesting of the raw material for herbal medicines and other natural health
care products. These practices, if not controlled, may lead to the extinction
of endangered species and the destruction of natural habitats and resources.

Another
related issue is that at present, the requirements for protection provided under
international standards for patent law and by most national conventional patent
laws are inadequate to protect traditional knowledge and biodiversity.

Tried
and tested methods and products

  • 25%
    of modern medicines are made from plants first used traditionally.
  • Acupuncture
    has been proven effective in relieving postoperative pain, nausea during pregnancy,
    nausea and vomiting resulting from chemotherapy, and dental pain with extremely
    low side effects. It can also alleviate anxiety, panic disorders and insomnia.
  • Yoga can reduce asthma attacks
    while Tai Ji techniques can help the elderly reduce their fear of falls.
  • TM
    can also have impact on infectious diseases. For example, the Chinese herbal remedy
    Artemisia annua, used in China for almost 2000 years has been found to be effective
    against resistant malaria and could create a breakthrough in preventing almost
    one million deaths annually, most of them children, from severe malaria.
  • In
    South Africa, the Medical Research Council is conducting studies on the efficacy
    of the plant Sutherlandia Microphylla in treating AIDS patients. Traditionally
    used as a tonic, this plant may increase energy, appetite and body mass in people
    living with HIV.

WHO
efforts in promoting safe, effective and affordable traditional medicine

The
World Health Organization launched its first ever comprehensive traditional medicine
strategy in 2002. The strategy is designed to assist countries to:


  • Develop national policies on the
    evaluation and regulation of TM/CAM practices;
  • Create
    a stronger evidence base on the safety, efficacy and quality of the TAM/CAM products
    and practices;
  • Ensure availability
    and affordability of TM/CAM including essential herbal medicines;
  • Promote
    therapeutically sound use of TM/CAM by providers and consumers;
  • Document
    traditional medicines and remedies.

At
present, WHO is supporting clinical studies on antimalarials in three African
countries; the studies are revealing good potential for herbal antimalarials.

Other
collaboration is taking place with Burkina Faso, the Democratic Republic of the
Congo, Ghana, Mali, Nigeria, Kenya, Uganda, and Zimbabwe in the research and evaluation
of herbal treatments for HIV/ AIDS, malaria, sickle cell anaemia and Diabetes
Mellitus.

In Tanzania,
WHO, in collaboration with China, is providing technical support to the government
for the production of antimalarials derived from the Chinese herb Artemisia annua.
Local production of the medicine will bring the price of one dose down from US
$6 or $7 to a more affordable $2.

In
2003, WHO support has so far facilitated the development and introduction of traditional
and alternative health care curricula in seven tertiary education institutions
in the Philippines.

Training
workshops on the use of traditional medicines for selected diseases and disorders
have also been organized in China, Mongolia and Vietnam.

Priorities
for promoting the use of traditional medicines

Over
one-third of the population in developing countries lack access to essential medicines.
The provision of safe and effective TM/CAM therapies could become a critical tool
to increase access to health care.

While
China, the Democratic People’s Republic of Korea, the Republic of Korea and Vietnam
have fully integrated traditional medicine into their health care systems, many
countries are yet to collect and integrate standardized evidence on this type
of health care.

70 countries
have a national regulation on herbal medicines but the legislative control of
medicinal plants has not evolved around a structured model. This is because medicinal
products or herbs are defined differently in different countries and diverse approaches
have been adopted with regard to licensing, dispensing, manufacturing and trading.

The
limited scientific evidence about TM/CAM’s safety and efficacy as well as other
considerations make it important for governments to:

  • Formulate
    national policy and regulation for the proper use of TM/CAM and its integration
    into national health care systems in line with the provisions of the WHO strategies
    on Traditional Medicines;
  • Establish
    regulatory mechanisms to control the safety and quality of products and of TM/CAM
    practice;
  • Create awareness
    about safe and effective TM/CAM therapies among the public and consumers;
  • Cultivate
    and conserve medicinal plants to ensure their sustainable use.

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Wednesday, January 16, 2008

Cancer article

Cancer

WHAT IS CANCER?

Cancer
is a generic term for a group of more than 100 diseases that can affect any part
of the body. Other terms used are malignant tumours and neoplasms. One defining
feature of cancer is the rapid creation of abnormal cells which grow beyond their
usual boundaries, and which can invade adjoining parts of the body and spread
to other organs, a process referred to as metastasis. Metastases are the major
cause of death from cancer.

FACTS ABOUT CANCER

Cancer
is a leading cause of death worldwide. From a total of 58 million deaths worldwide
in 2005, cancer accounts for 7.6 million (or 13%) of all deaths. The main types
of cancer leading to overall cancer mortality are:

  • lung
    (1.3 million deaths/year);
  • Stomach (almost 1 million deaths/year);
  • Liver
    (662,000 deaths/year);
  • Colon (655,000 deaths/year) and
  • Breast (502,000
    deaths/year).

More than 70% of all cancer deaths in 2005 occurred
in low and middle income countries. Deaths from cancer in the world are projected
to continue rising, with an estimated 9 million people dying from cancer in 2015
and 11.4 million dying in 2030.

The most frequent cancer types world wide
are:

  • Among men (in order of number of global deaths): lung,
    stomach, liver, colorectal, oesophagus and prostate.
  • Among women (in order
    of number of global deaths): breast, lung, stomach, colorectal and cervical.

QUICK
CANCER FACTS

  • 40% of cancer can be prevented (by a healthy
    diet, physical activity and not using tobacco).
  • Tobacco use is the single
    largest preventable cause of cancer in the world. Tobacco use causes cancer of
    the lung, throat, mouth, pancreas, bladder, stomach, liver, kidney and other types;
    Environmental tobacco smoke (passive smoking) causes lung cancer.
  • One-fifth
    of cancers worldwide are due to chronic infections, mainly from hepatitis B viruses
    HBV (causing liver), human papilloma viruses HPV (causing cervix), Helicobacter
    pylori (causing stomach), schistosomes (causing bladder), the liver fluke (bile
    duct) and human immunodeficiency virus HIV (Kaposi sarcoma and lymphomas).

WHAT
CAUSES CANCER?

Cancer occurs because of changes of the genes responsible
for cell growth and repair. These changes are the result of the interaction between
genetic host factors and external agents which can be categorized as:


  • physical carcinogens such as ultraviolet (UV) and ionizing radiation
  • chemical
    carcinogens such a asbestos and tobacco smoke
  • biological carcinogens such
    as
    • infections by virus (Hepatitis B Virus and liver cancer,
      Human Papilloma Virus (HPV) and cervical cancer) and bacteria (Helicobater pylori
      and gastric cancer) and parasites (schistosomiasis and bladder cancer)
    • contamination
      of food by mycotoxins such as aflatoxins (products of Aspergillus fungi) causing
      liver cancer.

Tobacco use is the single most important
risk factor for cancer and causes a large variety of cancer types such as lung,
larynx, oesophagus, stomach, bladder, oral cavity and others . Although there
are still some open questions, there is sufficient evidence that dietary factors
also play an important role in causing cancer. This applies to obesity as a compound
risk factor per se as well as to the composition of the diet such as lack of fruit
and vegetables and high salt intake. Lack of physical activity has a distinct
role as risk factor for cancer. There is solid evidence about alcohol causing
several cancer types such as oesophagus, pharynx, larynx, liver, breast, and other
cancer types.

HOW DOES CANCER DEVELOP?

Cancer
arises from one single cell. The transformation from a normal cell into
a tumour cell is a multistage process, typically a progression from a pre-cancerous
lesion to malignant tumours. The development of cancer may be initiated by external
agents and inherited genetic factors. Ageing is another fundamental factor
for the development of cancer. The incidence of cancer rises dramatically with
age, most likely due to risk accumulation over the life course combined with the
tendency for cellular repair mechanisms to be less effective as a person grows
older.

HOW CAN THE BURDEN OF CANCER BE REDUCED ?

The
existing body of knowledge about the causes of cancer and about interventions
to prevent and manage cancer is extensive. Cancer control is understood
as public health actions which are aimed at translating this knowledge into practice.
It includes the systematic and equitable implementation of evidence-based strategies
for cancer prevention, early detection of cancer and management of patients with
cancer.

  • Up to one third of the cancer burden could be reduced
    by implementing cancer preventing strategies which are aimed at reducing
    the exposure to cancer risk mainly by:
    • changes in tobacco
      and alcohol use, and dietary and physical activity patterns
    • immunization against
      HPV infection
    • the control of occupational hazards
    • reducing exposure to
      sunlight
  • Another third of the cancer burden could be cured if detected
    early and treated adequately
    .
    • Early detection of
      cancer is based on the observation that treatment is more effective when cancer
      is detected earlier. The aim is to detect the cancer when it is localized. There
      are two components of early detection programmes for cancer:
      • Education
        to promote early diagnosis by recognizing early signs of cancer such as:
        lumps, sores, persistent indigestion, persistent coughing, and bleeding from the
        body's orifices; and the importance of seeking prompt medical attention for these
        symptoms.
      • Screening is the identification by means of tests of people
        with early cancer or pre-cancer before signs are detectable. Screening tests are
        available for breast cancer (Mammography) and Cervical cancer (Cytology tests).
  • Treatment of cancer is aimed at curing, prolonging
    life and improving quality of life
    of patients with cancer. Some of the most
    common cancer types such as breast cancer, cervical cancer and colorectal cancer
    have a high cure rate when detected early and treated according to best evidence.
    The principal methods of treatment are surgery, radiotherapy and chemotherapy.
    Fundamental for adequate treatment is an accurate diagnosis by means of investigations
    involving imaging technology (ultrasound, endoscopy, radiography) and laboratory
    (pathology).
  • Relief from pain and other problems can be achieved in over 90%
    of all cancer patients by means of palliative care. Effective strategies
    exist for the provision of palliative care services for cancer patients and their
    families, even in low resource settings.

WHO'S
STRATEGY FOR PREVENTION AND CONTROL OF CANCER

Following the adoption of
a Cancer Prevention and Control Resolution at the 58th WHA on May 2005, WHO is
developing the Global WHO Cancer Control Strategy. The Strategy aims at
reducing the cancer burden and cancer risk factors as well as improving the quality
of life of patients and their families worldwide by means of planning and implementing
cancer prevention and control strategies. The cancer control strategy is integrated
into the overall WHO chronic disease prevention and control framework of the Department
of Chronic Diseases and Health Promotion. The cancer control strategy is based
on the following guiding principles:

  • People-centered:
    the ultimate goal is to improve the well-being of the people, communities, families
    and individuals.
  • Equity: the strategy focuses on the needs of low-and
    middle-income countries and of vulnerable and marginalized populations.
  • Ownership:
    the strategy guarantees the strong commitment and active involvement of key stakeholders
    in each stage of the decision-making process and implementation.
  • Partnership
    and multisectoral approach:
    the strategy ensures the wide participation and
    collaboration of all sectors: public and private,
  • Sustainability: the
    strategy emphasizes the need for national governments and partners collectively
    strive for financial and technical self-reliance, to ensure the continuation of
    benefits from established programmes after major assistance has been completed.
  • Integration: the strategy is embedded within the overall framework
    of chronic disease prevention and control and other related areas (such as environmental
    health, communicable diseases, etc).
  • Stepwise approach: the strategy
    considers the implementation of interventions, at a national or sub-national level,
    in a sequential manner.
  • Evidence-based: the strategy is based on research
    results, programme evaluation, economic analysis, best practice, and lessons from
    countries.

WHO, in cooperation with its cancer research agency, the
International Agency for Research in Cancer (IARC), and other organizations of
the United Nations system, will provide the leadership for international cancer
prevention and control and will develop the following actions:


  • Advocacy and political commitment for cancer prevention and control
  • Generation
    of new knowledge and dissemination and diffusion of existing knowledge to facilitate
    the application and programme delivery of evidence-based approaches to cancer
    control
  • Development of standards and tools for guiding effective cancer control
    planning and implementation of evidence-interventions for prevention, early detection,
    treatment and palliative care
  • Facilitating the development of multisectoral
    networks of cancer control partners at the global, regional and national levels
  • Building capacity for developing and implementing effective policies and programmes
    and strengthening health systems
  • Provision of technical assistance for the
    rapid, effective and efficient translation of evidence-based cancer control interventions
    into public health policies and programmes in developing countries