Memorandum by Michael Marmot, Professor
of Epidemiology and Public Health, UCL—Department of Epidemiology
and Public Health
The principal issues on which the Committee
would welcome your views are:
1. A recent report on Communicable
Diseases by the UK Department of Health stated that "post-war
optimism that their conquest was near has proved dramatically
unfounded". What is your assessment of the overall position?
More specifically, is it simply that not enough progress is being
made in reducing the spread of such diseases? Or is the global
situation actually deteriorating? Would it be an exaggeration
to talk of a crisis
Over the long-term, arguably a positive trend globally
(Figure 1; relating to changes in social determinants of health—poverty,
living/working conditions, as well as health care and vaccines).
This does not address resurgence (TB, malaria) nor does is account
for 49 new or re-emerging infectious diseases declared a global
health crisis by WHO in 1995. It does not address the issue of
pandemics either.
Disease specific impacts are also positive in
many cases (see measles, Figure 2).
A problem to consider from the point of view
of health care, vaccines development and the role of the Extended
Programme on Immunisation (EPI) is both the weakness of health
care systems to deliver locally, effectively and equitably (see
Figure 3), and the potential for selective PHC emphasis on vertical
single-disease control programmes to alienate populations adversely
affected by much wider conditions of poverty and disempowerment
(relative health care but also to the wider social determinants),
leading to falling rates of vaccine uptake (or active refusal)
with consequences for herd immunity (see Figure 4; Case example:
"The Congolese are dying of such diseases as kwashiorkor,
which are easily treated. Why vaccinate against polio instead
of curing the real killer diseases? Today, the priority of the
Congolese children is not vaccination of any kind. It is first
of all and especially to control the malnutrition caused by the
war of the multinationals and the pro-American invaders of the
Congo.")
The positive trends in the global picture reflect
progress in some regions, and may conceal or mitigate stagnation
or actual reversal of disease control gains (for example with
TB and HIV/AIDS in the former Soviet Union and Sub-Saharan Africa).
2. What reliable data exist regarding the
numbers of people infected globally with the four diseases[1]
on which the Committee is focusing particular attention? What
trends are discernible in both the numbers infected and the patterns
of infection? And what are the main underlying causes of infection
and of any changes in its incidence and pattern?
WHO (probably) houses reliable data on trends
and numbers; it is arguable that patterns (especially regarding
main underlying causes of infection) could be substantially strengthened—e.g.
through the establishment of a global observatory (under consideration
and planning in WHO HQ), and/or the establishment of the more
robust monitoring and reporting framework and mechanism—focusing
on health equity and the determinants of health (see CSDH recommendations).
TUBERCULOSIS
There were an estimated 8.3 million (5th-95th
centiles, 7.3-9.2 million) new TB cases in 2000 (137/100 000 population;
range, 121/100 000-151/100 000). Tuberculosis incidence rates
were highest in the WHO African Region (290/100 000 per year;
range, 265/100 000-331/100 000), as was the annual rate of increase
in the number of cases (6%). Nine percent (7%-12%) of all new
TB cases in adults (aged 15-49 years) were attributable to HIV
infection, but the proportion was much greater in the WHO African
Region (31%) and some industrialized countries, notably the United
States (26%). There were an estimated 1.8 million (5th-95th centiles,
1.6-2.2 million) deaths from TB, of which 12% (226 000) were attributable
to HIV. Tuberculosis was the cause of 11% of all adult AIDS deaths.
The prevalence of M tuberculosis-HIV coinfection in adults was
0.36% (11 million people). Coinfection prevalence rates equalled
or exceeded 5% in eight African countries. In South Africa alone
there were two million coinfected adults.
PPHC under CSDH has been conducting analysis
of the factors relating to TB infection (Tables 1 and 2).
Table 1
RELATIVE RISK, PREVALENCE AND POPULATION
ATTRIBUTABLE RISK OF RISK FACTORS FOR TB, IN 22 HIGH TB BURDEN
COUNTRIES
|
| Relative risk for active TB disease (range)
| Weighted prevalence, total population, 22 HBCs
| Population Attributable Fraction (Range)**
|
|
| HIV infection | 8.3 (6.1-10.8)
| 1.1% | 7.3% (5.2-9.6)
|
| Malnutrition | 4.0 (2.0-6.0)
| 17.2% | 34.1% (14.7-46.3)
|
| Diabetes | 3.0 (1.5-7.8)
| 3.4% | 6.3% (1.6-18.6)
|
| Alcohol dependence | 2.9 (1.9-4.6)
| 3.2%** | 5.7% (2.8-10.3)
|
| Active smoking | 2.6 (1.6-4.3)
| 18.2% | 22.7% (9.9-37.4)
|
| Indoor pollution | 1.5 (1.2-3.2)
| 71.1% | 26.2% (12.4-61.0)
|
|
(Source: WHO 2007)
* Based on global estimate of 6% for men and 0.4% for women (Rehm et al 2007).
** Note that sum of PAFs should normally be <100%, since most causal pathways requires presence of two or more risk factors simlultaneously or in sequence. The sum is less than 100% in Table 1 simply because only a few selected factors are considered.
|
Table 2
POPULATION ATTRIBUTABLE FRACTION IN SIX WHO REGIONS (HIGH
TB BURDEN COUNTRIES ONLY)
|
| WHO region | HIV
| Malnutrition | Diabetes
| Alcohol
dependence
| Smoking | Indoor air
pollution
|
|
| Africa | 28%
| 47% | 3%
| - | 10%
| 28% |
| Americas | 4%
| 17% | 9%
| - | 18%
| 6% |
| Eastern Mediterranean | 1%
| 42% | 10%
| - | 17%
| 27% |
| Europe | 7% |
8% | 14%
| - | 32%
| 3% |
| South East Asia | 5%
| 37% | 6%
| - | 23%
| 27% |
| Western Pacific | 1%
| 28% | 5%
| - | 29%
| 28% |
|
HIV/AIDS
Table 1
TRENDS IN HIV INFECTIONS BY REGION
|
| Region | No of people living with HIV (end of 1998) [39]
| No of people living with
HIV (end of 2003) [40]
| % increase
1998-2003
|
|
| Sub-Saharan Africa | 22,500,000
| 25,000,000 | 11%
|
| South and South-East Asia | 6,700,000
| 6,500,000 | -3%*
|
| Eastern Europe and Central Asia | 270,000
| 1,300,000 | 381%
|
| Western Europe | 500,000
| 580,000 | 16%
|
| East Asia | 560,000
| 900,000 | 61%
|
| Oceania | 12,000
| 32,000 | 167%
|
North Africa and
Middle East | 210,000
| 480,000 | 129%
|
| North America | 890,000
| 1,000,000 | 12%
|
| Caribbean | 330,000
| 430,000 | 30%
|
| Latin America | 1,400,000
| 1,600,000 | 14%
|
| Total | 33,372,000
| 37,822,000 | 13%
|
|
| * This apparent decrease is due to inconsistencies in data collection methods between earlier and later years, as well as revised estimates by UNAIDS.
|
Table 2
SUMMARY OF DEMOGRAPHIC IMPACTS OF AIDS
|
| Demography [9] | Without
AIDS
| With
AIDS |
Without
AIDS | With
AIDS
| Without
AIDS |
With
AIDS |
|
| 1995-2000
| | 2010-15
| | 2020-25
| |
| Life expectancy at birth (years) | 63.9
| 62.4 | 68.4
| 64.2 | 70.8
| 65.9 |
| Number of deaths (millions) | 159
| 170 | 174
| 207 | 193
| 231 |
| Crude death rate per 1,000 | 9.0
| 9.6 | 8.1
| 9.8 | 8.0
| 10.1 |
| Infant mortality rate per 1,000 | 66.4
| 67.5 | 49.8
| 51.3 | 40.9
| 42.1 |
| Child mortality rate per 1,000 | 93.9
| 98.8 | 68.9
| 75.8 | 56.1
| 62.3 |
| Population size (millions) | 3,666
| 3,639 | 4,310
| 4,204 | 4,805
| 4,599 |
|
| * UNAIDS Population Division, 2003.
|
One of the major reasons for the apparent ineffectiveness
of global [HIV/AIDS] interventions is historical weaknesses in
the health systems of underdeveloped countries, which contribute
to bottlenecks in the distribution and utilisation of funds. Strengthening
these health systems, although a vital component in addressing
the global epidemic, must however be accompanied by mitigation
of other determinants as well. These are intrinsically complex
and include social and environmental factors, sexual behaviour,
issues of human rights and biological factors, all of which contribute
to HIV transmission, progression and mortality. An equally important
factor is ensuring an equitable balance between prevention and
treatment programmes in order to holistically address the challenges
presented by the epidemic (Coovadia & Hadingham, 2005).
MALARIA
As of 2004, 107 countries and territories have reported areas
at risk of malaria transmission. Although this number is considerably
less than in the 1950s, with 140 endemic countries or territories,
3.2 billion people are still at risk. Present estimates are that
around 350-500 million clinical disease episodes occur annually
(2). Around 60% of the cases of clinical malaria and over 80%
of the deaths (1) occur in Africa south of the Sahara. Of the
more than one million Africans who die from malaria each year
(1), most are children under five years of age. In addition to
acute disease episodes and deaths in Africa, malaria also contributes
significantly to anaemia in children and pregnant women, adverse
birth outcomes such as spontaneous abortion, stillbirth, premature
delivery and low birth weight, and overall child mortality. The
disease is estimated to be responsible for an estimated average
annual reduction of 1.3% in economic growth for those countries
with the highest burden (3).
The wide variation seen in the burden of malaria between
different regions of the world is driven by several factors. First,
there is great variation in parasite-vector-human transmission
dynamics that favour or limit the transmission of malaria infection
and the associated risk of disease and death. Of the four species
of Plasmodium that infect humans—P falciparum, P vivax,
P malariae and P ovale—P falciparum causes most of the severe
disease and deaths attributable to malaria and is most prevalent
in Africa south of the Sahara and in certain areas of South-East
Asia and the Western Pacific. The second most common malaria species,
P vivax, is rarely fatal and commonly found in most of Asia, and
in parts of the Americas, Europe and North Africa. There are over
40 species of anopheline mosquitoes that transmit human malaria,
which differ in their transmission potential. The most competent
and efficient malaria vector, Anopheles gambiae, occurs exclusively
in Africa and is also one of the most difficult to control. Climatic
conditions determine the presence or absence of anopheline's vectors.
Tropical areas of the world have the best combination of adequate
rainfall, temperature and humidity allowing for breeding and survival
of anophelines.
The second major factor contributing to regional and local
variability in malaria burden is differences in levels of socioeconomic
development. Determinants include general poverty, quality of
housing and access to health care and health education, as well
as the existence of active malaria control programmes providing
access to malaria prevention and treatment measures. The poorest
nations generally have the least resources for adequate control
efforts. In many poor countries, exposure to malaria of vulnerable
populations is enhanced by migrations enforced by poverty and/or
conflict. http://www.rbm.who.int/wmr2005/html/1-2.htm#box2
5. What do you consider to be the principal blockages to
achieving progress in the prevention or control of the four diseases?
And how might these blockages be removed by more, or better-targeted
or better-coordinated intergovernmental action?
Emphasis of concept, policy, finance and action on treatment
over prevention (HIV/AIDS (PEPFAR, see below), TB (DOTS—see
Vietnam/Morocco case studies where over 85% case detection and
70% treatment (Stop TB criteria for effective control and elimination)
have not satisfactorily affected trends in infection downwards—Mario
Raviglione, CSDH, October 2007).
The money appears to be available (see below, G8 financing
to health), but it is not being channelled in the right direction
(e.g. towards effective action on the underlying causes of vulnerability).
Much of the aid flowing to "Total Health" goes
to the large single-disease global programmes—these arguably
limit and distort coherent national and local level coherence
of action across the determinants of health, whilst in some cases
establishing parallel structures to the national and local health
care system, and drawing off health workers from that system.
PEPFAR (President Bush's Emergency Plan for AIDS Relief)—offering
around USD$15 billion over 10 years, provides a good example of
a trend in financing action moving away from investment in prevention.
6. What role does your organisation play in combating the
four diseases? Do you believe that it is correctly configured
and adequately resourced to do the job? With which other organisations
do you collaborate? How would you assess the degree of synergy?
THE COMMISSION
ON SOCIAL
DETERMINANTS OF
HEALTH; UCL INSTITUTE
The CSDH marshalls global evidence on what causes poor health—including
both structural factors of social, economic, political and cultural
arrangements (locally, nationally and internationally)—and
on what kinds of interventions are effective in maintaining good
health equitably across populations.
7. What are the main non-health causes (e.g. global warming,
poverty, changes in land use, international travel, lifestyle,
population) of the spread of the four diseases? To what extent
can intergovernmental action in non-health fields contribute to
alleviation of their spread? What action is taking place or planned
in these areas? And what more needs to be done? Do you consider
that there is sufficient "joined-up" thinking in approaching
the problem?
9. Tuberculosis is potentially curable by long-term antimicrobial
therapies. Yet the numbers of reported cases worldwide seem to
be rising. Are the necessary medicines not getting through to
patients? What are the barriers to effective long-term therapy?
Are we now seeing infections which stem from other conditions—e.g.
HIV/AIDS? Or are there other reasons why a treatable disease should
be spreading? How might intergovernmental action help to deal
with this situation?
A lack of cooperation between tuberculosis and HIV/AIDS programs
is causing deaths from the two diseases in many countries, Alasdair
Reid, HIV/TB adviser for UNAIDS, said on Friday at the 38th Union
World Conference on Lung Health in Cape Town, South Africa
Up to half of reported HIV/AIDS-related deaths are caused
by TB, according to Reid. He added that in 2005, about 7% of people
with TB worldwide were tested for HIV and that fewer than one
in 200 people living with HIV/AIDS were tested for TB. According
to Reid, testing people who have TB for HIV and vice versa could
lead to earlier detection, increased access to antiretrovirals
and the prevention of "thousands of deaths".
World Health Organization data indicate that 90% of HIV-positive
people in Africa die within months of contracting TB.
IUATLD has proposed a program—called "Integrated
Care for TB Patients Living with HIV/AIDS"—to simultaneously
address both diseases. Central components of the strategy include
increased collaboration in addressing TB and HIV, and testing
for the two diseases. The strategy is being tested in various
countries, including the Democratic Republic of Congo, Uganda
and Zimbabwe. According to Reid, a new funding model should be
developed to address the two diseases. "Currently, money
is raised for either HIV or TB, and funds dedicated for HIV can't
be used for TB or vice versa," he said, adding, "This
has to change. When you want to tackle HIV you need to tackle
TB, especially in Africa where so many people are co-infected"
( Inter Press Service, 11/11).
Early data from worldwide monitoring of joint TB/HIV activities
have indicated some progress compared with previous years, according
to the SAPA/Independent Online. Since 2005, there has been a threefold
increase in the number of HIV-positive people who have been screened
for TB and a sixfold increase in the number of people with TB
who were tested for HIV. However, Reid said that without immediate
action, "it will be very, very difficult" to achieve
the HIV/AIDS targets in the UN Millennium Development Goals and
that "thousands of people with HIV will continue to die of
preventable, treatable" TB (SAPA/Independent Online, 11/9).
TB Alert, 2008.
OVER-EMPHASIS
ON TREATMENT:
DOTS
DOTS programmes are not reaching the very poorest in communities;
there is inadequate monitoring, using socioeconomic position,
to assess equity in access to DOTS programmes.
14. Are there any difficulties with regard to patents or
intellectual property which are impeding the flow of medicines
or other control methods to those infected? Is intergovernmental
action needed to improve the situation?
Two well-known WTO agreements directly commodify health.
GATS (General Agreement on Trade in Services) may accelerate health
care commercialization or at least preclude efforts to reverse
it; TRIPS (Agreement on Trade-Related Intellectual Property Rights)
extends patent protection that already limits some developing
countries' access to essential medicine and may eventually limit
access more broadly, while creating perverse incentives in medical
research.
Crucially, until governments have demonstrated the ability
to regulate private investment and provision in health services
in ways that enhance health equity, they should avoid making any
commitments in GATS or bilateral or regional agreements that involve
health services. It is not clear that any government, anywhere
in the world, has yet met this test, leading some analysts to
urge cancellation of all existing GATS commitments on health services
(most of which were from developing nations) and removing health
services from the scope of the Agreement. Some progress toward
allowing easier access to cheaper generic drugs under TRIPS was
made in 2003. The amended rules, however, remain cumbersome and
costly,12 leading to calls for moving intellectual property rights
out of binding trade treaties into some other forum for resolution,
such as the World Intellectual Property Organization (WIPO) where
such disputes were once settled diplomatically. A more far-reaching
change would involve multilateral agreement on alternatives to
financing pharmaceutical research through private investment in
anticipation of patent protected returns (Labonte & Schrecker,
2008).
17. What intergovernmental planning has been undertaken
to cope with the impact of an outbreak of infectious disease caused
by deliberate release of micro-organisms into the environment?
Is there adequate liaison between the various agencies involved,
including intelligence, law enforcement and health care professionals?
How could action by intergovernmental bodies help further?
N/a
18. Though our remit is focused specifically on known infectious
diseases, we would be interested to know how you view the global
threat from new or previously unrecognised ones and from the transmission
of infections from animals to humans.
There is a strong argument for greater attention to neglected
infectious diseases:
Table 1
THE BURDEN OF THE 13 NEGLECTED TROPICAL DISEASES IN TERMS
OF ESTIMATED MORTALITY, MORBIDITY AND POPULATION AT RISK
|
| Disease | Abbreviation
| Mortality (annually, thousands)
| Morbidity (annually, million)
| Disability adjusted life years (annually thousands)
| Population
at risk
(million)
|
|
| Buruli ulcer | BUR
| | Incidence: 0.003
| | |
| Chagas disease | CHAG
| | | |
|
| Cholera | CHOL
| Incidence: 120 | 1-2
| N/A | |
| Dengue fever *1 | DEN
| Incidence: 19 |
| 528 (2001) |
|
| Dracunculiasis | DRAC
| | Incidence: 0.016 (2004)
| | 11 African countries
|
| Human African trypanosomisasis | HAT
| 49 (2001) |
| 1,332 (2001) |
|
| Leishmaniasis *2 | LEISH
| Incidence: 59 | Incidence: 0.5 VL & 1.5 CL
| 2,357 | >350
|
| Leprosy | LEP
| | Prevalence: 0.225
| 177 | |
| Lymphatic filariasis | LF
| N/A | Prevalence: 120
| 5,644 | |
| Onchocerciasis | ONCHO
| N/A | |
| |
| Schistosomiasis *3 | SCHISTO
| | Prevalence: 193
| 1,759 | 652
|
| Soil-transmitted helminthes *4 | STH
| N/A? | Prevalence: 2,000
| 4,705 | 3,195
|
| Trachoma | TRACH
| N/A | Prevalence: 81 (Trichiasis 7.6, blindness 1.9)
| 3,997 | 10% of world's population
|
|
There is also a very strong case for much closer international
attention to non-communicable diseases, since they are, if anything,
the major critical threat to global health.
February 2008
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HIV/AIDS, Tuberculosis, Malaria and Avian Influenza. Back
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