Plagues,
Pestilences and Diseases
Livestock diseases ravage Africa
Business Feb 12, 2011
By Jimoh Babatunde
Vanguard
New assessments from International Livestock Research Institute
(ILRI) have spelt out how livestock diseases present ‘double
trouble’ in developing countries where increasing numbers of
domestic livestock and more resource-intensive production methods
are encouraging animal epidemics.
Livestock
According to new assessments, reported yesterday at the
International Conference on Leveraging Agriculture for Improving
Nutrition & Health in New Delhi, India, “Wealthy countries are
effectively dealing with livestock diseases, but in Africa and
Asia, the capacity of veterinary services to track and control
outbreaks is lagging dangerously behind livestock
intensification,’ said John McDermott, deputy director general for
research at the International Livestock Research Institute (ILRI),
which spearheaded the work.
This lack of capacity, according to the reports, is particularly
dangerous because many poor people in the world still rely on farm
animals to feed their families, while rising demand for meat, milk
and eggs among urban consumers in the developing world is fueling
a rapid intensification of livestock production.’
On the trouble being faced by the developing countries, the new
assessments revealed that “First, livestock diseases imperil food
security in the developing world, where some 700 million people
keep farm animals and up to 40 percent of household income depends
on them, by reducing the availability of a critical source of
protein.
“Second, animal diseases also threaten human health directly when
viruses such as the bird flu (H5N1), SARS and Nipah viruses ‘jump’
from their livestock hosts into human populations.”
McDermott, one of the co-author with Delia Grace, said ‘In the
poorest regions of the world, livestock plagues that were better
controlled in the past are regaining ground,’ they warn, with
‘lethal and devastating impacts’ on livestock and the farmers and
traders that depend on them. These ‘population-decimating plagues’
include diseases that kill both people and their animals and
destroy livelihoods.”
Livestock-specific diseases include contagious bovine ‘lung
plague’ of cattle, buffalo and yaks, peste des petits ruminants
(an acute respiratory ailment of goats and sheep), swine fever
(‘hog cholera’) and Newcastle disease (a highly infectious disease
of domestic poultry and wild birds). The world’s livestock plagues
also include avian influenza (bird flu) and other ‘zoonotic’
diseases, which, being transmissible between animals and people,
directly threaten human as well as animal health.
McDermott and Grace warn that new trends, including rapid
urbanization and climate change, could act as ‘wild cards,’
altering the present distribution of diseases, sometimes
‘dramatically for the worse.’ The authors say developing countries
need to speed up their testing and adoption of new approaches,
appropriate for their development context, to detect and then to
stop or contain livestock epidemics before they become widespread.
In a separate but related policy analysis presented at the New
Delhi conference, McDermott and Grace focus on links between
agricultural intensification and the spread of zoonotic diseases.
The researchers warn of a dangerous disconnect: the agricultural
intensification now being pursued in the developing world, they
say, is typically focused on increasing food production and
profitability, while potential effects on human health remain
‘largely ignored.’
A remarkable 61 percent of all human pathogens, and 75 percent of
new human pathogens, are transmitted by animals, and some of the
most lethal bugs affecting humans originate in our domesticated
animals. Notable examples of diseases passed from animals to
human beings include avian influenza, whose spread was primarily
caused by domesticated birds; and the Nipah virus infection, which
causes influenza-like symptoms, often followed by inflammation of
the brain and death, and which spilled over to people from pigs
kept in greater densities by smallholders.
The spread and subsequent establishment of avian influenza in
previously disease-free countries, such as Indonesia, was a
classic example, McDermott and Grace say, of the risks posed by
high-density chicken and duck operations and long poultry ‘value
chains,’ as well as the rapid global movement of both people and
livestock.
In addition, large-scale irrigation aimed at boosting agricultural
productivity, they say, has created conditions that facilitate the
establishment of the Rift Valley fever virus in new regions, with
occasional outbreaks killing hundreds of people along with
thousands of animals.
The economic impacts of such zoonotic diseases are enormous. The
World Bank estimates that if avian influenza becomes transmissible
from human to human, the potential cost of a resulting pandemic
could be USD3 trillion. Rich countries are better equipped than
poor countries to cope with new diseases—and they are investing
heavily in global surveillance and risk reduction activities—but
no one is spared the threat as growing numbers of livestock and
easy movement across borders increase the chances of global
pandemics.
But while absolute economic losses from livestock diseases are
greater in rich countries, the impact on the health and
livelihoods of people is worse in poor countries. McDermott and
Grace point out, for example, that zoonotic diseases and
food-borne illnesses associated with livestock account for at
least 16 percent of the infectious disease burden in low-income
countries, compared to just 4 percent in high-income nations.
Yet despite the great threats posed by livestock diseases,
McDermott and Grace see a need for a more intelligent response to
outbreaks that considers the local disease context as well as the
livelihoods of people. They observe that ‘while few argue that
disease control is a bad thing, recent experiences remind us that,
if livestock epidemics have negative impacts, so too can the
actions taken to control or prevent them.’
An exclusive focus on avian influenza preparedness activities in
Africa relative to other more important disease concerns, they
point out, invested scarce financial resources to focus on a
disease that, due to a low-density of chicken operations and
scarcity of domestic ducks, is unlikely to do great damage to much
of the continent. And they argue that a wholesale slaughter of
pigs in Cairo instituted after an outbreak of H1N1 was ‘costly and
epidemiologically pointless’ because the disease was already being
spread ‘by human-to-human transmission.’
McDermott and Grace conclude that to build surveillance systems
able to detect animal disease outbreaks in their earliest stages,
developing countries will need to work across sectors, integrating
veterinary, medical, and environmental expertise in ‘one-health’
approaches to assessing, prioritizing and managing the risks posed
by livestock diseases.