40 / 88
40
THE BURDEN OF WATER ASSOCIATED DISEASE
Infectious disease
Estimates of the global burden of water-associated human dis-
eases provide a simple index hiding a complex reality. WHO
estimates that worldwide some 2.2 million people die each year
from diarrhoeal disease, 3.7 per cent of all deaths and at any one
time over half of the world’s hospitals beds are filled with people
suffering from water related diseases (UNDP 2006). Of the 10.4
million deaths of children under five, 17 per cent are attributed
to diarrhoeal disease, i.e. an estimated 1.8 million under-fives die
annually as a result of diarrhoeal diseases. For an estimated 88
per cent of diarrhoea cases the underlying cause is unsafe water,
inadequate sanitation and poor hygiene. Moreover, it is estimated
that 50 per cent of malnutrition is associated with repeated diar-
rhoea or intestinal worm infections. Childhood malnutrition is at
the root of 35 per cent of all global child mortality (WHO, 2008).
The burden of disease is about more than just mortality; it
also takes into account the proportion of healthy life years lost.
The Disability-Adjusted Life Year (DALY) is a time-based mea-
sure of the burden on community health that combines years
of life lost due to premature mortality and years of life lost due
to periods of illness. Diarrhoeal diseases rank second in terms
of global DALYs lost (see: Table 1).
It is difficult to tease out which fraction of the disease burden
can be attributed to the poor management of wastewater. The
role of wastewater in human ill-health can pass through one
WASTEWATER, HEALTH AND HUMAN
WELLBEING
Securing safe water and reducing the unregulated discharge of wastewater are among
the most important factors influencing world health. Unmanaged wastewater is a vector
of disease, causing child mortality and reduced labour productivity, but receives a dispro-
portionately low and often poorly targeted share of development aid and investment in
developing countries. At least 1.8 million children under five years die every year due to
water related disease, or one every 20 seconds (WHO, 2008).
Figure 15:
Distribution of causes of death among children un-
der five years and within the neonatal period, 2004 (Figure from
WHO, 2008).
Source: WHO, 2008.
Distribution of causes of death among children
under five years and within neonatal period
Neonatal deaths
Acute respiratory infections
Diarrhoeal diseases
Malaria
Other infectous and parasitic diseases
HIV/AIDS
Percentage
Injuries
Non communicable diseases
Prematurity,
low birth weight
Birth asphyxia
and birth trauma
Neonatal
infections
Other non-infectious
Diarrhieal diseases
Neonatal tetanus
Congenital anomalies
Other
Measles
0
5
10
15 20 25 30 35 40
Water linked diseases
Postneonatal diseases