Impact of water resources
development on health: Ghana
Francis Anto
(PhD)
Navrongo Health Research
Centre - GHS
Navrongo Health Research Centre- Ghana Health Service
Map of Ghana showing some water development
projects
Tono dam
Proposed Bui dam
Volta Lake
Kassena-Nankana district showing the Tono dam
Map of KND showing clusters in irrigated area
Paga H/C
Ñ
Ñ
WFC WFD
W EA W EB
W EC
W ED
Ñ
WMH
TBB
Chiana H/C
Ñ
SGS SGT
TBA SGR
SG Q
SGN
SAF
SAG
SG M
SG K SGL
Ñ
SHH SHG
SGJ
Biu H/C
KNE H/C
Health Impact of water resources
development
Programmes of water resources development and
the resultant population movements are known
to have worsened the transmission of
schistosomiasis in countries like Ghana, Nigeria,
Sudan, Brazil and the Philippines (Iarotski and
Davis, 1981).
This has led to an increase in both prevalence and
intensity of infection.
Health Impact of water resources
development cont.
Water resources development has become
increasingly important in African countries
including Ghana
Although improved hydraulic infrastructure holds
potential for:
1. alleviating poverty
2. promoting economic growth
3. improving food security and mitigating floods,
adverse health effects may undermine these
objectives (Hunter et al. 1993; Jobin 1999;
Keiser et al. 2005), if the appropriate measures
are not put in place
Impact of the Tono irrigation
system on health
The largest irrigation system in Ghana (Tono irrigation
system-ICOUR) is located in the Kassena-Nankana
district of the upper east region
The region has about 144 small dams and 70 dug-outs
These water development schemes have worsened the
schistosomiasis burden of the region (Scott, 1977;
Amankwa, et al., 1994; Hunter, 2003)
Leading to a prevalence level of about 70% among schoolage children living along the Tono irrigation canals
(Amankwa, et al., 1994)
Fig. 1. Prevalence of Schistosomiasis in School-age children in the
Kassena-Nankana district of northern Ghana, 2006
60
Infection
S. mansoni
S. haematobium
% infection levels
50
40
30
20
10
0
Overall
Males
Females
In-school
Not-in school
Categories
Overall infection was 48%, more males (52%) than females (41%) infected p=0.002
Overall infection in in-school children similar to those not in-school
Fig. 2. Prevalence of schistosomiasis in school-age children in the
Kassena-Nankana district of northern Ghana in relation to water
contact activities, 2006
60
% infection levels
50
40
30
20
10
0
Yes
No
Swimming
Yes
No
Tomato farm
Yes
No
Rice farm
Water contact activities
71% swim in canals, 60% wash items in canals, More swimmers (p=0.004)
than non-swimmers were infected. More workers on tomato farms
(p=0.003) than non workers were infected
Table 1. Malaria transmission intensity
in the Kassena-Nankana district
Geographical zone
Transmission
Intensity
36.7
Biting rate
Irrigated
(bite per man Non-irrigated lowland 5.9
per night )
Rocky highland
5.2
EIR
Irrigated
630
(Infective
Non-irrigated lowland 228
bite per year)
Rocky highland
360
(Appawu et al, 2004)
Table 2. Malariometric characteristics of children (<5 yrs) surveyed in
KND (2001-2002)
Parameters
Geographical zone
Rural
irrigated
Rural nonirrigated
Central more
urbanized
P-value
Overall parasite
prevalence
48%
56%
30%
<0.001
Overall bednet use
80%
23%
34%
<0.001
Severe anaemia
(Hb<6.0g/dL)
1.3%
3.5%
3.5%
>0.5
Fever (axillary
temperature ≥37.5oC
8.3%
9.1%
13.3%
>0.5
All cause mortality
100.5/1000 153.7/1000
live births
live births
95.9/1000 live
births
<0.05
Malaria specific
mortality
26.4/1000
live births
27.7/1000 live
births
>0.05
48.4/1000
live births
Fig. 3. Seasonal prevalence of malaria infection in children under
5 years in rural northern Ghana by place of residence, 2001-2002
80
Percentage infection levels
70
60
50
40
30
20
10
0
Dry season
Wet season
Rural non-irrigated area
Dry season
Wet season
Rural irrigated area
Dry season
Wet season
Central more urbanized
Season and location
Prevalence of infection was seasonal in rural non-irrigated area (dry=37.7%; wet 72.2%, p<0.001).
The prevalence of infection in the rural irrigated (dry=41.3%; wet 55.4%, p>0.05) and central more
urbanized (dry=22.6%; wet 34.3%, p>0.05) areas was not seasonal
Fig. 4. Prevalence of parasitemia in children sleeping or not
sleeping under bed nets in the KND 2001-2002
Percentage of children with malaria
infection
56
54
52
50
48
46
44
42
Yes bed net
No bed net
Net use
Bed net was found to protect those who used them
from malaria infection (p=0.003)
Fig. 5. Malaria parasitemia and all cause mortality in children under 5
years of age in the Kassena-Nankana district of northern Ghana, 20012002
180
Allcause mortality
Malaria parasitemia
Percentage of children with
malaria infection
160
140
120
100
80
60
40
20
0
Rural Irrigated
Central urbanized
Rural non-irrigated
Total
Area of residence
All cause mortality was highest in the rural non-irrigated area
where malaria infection was also highest
Impact of Akosombo dam on health
When Ghana gained independence in 1957 from
British colonial rule, it was envisioned that the
Akosombo dam project was the most
economical source of energy needed for the
industrialization and modernization of the
country
This led to an increase in prevalence of
schistosomiasis from about 3% in 1961 to about
84% by 1967 in schoolchildren [upstream: Kete
Krachi, and Yeji] (Paperna, 1969)
And also from about 17% in 1963 to 74.6% in 1981
[downstream: Bator](Wen and Chu 1984)
Bui dam site
Bui dam
Having had problems with the supply of
adequate electricity from Akosombo dam,
for over a year now, the government of
Ghana is embarking on building of another
hydroelectric dam, the Bui dam.
In addition to generating electricity, there will
be an irrigation system and
A modern city, the Bui city
Ecological changes with dam
construction
Flow of the river
slow down
Increased aquatic
vegetation
Inundation of
forest vegetation
Proliferation
of water
snails
Reduction in tsetse
Fly population
Increased
schistosomiasis
Favourable
habitat for
mosquito breeding
Increased malaria
Prevalence
Increased LF
Prevalence
Temporary reduction
In incidence of
trypanosomiasis
Creation of ponds
Proliferation of
cyclops
Reduction in Black
Fly population
Reduction in
Prevalence of
River blindness
Increase in
Prevalence of
Guinea worm
Vegetative re-growth
Rapid rebound of
infestation
Some beneficial effects
1. Reduction in incidence of onchocerciasis
2. With the irrigation scheme, there will be
improvement in food production in the
long term
Current situation at the Bui site I
The health and nutritional status of the
communities in the Bui project area have
been described as poor
That malnutrition is pervasive with a high
prevalence of infectious diseases including
schistosomiasis.
There is lack of potable water and
inadequate health services and facilities
Poor environmental sanitation and housing
(Environmental impact assessment report)
Current situation at the Bui site II
Similar to the Volta basin, schistosomiasis is
prevalent in the Bui project area (ERM
report, 2007)
There is therefore a very high likelihood that
the prevalence and intensity of the disease
will rise as a result of the development of
the water project
Potential health problems (Bui)
According to the EIA report:
The creation of the dam will impact significantly on disease incidences
in the local region
Specifically:
Bilharzia
Trypanosomiasis
Guinea worm
Intestinal worms
and onchocerciasis.
Health impacts may also arise in the long term owing to:
the loss of medicinal plants
reduced food security arising from lower farm productivity
and in-migration of people carrying communicable diseases
Conclusion
There is no doubt that water resources
development increases the incidence of
several tropical diseases
1.
2.
3.
4.
Dams in Cameroon (Atangana et al. 1979)
Kenya (Oomen 1981; Roggeri 1985)
Mali (King 1996)
Ethiopia (Lautze et al, 2007) have resulted in an
increased malaria burden
5. Ghana (Wen &Chu, 1984) schistosomiasis
6. Ghana (Ampofo and Zuta,1995) Barekese dam
Recommendations
Communities closest to the reservoir appear to be the
worst affected
Large water impoundments in malaria endemic parts of
sub-Saharan Africa are likely to increase the force of
malaria transmission
Appropriate measures need to be put in place to mitigate
the impact through informed prevention strategies
This requires an integrated approach to water resources
development that substantially incorporates health
parameters into development plans and encourages ongoing collaboration between the water and health
sectors
Recommendations
1.
Malaria
•
•
2.
Promotion of ITNs
Indoor residual spraying
Schistosomiasis
•
•
3.
Annual chemotherapy (praziquantel)
Mollusciciding (baylucide)
Lymphatic filariasis
•
4.
Annual ivermectin plus albendazole
Guinea worm
•
•
5.
Potable water
Control of cyclps (Abate)
Buruli uncer
•
Effective community surveillance
Potential areas of research
collaboration
•
•
•
•
•
•
•
Malaria
Schistosomiasis
Guinea worm
Onchocerciasis
Lymphatic filariasis
Buruli ulcer
Socio-economic studies
Thank you all