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

Volta Lake

Tono dam

Proposed Bui dam

Kassena-Nankana district showing the Tono dam

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WMH

Chiana H/C

Biu H/C

KNE H/C

Paga H/C

Map of KND showing clusters in irrigated area

SGJ

SGM

SGK

SGN

SHG

SAF

WFD

SGL

WEC

SGQ

WED

WEA

TBB

SAG

SGRSGS

WEB

TBA

WFC

SHH

SGT

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 poverty2. promoting economic growth3. 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 school-age 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

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Overall Males Females In-school Not-in school

Categories

% i

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ve

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Infection

S. mansoni

S. haematobium

Overall infection was 48%, more males (52%) than females (41%) infected p=0.002Overall 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

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60

Yes No Yes No Yes No

Swimming Tomato farm Rice farm

Water contact activities

% i

nfe

cti

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levels

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

Biting rate

(bite per man per night )

Irrigated 36.7

Non-irrigated lowland 5.9

Rocky highland 5.2

EIR

(Infective bite per year)

Irrigated 630

Non-irrigated lowland 228

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 non-irrigated

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 live births

153.7/1000 live births

95.9/1000 live births

<0.05

Malaria specific mortality

26.4/1000 live births

48.4/1000 live births

27.7/1000 live births

>0.05

Fig. 3. Seasonal prevalence of malaria infection in children under 5 years in rural northern Ghana by place of residence, 2001-2002

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60

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80

Dry season Wet season Dry season Wet season Dry season Wet season

Rural non-irrigated area Rural irrigated area Central more urbanized

Season and location

Pe

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nta

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infe

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lev

els

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

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48

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52

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56

Yes bed net No bed net

Net use

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ildre

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lari

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infe

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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, 2001-

2002

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40

60

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140

160

180

Rural Irrigated Central urbanized Rural non-irrigated Total

Area of residence

Per

cen

tag

e o

f ch

ildre

n w

ith

m

alar

ia in

fect

ion

Allcause mortality

Malaria parasitemia

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

Favourable habitat for

mosquito breeding

Proliferation of water snails

Increased schistosomiasis

Reduction in tsetse Fly population

Temporary reduction In incidence of

trypanosomiasis

Vegetative re-growth

Increased malaria Prevalence

Increased LF Prevalence

Creation of ponds

Proliferation of cyclops

Increase in Prevalence ofGuinea worm

Reduction in Black Fly population

Reduction in Prevalence of

River blindness

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 regionSpecifically: BilharziaTrypanosomiasisGuinea wormIntestinal worms and onchocerciasis.

Health impacts may also arise in the long term owing to: the loss of medicinal plantsreduced 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. Dams in Cameroon (Atangana et al. 1979)

2. Kenya (Oomen 1981; Roggeri 1985)

3. Mali (King 1996)

4. 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 on-going collaboration between the water and health sectors

Recommendations

1. Malaria • Promotion of ITNs• Indoor residual spraying

2. Schistosomiasis • Annual chemotherapy (praziquantel)• Mollusciciding (baylucide)

3. Lymphatic filariasis• Annual ivermectin plus albendazole

4. Guinea worm• Potable water• Control of cyclps (Abate)

5. 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