schistosomiasis control in kwabeng

Schistosomiasis Control in Kwabeng

Tufts University Department of Civil and Environmental Engineering

Social, Environmental, and Engineering Challenges to Reducing Schistosomiasis Incidence

in a Rural Town in Eastern Ghana

Tufts University, Dept. of Civil & Environmental Engineering

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Project Team

Student Members: – Casey Caldwell, Robert Curry, Charline

Han, Daron Kurkjian, Kelly Sanborn, and Katie Shuman

Faculty Advisors: – John Durant and David Gute


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The Problem Schistosomiasis is water-borne parasitic disease that

is contracted by coming into contact with contaminated water

We hypothesized that hydraulic alterations to the river in Kwabeng have increased the incidence of schistosomiasis

Source: Rob Curry


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Life Cycle of Schistosomiasis

Source: http://www.payer.de/entwicklung/entw2039.gif


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Long Term Project Objective

Decrease, if not eliminate, the incidence of schistosomiasis in Kwabeng, Ghana

Promote better management of water resources in Kwabeng

Assess the transportability of our approach to other affected communities


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First Year Project Objectives

Research the nature and complexity of the problem

Establish baseline data for Kwabeng Create relationships with community

members Design a matrix to determine the best

possible solutions


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Research Methods in Kwabeng

Gathered water data– Velocity,

Temperature, pH, Dissolved Oxygen, Specific Conductivity

Source: Rob Curry

Average Max MinSpC

(mJ/cm)0.118 0.124 0.097

pH 7.20 7.80 6.86

Temp

(oC)25.59 29.58 24.15

DO (mg/L)

7.33 7.85 6.29


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Identified presence of schistosomiasis in water and in children– Collected snails– Identified schistosomes in snails– Conducted school surveys to determine

incidence of infection in children, along with river use habits


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Snail and Velocity Correlation

0

5

10

15

20

25

0 0.1 0.2 0.3 0.4 0.5 0.6

Velocity (meters/second)

Nu

mb

er o

f sn

ails


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Met with community members and leaders– Gathered community

acceptance and historical data for the town

Helped establish a committee to continue project efforts in Kwabeng

Source: Katie Shuman


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Made maps of the before and after mining company changes

Used a GPS unit, measuring tape, and compass

Digitized the maps for use in GIS


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Identifying Interventions

Identified three types of interventions– Reduce number of snails in the river– Prevent people from exposure to parasites – Reduce the population of parasites in

snails


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Selection Criteria

Cost– Relative cost taking into account capital cost and

O & M Feasibility

– How possible the intervention technology is in Kwabeng

• Access to equipment• Human health and safety concerns

Community Acceptance– How well the proposed solution resonates with the

community• Cultural, political and economic implications


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Selection Criteria Continued

Efficacy– Success rate in decreasing the incidence

of schistosomiasis• Can the intervention stand alone• Has it been successful in other areas

Sustainability– Longevity of the intervention


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Numbering System

Cost: • 1 = most expensive 5 = least expensive

Feasibility: • 1 = least feasible 5 = most feasible

Community Acceptance: • 1 = not supported 5 = very supported

Efficacy:• 1 = not effective 5 = very effective

at decreasing infection Sustainability:

• 1 = not sustainable 5 = indefinitely sustainable


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All Possible Rated Interventions

Total RatingSpecific Intervention UW 10% UW 15% UW 15% UW 35% UW 25% (Max:5)

Increase staff school visits 3 0.3 4 0.6 3 0.45 3 1.05 3 0.75 3.15Free schisto screening & drugs 2 0.2 2 0.3 4 0.6 4 1.4 3 0.75 3.25

Public Latrines 3 0.3 5 0.75 2 0.3 4 1.4 1 0.25 3.00Town-wide education campaign 5 0.5 3 0.45 4 0.6 3 1.05 3 0.75 3.35

Do nothing 5 0.5 5 0.75 1 0.15 1 0.35 1 0.25 2.00Increase Predators 4 0.4 2 0.3 3 0.45 1 0.35 1 0.25 1.75

Increase Direct Snail Competitors 4 0.4 2 0.3 3 0.45 1 0.35 2 0.5 2.00Plants- for Shade 5 0.5 3 0.45 3 0.45 3 1.05 3 0.75 3.20Plants-in Water 3 0.3 4 0.6 3 0.45 3 1.05 2 0.5 2.90

Increase slope of channel 1 0.1 1 0.15 2 0.3 4 1.4 5 1.25 3.20Reduce Cross-sectional area 1 0.1 1 0.15 2 0.3 4 1.4 4 1 2.95

Restoring Flow or Modified Flow 1 0.1 4 0.6 4 0.6 5 1.75 5 1.25 4.30Herbicide 3 0.3 2 0.3 1 0.15 3 1.05 2 0.5 2.30

Mollusicide 3 0.3 2 0.3 1 0.15 2 0.7 2 0.5 1.95Public showers 2 0.2 3 0.45 3 0.45 2 0.7 3 0.75 2.55

Wells 3 0.3 4 0.6 2 0.3 2 0.7 3 0.75 2.65Public Taps 3 0.3 4 0.6 4 0.6 2 0.7 3 0.75 2.95

Recreation Area 3 0.3 4 0.6 3 0.45 1 0.35 4 1 2.70Expand Household Distribution System 2 0.2 4 0.6 4 0.6 2 0.7 4 1 3.10

SustainabilityCost Feasibility Community Acceptance Efficacy


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Snail Control: Reducing the amount of snails in the river

Type of Intervention

Specific Intervention

Cost Sustainability Community Acceptance

Efficacy Feasibility Total

Weighted Score

- Purchase cost - Monitoring

- Talapia already present in the water, problem persists

People eat snails from the river, must be Bulinus specific

Low, ecologically impractical

- Must teach people to not eat the predatory fish

Increase Predators

4 1 3 1 2

1.75

-Purchase cost -Monitoring

-Acuta already present, Bulinus still present -Rebalancing effect of nature, would force restocking of competitors

Unknown, likely to be neutral

Low, plant and algal food source would need to be highly degraded

-Predators of competitors would be attracted to rivers

Increase Direct Snail Competitors

4 2 3 1 2

2.00

-Purchase cost -Monitoring

-Depends on community education that trees need to protect river from becoming hospitable to plants that snails live on

High, restoration efforts good, some farmers close to rivers may oppose

High, areas with less plants had few to no snails

-Deforestation on banks could quickly revert situation to present conditions

Plants- for Shade

5 3 3 3 3

3.20

-Labor

-Need to constantly “weed” entire watershed

Plants are part of river ecosystem

Plants provide part of the surface snails live on, branches and other submerged surfaces would need to be removed as well

-Would expose workers to river -Safety issues

Biological Controls

Plants-in Water

3 2 3 3 4

2.90


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Type of Intervention


Cost Sustainability Community Acceptance Efficacy Feasibility Total

Weighted Score

Labor: Construction: Overhead: Design: Volunteered

High, permanent structure

- Need partnership with mining co. - Mining operations to resume June 04 -Reduces recreational use of river -Massive earth moving work may be opposed

High, targets snail habitat

- Mining co. has access to equipment and experience altering rivers - Construction already done on Abudusu -Difficult to implement

Increase slope of channel

1 5 2 4 1

3.20


-High, permanent structure -May require routine maintenance

-Reduces recreational use of river -may impede water gathering - Need partnership with mining co.


- Mining co. has access to equipment and experience altering rivers -may interfere with river uses

Reduce Cross-sectional area

1 4 2 4 1

2.95


-High, permanent features -Community & Government Vigilance in protection of river

- Need partnership with mining co. - Support from some Assembly men and farmers


- Mining co. has access to equipment and experience altering the specific rivers -Dependent on Mining Co. Compliance

Increase Velocity – River Alteration

Increase Input through

Restoring Original Flow or Modified

Flow

1 5 4 5 4

4.30

-Purchase cost -Labor to apply

- Need to continually reapply

-Very low -Water supply would be contaminated with herbicides

-High, depending on dose

-Pesticide application could negatively impact agriculture on farms Herbicide

3 2 1 3 2

2.30

-Purchase cost -Labor

- Need to continually reapply

-Low -Adding pesticide to public water supply

-Neutral, dosages commonly used are ineffective to control snail population

-Some snails are food source, would have to prevent contaminating food supply

Chemical Controls

Mollusicide

3 2 1 2 2

1.95


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Biological Controls

Harvesting Aquatic Plants– High labor demand– Competing growth surfaces reduce efficacy– Continual removal of aquatic plants will lower

biological productivity of river– Kwabeng community view option as drastic

Adding Terrestrial Plants for Shade– Shade reduces aquatic plant life in

river, habitat of the snails– Competing land requirements from

farmers near banks of river– Correlation between high shade and

low/no snail population

Source: http://www.kauai-vacation-rentals.com/shadesofgreen/100shades.htm


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Biological Controls Increase Snail Predator Population

– Fishing of beneficial predators would limit snail reduction gains

– Ecological equilibrium would require constant addition of fish to effectively reduce snail populations

– Risk of unintended consequences of species introduction– Population monitoring costs high

Increase Direct Snail Competitors– Competitive species could be local foods (certain snail

species) – Ecological equilibrium between species will require

excessive competitor population


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Chemical Controls Herbicide

– Ineffective long term solution– Risk to farmers who irrigate from river water– Town water supply impacted

Molluscicide– Requires 8 hour contact time with river– Temporary solution– If implemented incorrectly could increase chemical

resistance of snails– Towns water supply impacted


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Increasing the River Velocity Increase slope channel

– Effective, but impractical– Major earth moving needed– Water supply weir would need to be removed– Changes to the water supply system drastic

Reduce Cross-Sectional Area– Entire river would need width contraction – high expense– Maintenance against erosion could be high, with seasonal

storm and flood events– Community skeptical of option


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Increasing the River Velocity

Increase Input Through River Restoration– Rejoin the Awusu and the

Abodusu Rivers– Partnership with Mining Co.

necessary• Earth moving equipment in

hands of Mining Co.• Experience in river alterations

– Highly effective– Desired by many in community

Source: Charline Han


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Cost Feasibility Community Acceptance

Efficacy Sustainability Total

-construction costs -pay attendant -maintenance -water costs

-would need land -need to have water co. bring in pipes

- Children should shower for free b/c they use latrines for free

-Must be coupled with other intervention -doesn’t prevent river use

-workmanship and

maintenance Public

showers

2 3 3 2 3

2.55

- pay attendant -construction with machinery -maintenance

-don’t know depth to water table

- People prefer to get water from river or taps


-too much use could effect water table Wells

3 4 2 2 3

2.65

-expand of water system -pay attendant -maintenance -water costs

- 9 taps already exist in town

- Many people use public taps - Children in charge of getting water pocket money and go to river

- Must be coupled with other intervention -doesn’t prevent river use

-water co. must maintain water system and quality

Public Taps

3 4 4 2 3

2.95

-construction -maintenance

-Are supplies available in Ghana?

-would children use it?


-workmanship and

maintenance Recreation

Area

3 4 3 1 4

2.70

-pay water co. to expand -water costs -maintenance(?)

- Ghana Water Co Ltd. not cooperating with secondary school

- Very expensive


-water co. must maintain water system and quality

Expand Household

Distribution System

2 3 4 2 4

2.95

Alternatives to Using the River


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Public Showers

Construction, operation, and maintenance costs

Adults would be willing to pay a small fee, but children would have to be free.

Attendant needed for maintenance and up keep.

Need cooperation with Ghana Water Ltd. Does not prevent river use Must be coupled with other interventions


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Public Wells Construction, operation, and

maintenance costs Don’t know depth to water table Small fee for usage (1-2¢) Community is resistant to using

wells because they are usually hand dug and the water does not come from the river

Does not prevent river use Must be coupled with other

interventions Source: Charline Han


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Public Taps


Many taps already in town Small fee for usage (1-2¢) Does not prevent river use Must be coupled with other interventions


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Recreation Area

Construction cost and constructability.– Are supplies available in Ghana?

Will Children use it? Does not prevent river use Must be coupled with other

interventions


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Expand Household Distribution System

Implementation costs high as are recurring costs

Not everyone has a “house” Requires cooperation of Ghana Water

Ltd. Does not prevent river use Must be coupled with other

interventions


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Specific Intervention Cost Feasibility Community Acceptance Efficacy Sustainability Total

Weighted Rating

Salary of nurse

- 1 nurse has outings to schools three times per week over entire district for many illnesses (including schisto) - Cooperation of Ghana Health Services that runs clinic - Physical space availability at clinic

- Committee supports increased assistance at clinic - Accountability is a concern

- Double the rate of screening - Students are required to self diagnose symptoms

- Long term funding needed - Follow up needed

Medical treatment – Increase staff for existing school visit

treatment system

3 4 3 3 3

3.15

Diagnosis - Salary for a team of nurses/DRs/lab techs for 1 day Treatment - Praziquantel: $1.33 per dose for adult, $0.66 per dose for children

- Commitment from health personnel

- Committee ID poverty as a barrier - Committee recognized difficulties in accessing drugs - focused screening

- People are constantly reinfected - One dose treatment

- Praziquantel gives little to no immunity - Reduces return of eggs to river

Medical treatment – Monthly free schisto screening & drug

distribution day

2 2 4 4 3

3.25

Construction - $2-3 per day cost of labor - Equipment costs - Capital costs for building materials O & M - $10-12 per month Income - Children use for free - $0.10 per use

- Access to construction equipment

- Public latrines exist in town – new set just built - Drug problem at latrines - Must be free for children - Cost discourages use

- Eggs could be entering the river if not designed properly - Proximity to residences - Cost discourages use

- Finite life span Reducing egg return to river from humans – latrines

3 5 2 4 1

3.00

Children

- 5 Primary schools - Teachers are qualified to teach health issues - Hard to teach very young children

- District commissioner very helpful - Not all children go to school

- Constant reeducation process as children enter/leave school

- Cost of teacher/health care professional’s time

- Difficult to bring adults together physically to educate them - Differing levels of education and understanding within the community

- Adults don’t prioritize schistosomiasis - Community resistance to behavioral changes

- Constant reeducation necessary - Comprehensive education program could greatly reduce (re)infection rates

- Constant reeducation necessary

Town-wide education campaign

Adults

5 3 4 3 3

3.35

- Makes people feel weak and anemic

- Feasible - Invested in finding a solution to the problem

- Current interventions are not very effective

- Hypothesize that incidence will increase

Do nothing

5 5 1 1 1

2.00

Schistosome Control: Reducing parasite population in snails


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Medical Treatment-Increase Staff for Existing School Visit Treatment System

Currently one nurse conducts school visits to evaluate children’s health

Students are required to self-assess illnesses Town clinic run by Ghana Health Services,

therefore requires cooperation Community questions current system’s

accountability and supports increased assistance

Long term monitoring needed


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Medical Treatment-Monthly Free Schistosomiasis Screening and Drug Distribution Days

Salary of nurse, MDs, and lab techs Cost of Praziquantel (most common

drug used for treatment) Reinfection rate a concern Medication does not confer immunity Reduces egg return to the river, thus

breaking life cycle


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Latrines - Reducing Egg Return to River from Humans


Small income generated because adults would pay to use latrines

Latrines already exist in town and are not widely used because of their cost to the users

Finite life span, therefore lacks sustainability Reduces egg return to the river, thus

breaking life cycle


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Town-wide Education Campaign Two target populations: children

and adults Cost of educated health

personnel Behavioral changes are often

difficult to implement and sustain

Constant reeducation necessary

Preventing schistosomiasis is not presently a priority in Kwabeng

Source: Charline Han


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No Action Alternative

Side effect of schistosomiasis is anemia, which makes people feel weak and decreases worker productivity

Community is invested in working with us to find a solution

Hypothesis that incidence rates on the rise


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Conclusions and Recommendations

Top three interventions1. Increase river velocity by river restoration2. Town-wide education campaign3. Monthly schistosomiasis screening and

treatment days Interventions can be used in

conjunction with each other– Lower scoring interventions can be used

to supplement main intervention


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Future Work Ongoing

– Locate sources of funding– Identify international partners

Year 2 – In depth data collection on the recommended interventions and selection of the best intervention

Year 3 – Design of selected intervention Year 4 – Implementation Year 5 – Monitoring and evaluation


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Acknowledgements

Professors John Durant and David Gute Kwabena Kyei-Aboagye Dr. Kwame Boadu Kwabeng District Superintendent of Schools Professor Manu, University of Ghana Provost Bharucha Tufts University Center for Children Department of Civil and Environmental

Engineering

schistosomiasis control in kwabeng

Documents

rob currytufts university

long plants0

david gutetufts university

bankside plants0

bank835few of crab grass

darondescription of

gutedescription of site

schistosomiasis incidencein