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Schistosomiasis Control in Kwabeng. Social, Environmental, and Engineering Challenges to Reducing Schistosomiasis Incidence in a Rural Town in Eastern Ghana. Tufts University Department of Civil and Environmental Engineering. Project Team. Student Members: - PowerPoint PPT Presentation
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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
2
Project Team
Student Members: – Casey Caldwell, Robert Curry, Charline
Han, Daron Kurkjian, Kelly Sanborn, and Katie Shuman
Faculty Advisors: – John Durant and David Gute
Tufts University, Dept. of Civil & Environmental Engineering
3
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
Tufts University, Dept. of Civil & Environmental Engineering
4
Life Cycle of Schistosomiasis
Source: http://www.payer.de/entwicklung/entw2039.gif
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
6
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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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Research Methods in Kwabeng
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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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Research Methods in Kwabeng
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
Tufts University, Dept. of Civil & Environmental Engineering
11
Research Methods in Kwabeng
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
Tufts University, Dept. of Civil & Environmental Engineering
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Tufts University, Dept. of Civil & Environmental Engineering
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Tufts University, Dept. of Civil & Environmental Engineering
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Tufts University, Dept. of Civil & Environmental Engineering
15
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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Type of Intervention
Specific 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
Labor: Construction: Overhead: Design: Volunteered
-High, permanent structure -May require routine maintenance
-Reduces recreational use of river -may impede water gathering - Need partnership with mining co.
High, targets snail habitat
- 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
Labor: Construction: Overhead: Design: Volunteered
-High, permanent features -Community & Government Vigilance in protection of river
- Need partnership with mining co. - Support from some Assembly men and farmers
High, targets snail habitat
- 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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
29
Specific Intervention
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
-Must be coupled with other intervention -doesn’t prevent river use
-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?
-Must be coupled with other intervention -doesn’t prevent river use
-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
-Must be coupled with other intervention -doesn’t prevent river use
-water co. must maintain water system and quality
Expand Household
Distribution System
2 3 4 2 4
2.95
Alternatives to Using the River
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
31
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
Tufts University, Dept. of Civil & Environmental Engineering
32
Tufts University, Dept. of Civil & Environmental Engineering
33
Public Taps
Construction, operation, and maintenance costs
Many taps already in town Small fee for usage (1-2¢) Does not prevent river use Must be coupled with other interventions
Tufts University, Dept. of Civil & Environmental Engineering
34
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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
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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
Tufts University, Dept. of Civil & Environmental Engineering
37
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
Tufts University, Dept. of Civil & Environmental Engineering
38
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
Tufts University, Dept. of Civil & Environmental Engineering
39
Latrines - Reducing Egg Return to River from Humans
Construction, operation, and maintenance costs
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
Tufts University, Dept. of Civil & Environmental Engineering
40
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
Tufts University, Dept. of Civil & Environmental Engineering
41
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
Tufts University, Dept. of Civil & Environmental Engineering
42
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
Tufts University, Dept. of Civil & Environmental Engineering
43
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
Tufts University, Dept. of Civil & Environmental Engineering
44
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