ISNTD WASH Conference - 1st November 2016 by Suzy Campbell
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Transcript of ISNTD WASH Conference - 1st November 2016 by Suzy Campbell
WASH: Soil-transmitted helminthiasis & schistosomiasisTimor-Leste & Cameroon
Suzy CampbellResearch Associate – COUNTDOWNLSTM, Liverpool [email protected]
Presentation overview
1. Background to soil-transmitted helminths (STH) & schistosomiasis
2. WASH & environmental risk factors for STH in Timor-Leste
Baseline analyses of WASH associations with STH, WASH for WORMS RCT 3. STH & schistosomiasis prevalence, WASH observations in Central Africa, Cameroon
Barombi Mbo & Kotto crater lakes, historical transmission foci
1. Future research priorities
The parasites
1. Soil-transmitted helminthiasis (STH): Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), Necator americanus, Ancylostoma duodenale and A. ceylanicum (hookworm), Strongyloides stercoralis (threadworm), Enterobius vermicularis (pinworm)
2. Schistosomiasis: Schistosoma haematobium (urogenital), S. mansoni (intestinal) Exposure routesSigns and symptoms
Water, sanitation and hygiene (WASH)
Standard helminth control: periodic preventive chemotherapy (deworming)
Chemotherapy: ↓ STH load but does not prevent re-infection (rapid)
WASH: Cornerstone of prevention of infections - can reduce environmental contamination and therefore transmission
• Water: Provision of access to fresh water• Sanitation: Safe separation of humans from excreta • Hygiene: Behaviours that reduce exposure to (re)infection
Integrated
WASH & environmental risk factors in Timor-Leste
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Aim: To assess STH intensity of infection associations with WASH and environmental risk factors for infection
Cross-sectional analysis: baseline data; 24 villages Manufahi District
WASH for WORMS RCT: To determine effectiveness of WASH programme in reducing the prevalence of STH and intestinal protozoa following mass albendazole chemotherapy in Timor-Leste
Epidemiological analysis
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qPCR data: categorised into heavy & moderate-light intensity of infection
Analyse Necator americanus intensity of infection associations with • ~50 WASH risk factors, grouped by domains (e.g. individual sanitation, individual water
supply) • Environmental variables (temperature, precipitation, elevation, slope, vegetation (NDVI),
landcover, soil type, soil pH)• Relative poverty: socioeconomic quintile (principal component analysis)
STH clustering: mixed effects multinomial regression modelling • Village, household random effects
Model adjusted for age, sex, SES quintile
STH infections, Manufahi District
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N= 2152 (1038 males, 1114 females)
77.8%
18.8%
1.0% 0.7% Open defecation
House toilet
Village/school/neighbourtoiletMissing
50%
26%
12%
6%4%
2%
Unprotected spring
Surface water
Piped water (shared/to yard orhouse)Tubewell/borehole
Protected spring
Other/missing
Water access
Main place of defecation
Parasite Prevalence n (%)
Heavy intensity
n (%)
Moderate-light intensity n (%)
STH overall 1486 (69)
N. americanus 1298 (60) 1117 (52) 182 (8.5)
Ascaris spp. 526 (24) 217 (10) 311 (15)
Ancylostoma spp. 102 (4.7)
Trichuris trichiura 7 (0.33)
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Results & Implications
STH infections in Manufahi, Timor-Leste, are highly endemic
Environmental variables generally associated with N. americanus infection intensity. Few WASH risk factors significant
High-transmission environment: WASH is only identified means of reducing/preventing transmission justifies integrated STH control strategies
Possible scale of risk increasing with IOI. Use of prevalence metrics alone could mask significant IOI associations WASH: is key evidence of benefit overlooked?
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Now Cameroon
1. Soil-transmitted helminthiasis (STH): Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), Necator americanus, Ancylostoma duodenale and A. ceylanicum (hookworm), Strongyloides stercoralis (threadworm), Enterobius vermicularis (pinworm)
2. Schistosomiasis: Schistosoma haematobium (urogenital), S. mansoni (intestinal)
STH & schistosomiasis fieldwork, crater lakes of Cameroon
Barombi Mbo & Barombi Kotto May-June 2016
3 correlated projects:
•Testing residents for schistosomiasis•Testing residents for STH (particularly strongyloidiasis)•Malacology (snail) surveys for Biomphalaria & Bulinus
What WASH would work here & for which disease?
Schistosomiasis results
Barombi Mbo: 115 participants provided stool/urine; 10 (8.5%) Schistosoma haematobiumSchistosomiasis host snails found at only 2 lake locations, predominantly at sites with most human-water contact
Barombi Kotto: 117 participants provided stool/urine; 64 (50.8%) S. haematobium (14/59 25% of PSAC; 40/79 51% of SAC; 31/74 (45%) of adults)Host snails found at all locations around island, evenly spread
STH results
2016 2004
Barombi Mbo A. lumbricoides 0% 70%
T. trichiura 8% 77%
hookworm 4% 30%
Barombi Kotto A. lumbricoides 0% 18%
T. trichiura 0% 35%
hookworm 3% 12%
Treatment statistics & WASH at Barombi Mbo
WASH improvements – just at Barombi Mbo?
Multi-components that need better integration!
Concluding remarks
For STH & schistosomiasis “multi-component” integrated control (augmenting chemotherapy with WASH), we need to strengthen the evidence base
Research priority: strengthening WASH evidence for STH control
• WASH measurement guidelines for STH epidemiological research• indicators, statistics for measurement, modelling approaches• mixed-methods approaches to investigate amenable behavioural patterns
Need for environmental frameworks
Sustainable Development Goals global impetus for improved WASH
WASH for WORMSNHMRC Partnership Project GrantArchie Clements (ANU)Ross Andrews (Menzies)James McCarthy (QIMR Berghofer)Jim Black (Uni Melbourne)Rebecca Traub (Uni Melbourne)Darren Gray (ANU)Susana Nery (ANU)Gail Williams (UQ)Martha Morrow (Uni Melbourne)Andrew Vallely (Uni NSW)Alex Grumbley (WaterAid Timor-Leste)
Thank you ISNTD & acknowledgements
Naomi Francis (Uni Melbourne)Stacey Llewellyn & lab teamSalvador Amaral & field teamWaterAid Australia and Timor-Leste WASH teamsTimor-Leste National LaboratoryTimor-Leste Ministry of Health
COUNTDOWN SCH & STH Russell Stothard (LSTM)Louis-Albert Tchuem-Tchuenté (CSP) & teamMike Yaw Osei-Atweneboana (CSIR) & teamNana-Kwadwo Biritwum (GHS) & teamMargaret Gyapong (GHS) & teamSally Theobald (LSTM)Louis Niessen (LSTM)Emily Adams (LSTM)Lucas Cunningham (LSTM)Maame Esi Woode (LSTM)Eleanor MacPherson (LSTM)Estelle Koukouam Magne (Catholic Uni C. Afr.)Hermine Jatsa Boukeng (Uni of Yaoundé I)
Save the date!
Towards Elimination of Schistosomiasis in Cameroon: Developing a Modern National Agenda Integrating Research and Control
Organiser: Prof. L-A Tchuem-Tchuenté (National Coordinator, Schistosomiasis Control Programme)
March 22-23rd 2017, Mont Febe Hotel, Yaoundé CAMEROON