WASH: Soil-transmitted helminthiasis & schistosomiasisTimor-Leste & Cameroon

Suzy CampbellResearch Associate – COUNTDOWNLSTM, Liverpool Suzanne.Campbell@lstmed.ac.uk

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