An interdisciplinary study of typhoid fever in Central Division, - - PowerPoint PPT Presentation

9th International Conference on Typhoid and Invasive NTS disease , May 1st, 2015 Bali, Indonesia

Aaron P Jenkins , Namrata Prasad , Lanieta Naucukidi , Varanisese Rosa , Shalini Pravin , Gandercillar Vosaki , Rina Kumar, Talitha Cambemaiwai , Mike Kama, Kylie M. Jenkins , Stacy Jupiter, John A. Crump , Edward K. Mulholland , Pierre Horwitz , Richard Strugnell

An interdisciplinary study of typhoid fever in Central Division, Republic of Fiji

Outline

• The study framework
• Where are the cases – GIS
• Case /control
• Environmental investigations
• Molecular detection -rPCR

Salmonella Typhi bloodstream infections detected by passive surveillance, Fiji, 1991 -2014

Adapted from Kool et al. 2010 Number of lab confirmed Typhoid cases

50 100 150 200 250 300 350 400 450 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Primary threats to natural systems

Cyclones & Heavy Rain Catchment Modification Runoff Damage to Infrastructure Animal & Human Density Sediments & Nutrients + + + + Contaminated food & water Bacterial Carriage

(eg. S.Typhi)

Human Well-Being (Disease Burden, Nutrition & Livelihoods) Sociocultural/ Behaviour Food Fish & Invertebrates River & Reef Health + + + + +

• +

Jenkins & Jupiter (2014) , in press Jenkins & Jupiter (2015) Wetlands Hum Health, in press

Conceptual model of mechanisms determining health in high island river basins

Typhoid resurgence

Is it related to aquatic resource decline?

Case control study (2014- 15): Geospatial analysis (2008-2014) Environmental- Microbiological (water, soil) Molecular detection (rPCR & sequencing)

Outcome harvesting Catchment Health Index (Typhoid epidemiology, flood risk, resource availability)

Interdisciplinary research elements

SUVA

Geospatial analysis of cases (2008-2014) Central Division

SUVA

Geospatial analysis

Typhoid Incidence 2013

Typhoid Incidence 2014

Rural high incidence setting

Urban high incidence setting

Geospatial distribution of cases (2013-2014)

Potential landscape/temporal predictors:

• Forest cover
• Road density
• # River crossings
• Level of cultivation
• Relative Erosion Potential
• Rainfall

Environmental sampling

• Water – stored, source, nearby stream
• Soil – toilet, toilet drain, household garden
• On site – Temp, pH, conductivity, DO
• Lab process – Total Coliforms, E.coli
• Filtered (0.4 microns) – stored for PCR
• Filtrate – Nitrates, Phosphates, Ammonia

WATER SOIL

Mean Most Probable Number E.coli / 100ml +/- se

Safe drinking/eating Safe swimming

1 10 100 1000 10000

Stored Source Near Stream

Cases Controls

*

16 21

1 10 100 1000 10000

Toilet Toilet Drain House Garden

15 23 45 45

* Mean Most Probable Number of Escherichia coli in water & soil of cases & controls

30 22 44 14 12 21

RURAL URBAN

100 200 300 400 500 600 700 800 Rural Urban Rural Urban Stored Source

Total Coliforms E.coli

26 44 26 44 61 61

Mean Most Probable Number CFUs / 100ml +/- se Total Coliforms and Escherichia coli in Rural vs Urban Drinking Water

*

46 46

* * *

Mean concentration of nutrients in water & soil of cases & controls Mean concentration (mg/L) +/- se

0.5 1 1.5 2 2.5 3 3.5 4 Phosphate Nitrate Ammonia

Case Control

1 2 3 4 5 6 7 8 Phosphate Nitrate Ammonia

Case Control

WATER SOIL * *

Molecular detection

• rPCR on water & soil samples
• Assay works in soil…a first?
• 5 positives from 50 samples – all case houses

Muddy water below house entrance

Conclusions

• In endemic, high-incidence, flood prone settings

environmental sources of exposure are likely

• Localized behaviors, household environments or

river basin settings may enhance risk of typhoid

• Focus on natural and built infrastructure +

vaccination

• Pacific Islands as model systems for typhoid

control and elimination?

Said Lao Tsu, 2,500 years ago. “Thirty spokes share the wheel’s hub; It is the center hole that makes it useful.”

a.jenkins@ecu.edu.au

THANK YOU