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Patricia Weiss 1 , Tiong Gim Aw 2 , Joan B. Rose 2

Microbial Quality and Safety of Well Water in Rural Nicaragua as Determined by Low Cost Bacterial Test . Patricia Weiss 1 , Tiong Gim Aw 2 , Joan B. Rose 2 1 School of Public Health, College of Human Medicine, Michigan State University, East Lansing, Michigan, 48824, United States.

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Patricia Weiss 1 , Tiong Gim Aw 2 , Joan B. Rose 2

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  1. Microbial Quality and Safety of Well Water in Rural Nicaragua as Determined by Low Cost Bacterial Test Patricia Weiss1, Tiong Gim Aw2, Joan B. Rose2 1School of Public Health, College of Human Medicine, Michigan State University, East Lansing, Michigan, 48824, United States. 2Department of Fisheries and Wildlife, 3 Natural Resources, Michigan State University, East Lansing, Michigan, 48824, United States.

  2. Introduction • 783 million people lack access to safe water (United Nations, 2013) • 2.5 billion people do not have improved sanitation (United Nations, 2013) • 1.1 billion practice open defecation (World Health Organization, 2010) • Most of these people live in rural villages such as Pueblo Nuevo, Nicaragua

  3. Objectives of Study • Test microbial water quality of hand dug wells in Pueblo Nuevo, Nicaragua • Determine Sources of Contamination

  4. Background on Nicaragua • 1979 opposition to governmental manipulation—Marxist Sandinistas came into power (Central Intelligence Agency, n.d.) • 1988 hurricane Joan caused more damage to infrastructure and economy (Central Intelligence Agency, n.d.). • About 50% have access to improved sanitation (63% in urban areas and 37% in rural areas) (Central Intelligence Agency, n.d.) • 20% without safe drinking water in Latin America (Pearce-Oroz, 2011) • Government is slowly improving access to water and sanitation (Social Investments Funds)

  5. Location • Pueblo Nuevo is located on the Caribbean Coast

  6. Cases of Illness in Pueblo Nuevo2012 • Water-related Diarrhea: 5,675 Cases • Parasites: 2,850 Cases • Pneumonia: 47 Cases • Respiratory Infections: 8,750 Cases • Injuries due to Weapons: 467 Cases • Pregnancy Issues: 272 Cases *Provided by Dr.AlejandroPicado

  7. Types of Wells Sampled Rope Pump Well Simple Well

  8. Location of Wells

  9. Methods • Compartment Bag Test (CBT) – E.coli • Membrane Filtration & qPCR – • Microbial source tracking markers: B.theta (human), M2/M3 (bovine) • E. coli, enterococci

  10. Compartment Bag Test

  11. Compartment Bag Test 8 key steps to perform CBT • Prepare dilutions • Collect and record • Mix water sample with growth medium • Open and fill CBT • Seal • Incubate • Score and record results on data sheets • MPN chart for quality rating

  12. Last Step: Decontamination • Each bucket=13.4L • 5 ml bleach per bucket • Put rope etc. in bucket for at least half hour • 0.05g Sodium Thiosulfate

  13. Membrane Filtration • Filtered 1.4-1.8L of well water

  14. DNA Extraction and qPCR • DNA extracted using QIAamp DNA mini kit (Qiagen) • Platform used: Roche LightCycler® 480 Real-Time PCR System with 96 well block

  15. Results and Discussion • Results of Compartment Bag Test and qPCR

  16. Compartment Bag Test Results • 32 wells total • 87.5% of wells contaminated with E. coli • Contamination ranged from 3-404.5 MPN/100 ml • Geometric mean 25.8/100 ml

  17. Comprehensive Water Quality Rating

  18. Average MPN of E. coli Relative to Depth and Elevation

  19. Comparison of E. coli MPN between simple and rope-pump wells Geometric Mean *Used MPN of 3 for lower confidence interval 64.1% Reduction in E. coli t-Test, t=0.88, p = 0.19 Log-transformed t-Test t=-2.11, p = 0.02 Similar to results seen in Gorter et al. (1998)—Using geometric mean overall 47% reduction of fecal coliforms seen in rope-pumps.

  20. qPCR detection of molecular markers (No. sample tested: 31)

  21. Conclusion • Generally the well water was deemed unsafe in this small rural area in Nicaragua. • The CBT made it possible to test in the field for E.coli contamination in a rural location where supplies and lab equipment was limited. • qPCR analysis indicated bovine fecal pollution in the well water samples.

  22. Acknowledgement • Michigan State University School of Public Health and College of Human Medicine • Thanks to Mark Sobsey for helping with Bag Test • Regina Weiss, SammiaForbes, Ashley Hodges, guide Don Tito, Director Don Miguel, and Dr.AlejandroPicado • Fundacionpara la Autonomia y el Desarollo De la Costa Atlantica de Nicaragua (FADCANIC)

  23. Questions?

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