Water Resources Research Act Program

Details for Project ID 2016LA103B

Occurrence and Control of Naegleria fowleri in Groundwater Sources in Louisiana

Institute: Louisiana
Year Established: 2016 Start Date: 2016-03-01 End Date: 2018-02-28
Total Federal Funds: $17,653 Total Non-Federal Funds: $37,270

Principal Investigators: Samendra Sherchan, Jeffrey Wickliffe

Project Summary: Naegleria fowleri, also known as “the brain-eating amoeba”, is a free living amoebae found naturally in hot springs and warm surface waters. N. fowleri can cause primary meningoencephalitis (PAM), most often leading to death within 4 to 6 days if inhaled or forced into the nasal passages when swimming or diving. It is naturally found in soil and warm water and is fairly resistant to chlorine based disinfection (Miller et. al., 2015). It has a three stage lifecycle. N. fowleri exists in soil in a cystic form and excysts to a flagellate stage when in contact with warm water and a source of food (bacteria). The flagellate stage feeds on bacteria at the air- water interface in hot springs, surface water, and other water systems that may remain still for prolonged periods (Mull et. al., 2013). In 2011, two people died of Primary Amoebic Meningoencephalitis (PAM) caused by N. fowleri in DeSoto Parish and St. Bernard Parish, Louisiana. Both cases involved the use of a neti-pot. In 2013, there was second death in St. Bernard Parish (4-year old boy) caused by PAM and confirmed to be N. fowleri (Nf) infection. Testing conducted in 2013 by Louisiana Department of Health and Hospitals (DHH)/CDC in both St. Bernard and DeSoto found this amoeba in the treated distribution system water supply. To date, a total of 6 Louisiana’s public water systems have tested positive for N. fowleri (Louisiana DHH; Bartrand et. al., 2014; Cope et. al., 2015). The purpose of this study is to determine the occurrence and quantity of the protozoan pathogen, N. fowleri, in groundwater sources in Louisiana. The deaths of three people due to N. fowleri in DeSoto Parish and St. Bernard Parish in 2011 and 2013 promoted an interest in understanding its occurrence in groundwater sources in Louisiana. No study of well water has been conducted previously in the State, and the presence of N. fowleri in ground water is currently not regulated in the United States. However, over 42 million people in the United States are dependent on individual wells for their drinking water. In most states, individual drinking water systems are not regulated by local health and environmental agencies. For this reason, few studies have been conducted on the microbial and chemical water quality of this water. In the United States there are approximately 100,000 small water systems (those that serve less than 10,000 people) and approximately 500,000 people depend on private wells for their drinking water in Louisiana (Louisiana DHH). This project involves a field study to assess the occurrence of N. fowleri in non-disinfected small drinking water systems and individual household well water systems in Louisiana. Grab samples (Standard Methods 1060) from well water systems will be collected using one liter sterile polyethylene bottles. Each sample will be concentrated by centrifugation, then 1 mL of the resulting pellet will be placed on an agar culture plate and the remaining pellet volume will be processed using the immunomagnetic separation (IMS) procedure and real-time Polymerase Chain Reaction (PCR) TaqMan assay as described by Mull et al., 2013. Water samples will also be tested for temperature, pH, turbidity, chlorine residual, specific conductance, organic matter, iron, coliform bacteria and heterotrophic bacterial count (HPC), and E. coli using standard methods. The data collected will be analyzed to assess environmental and other water quality factors that may be associated with the occurrence of N. fowleri in these water supplies. The objectives of the project are to 1) determine the occurrence and quantity of N. fowleri in individual and small system non-disinfected groundwater systems in Louisiana and 2) attempt to identify factors related to the occurrence of N. fowleri in these systems.