Louisiana Response to Naegleria fowleri in Drinking Water

Transcription

1 Louisiana Response to Naegleria fowleri in Drinking Water Jonathan Jake Causey, P.E.; Louisiana DHH 2014 SWAWWA

2 Overview Louisiana background St. Bernard Parish DeSoto Parish Risk mitigation and communication Science Advisory Workgroup Emergency Rule Increased monitoring requirements Monitoring Plan Portal St. Bernard and DeSoto follow-up sampling Laboratory testing capacity Statewide surveillance program Questions

3 Louisiana Background In 2011, two people died of Primary Amebic Meningoencephalitis (PAM) caused by Naegleria fowleri (brain-eating amoeba) in DeSoto Parish and St. Bernard Parish. 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 Naegleria fowleri (Nf) infection. Testing conducted in 2013 by Louisiana DHH/CDC in both St. Bernard and DeSoto found this amoeba in the treated distribution system water supply. Both systems use conventional treatment and chloramine disinfection to treat surface water. Common issue: low to no chlorine residuals in areas where Nf was detected. 3

4 Louisiana Background DeSoto St. Bernard 4

5 St. Bernard Parish: Initial CDC Samples 5

6 DeSoto Parish: Initial CDC Samples 6

7 Risk Mitigation and Communication LDHH, CDC, and EPA formed response team LDHH directed St. Bernard water utility to raise residual chlorine levels to 1.0 mg/l throughout the system ( chlorine burn ) LDHH conducted weekly testing of chlorine residuals LDHH and CDC communications teams developed briefing documents and fact sheets Challenge: How to communicate to the public that water was Safe to Drink but Not Safe to Get Up Your Nose Schools shut down swimming pools and turned off drinking water fountains

8 2011 PAM Case St. Bernard Chlorine Burn: Week 1 WTP 2013 PAM Case

9 2011 PAM Case St. Bernard Chlorine Burn: Week 2 WTP 2013 PAM Case

10 St. Bernard Chlorine Burn: Week PAM Case WTP 2013 PAM Case

11 St. Bernard Chlorine Burn: Week PAM Case Another 6 weeks were needed to achieve 1 mg/l FC at all DS locations WTP 2013 PAM Case

12 Science Advisory Workgroup In response to the detection of Naegleria fowleri in St. Bernard Parish and DeSoto Parish systems in Louisiana, the Department of Health and Hospitals formed a Science Advisory Workgroup. The workgroup consists of: Louisiana DHH U.S. Environmental Protection Agency Tulane University City of Peoria, AZ Southern Australia Louisiana Poison Control Corona Environmental Consulting U.S. Centers for Disease Control Louisiana State University University of Arizona City of Tucson, AZ Western Australia Arizona DEQ Later Karachi, Pakistan 12

13 Science Advisory Workgroup Key objectives of the NFSAWG include: 1. Informing LDHH about the current state of knowledge regarding Naegleria fowleri 2. Informing ongoing and anticipated rulemaking 3. Identify opportunities and methods to better educate water systems on current standards and regulations Some of the questions to answer are as follows: 1. What is the occurrence of Naegleria fowleri in public water system distribution systems? 2. What is the risk of infection of Naegleria fowleri when it is present in a public water supply? 3. What treatment, operational, and/or monitoring practices are necessary to control the presence of Naegleria fowleri in public water systems at a level that will prevent or reduce the risk of infection to an acceptable level? 13

14 Emergency Rule LDHH issued an Emergency Rule (ER) on November 6, 2013 that remains in effect: The purpose is to ensure that all points in the distribution system maintain a disinfectant residual level that will control the Naegleria fowleri amoeba and to ensure adequate monitoring by public water systems for total coliform and disinfectant residual levels in the distribution system Effective November 6, 2013, 25% more monitoring required for disinfectant residual concentration (chlorine or chloramine). Effective February 1, 2014, 50% more sites required for total coliform and chlorine monitoring and the new minimum disinfectant residual level is: 0.5 mg/l of free chlorine; or 0.5 mg/l of chloramine residual (measured as total chlorine) for systems that feed ammonia. 14

15 What else does the Emergency Rule require? All systems must submit and maintain a monitoring plan with all total coliform and chlorine residual sample sites (POE, TCR, ACR, and MRT) by January 1, The monitoring plan shall be entered and submitted via the Monitoring Plan Portal (MPP) - with valid 911 street addresses or latitude/longitude coordinates for each sample site. Systems (GW and SW) that chloraminate (chlorine with ammonia addition) must develop and submit a Nitrification Control Plan by March 1, Chlorine residuals must be measured using EPA-approved analytical methods. New analytical methods added to Table 1 of LAC 51:XII.1105.C. But this means that color wheels are no longer acceptable for measuring the disinfectant residual concentration (free or total chlorine). Clarifies that records of chemical tests/measurements shall be kept and maintained as prescribed by federal regulations (i.e., 10 years for chlorine residuals). 15

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18 St Bernard and DeSoto Follow-up Results LDHH / CDC sampling and analysis conducted following 60 day free chlorine burn and return to chloramination Sampling Period St. Bernard DeSoto January 2014 Negative Negative May 2014 Negative Negative September 2014 Result pending Result pending 18

19 LDHH Develops Laboratory Testing Capacity LDHH developed laboratory testing capacity following methods in peer reviewed literature, CDC, Australian, and other laboratories Two collection methods: 1) 1L grabs, and 2) 100L samples concentrated on ultrafilters (UFs) Samples are concentrated by centrifugation (for the UFs after backwashing). Supernatant removed and packed pellet mixed with a culture of E.coli and plated on Nelson s agar and incubated at 42 deg C for up to 7 days 19

20 LDHH Develops Laboratory Testing Capacity Plates examined daily using an inverted microscope to observe the development of amoebae If trophozoites are detected, this indicates the presence of thermophilic amoebae On an amoebae positive plate, a portion of the growth where they are observed is tested for the production of flagella Flagella positive amoebae are the genus Naegleria At 7 days incubation, the entire surface of the plate is harvested, centrifuged to produce a pellet, and analyzed by qpcr to determine if the Naegleria detected is the species fowleri Ongoing precision and recovery, matrix spikes, methods blanks, and negative controls are included with each sample batch 20

21 LDHH Launches Surveillance Program August 11, 2014: DHH launched a Naegleria fowleri surveillance program to begin investigating water system sources and treated water distribution system locations Statewide geographic coverage Small and large water systems Predominantly chloramine residual disinfectant, but some free chlorine Predominantly surface water supply, but some groundwater Sampling intended to continue until water sample temperatures drop below 20 degrees C Also closely monitoring disinfectant residual concentrations compared with 0.5 mg/l minimum requirement 21

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26 Additional Responses Water system training Delivered eight 16-hour distribution system water quality training courses across the state Focused on monitoring, reporting, maintaining disinfectant residuals Lots of lessons learned Information management system improvements Disinfectant residual data capture and reporting Act 573 of the 2014 Louisiana Legislative Session Requires DHH to promulgate a rule requiring more than a trace amount of chlorine residual. Published White Paper that was included in the October JAWWA 26

27 Bartrand et al E418 Peer-Reviewed Naegleria fowleri: An emerging drinking water pathogen TIMOTHY A. BARTRAND 1, JONATHAN JAKE CAUSEY, 2 AND JENNIFER L. CLANCY 1 1 Corona Environmental Consulting, LLC 2 DHH-OPH Engineering Services, Louisiana Department of Health and Hospitals, Office of Public Health Naegleria fowleri (N. fowleri) is a free-living, trophic amoeba that is nearly ubiquitous in the environment and can be present in high numbers in warm waters. It is the causative agent of primary amoebic meningoencephalitis (PAM), a rare but particularly lethal disease with a very low survival incidence. Although N. fowleri was isolated from drinking water supplies in Australia in the 1980s, it was not considered a drinking water threat in the United States until recent cases were associated with a groundwater system in Arizona and surface water systems in Louisiana. N. fowleri in drinking water treatment and distribution systems can be managed using disinfectant concentrations typically encountered in well-run plants although nitrification and attendant low disinfectant residuals may pose a challenge for some systems. The greatest challenge for N. fowleri control is in premise plumbing systems where conditions are largely outside the control of utilities, residuals might be low or nonexistent, and where water temperatures could be high enough to support rapid growth of the amoebae. This article reviews published studies describing the environmental occurrence, survival, pathogenicity, and disinfection of N. fowleri. In addition, this article provides information about this little known and poorly understood parasite with respect to its occurrence in the environment; how the amoeba amplifies in water systems such that it can cause infection; how N. fowleri has been successfully controlled for decades in water systems through treatment and distribution system management in Australia; and the knowledge gaps and information needed to address N. fowleri as an emerging pathogen in US water supplies. Keywords: Naegleria fowleri, premise plumbing, microbial risk JOURNAL AWWA Primary amoebic meningoencephalitis (PAM) occurs infrequently in the United States with 132 cases identified between 1962 and 2013 (CDC, 2014). When it does occur, cases are often reported in the popular media. In these reports, N. fowleri is usually referred to as the brain-eating amoeba, and it is noted that infections are nearly always fatal. The implication of treated drinking water in cases of PAM in Louisiana (CDC, 2014) has increased the profile of N. fowleri as a pathogen of concern in the drinking water community in the United States. In response to public concerns over PAM, Louisiana promulgated an emergency rule (La. Admin. Code 51:XII.311, 355, 357, 361, 363, 367, 903, 1102, 1105, 1113, 1117, 1125, 1133, 1135, 1139, and 1503) requiring higher disinfection residuals and more frequent residual measurements in public water supply distribution systems. N. fowleri is a free-living amoeba (FLA) that occurs naturally in soil and water. The life stages of N. fowleri are ameboid trophozoite, flagellate, and cyst. Only the ameboid trophozoite is infectious (CDC, 2013). N. fowleri grows well at temperatures between 25 and 42 C and survives for extended periods at lower temperatures, particularly in its encysted form (CDC, 2013; see the photographs on page E420). Although more than 30 species of Naegleria have been identified through DNA sequencing, N. fowleri is the only species that has been implicated in human disease to date (De Jonckheere, 2004; De Jonckheere, 2002). De Jonckheere (2011) notes N. fowleri has been detected on all continents except Antarctica, and PAM cases have occurred in tropical, subtropical, and even temperate regions. As of 2011, eight types of N. fowleri had been identified, and those types occur with differing frequency on the different continents. There does not appear to be a significant difference in the virulence of the types (De Jonckheere, 2011). Two additional Naegleria species, N. australiensis and N. italica, have been shown to cause infections in lab animals (De Jonckheere, 2002). PA M is a disease with a high fatality rate, ~ 98%, and death normally occurs within 1 12 days postinfection (CDC, 2011). Most victims of PA M are children or young adults in good health with a history of swimming in naturally warm or thermally polluted waters where growth of the amoebae is favored. Cases potentially linked to inhalation of drinking water or perhaps from contamination of premise plumbing have been suggested in reports of PAM among people with no recent history of swimming (Hunte et al, 2013; Kazi & Riaz, 2013; State of Louisiana Department of Health and Hospitals, 2013; Movahedi et al, 2012; Yoder et al, 2012; Khanna et al, 2011, Shakoor et al, 2011). Some of these nonswimming cases appear related to specific practices such as neti pot use or ritual nasal cleansing; however, the most recent cases in Karachi, Pakistan, have no connection to ritual nasal cleansing or any recreational water exposure (Zafar, 2014). Although occurrence of N. fowleri is widespread in the natural environment, there are relatively few cases of PAM reported annually. This paradox forms the backdrop for this review American Water Works Association OCTOBER :10

28 Next Steps Laboratory Method Development Continued development of laboratory methodologies for the detection of thermophilic amoeba, Naegleria, and Naegleria fowleri. Other amoeba s need consideration or should be part of the analysis such as Acanthamoeba? Occurrence study in groundwater sources Louisiana has approximately 2500 public supply water wells Need a better understanding of the likelihood of having Naegleria fowleri present when thermophilic amoebas and/or thermophilic Naegleria are present. These should likely be used as indicators similar to total coliforms Data to allow estimation of the contamination of distribution system water with N. fowleri during maintenance, main breaks, and other disturbances in distribution 28

29 Questions Jonathan Jake Causey, P.E. Chief Engineer / Safe Drinking Water Administrator DHH-OPH, Engineering Services Jake.causey@la.gov LDHH Safe Drinking Water Program: Louisiana Information and Press Releases on Naegleria fowleri: