2005 Progress Report: Community-Randomized Intervention Trial with UV Disinfection for Estimating the Risk of Pediatric Illness from Municipal Groundwater Consumption

EPA Grant Number: R831630
Title: Community-Randomized Intervention Trial with UV Disinfection for Estimating the Risk of Pediatric Illness from Municipal Groundwater Consumption
Investigators: Borchardt, Mark , Belongia, Edward , Kieke, Amy , Kieke, Burney , Loge, Frank
Current Investigators: Borchardt, Mark , Belongia, Edward , Kieke, Burney , Loge, Frank
Institution: Marshfield Clinic Research Foundation , Washington State University
EPA Project Officer: Hiscock, Michael
Project Period: January 1, 2005 through December 31, 2007 (Extended to December 31, 2009)
Project Period Covered by this Report: January 1, 2005 through December 31,2005
Project Amount: $2,289,169
RFA: Microbial Risk in Drinking Water (2003) RFA Text |  Recipients Lists
Research Category: Drinking Water , Water , Health Effects

Objective:

  1. Estimate the attributable risk for acute gastrointestinal illness (AGI) and febrile illness from drinking municipal water in communities that use non-disinfected groundwater.
  2. Partition the attributable risk for AGI and febrile illness into two components, risk related to contaminated source waters and risk related to water distribution systems.
  3. Determine if there is an association between virus concentration in water (e.g. adenoviruses 40/41, coxsackievirus, echovirus, and noroviruses) and community illness rates.

Progress Summary:

Year 1 activities focused on four major tasks that had to be completed before the full epidemiologic investigation could be launched: 1) Enroll study communities; 2) Install ultraviolet light (UV) disinfection; 3) Develop and validate laboratory methods; and 4) Prepare data collection instruments and study subject recruitment procedures.  Significant progress was made in each task, setting the stage for the full study to begin in mid-April 2006.

Community enrollment.  This study is designed as a community intervention, and as described in the research proposal, the target enrollment number was 14 communities.  A substantial amount of time in Year 1 was spent meeting with community leaders, such as city councils and water commissions, describing the study and requesting their community’s participation.  Fifty Wisconsin communities were approached, 40 agreed to participate, and from these the study team selected 14.  The communities are:  Adams, Baldwin, Barron, Cameron, Chetek, Crandon, Cumberland, Fall River, Ladysmith, Lake Hallie, Prairie du Sac, Rice Lake, Spring Green, and Tomahawk.  The source of drinking water for all study communities is non-disinfected groundwater from sand and gravel or sandstone aquifers.

UV installations.  The intervention is UV disinfection installed at every drinking water well serving the citizens of a community.  By intervening at the wellheads, no matter where a study subject is exposed to water in his or her community, the water has been UV disinfected.  Communities without UV disinfection are the controls.  After disease surveillance for six months, the plan is to remove the UV lights and install them on every wellhead in the control communities, having them become intervention communities, and the communities that just had the UV removed will then become the controls.  After this intervention crossover, surveillance will continue for another six months.

The study team has installed 17 UV disinfection reactors on 17 wellheads in eight communities.  This process was extraordinarily expeditious with engineering drawings, state plan review and approvals, community meetings, and contract negotiations with the UV manufacturer and installation company all competed in Year 1.  The time from ordering the UV units to installation was only three months, a remarkable accomplishment considering there are only a handful of UV installations in the United States on municipal wellheads.  All UV units are now operating and delivering a disinfecting dose of at least 50 mJ/cm2.  The other six communities now serving as controls have a total of 17 wellheads among them, each of which is matched to receive during the crossover-phase one of the reactors currently disinfecting in the intervention communities.

Laboratory methods.  In the laboratory, Year 1 work centered on developing and validating three methodological approaches: glass wool concentration of waterborne viruses, quantitative reverse transcription-polymerase chain reaction (qRT-PCR or qPCR) of noroviruses, enteroviruses, and adenoviruses, and infectivity assays of adenoviruses and enteroviruses by integrated cell culture/PCR.  These methods are necessary for quantifying the levels of viruses in the drinking water of the study communities and conducting the risk assessment component of the research plan.

The study team was successful in developing a glass wool filter capable of filtering water at a rate of four liters per minute and recovering viruses with an efficiency of 20% to 80%, depending on virus type and water matrix.  These results were presented recently at a meeting on large-volume water sampling held at EPA-Cincinnati and are being prepared for a manuscript.

Also successfully completed are the qPCR and qRT-PCR methods for quantifying adenoviruses, noroviruses, and enteroviruses.  Standard curves, limits of detection, and the method for quantifying the level of PCR inhibition have all been established and are now routinely used in the laboratory.  Method development and validation of the integrated cell culture approach is ongoing.

Preliminary water samples from the study communities were analyzed for enteroviruses and adenoviruses by qRT-PCR/qPCR.  Ten of the fourteen were virus-positive in these one-time samples, with virus levels ranging from 1075 to 41,005 enterovirus genomic copies per liter and 31 to 249 adenovirus copies per liter.  One sample was positive for norovirus.  Interestingly, this sample was taken from a community that one week after the sample was taken had a large norovirus outbreak resulting in school closings.

Epidemiological methods.  Preparations in Year 1 for the epidemiological arm of the study have focused on developing forms, establishing recruitment procedures, and enrolling study subjects.  Focus groups were held in two communities, Prairie du Sac and Crandon, in April 2005 as a means of gathering feedback and opinions from potential study participants.   The focus groups reviewed draft layouts of the forms, described their motivations for participating in research, and provided ideas for enrollment incentives.  This information was very useful and it was incorporated into the study procedures.

Of particular value was an ad hoc group of five scientific advisors, who assembled for a one day meeting, July 20, 2006 in Minneapolis.  Advisors were asked to review study plans and procedures and provide advice based on their own research experiences.  The discussion was animated and informative, and provided the study team with numerous ideas for improving the overall study process. 

A number of forms have been developed: 1) Brochure explaining the study objectives and design and answering frequently asked questions.  The brochure was mailed to every water customer in the 14 study communities; 2) Questionnaire for assessing baseline health status; 3) Weekly symptom checklist for tracking diarrheal and febrile illnesses; 4) Recruitment letter mailed to families with children living in the study communities; 5) Telephone script, used by recruiters following up with a phone call after the recruitment letter had been received; 6) Magnetic study calendar for participating families to place on their refrigerator and track important study dates; and 7) Instructions for completing the forms.

Recruitment involved a number of steps.  Families with young children in the study communities were identified from lists of addresses purchased from two direct mail companies that sell mailing lists by specific demographic group and market segment.  These address lists were merged with the billing addresses from the water utilities as a means of identifying families living within city limits and drinking municipal water.  Letters describing the study were sent to every family and several days later they were contacted by a telephone to request their participation and evaluate their child’s eligibility.  A child was eligible if she was between 6 months and 12 years of age, did not attend daycare or school outside the community for more than 20 hours per week, and did not have a chronic gastrointestinal illness, such as irritable bowel syndrome.  Eligible children were enrolled during this phone call.

A pilot study was conducted in Clintonville, Wisconsin in September 2005, to evaluate the forms, recruitment procedures, and water sampling procedures.  The Marshfield Clinic IRB and EPA Human Subject Protection Officer reviewed and approved all study forms and recruitment procedures.

Recruitment of study subjects began in mid-January 2006, and as of March 31, 2006, 1,786 people have enrolled from 673 households.  One of the recommendations of the scientific advisors was to enroll the adult responsible for tracking their children’s health as this provided additional people for observation for little additional cost.  Of the 1,786 study subjects, 636 are adults and 1,150 are children between the ages of 6 months and 12 years old.  The enrollment target was 980 households, and one person per household.  Fewer households have been enrolled than planned, but the number of people enrolled per household is greater than expected, 2.65.  The average number of children per household is 1.7.  The study team is planning a second recruitment effort in seven study communities where the number of enrolled households is lower than expected. 

Future Activities:

The full study was launched April 10, 2006. Surveillance of the study families, via the weekly symptom checklists, will continue for two three-month periods in 2006, April though June and September through November.  During these periods, the study communities will be visited approximately monthly for water sampling.  Samples will be taken from all wells and from six to eight households in each community, and if a UV reactor has been installed, before and after UV treatment. Laboratory analyses for waterborne viruses are scheduled to begin in July 2006.

A second recruitment effort is underway in seven study communities that did not meet the enrollment target.  Enrolled families are being asked to refer friends and neighbors as potential recruits.  Newspaper articles, radio spots, and advertisements are being used to recruit more families.  The study team is hosting research open houses in each of the seven communities and enrolling additional families during this time.

At the end of November 2006, assuming adequate funding, the UV disinfection reactors will be crossed-over between intervention and control communities.  Engineering drawings for the second set of UV installations should be completed by September 2006.

Supplemental funds will be requested for collecting monthly saliva specimens from every study subject during two surveillance periods.  The saliva will be evaluated for seroconversion to several waterborne viruses.

Journal Articles:

No journal articles submitted with this report: View all 26 publications for this project

Supplemental Keywords:

Epidemiology, human health, pathogens;, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Water, Environmental Chemistry, Health Risk Assessment, Drinking Water, Environmental Engineering, microbial contamination, microbial risk assessment, monitoring, real time analysis, aquatic organisms, other - risk assessment, early warning, UV disinfection, children, municipal groundwater, water quality, drinking water contaminants, drinking water system

Relevant Websites:

Marshfield Clinic Research Foundation http://marshfieldclinic.org/research/pages/index.aspxexit EPA

Principal Investigator Profile http://www.marshfieldclinic.org/nfmc/pages/default.aspx?page=InvestigatorDetails&id=3exit EPA

 

Progress and Final Reports:

Original Abstract
  • 2006 Progress Report
  • 2007 Progress Report
  • 2008 Progress Report
  • Final