NYC’s Waterborne Disease Risk Assessment Program – 20 Years Later:

Program Implementation and Data Findings

2013 NYC Watershed / Tifft Science & Technology SymposiumSeptember 18, 2013

Presented by Anne Seeley, MPH (NYCDEP)with Sharon Balter, MD (NYCDOHMH-DEP); David Lipsky, PhD (NYCDEP);

Daniel Cimini, RN (NYCDOHMH) & Lisa Alleyne, MPA (NYCDOHMH)

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Presentation Outline

• Background

• WDRAP Program Description

• Results

• Special Projects & Activities

• Conclusions & Summary

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Background - Why WDRAP?

• Giardia & Cryptosporidium found in US waters

• Chlorine resistance of cysts/oocysts

• Crypto illness special risk to AIDs population

• Milwaukee Crypto Outbreak - 1993

• Drinking water & public health community concern

• EPA - Surface Water Treatment Rule Serieso SWTR, IESWTR, LT1ESWTR, LT2ESWTRo Requirements for filtered & unfiltered systems

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Background – Regulatory Context

Surface Water Treatment Rule

Filtration Avoidance Requirements

• Source Water Quality Criteria

• Disinfection Requirements

• Site-Specific Conditions

o Watershed Control

o Compliance w/Total Coliform & TTHM standards

o No waterborne disease outbreaks

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Giardiasis & Cryptosporidiosis - Some Facts & Challenges

Background

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• Numerous Potential Routes of Transmission

• Non-specific symptoms (GI Illness)

• Requires special testing to diagnose

• Low # case reports / Crypto not reportable (‘til ‘94)

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WDRAP - Description

• Joint NYC agency program:

NYCDEP (BWS) & NYCDOHMH (BCD)

• Parasitic Disease Surveillance Program

Established 1993 at DOHMH

• Funded by DEP under FAD

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WDRAP - Description

Objectives:

• Collect data on rates of giardiasis & cryptosporidiosis, and on demographics & risk factors

• Provide systems to track diarrheal illness to ensure rapid detection of any potential outbreaks

• Conduct outreach & education / special studies

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Disease Surveillance – Giardiasis (G) & Cryptosporidiosis (C)

WDRAP - Description

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• Objectives:

o G & C rates full capture of all lab-diagnosed cases.

o Demographic & risk factor

• Disease Surveillance (DS)o Active Disease Surveillance: 1993(G) /1994(C) – ‘til 2011

Call / visit all labs (N = ~70)

o Electronic Reporting: 2011 – present

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Disease Surveillance – Case Interviews

WDRAP - Description

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• Cryptosporidiosis – Interviews for demographic & risk factor info – all cases

• Giardiasis -- Interviews of patients with high risk to transmit to others -- All ‘93 – ’95; Now only food handlers, health care workers, day care attendees

• Contact of health care providers to verify information

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WDRAP - Description

• Demographic data collected: o Geography (citywide, by borough, by neighborhood/UHF code)o Gendero Ageo Race/ethnicity (crypto only)o Census track poverty level

• Potential Risk Factor data collected, including: o High-Risk Sexual Activityo International Travelo Contact w/ Animalso Recreational Watero Drinking Water (plain tap, filtered, boiled, incidental tap…)

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Outbreak Detection Systems (Syndromic Surveillance)

WDRAP - Description

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• Emergency Department (ED) Monitoringo ~ 49 EDs (out of 52 in NYC)

o ~ 11,000 visits/day

• Anti-diarrheal Medication (ADM) Monitoringo ADM (by DEP) & OTC (by DOHMH)o > 300 stores / all boroughs

o > 30,000 sales/day (non-prescription)

• Clinical Lab Monitoringo Major parasitic lab serving NYC

• Nursing Home Programo ~ 8 sentinel nursing homes

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Outbreak Detection System Features

WDRAP Description

System Data Frequency

Geographic Unit

Data Analysis

ED(Emergency Dept.)

7 day/wk Citywide, Zip, Hosp,

EARS-X

OTC(Over-the-Counter ADM)

7 day/wk Citywide SAS (CUSUM)

ADM(Anti-diarrheal Meds.)

7 day/wk Citywide, Borough

SaTScan / CUSUM

Clinical Lab ~ 3 day/wk Metro NYC SAS / CUSUM

Nursing Home Outbreaks B (except SI) Signal = Outbreak

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From Milwaukee Outbreak – re sales of Anti-Diarrheal Medications

(credit: B. Mekenzie)

Outbreak Detection

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Results – Disease Surveillance

Jul-9

3

Jan-

94

Jul-9

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95

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96

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12

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0

50

100

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350

Fig. 1: Giardiasis, number of cases by month of diagnosis, New York City, July 1993 - December 2012

Month of Diagnosis

Nu

mb

er o

f C

ases

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Results – Disease SurveillanceJa

n-95

Jul-9

5

Jan-

96

Jul-9

6

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97

Jul-9

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99

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Fig. 3: Cryptosporidiosis, number of cases by month of onset,

New York City, Jan 1995 – Dec 2012

Month of Onset

Nu

mb

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of

Ca

se

s

This increase in cases in August 2000 was suspected to be related to an outbreak at a re-sort in Florida at which a group of Staten Island residents had vacationed that month.

The increase of cryptosporidiosis cases reported in August 2005 is suspected to be due to a sur-veillance bias caused by publicity around an out-break in upstate NY related to recreational water exposure at a spray park.

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Results – Disease Surveillance

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 20120

50

100

150

200

250

300

350

400

450

Fig. 6: Cryptosporidiosis, number of cases by year of diagnosis and immune status, New York City, 1995 - 2012

Persons with HIV/AIDS Immunocompetent

Immunocompromised, Not HIV/AIDS Immune Status Unknown

Year

Nu

mb

er o

f ca

ses

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Results – Disease Surveillance

Cryptosporidiosis – by UHF neighborhood

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Results – Disease Surveillance TABLE 10: Cryptosporidiosis, number of cases and annual case rate per 100,000 population by age group and sex, New York City, 2012 Sex Age group

Male number (rate)

Female number (rate)

Total number (rate)

<5 years 6 (2.3)

8 (3.2)

14 (2.7)

5-9 years 1 (0.4)

2 (0.9)

3 (0.6)

10-19 years 3 (0.6)

5 (1.0)

8 (0.8)

20-44 years 63 (4.1)

11 (0.7)

74 (2.3)

45-59 years 19 (2.6)

6 (0.7)

25 (1.6)

≥ 60 years 1 (0.2)

0

1 (0.1)

Total 93 (2.4)

32 (0.7)

125 (1.5)

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Average of percent of interviewed cryptosporidiosis case patientsreporting selected risk exposures before disease onset – (Average of annual percent positive reports 1995 – 2012)

Results - Risk Factor Interviews

ActivityImmunocompetentPatients

Persons with HIV/AIDS

International Travel 39% 10%

High-Risk Sexual Activity 15% 23%

Contact with Animals 32% 35%

Recreational Water Contact 35% 13%

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Results – Syndromic Surveillance

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Syndromic Surveillance Systems Combined --Fig. 9: Signals for GI Illness, New York City, Jan – June 2012

Results – Syndromic Surveillance

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Syndromic Surveillance Systems Combined –Figure 10: Signals for GI Illness, New York City, July – Dec 2012

Results – Syndromic Surveillance

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Special Projects & Activities

• Outreach & Education – NYCo Medical / public health communityo Immunocompromised populationo General population

• Action Plans (CAP, CGAP)

• Water Security Initiativeo Electronic Data Dashboardo Retrospective Study

• Event Investigations (e.g., 2003 Blackout, Hurricane Sandy)

• Communication - Generalo CDC Working Group on Waterborne Crypto /Communication Groupo Utility-Health Collaboration Project (Water Research Foundation)

• Special Studies - (Crypto case-control, Giardiasis Summer Study…)

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Disease Surveillance -- re rates, demographics, risk factors

Conclusions – What have we learned?

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• Full capture (diagnosed cases) achieved

• G & C significant decline over years o Especially HIV/AIDS pop.o HAART: Advances in treatment of HIV/AIDS has significantly changed the crypto profile in NYC (and US)

• Determinations about risk factors for cryptosporidiosis cannot be made w/o controls

• Rates higher in some sub-groups / patterns suggest exposures other than a common community-level exposure contributes to cases

• G & C surveillance results do not suggest an association between illness and the NYC water supply.

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Conclusions – What have we learned?

Outbreak Detection (OD) Systems

• Multiple OD systems in operationo Some system interruptions (data not in our control, tech

issues, resources)

• Sensitivity & timelinesso Difficult to fully assess w/o outbreakso Strength from overlap (concurrent signals)o DEP & DOHMH believe would detect sizable community GI

outbreako Some GI events observed in OD data:

-- NYC metro area: foodborne - imported raspberries -- 2003 blackout: attributed to foodborne

Continued…

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Conclusions – What have we learned?

Outbreak Detection (OD) Systems, cont’d

• No evidence of a waterborne disease outbreak

• Some seasonal patterns – consistent w/ seasonal viral GI illness

• Importance of communication links o DOHMH – DEPo Various data sources (doctors/HCPs, hospitals, pharmacies)

• Importance of preparedness (e.g., communication tools, drills)

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Summary

• Extensive public health surveillance systems are in place in NYC to detect GI illness / outbreaks

• NYC data indicates unlikely that drinking water represents major risk of exposure for giardiasis or cryptosporidiosis

• No indications of waterborne outbreaks have been detected

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Closing

ACKNOWLEDGEMENTS (WDRAP Team): • NYCDOHMH: M. Layton, D. Weiss, S. Balter, D. Cimini, L. Alleyne, and others• NYCDEP: S. Schindler, D. Lipsky, A. Seeley

CONTACT: • Anne Seeley (aseeley@dep.nyc.gov / 718-595-5346)• Sharon Balter (sbalter@health.nyc.gov / 347-396-2674

WEBSITES:• DEP website:

http://www.nyc.gov/html/dep/html/drinking_water/wdrap.shtml

• DOHMH websites: http://www.nyc.gov/html/doh/html/diseases/cdgia.shtmlhttp://www.nyc.gov/html/doh/html/diseases/cdcry.shtml

-- THANK YOU --