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Surveillance and early
warning systems for waterrelated diseases
Enzo Funari
National Institute of Health
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Importance of Water-related
diseases

Database from different Countries, literature
data and available information show the
continued impact of water-related diseases on
human health.
 These diseases have been recognized as a
major threat to sustainable human development
in a number of international forums
 The Protocol on Water and Health represents a
very useful international tool for a co-ordinated
fight against water-related diseases.
WHO database
 Mortality
data in the period 1995- 2000 in
EECCA countries (Eastern Europe,
Caucasus and Central Asia):
 diarrhoeal death (below-five years group)
decreases by some 72% ;
 It can be reasonably estimated that in this
period nearly half a million children
(438,306) died for this disease
Current information on WRD
(EUR A)*
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Reported burden of disease for priority WRDs:
874,459 cases from 1999 to 2005.
 With a reporting efficiency of 30%, reasonable
estimate: 2.5 million cases.
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For emerging WRDs (same period of time) :
1,006,462 cases……..,
With an efficiency reporting of 20%, 5 million
cases.
*Centralized Information System for Infectious Disease – CISID.
Priority diseases
The Parties decided unanimously to focus
on two categories of water-related
diseases:
 Priority WRDs, with high epidemic
potential such as cholera,
enterohaemorrhagic E. coli, viral hepatitis
A, bacillary dysentery, and typhoid.
Emerging diseases
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emerging diseases:
showing a rapid increase in the affected
population, or
being observed in countries where they
were previously absent such as
campylobacteriosis, cryptosporidiosis,
giardiasis, and legionellosis.
Local diseases
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Diseases having potentially a grave local
impact, such as :
Blue baby syndrome
Arsenicosis
Viral infections particularly norovirus
Parasitic diseases
Surveillance systems
 Public
health surveillance has been
defined as "the ongoing and systematic
collection, analysis and interpretation of
health data to describe and monitor a
health event" (Klaucke, 1992).
 Information from surveillance systems is
used to plan public health interventions
and monitor whether they have been
effective in improving public health.
Why setting up a specific
surveillance system on WRDs?
 Why
should a health authority commit
financial resources and personnel time to
the surveillance of waterborne disease?
 Is waterborne disease an important health
problem?
 How will the information collected in a
waterborne disease surveillance system
be used to improve the health of the
public?
Because data and information can
be used ..
 to
identify communities where there are
problems with waterborne disease that
require intervention measures to control
and prevent disease.
 to target resources toward the areas with
the greatest needs.
 to check the effectiveness of
interventions in reducing disease.
Utility of data and information from
Surveillance Systems
Some examples:
 Information on incidence of typhoid fever→ need
for targeted vaccine campaigns in specific
geographic locations.
 Information on epidemic and endemic giardiasis
and cryptosporidiosis in communities that use
surface water supplies → need for water
filtration processes because chlorination is not
very effective against these pathogens.
Utility of data and information from
Surveillance Systems
 Information
on outbreaks of waterborne
disease in adequately treated, piped water
supplies → intrusion problems in the
water distribution system → need for
booster chlorination systems in the
distribution system or additional water
treatment on a household level
How to plan a WRD surveillance
system
DETECTION, INVESTIGATION AND
REPORTING OF WATER-RELATED
DISEASE OUTBREAKS
Health outcomes
focus on the detection of individual
cases or of outbreaks .
 monitor broad categories of health
outcomes, such as diarrhoeal disease,
or few specific pathogens ( typhoid
fever, hepatitis , cholera, etc).
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Sources of data and who collect
them
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Many countries have regulations on diseases to
be reported
 in Central Asia: cholera, salmonellosis,
shigellosis, pathogenic E. coli, typhoid and
hepatitis A.
 in some countries, clusters of >5 cases of acute
gastroenteritis must be reported.
 in most parts of the United States: individual
cases of salmonellosis, shigellosis, hepatitis A
virus, typhoid fever, cholera, E. coli O157:H7,
cryptosporidiosis and giardiasis are reported
Data collection
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Surveillance systems typically collect
information on:
Date of onset of illness
Symptoms
Etiology (diagnosis, laboratory confirmation)
Geographic location
Age
Sex
Risk factors such as other ill household
members, source of drinking-water, exposure to
animals, travel, exposure to recreational water
Sources of data and reporting
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In the United Kingdom:
1) Reports from local health officers and microbiologists
in the Public Health Laboratory Service;
2) Laboratory-based surveillance of notifiable diseases;
3) Surveys of water quality and environmental sampling
reports; and
4) Reports from drinking-water authorities on suspected
or confirmed incidents of water contamination.
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Information on reported outbreaks is compiled and
published every six months
Surveillance Approaches for
Regions with Limited Resources
surveillance activities should be linked to
specific health goals:
 network of sentinel sites: clinics and/or
laboratories more experienced can be
used to collect more detailed and
accurate information on specific risk
factors, susceptible populations, etc.
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Surveillance Approaches for
Regions with Limited Resources
 Focused
surveys: targeted surveys on a
variety of health outcomes.
 School surveys on children health;
 Household surveys;
 etc
Control and prevention of WRDs
 Trigger
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events:
Increase of cases of a diseases;
Analysis of drinking water
Failure in the treatment of raw waters
Unusual event in the catchement area
Customers’ complaints
Acute reaction
The major goal of this phase is to reduce the risk :
 Treatment failures have to be corrected;
 An alternative water supply has to be activated.
 High-risk persons should be excluded from
water consumption (these should be identified
in advance!)
 Consumers may be advised to boil all water
before consuming it.
 Information has to be given to the public by only
one person, possibly a professional in this
position.
Analysis
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Epidemiological study for the risk
assessment of water-related disease
outbreaks
Detailed hygienic-ecological site
inspection in order to identify the causes
of an outbreak.
Analysis
 In
this phase the development of the
outbreak situation has to be checked
critically: Do new cases occur? Does the
incidence of cases increase or decrease?
The immediate control measures have
continuously to be revaluated.
 Recommendations for long term control
measures should be given.
Normalisation
Before normalisation of the situation can be
declared, the following questions have to be
answered:
- Are the causes of the outbreak completely
understood?
- Have efficient control measures been
implemented?
- With respect to the incubation period, do new
cases occur?
- Do water sample results meet microbiological or
chemical requirements since at least three
days?
Organizational aspects
 All
these activities require collaborations
among:
 institutional actors
 experts
A coordinating organism should be created
at national and/or local level
Task force on WRD Surveillance
systems

The First Meeting of the Parties
(Geneva, 17-19 January 2007)
established a Task Force on
“Surveillance and early-warning
systems, contingency plans and
response capacities”, coordinated by
Italy.
Mandate
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(a)
Prepare guidelines on surveillance,
outbreak detection and early warning
systems, contingency plans and capacity
response, taking into account established
WHO guidelines for adoption by the Parties at
their second meeting:
(b)
Support the guidelines’ implementation
by providing assistance, upon request, to
Parties and non-Parties through in-country
missions (up to six missions should be
organized in 2008-2009).
1° meeting of the task force
 At
the Italian National Institute of Health,
in Rome on 24-25 September 2007.
 The
meeting was attended by
representatives from Finland, Germany,
Hungary, Italy, Kyrgyzstan, Norway,
Romania and Slovakia
Work plan of the task force up to
the second meeting of the Parties
 Questionnaire
to assess the current
capacity of the surveillance systems on
WRDs;
 (b) Guidance materials (technical and
policy guidelines);
 (c) Scientific workshop;
 (d) Assistance and in-country support.
Questionnaire
Data and information on :
 priority, emerging and locally important
diseases;
 organization of the surveillance systems;
 laboratory capabilities;
 public information;
 outbreak detection capability;
 response capacity;
 training;
 databases and mapping/GIS resources
Technical guidelines
 Largely
based on a document
prepared by the WHO collaborating
centre on health promoting water
management and risk communication
at the Institute of Hygiene, University
of Bonn, Germany
Technical guidelines
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1 INTRODUCTION
2 WATER-RELATED PATHOGENS
2.1 DEFINITIONS
2.1.1
BACTERIOLOGICAL DISEASES
2.1.2
VIRAL INFECTIONS
2.1.3
PROTOZOAN DISEASES
2.1.4
HELMINTHIC DISEASES
2.1.5
CYANOBACTERIA IN DRINKING
WATERS
Technical guidelines
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2.2 MONITORING STRATEGIES
 2.2.1
PATHOGENS TRANSMITTED BY
DRINKING-WATER
 2.2.2
A BRIEF HISTORY ON THE
DEVELOPMENT OF MEASURES ENSURING THE
SUPPLY OF HYGIENICALLY SOUND WATER
 2.2.3
PARASITE-INDUCED OUTBREAKS WITH
SPECIAL REFERENCE TO THE MILWAUKEE CASE
 2.2.4
PROTECTION MEASURES
 2.2.5
DRINKING-WATER CONTAMINATION IN
THE DISTRIBUTION NETWORK
 2.2.6
SURVEILLANCE
Technical guidelines
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3 CHEMICAL RISKS
 3.1 CHEMICAL CONSIDERATIONS
 3.1.1
ORGANOLEPTIC ASSESSMENT
 3.1.2
UNDESIRED EFFECT IN DRINKINGWATER PREPARATION
 3.1.3
BASIS FOR CALCULATING THE
GUIDELINE VALUES
 3.2 SELECTED PARAMETERS
 3.2.1
INORGANICS
 3.3 RADIO ACTIVITY
 3.4 CONCLUSIONS
Technical guidelines
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4 WATER SAFETY
4.1 WATER SOURCE
4.1.1
VULNERABILITY OF THE WATER
SOURCE
4.1.2
GROUNDWATER PROTECTION
MEASURES AND THEIR EFFECTIVENESS
4.1.3
SURFACE WATER PROTECTION
MEASURES AND THEIR EFFECTIVENESS
Technical guidelines
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4.2
WATER TREATMENT
4.2.1
BASIC RURAL WATER TREATMENT
4.2.2
CENTRALISED WATER TREATMENT
4.2.3
VULNERABILITY OF THE
PRODUCTION UNITS
4.2.4
POINT-OF-USE (POU) TREATMENT
4.2.5
CHOICE OF HOUSEHOLD
TREATMENT METHOD
4.2.6
NEED FOR BEHAVIOURAL,
MOTIVATIONAL AND ECONOMIC SUPPORT
Technical guidelines
 4.3
QUALITY CHANGES IN THE
NETWORK
 4.3.1
INTEGRITY OF THE NETWORK
 4.3.2
VULNERABILITY OF THE
DISTRIBUTION NETWORKS
 4.3.3
COMPROMISED NETWORKS
Technical guidelines
 4.4
WATER SAFETY PLANS
 4.4.1
HAZARD ASSESSMENT AND
RISK PRIORITIZATION
 4.4.2
Operational monitoring and
selection of operational control
parameters.
 4.4.3
Verification and auditing
 4.4.4
WATER SAFETY PLANS
Technical guidelines
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5 ESSENTIAL EPIDEMIOLOGY
5.1 BASIC DEFINITIONS
5.1.1
Surveillance
5.1.2
Mortality
5.1.3
Morbidity
5.1.4
Prevalence and incidence
5.1.5
Endemic, epidemic and pandemic
disease distribution
 5.1.6
Outbreak
 5.1.7
Population at risk
Technical guidelines
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5.6 DETECTION, INVESTIGATION AND
REPORTING OF WATER-RELATED DISEASE
OUTBREAKS
5.6.1
PREPARATION
5.6.2
RESPONSE
5.6.3
Trigger event
5.6.4
Acute reaction
5.6.5
Analysis
5.6.6
Normalisation
Technical guidelines
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6
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6.1.2
APPROACHES FOR WATERBORNE
DISEASE SURVEILLANCE
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6.2 SETTING UP A NATIONAL SURVEILLANCE
SYSTEM
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6.2.2
6.2.3
6.2.4
6.2.5
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ESSENTIAL SURVEILLANCE
DATA COLLECTION
DATA MANAGEMENT AND ANALYSIS
INFORMATION FLOW
INFORMATION USE
Technical guidelines
 6.3EVALUATING
A SURVEILLANCE
SYSTEM
 6.3.1
EVALUATION CRITERIA
 6.3.2
PROCESS EVALUATION
CRITERIA
Technical guidelines
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7 DATA MANAGEMENT AND ANALYSIS
USING GEOGRAPHICAL INFORMATION
SYSTEMS (GIS)
 7.1
INTRODUCTION TO GIS
 7.2
APPLICATION OF GIS TO
WATERBORNE DISEASE EPIDEMIOLOGY
 7.3
EXAMPLE: GIS-SUPPORTED
EPIDEMIOLOGICAL CONFIRMATION OF THE
FIRST WATERBORNE GIARDIASIS
OUTBREAK IN GERMANY
Policy guidelines
SECTION 1: POLICY SETTING
Problem setting
Water-related diseases
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Definition of water-related diseases
Economic importance to national development
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National policy requirements
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National health systems and water-related diseases
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Core functions
Laboratory management and accreditation
Capacity building and continuous education
Importance of outbreak detection, prevention and management
Intersectoral collaboration
International policy aspects
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Transboundary cooperation
Compliance with binding international agreements
Participating to international cooperation programmes
Scientific workshop
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“ how to assess the relative weight of
water-related diseases in the overall
burden of communicable disease in the
WHO European Region”
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Experiences in different Countries
Data analysis
Scientific literature
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Assistance and training
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To be better defined on the basis of the
analysis of the replies to the
questionnaire
Some countries have already requested
assistance for the organization of waterrelated disease surveillance system or
training.
Future workplan
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The activities of the Task force are scheduled as
follows:
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May 2008: first draft of the policy guidance document;
September 2008: first draft of the document with the
analysis of the results from the replies to the
questionnaire; completion of the technical guidelines
October 2008: Second meeting of the Task Force;
December 2008: Scientific workshop.