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Surveillance and early warning systems for water related diseases

Enzo Funari National Institute of Health

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)*

  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.

 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

 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

 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).

Sources of data and who collect them

    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

        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

    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.

  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.

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 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

  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

  (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

 1  2 INTRODUCTION WATER-RELATED PATHOGENS  2.1 DEFINITIONS  2.1.1

 2.1.2

 2.1.3

BACTERIOLOGICAL DISEASES VIRAL INFECTIONS PROTOZOAN DISEASES  2.1.4

HELMINTHIC DISEASES  2.1.5

WATERS CYANOBACTERIA IN DRINKING

Technical guidelines

       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

         3 CHEMICAL RISKS 3.1 CHEMICAL CONSIDERATIONS 3.1.1

ORGANOLEPTIC ASSESSMENT 3.1.2

UNDESIRED EFFECT IN DRINKING WATER 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

 4 WATER SAFETY  4.1 WATER SOURCE  4.1.1

SOURCE VULNERABILITY OF THE WATER  4.1.2

GROUNDWATER PROTECTION MEASURES AND THEIR EFFECTIVENESS  4.1.3

SURFACE WATER PROTECTION MEASURES AND THEIR EFFECTIVENESS

Technical guidelines

 4.2

 4.2.1

 4.2.2

 4.2.4

WATER TREATMENT BASIC RURAL WATER TREATMENT CENTRALISED WATER TREATMENT  4.2.3

VULNERABILITY OF THE PRODUCTION UNITS 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

4.4.4

Verification and auditing WATER SAFETY PLANS

Technical guidelines

         5 ESSENTIAL EPIDEMIOLOGY 5.1 BASIC DEFINITIONS 5.1.1

Surveillance 5.1.2

Mortality 5.1.3

5.1.4

5.1.5

Endemic, epidemic and pandemic disease distribution 5.1.6

Outbreak 5.1.7

Morbidity Prevalence and incidence Population at risk

Technical guidelines

 5.6 DETECTION, INVESTIGATION AND REPORTING OF WATER-RELATED DISEASE OUTBREAKS  5.6.1

 5.6.2

 5.6.3

PREPARATION RESPONSE Trigger event    5.6.4

5.6.5

5.6.6

Acute reaction Analysis Normalisation

Technical guidelines

 6 ESSENTIAL SURVEILLANCE  6.1.2

APPROACHES FOR WATERBORNE DISEASE SURVEILLANCE  6.2 SETTING UP A NATIONAL SURVEILLANCE SYSTEM     6.2.2

6.2.3

6.2.4

6.2.5

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

 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 Definition of water-related diseases Economic importance to national development National policy requirements • • • National health systems and water-related diseases Core functions Laboratory management and accreditation Capacity building and continuous education Importance of outbreak detection, prevention and management Intersectoral collaboration International policy aspects Transboundary cooperation Compliance with binding international agreements Participating to international cooperation programmes

Scientific workshop

 “ how to assess the relative weight of water-related diseases in the overall burden of communicable disease in the WHO European Region”    Experiences in different Countries Data analysis Scientific literature

Assistance and training

  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 water related disease surveillance system or training.

Future workplan

 The activities of the Task force are scheduled as follows:  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.