1

Geographical Information

System (GIS) in

Communicable Disease Control

Prof Dr Shamsul Azhar Shah

Department of Community Health

Faculty of Medicine

Universiti Kebangsaan Malaysia (UKM)

2

OVERVIEW

• Introduction

• Disease Surveillance

• Emerging/Re-emerging issues

• Feature Unique to Communicable Diseases

• Factors Influencing Transmission

• GIS function

• GIS in Public Health/Epidemiology

• Usage of GIS in Communicable Diseases

3

INTRODUCTION

• Populations and communities are geographically distributed and communities tend to have their own defining characteristics.

• Environment, which includes both physical (i.e., air quality, water quality, soil characteristics, radiation) , socio economic and lifestyle aspects have marked geographical variation.

• Communicable diseases - significantly affect the quality of life and the life span of all communities

– with certain parts of society being more vulnerable than others.

• Public health action prevents, limits and controls such diseases

– through disease prevention strategies and health promotion programs, including surveillance, investigation of reported cases and outbreaks, and appropriate action to prevent further spread.

• Maintenance of a strong communicable disease response is an integral part of a national strategy to maintain and improve the public health.

4

5

DISEASE SURVEILLANCE

• Disease surveillance is an epidemiological practice

by which the spread of disease is monitored in

order to establish patterns of progression.

• The main role of disease surveillance is to

– predict

– observe

– minimize

the harm caused by outbreak, epidemic, and pandemic

situations, as well as increase our knowledge as to what

factors might contribute to such circumstances.

6

EMERGING/RE-EMERGING

• Emerging infectious disease:

– An infectious disease that has newly appeared in a population or that has been known for some time but is rapidly increasing in incidence or geographic range.

• Re-emerging

– diseases are those that have been around for decades or centuries, but have come back in a different form or a different location

7

SOME EXAMPLES:

EMERGING AND RE-EMERGING

EMERGING/NEWLY EMERGING

• Ebola

• Pandemic Influenza (H5N1, H1N1, MERSCOV...)

• SARS

• Nipah

• West Nile

• Mostly zoonotics

RE-EMERGING

• Tuberculosis

• Malaria

• Dengue

• Cholera

• Typhoid

8

FEATURES UNIQUE TO

INFECTIOUS DISEASES

1. A case may also be a source

2. People may be immune

3. A case may be a source without being

recognized.

4. There is often a need for urgency

5. Preventive measures often have good

scientific basis.

9

Agent

Host

Environment

• Age

• Sex

• Genotype

• Behaviour

• Nutritional status

• Health status

• Infectivity

• Pathogenicity

• Virulence

• Immunogenicity

• Antigenic stability

• Survival

• Weather

• Housing

• Geography

• Occupational setting

• Air quality

• Food

Factors influencing disease

transmission

10

GIS FUNCTION

11

WHAT IS GIS? • A special kind of information system

– Capture, store, manage, retrieve, analyse & present

spatial information

– Mainly about location

• Integrate many different types of data

• With GIS we can easily: – Draw maps and visualise spatial distributions

– Edit and alter existing data

– Accurately measure distances and areas

– Overlay maps of different areas

12

Imagine an overhead projector, with a series of transparencies laid upon

it. Each transparency is about your town, drawn to the same scale, and

can therefore be integrated with the others. But each transparency deals

with a different topic: roads, places, earthquakes, census divisions, soil

landscape data, and ecological zones:

GIS - An Analogy

13

The Global Positioning System

(GPS) is a system allowing to

precisely identify locations on

the Earth

Global Positioning System Device

GPS

Space Segment

Control segment

User segment

14

Global Positioning System

Device

15

WHAT GIS CAN HELP

PUBLIC HEALTH? • Research Tools and Planning

– Constructing mathematical models

– Service planning and optimisation

– Making predictions

• Spatial Decision Support Systems

– Infrastructure – roads, towns, services

– Census – population statistics

– Medical resource (hospitals, clinics, available beds)

• Emergency Response Systems

– Medicare records, 911 services

– disease registers systems

16

GIS in Public Health

Incidence/Prevalence Spatial analysis Risk mapping

Service utilization

Cluster detection

17

GIS Applications in Epidemiology

1. Data Visualisation and Exploration

2. Data Integration

3. Monitoring

4. Geostatistics and Modelling

5. Spatial Interaction and Diffusion

6. Data Sharing and Web Services

18

USAGE OF GIS IN

COMMUNICABLE

DISEASE CONTROL

19

DENGUE

•Vectorborne disease

•Spread by mossquitoes

(Aedes spp)

20

STUDY LOCATION: PETALING JAYA AND SUBANG, MALAYSIA

Number of cases map by area

21

Point/Dot

representing the

cases overlayed

with NVDI map

(normalized

difference

vegetative index)

22

Dengue cases

overlayed with

LST map (Land

surface

temperature)

23

Point location of dengue cases in

MPPJ and MPSJ for year 2002

Landuse Map Classification

using Landsat

Areas circled in black indicates with a high

number of dengue fever cases. The cases

were found to be mainly focused in

buildup areas.

IKONOS satellite imagery was used for point

location of cases as well as the identification

of the area type (squatter colonies, high dense

residential area & etc.) because of its 1m

spatial resolution.

24

Factors of dengue transmission in Majlis Perbandaran Petaling Jaya(MPPJ) and Majlis Perbandaran Subang Jaya(MPSJ) using remote sensing and geographic information system (GIS)

25

Population Density Map and Dengue

Case of Petaling Jaya (MPPJ) year

2001

Population Density Map and Dengue

Case of Petaling Jaya (MPPJ) year 2002

26

Dengue

outbreak pattern

in 2002 from

Epid Week 1 to

Epid Week 52.

27

28

BACK

29

BACK

30

BACK

31

BACK

32

BACK

33

BACK

34

BACK

35

BACK

36

Spatial statistics

37

TYPHOID

•Salmonella typhi

•Transmitted via food and water

•Human host

38

STUDY LOCATION: KOTA BHARU, KELANTAN, MALAYSIA

39

NUMBER OF CASES BY AREA

40

INCIDENCE MAP

41

HOTSPOT ANALYSIS

42

HOTSPOT CLUSTERS BY POPULATION CENCUS

43

HOTSPOT WITH 500M BUFFER ZONE FROM RIVER

TUBERCULOSIS

•Mycobacterium tuberculosis

•Human to human

44

45

STUDY LOCATION: KOTA BHARU, KELANTAN, MALAYSIA

46

TB clusters in Kelantan, 2003-2007 by using SaTScan, Poisson model with pure space model

Clusters of pulmonary TB

Clusters of extra-pulmonary TB

47

STUDY LOCATION: CHERAS, KUALA LUMPUR (2008-2012)

48

CHIKUGUNYA

•Vectorborne diseases

•Transmitted by mosquitoes (Aedes spp)

49

STUDY LOCATION: SELANGOR, N.SEMBILAN, PAHANG AND

JOHOR, MALAYSIA

50

SEROPOSITIVE OF CHIKUGUNYA IN THE

STUDY AREA

51

Red dots:

chikungunya

seropositive

Black dots:

chikungunya

seronegative

INFLUENZA

•Influenza A and B

•Human to human

•Animal to human

52

53

STUDY LOCATION: NIIGATA, JAPAN

Address matching system

54

Cases of influenza patients in 3 clinics

55

Total influenza patients within 500m mesh

PAY ATTENTION NOW TO

THE NEXT FOLLOWING

SLIDES

56

57

05－07w

58

06－08w

59

07－09w

60

08－10w

61

09－11w

62

10－12w

63

11－13w

64

12－14w

CHALLENGES IN

IMPLEMENTATION

65

66

What are the challenges?

• Abundance of data but incomplete (certain main

variables missing e.g. coordinates, case

confirmation)

• Not more than 5 years of data could be found (data

went missing, no back up)

• Not enough trained personnel in mapping (no

continuity, promotion to other unit)

• Not many epidemiologists trained with GIS

67

Most important…

• Can it be used as a surveillance

system where we need to make

sure it is ongoing, analysed and

utilised?

68

Conclusions • GIS is a relatively recent and complex

technology – which explains why it has not been used to its

full potential, especially in the health domain where it is extremely promising.

• A tool of prime importance in the surveillance and control of communicable diseases – Must be used in outbreak investigation

• Varieties of analysis could be done using GIS and different personnel need different aspect of the analysis

• We need to overcome manpower problems, data entry problems, mapping software etc.

• GIS is not a magical solution to all the difficulties regarding information in health care, but is a powerful tool capable of transforming the way with which information is dealt with.

69

70

Thank You