THE PHILIPPINES: ASSOCIATION WITH TEMPERATURE, HUMIDITY AND - - PowerPoint PPT Presentation

DENGUE AND MALARIA CASES IN THE PHILIPPINES: ASSOCIATION WITH TEMPERATURE, HUMIDITY AND RAINFALL

Maria Ruth B. Pineda-Cortel, Ph.D. University of Santo Tomas Philippines

Objectives of the Study

Identify trends, distribution patterns, and relations among diseases, variability of climate and socio- economic conditions ■ Present the number of cases of dengue and malaria from 2008 to 2015 in the Philippines: trends and patterns ■ Determine if climate factors (temperature, rainfall and humidity) are significantly associated with dengue and malaria cases in the Philippines

– percent of the cases contributed by the climate factors – climatic factor with greatest effect on the prediction of dengue and malarial

■ Determine effect of socio-economic conditions on the cases

Conceptual Framework

CLIMATE FACTORS INDEPENDENT VARIABLE MEAN TEMPERATURE RAINFALL RELATIVE HUMIDITY DEPENDENT VARIABLE DENGUE AND MALARIA CASES

Data Collection

■ Data on climatic factors were obtained from PAGASA

– mean temperature, amount of rainfall, and relative humidity

■ Data on dengue and malaria cases were obtained from DOH and from different regions in the Philippines

– 2008 to the third quarter of 2015

Statistical Analysis

■ Time series and structural analysis using Eviews 9.5 SV ■ Augmented Dickey Fuller (ADF) was used to test for stationarity ■ Granger causality was used to investigate causality between two variables

Total Dengue Cases (2008-2015)

20000 40000 60000 80000 100000 120000 140000 160000 180000 200000

Morbidity Mortality

100 200 300 400 500 600 700 800 900

NC NCR Regio gion n IVA

Regio gion n III

Region I

Suspected Dengue Cases in the Philippines per Region (2008-2015)

• Low: 2008, 2009 and 2014
• Spike: 2010, 2011, 2012, 2013

and 2015

• Highest: July to September
• Lowest: April and May
• Region 6 has the highest

count of suspected dengue case, on August 2010. OVERALL: NCR, Region 3 and 4a

Suspected Dengue Death Cases in the Philippines per Region (2008-2015)

• exhibit similar pattern with that of

morbidity cases

• 2010, 2011 and 2015
• Highest: July to September
• Lowest: April and May
• OVERALL: NCR, Region 4a and

Region 7

Total Suspected Malaria Cases in the Philippines (2008-2015)

0.00 1000.00 2000.00 3000.00 4000.00 5000.00 6000.00 7000.00 8000.00

Tot

• tal Suspe

pect cted ed Malaria a Cases es (2008 08- 2015) 5)

Suspected Malaria Cases in the Philippines (2008-2015)

• Lower cases than dengue
• Region

4b has extreme suspected cases of Malaria

• Palawan (1,401; 5)
• Occidental Mindoro (490; 5)
• Oriental Mindoro (383; 1)
• Romblon (244; 0)
• Marinduque (204; 2)

Minimum and Maximum Temperatures

• Min. Temp.
• Max. Temp.
• Rel. Hum.
• Ave. Temp. and Rh

Rainfall

• Ave. Rf

Association/Correlation with Climatic Factors

Correlation Min Temp Max Temp Rainfall Humidity Dengue .135**

• .044

.237** .173** Dengue Deaths .173**

• .040

.160** .063* Malaria .125** .061*

• .067**

.042

Dengue, dengue deaths and malaria cases are associated with the minimum temperature of the area. As the Minimum temperature increases, the Dengue, dengue deaths and malaria cases also increases. Dengue is positively related to amount of rainfall, i.e. as rainfall increases, dengue and dengue deaths also

• increases. However malaria has a different direction. As the rainfall increases the malaria cases decreases.

For the relative humidity, only dengue is related. As humidity increases, dengue and dengue deaths also increase.

**. Correlation is significant at the 0.01 level (2-tailed). *. Correlation is significant at the 0.05 level (2-tailed).

Pos

• sit

itiv ive e as asso sociati iation

• n of

dengue with minimum temperature

0.00 5.00 10.00 15.00 20.00 25.00 500 1000 1500 2000 2500 3000 3500 4000 4500

Dengue Cases and Minimum Temperature, 2015

Dengue Cases Min Temp

p = 0.135** p = .173**

Dengue Cases are positively associated with amount

• f rainfall

0.00 200.00 400.00 600.00 800.00 1000.00 1200.00 500 1000 1500 2000 2500 3000 3500 4000 4500

Dengue Cases and Rainfall, 2015

Dengue Cases Rainfall

p = 0.237** p = 0.160**

Dengue Cases are positively associated with relative humidity

72.000 74.000 76.000 78.000 80.000 82.000 84.000 86.000 88.000 90.000 92.000 94.000 500 1000 1500 2000 2500 3000 3500 4000 4500

Dengue and Relative Humidity, 2015

Dengue Cases Humidity

p = 0.173** p = 0.063*

Malaria is positively associated with temperature and negatively associated with rainfall.

0.00 5.00 10.00 15.00 20.00 25.00 200 400 600 800 1000 1200

Malaria, Temperature and Rainfall, 2015

Malaria Cases Rainfall Min Temp

Stationarity time series

■ Augmented Dickey Fuller ■ Some series are detected to be non-stationary. – Minimum Temperature in Regions 1, 2, 3, CAR and ARMM; – Malaria cases in Region 13 and Humidity in Region 10. – This means that these series are not constant over time and there is a presence of seasonality.

Seas asonality

• nality an

and tr trend nd me mean ans s th that at th there re ar are co common mmon mo months ths th that at deng ngue ue ca cases es ar are high h an and some me mo months ths ha have e th the e sma mall ll numb mber er of ca cases. es.

Granger Causality

■ A test to check if certain factors may be used to predict number of cases For dengue: ■ Minimum temperature contains information that can predict the number of Dengue cases (in most regions, except 8 and ARMM) ■ Rain infall l (3, 4a, 4b, 7, 9, NCR) ■ Humidity (11 only) For malaria: ■ min. temp. and rainfall can predict cases of Malaria in Reg egio ion 4b

• nl

nly

– Asia Pacific Network for Global Change Research (APN)

■ Department of Health (DOH) ■ Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) ■ University of Santo Tomas (UST)

Acknowledgments