This document discusses a presentation about the relationship between dengue fever and climate change in Japan. It begins with an introduction and literature review on the topics. It then outlines the research objectives, methodology, and study sites in Japan. The results sections shows findings from surveys of local departments on awareness of dengue fever, control strategies, and perceptions of climate change risks. Geographic information system analysis projects increasing average temperatures in Japan by 2100, which could expand mosquito habitat. The discussion analyzes variations in perceptions and strategies between regions and the impact of temperature on dengue risk. Limitations and areas for future work are also presented.

1. Relationship between
dengue fever and climate change in japan
Community Perception of Dengue Fever and Climate Change
Naoki Takabatake
2017/4/19
Ecologies and Politics of Health
http://blog.healthgenie.in/mosquito-borne-diseases-symptoms-prevention-and-treatment/

2. This talk will address the impacts of climate change and
dengue fever in Japan, and how Japanese cities cope with them.
• Literature Review:
• The Climatic and Ecological Context of Dengue Fever in Japan
• Community and Dengue Fever
• Dengue Outbreak in Tokyo, Japan
• Research Objectives
• Methodology
• Results
• Discussion
• Conclusion
Wu et al., 2016

3. Climate change expands the geographical and seasonal
distributions of Aedes genus.
• Climate change prolongs dengue seasons and extends their
ranges towards higher latitudes and elevations.
• Warmer temperatures:
• Shorten the extrinsic incubation period
• Boost the frequency of female mosquito bites
• Ae. Albopictus was already confirmed in the northern part of
Japan.
• Climate is one of the contributors to grow incidences of
dengue fever and expand their ranges.
Bouzid et al., 2014, Ebi, 2016, Gibbons et al., 2002, IPCC, 2011, Kolivras, 2010, Kutsuna et al., 2015, Ministry of the
Environment, 2013, Morin et al., 2013, Patz et al., 1996, Sato et al., 2011, Watts et al., 1986,, WHO, 2010, Wu et al., 2016

4. Community approaches are a key to prevent mosquito-borne
diseases.
• Lack of knowledge/education:
• Discourage to take action
• Leave responsibility to someone else
• Create a threat to public health
• Lack of funds slow down health sectors’ actions.
• Public health education programs
• Less preventive measures
• Cross-departmental communications are critical to avert mosquito-borne diseases.
McNaughton et al., 2010; Robbins, 2011; Tedesco et al., 2010; Tong et al., 2016

5. The 2014 dengue outbreak in Tokyo was the first outbreak in
70 years.
• Range expansion of Aedes albopictus from west to north in Japan.
• High population density induces mosquito bites.
• Well-planned urban cities may still face dengue outbreaks.
http://www.shoreexcursions.asia/explore-putrajaya-worlds-best-garden-city-1-day/ https://en.wikipedia.org/wiki/Yoyogi_Park#/media/File:Fountain_Yoyogipark.JPG
Gómez-Dantés 2009; Kutsuna et al., 2015; Mulligan et al., 2012

6. Research Objectives
• What strategies are Japanese health authorities using to prevent and control dengue fever and Aedes
mosquitoes?
• How do stakeholders perceive the risk of dengue fever, mosquito-borne diseases, and climate
change to their communities?
• How do management strategies and perceptions of dengue fever risk vary in different climate
regions?
• How does the temperature impact on the spatial risk of dengue fever in Japan?

7. Methodology and Study Sites
• Surveys
• The Internet-based survey was sent out to 196 departments
• First survey – 1/30/2017
• Second survey – 2/12/2017
• Third survey – 2/21/2017
• Study Sites:
• Tokyo (Capital of Japan)
• Niigata (Located in North)
• Okinawa (Located in South)
• Geographic Information Systems (GIS)
• Temperature data between 1950 and 2016 collected from the Japan
Meteorological Agency and projected the change in temperatures
up to 2100.
• About 120 weather stations across Japan were chosen.

8. Results – Awareness and Knowledge of Dengue Fever and Aedes Genus
Q8. How knowledgeable are
you with symptoms and signs
of dengue fever?
Q9. How knowledgeable are
you with habitats and feeding
practices of Aedes genus?
1.
Extremely
knowledgeable
5.
Not knowledgeable
at all
3.
Moderately
knowledgeable
1.
Extremely
knowledgeable
5.
Not knowledgeable
at all
3.
Moderately
knowledgeable
3.4
Niigata
3.7
Total
2.5
Tokyo
3.4
Tokyo
3.6
Total
4.0
Niigata
3.7
Okinawa
3.7
Okinawa

9. Results – Awareness and Knowledge of Dengue Fever and Aedes Genus
Q10. How strongly do you agree with the following
statement:
“Dengue fever is a serious mosquito-borne disease
in your city today.”
Q11. How strongly do you agree with the following
statement:
“Dengue fever is a serious mosquito-borne disease in
your city in the future because of climate change.”
1.
Strongly
agree
5.
Strongly
disagree
3.
Not sure
3.5
Tokyo 3.7
Niigata
3.4
Total
2.8
Okinawa
1.
Strongly
agree
5.
Strongly
disagree
3.
Not sure
2.4
Okinawa
2.9
Total
2.9
Tokyo
3.1
Niigata

10. Results – Awareness and Knowledge of Dengue Fever and Aedes Genus
(Table 8) Reasons why the 2014 dengue outbreak was limited only in Tokyo: Niigata =13, Tokyo = 10, and Okinawa = 3
Q18. Why do you think the 2014 dengue outbreak occurred only in Tokyo, but not in other parts of
Japan?
Ranked
Reason
Niigata Tokyo Okinawa Total
1 Importation/international travelers
(n = 6)
Importation/international
travelers
(n = 3)
Importation/international
travelers
(n = 4)
Importation/international
travelers
(n = 13)
2 Action prevented from spreading
(n = 2)
Luck (n = 2)
Population density (n = 2)
Population density (n = 1)
Movement of items (n =
1)
Luck (n = 2)
Movement of items (n =
2)
Action prevented from
spreading
(n = 2)
3 Population density (n = 1)
Movement of items (n = 1)
N/A N/A N/A

11. Results – Control Strategies
Low Priority
78%
High Priority (only
in an emergency)
9%
Not our
departmen
t task
13%
Q3. How high of a priority is management of
mosquito-borne disease in your city?
Low Priority High Priority (only in an emergency)
Not our department task
(Fig.10) Priority of mosquito-borne diseases in city agenda: Niigata = 9, Tokyo = 9, and Okinawa = 3

12. Results – Control Strategies
(Table 9) Necessary improvement to prevent and control dengue outbreaks: Niigata = 15, Tokyo = 11, and Okinawa = 5
Q19. Which of the following options help to prevent and control dengue outbreaks? Select as may
that apply.
Ranked
Reason
Niigata Tokyo Okinawa Total
1 More awareness of residents
about mosquito-borne diseases
(n = 11)
More awareness of residents
about mosquito-borne
diseases (n = 8)
More awareness of
residents about mosquito-
borne diseases (n = 4)
More awareness of
residents about mosquito-
borne diseases (n = 23)
2 More budget for prevention of
mosquito-borne diseases (n =
8)
More awareness of policy
makers or urban designers
about mosquito-borne diseases
(n = 8)
More communication among
departments (n = 3)
More awareness of health
or environmental officials
about mosquito-borne
diseases (n = 3)
More communication
between the city and
residents (n = 3)
More budget for
prevention of mosquito-
borne diseases (n = 12)
More awareness of health
or environmental officials
about mosquito-borne
diseases (n = 12)
3 N/A More budget for prevention
of mosquito-borne diseases
(n = 2)
N/A N/A

13. Results - Future Risks and Planning
Q21. How concerned are you that
climate change will increase the
dengue risk in your city?
1.
Extremely
concerned
3.
Moderately
concerned
5.
Not concerned
at all
3.8
Niigata
3.2
Tokyo
3.4
Okinawa
3.5
Total

14. Results – Geographic Information Systems
January, 1950 – Average Max Temperature January, 2100 – Average Max Temperature

15. Results – Geographic Information Systems
July, 1950 – Average Max Temperature July, 2100 – Average Max Temperature

16. Results – Geographic Information Systems
October, 1950 – Average Max Temperature October, 2100 – Average Max Temperature

17. Discussion
• How do management strategies and perceptions of dengue
fever risk vary in different climate regions?
Yes – Difference across Japan
• Awareness of stakeholders could change by the
circumstances they are surrounded by.
No - Differences across Japan
• Cross-departmental conversations do not often
happen unless they are in an emergency.
• The priority of mosquito-borne disease
managements is low.
• An increase in the awareness of residents is
important.
• How do stakeholders perceive the risk of dengue fever,
mosquito-borne diseases, and climate change to their
communities?
• Stakeholders in Japan were generally unsure about the
relationship between climate change and dengue fever
or mosquito-borne diseases in general.
• How does the temperature impact on the
spatial risk of dengue fever in Japan?
• The increase in temperatures allows
mosquitoes to move northwards.
• By 2100, Ae. albopictus will be
found at the large part of Japan.
• What strategies are Japanese health
authorities using to prevent and control
dengue fever and Aedes mosquitoes?
• Public health messages
• Reduce breeding sites of mosquitoes.

18. Limitations
Survey GIS
• No qualitative research
• Hard to generalize survey
results
• Shortage of responses
• Size of study sites
• Language translation
• Missing some elements
• Precipitation
• Population density

19. Conclusion and Future Work
• Ae. albopictus is widely recognized
throughout Japan.
• Dengue outbreaks because of climate
change haven’t been confirmed.
1. Why dengue outbreaks induced by climate
change haven’t taken place yet.
• GIS results showed that climate
change and the distribution of
mosquitoes were connected.
• Survey results indicated that humans
and climate change were
disconnected.
1. How to connect
stakeholders with climate
change and mosquito-
borne diseases.
• Survey results suggested that
stakeholders thought of the
importance of community
participation as well as public
health education programs
1. What Japanese citizens perceive the risk of
climate change and mosquito-borne
diseases.
2. If Japanese citizens follow the instructions
stakeholders tell and act based on them.

20. References
Bouzid, M., Colón-González, F. J., Lung, T., Lake, I. R., & Hunter, P. R. (2014). Climate change and the emergence of vector-borne diseases in Europe: case study of dengue
fever. BMC public health, 14(1), 781.
Ebi, K. L., & Nealon, J. (2016). Dengue in a changing climate. Environmental Research, 151, 115-123.
Gibbons, R. V., & Vaughn, D. W. (2002). Dengue: an escalating problem. Bmj, 324(7353), 1563-1566.
Gómez-Dantés, H., & Willoquet, J. R. (2009). Dengue in the Americas: challenges for prevention and control. Cadernos de saúde pública, 25, S19-S31.
Kutsuna, S., Kato, Y., Moi, M. L., Kotaki, A., Ota, M., Shinohara, K., ... & Sato, T. (2015). Autochthonous dengue fever, tokyo, japan, 2014. Headache, 17, 89-5.
McNaughton, D., Clough, A., Johnson, P., Ritchie, S., & O’Neill, S. (2010). Beyond the ‘back yard’: Lay knowledge about Aedes aegypti in northern Australia and its
implications for policy and practice. Acta tropica, 116(1), 74-80.
Ministry of the Environment. March 2013. Climate Change and Its Impacts in Japan, FY 2012: Consolidated Report on Observations, Projections and Impact Assessments of
Climate Change. Retrieved from https://www.env.go.jp/en/earth/cc/impacts_FY2012.pdf
Morin, C. W., Comrie, A. C., & Ernst, K. (2013). Climate and dengue transmission: evidence and implications. Environmental Health Perspectives (Online), 121(11-12), 1264.
Patz, J. A., Epstein, P. R., Burke, T. A., & Balbus, J. M. (1996). Global climate change and emerging infectious diseases. Jama, 275(3), 217-223.
Robbins, P. (2011). Political ecology: A critical introduction (Vol. 16). John Wiley & Sons.
Tedesco, C., Ruiz, M., & McLafferty, S. (2010). Mosquito politics: Local vector control policies and the spread of West Nile Virus in the Chicago region. Health & place, 16(6),
1188-1195.
Tong, M. X., Hansen, A., Hanson-Easey, S., Xiang, J., Cameron, S., Liu, Q., ... & Williams, C. (2016). Perceptions of capacity for infectious disease control and prevention to
meet the
challenges of dengue fever in the face of climate change: A survey among CDC staff in Guangdong Province, China. Environmental research, 148, 295-302.
Watts, D. M., Burke, D. S., Harrison, B. A., Whitmire, R. E., & Nisalak, A. (1986). Effect of temperature on the vector efficiency of Aedes aegypti for dengue 2 virus. ARMY
MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD. World Health Organization. (2010). First WHO report on neglected tropical
diseases: working to
overcome the global impact of neglected tropical diseases. In First WHO report on neglected tropical diseases: Working to overcome the global impact of
neglected tropical diseases. WHO.
Wu, X., Lu, Y., Zhou, S., Chen, L., & Xu, B. (2016). Impact of climate change on human infectious diseases: Empirical evidence and human adaptation. Environment
international, 86, 14-23.

21. Questions?
https://www.expedia.co.jp/en/Okinawa.d10805.Destination-Travel-Guides
Okinawa Niigata
https://www.pinterest.com/pin/200621358373710174/
Tokyo

22. Extra Information

23. Results – Control Strategies
Q5. How does your department communicate with residents during a mosquito-borne
disease outbreak? Select as many that apply.
Ranked Reason Niigata Tokyo Okinawa Total
1 City homepage (n = 20) City homepage
(n = 10)
City homepage
(n = 4)
City homepage
(n = 34)
2 Leaflets (n = 8) Advertisements (n = 1) Radio (n = 2)
Advertisements (n = 2)
Leaflets (n = 10)
3 Newspaper (n =5) N/A N/A Radio (n = 6)
(Table 3) Ways city departments communicate with residents during a mosquito-borne disease outbreak: Niigata = 21, Tokyo = 12, and Okinawa = 5

24. Q4. Which mosquito control strategy does your department take? Select as many that apply,
Ranked Reason Niigata Tokyo Okinawa Total
1 Adult control
(n = 11)
Public health
messages
(n = 7)
Larvicides
(n = 3)
Public health messages
(n = 18)
2 Public health
messages
(n = 10)
Larvicides
(n = 3)
Check abandoned, seasonal or
foreclosed homes (n = 2)
Notify partners and colleagues
about dengue control activities (n
=2)
Communicate with other community
organizations (n = 2)
Adult control (n = 14)
3 Pick up trash (n = 6) Adult control
(n = 2)
N/A Larvicides
(n = 11)
(Table 2) Mosquito-control strategy city departments take: Niigata = 9, Tokyo = 14, and Okinawa = 5
Results – Control Strategies

25. (Table 4) Measures city departments tell residents to take to prevent or control mosquitoes: Niigata = 18, Tokyo = 11, and Okinawa = 5
Results – Control Strategies
Q6. When your department communicates, what measures does your department tell residents to take?
Select as many that apply.
Ranked Reason Niigata Tokyo Okinawa Total
1 Cut trees and vegetation (n = 11) Mosquito repellent or
cream (n = 5)
Cover body with long
sleeves/pants
(n = 5)
Prevent water stagnation (n = 3)
Disposing of broken/old containers
(n = 3)
Mosquito repellent or cream (n = 3)
Cut trees or vegetation (n = 3)
Cut trees or vegetation
(n = 18)
2 Disposing of broken/old containers
(n = 9)
Covering water
containers (n = 4)
Change water in storage
tank frequently (n = 4)
Cut trees or vegetation
(n = 4)
N/A Mosquito repellent or
cream (n = 16)
3 Adulticides (n = 8)
Mosquito repellent or cream (n = 8)
Cover body with long sleeves/pants
(n = 8)
Change water in storage tank
frequently (n = 8)
N/A N/A Disposing of
broken/old containers
(n = 15)

26. Results – Future Risks and Planning
0
5
10
15
20
25
30
35
Niigata Tokyo Okinawa Total
Q13. Is your city trying to increase green space for either
water supply or recreational purposes?
Yes No

27. Temperature scale
28C°
(Ideal)
35C°
(Higher than 35C°
lowers activity levels)
0C°
(Lower than 0C° is fatal)
26C°
(Lower than 26C°
slows activity levels)
16C°
(Lower than 16C° lowers
activity to harmless
levels )

28. 28C°
(Ideal)
35C°
(Higher than 35C°
lowers activity levels)
0C°
(Lower than 0C° is fatal)
26C°
(Lower than 26C°
slows activity levels)
16C°
(Lower than 16C°
lowers activity to
harmless levels )
Temperature scale