public health and ecological forecasting ben zaitchik johns hopkins university
TRANSCRIPT
Four Thoughts These are highly mediated and often
multi-scale systems Models have a strong empirical
component In many cases, processes of interest
unfold over weeks, months or years Data accessibility and
communication are critical
Four Thoughts These are highly mediated and often
multi-scale systems Models have a strong empirical
component In many cases, processes of interest
unfold over weeks, months or years Data accessibility and
communication are critical
Anopheles darlingi is the
dominant malaria vector in the Peruvian
Amazon
Symptoms (e.g., fever, chills, etc.) appear ~5-10 days after being bitten by
an infected mosquito.
Biting rates are influenced by both
climate and land cover
Highest Deforestation Rate in Peru
Iquitos-Nauta Road Paving & Fujimori logging concessions
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140Reported Malaria, Loreto Province 1990-2013
P. vivaxP. falciparum
# C
as
es
(1
00
0s
) MAJOR FLOOD
Roll Back Malaria2nd highest increase in the Amazon
to 2006, Major decline to 2011
Land Use
Density of Anopheles
Adults
Anopheles Larva Habitat
Human Malaria
Infection
Precipitation &
Climate
Land Use
Density of Anopheles
Adults
Infrastructure
Migration, Colonization,
and Agriculture
Human Exposure
Anopheles Larva Habitat
Human Malaria
Infection
Precipitation &
Climate
Local: Predict Breeding Sites
Tmin
[5 day]
Rain[1 day]
SWnet
[1 day] SWnet
[5 day]
SoilMoisture[5 day]
Land Cover Variables
Denis Valle, Univ. of Florida
Regional: Predict casesModel for each district:
MALARIA RATE (t)
Annual
TREND
SEASONAL Cycles
CLIMATE Drivers
LAND COVER Characteristic
s
==
Captures the long-term
change in the mean of
malaria cases in the district
Variation in the series that is annual
in period. It is of direct interest (i.e., we do not remove seasonality, but
rather estimate it)
Influence both human exposure
(e.g., occupational labor) and
Anopheles density
Regional: Predict casesModel for each district:
MALARIA RATE (t)
Annual
TREND
SEASONAL Cycles
CLIMATE Drivers
LAND COVER Characteristic
s
==
TMPA rain rate is positively associated with
case count
Precipitation is negatively associated with vectors at local scale but positively associated with clinical cases at
district scale
Four Thoughts These are highly mediated and often
multi-scale systems Models have a strong empirical
component In many cases, processes of interest
unfold over weeks, months or years Data accessibility and
communication are critical
Thresholds of Rainfall, Temperature, and Humidity
Logistic Regression with multiple climate variables
Empirical The good news: in some applications
consistency may be as important as accuracy
The bad news: some forecasts are sensitive to thresholds and nonlinear responses
Four Thoughts These are highly mediated and often
multi-scale systems Models have a strong empirical
component In many cases, processes of interest
unfold over weeks, months or years Data accessibility and
communication are critical
Lead Time
Midekisa et al. (2012): Satellite rainfall is predictive of malaria in Ethiopia at 1-3 month lead
Lead Time Murray Valley Encephalitis Virus (MVEV) in Australia
has been predicted using TRMM at 2-month lead In our Amazon malaria risk model, satellite rainfall
rate is most predictive at 10 week lead. Rift Valley Fever warnings in East Africa make use
of satellite observations integrated over 3-months.
For hantavirus, seasonal rainfall anomalies can influence cases two or more years later.
Cholera dynamics have been related to precipitation at lead times from days to seasons.
Lead Time The good news: we can use satellite
rainfall observations to generate actionable forecasts.
The so-so news: many of these forecast horizons fall in between RT and research grade TRMM and GPM products.
Four Thoughts These are highly mediated and often
multi-scale systems Models have a strong empirical
component In many cases, processes of interest
unfold over weeks, months or years Data accessibility and
communication are critical
Data Accessibility Smooth web access, simple product
descriptions, and GIS compatibility are critical for this research community
The merged precipitation estimates are most widely used, but other products could also be valuable
Communication with users However, with accessibility comes
risk! We want to facilitate appropriate
interpretation and application of all GPM data products
Four Thoughts These are highly mediated and often
multi-scale systems Models have a strong empirical
component In many cases, processes of interest
unfold over weeks, months or years Data accessibility and
communication are critical