Malaria Elimination Transmission and Costing in the Asia-Pacific

1. METCAP Model
Malaria Elimination Transmission and Costing in the
Asia-Pacific

2. Dynamic epidemiological-economic
malaria model developed for 22
countries in the Asia-Pacific

3. Malaria elimination targets
02
2012 2014 2016 2018 2020 2022 2024 2026 2028 2030
Sri Lanka
Republic of Korea
Bhutan
Thailand
People’s Republic of China
Malaysia
Democratic People’s Republic of Korea
Bangladesh
Cambodia
Vanuatu
Nepal
Philippines
Viet Nam
Afghanistan
India
Indonesia
Lao PDR
Myanmar
Pakistan
Papua New Guinea
Solomon Islands
Timor-Leste

4. Purpose: to project rates of decline
to elimination by 2030 and
determine the costs for elimination
in the Asia-Pacific region

5. Epi
Model
Available
Health
System data
Malaria
Biology
Econ -Epi
Model
Environmental
conditions
Population
demographics
Cost Data
Proposed
Policy
interventions
Recommendations
Model Development
Analysis & Recommendations
Model Testing
How to develop an
epidemiological-economic
model?

6. Epi
Model
Available
Health
System data
Malaria
Biology
Econ -Epi
Model
Environmental
conditions
Population
demographics
Cost Data
Proposed
Policy
interventions
Recommendations
Model Development
Analysis & Recommendations
Model Testing
1. Write equations to describe biological behaviour of
malaria
2. Calibrate the model to existing environmental
conditions
3. Use population and health systems data to create
synthetic populations in silico that have features
similar to real populations

7. Epi
Model
Available
Health
System data
Malaria
Biology
Econ -Epi
Model
Environmental
conditions
Population
demographics
Cost Data
Proposed
Policy
interventions
Recommendations
Model Development
Analysis & Recommendations
Model Testing
4. Test out proposed interventions on the model
5. Incorporate cost data for each intervention
6. Analyse model output to make recommendations

8. Epidemiological Model Structure

9. Incorporating the characteristics of
Plasmodium falciparum malaria
Step by step approach

10. The non-immune may become infected with
malaria
S I R
Non-Immune ImmuneInfectious

11. The infected may recover naturally and
develop immunity to malaria
S I R
Non-Immune ImmuneInfectious

12. This immunity may be lost over time
S I R
Non-Immune ImmuneInfectious

13. But infections can be sub-microscopic (In),
asymptomatic (Ia) and clinical (Ic) with the
potential to become severe (Is)
Non-Immune ImmuneInfectious
S
In
RIa
Ic
Is

14. Natural recovery can occur with symptomatic
infections becoming asymptomatic and
eventually curing entirely (green arrows)
Non-Immune ImmuneInfectious
S
In
RIa
Ic
Is

15. Some infections will be treated through the
public health system (Th) and others through the
private sector (To)
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
H
To

16. Treated infections will cure to a state where false
positive test results will temporarily be possible
due to the presence of the HRP2 antigen.
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
H
To

17. The immune are also susceptible to infection
with a higher probability of developing an
asymptomatic infection
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
H
To

18. It is possible have more than one infection at the
same time (superinfection - orange arrows)
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
H
To

19. The Asia-Pacific has two major malaria species
P. falciparum P. vivax
?

20. Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
H
To
The model for Plasmodium vivax is
different from the model for
Plasmodium falciparum

21. Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
H
To
With Vivax malaria, hypnozoites
and the probability of relapse
must be incorporated in the model
structure

22. Treated infections and natural recoveries may
occur with (L) and without hypnozoites (R).
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
L
To

23. The presence of hypnozoites can trigger
relapses months after the initial infection
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
L
To

24. It is also possible have more than one infection at
the same time (superinfection - orange arrows)
Ia
Th
Non-Immune ImmuneInfectious
S
In
R
Ic
Is
L
To

25. P. falciparum
Interactions?
P. vivax

26. P. falciparum
Dual treatment (Treatment of mixed infection)
The untreated population infected with Pf malaria who are
simultaneously infected with and being treated with an ACT for Pv
malaria, will also be cured of their Pf malaria and vice versa.
P. vivax

27. P. falciparum
Triggering
Evidence suggests that the population cured from a Pf infection
have a higher probability of Pv relapse compared to the rest of
the population.
P. vivax

28. P. falciparum
Masking
Different brands of RDTs have different targets and it may be the
case that non-falciparum malaria is masked by falciparum
malaria.
P. vivax

29. Biology
Economic CostsGeographyHealth Systems
Information
DemographyEnvironment

30. Biology
Economic Costs
GeographyHealth Systems
Information
Demography
Environment
These elements are combined to project the
costs for and rates of decline to elimination
by 2030 in the Asia-Pacific region.
Model