Using Malaria Tools for Elimination Scenario Planning · [email protected] 1 Using Malaria Tools for Elimination Scenario Planning 1. Getting Started ... Generate a third scenario

MRC Centre for Outbreak Analysis & Modelling, Imperial College London

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Using Malaria Tools for Elimination Scenario Planning

1. Getting Started

Start the Malaria Tools software, then click on the New icon in the bottom left-

hand corner to open a new scenario. Use the Countries panel on the left to first

select your country and then the region/province you are considering within that

country.

2. Estimating the malaria baseline

The software can be used to estimate the malaria baseline from current prevalence

and interventions as explained in Part III of the Elimination Scenario Planning

manual (page 13-16) and in step 4 in Box 2 (page 17). The following steps should

be undertaken.

a) Click on the Current Transmission tab. Enter the most recent prevalence

data available for the region in the top panel of this screen. Four boxes

should be completed: prevalence (the measured prevalence), year (in which

the survey was conducted), lower age (of the population surveyed) and

upper age (of the population surveyed). If there is specific data on the

distribution of Anopheles vector species (An.funestus, An.arabiensis and

An.gambiae s.s.), this can also be entered. All prevalence measures are

given as percentages.


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b) Click on the Past ITN Use tab. This contains the country-level estimates of

percent ITN usage as reported in the World Malaria Report 2013. Slide the

bars for each year to adjust these to any region/province level data if these

are available, otherwise leave these at the pre-set values.

c) Click on the Current Drug Use tab. This contains estimates of current

percent treatment coverage levels estimated in Cohen et al. (2012). Change

the percentage of cases treated to values you have available – note that this

proportion represents those that seek treatment and receive an anti-malarial

across both the public and private sectors. Next change the proportion of all

those treated receiving either an ACT (selecting AL or DHA-PQ as

appropriate) or a non-ACT. These three values should sum to 100%. If AS

is first-line treatment, please select AL to represent this drug.


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d) Return to the Transmission Settings tab.

e) Now run the scenario by clicking on the Run icon in the bottom left-hand

corner. Once the simulation has completed, the new estimated malaria

baseline prevalence is shown in the top panel.

f) Save this scenario to ensure that these settings can be used for the next

steps .


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3. Making Predictions about Technical and Operational

Feasibility of Malaria Reduction

3.1 Introduction

Parts IV and V can be combined in the Malaria Tools software by exploring explicit

scenarios about the impact of interventions either alone or in combination. In

particular, the actions in Box 6 (page 30) can be undertaken in more detail for each

region/province. Selecting the Intervention Options tab allows the following

interventions and operational constraints on coverage to be adjusted:

a) Vector Control: For both ITNs (A) and IRS (B), decaying efficacy is

implemented automatically to capture wear-and-tear and decay of the

insecticide. Vector behaviour (including outdoor biting) and sleeping behaviour

is also captured in the software. Thus the coverage levels entered should be the

proportion of the population protected (i.e. those using bed nets or those

residing in sprayed houses) – see Figure 13 and Figure 14 on page 15 of the

Elimination Scenario Planning manual.

b) IPT/SMC (C) and Mass treatment (D): Options are available to specify the

target coverage which represents the proportion of the at-risk population

receiving the full intervention. Mass Treatment can be combined with an RDT

to implement a Mass Screen and Treat program.

A

B

C

D


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c) Vaccination: A hypothetical vaccine (such as RTS,S) can be considered at a

specified target coverage. This can be delivered through the Expanded Program

for Immunisation, EPI (E) or to the whole population via Mass Vaccination

(F).

d) First-line treatment (G): The software distinguishes between symptomatic

and asymptomatic infection. The coverage levels should therefore represent the

proportion of malarial fevers treated with an anti-malarial (adjusting for

treatment-seeking, diagnosis, supply chain and adherence). See Figure 18 on

page 25 of the Elimination Scenario Planning manual.

E

F

G


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3.2 An Example

As an example, we demonstrate a scenario for Houet province in Burkina Faso in

which bed net coverage is increased to 90% and SMC is introduced with a coverage

of 80%.

a) Baseline scenario

As detailed in section 2 above, start Malaria Tools, click New to create a new

scenario, then select Burkina Faso as the country, then Houet as the province.

Then click Run to run the model for the default settings for that province.

Note that by default, the software assumes no interventions (including bed nets) after

2013. Hence the output graph shows an increase in prevalence over time.

To keep bed nets at their 2013 level go to the Intervention Options tab and tick

Insecticide Treated Nets. Next highlight this option and make sure that the coverage

is as at 2013 levels. In this case our default settings are 39%. Click the Run icon again

to generate the new baseline scenario. The output graph now shows constant

prevalence over time.


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b) Increasing bed net coverage to 90%

To generate a second scenario, click New. This will create a new scenario with

the same settings as the previous scenario.

Now increase the coverage of ITNs to 90%. Click Run. The output window

will now show results for both scenarios. You will notice an initial decrease in

prevalence over time for the second scenario.

Other outputs (clinical incidence, severe disease incidence, mortality and EIR)

can be viewed by selecting different tabs in the output pane. The icons on the

right side of the graph allow you to switch between smoothed and seasonal

output, and between line and bar graphs.

c) Increasing SMC to 80% coverage

Generate a third scenario by clicking New. Tick the IPT/SMC intervention option

and highlight it, then tick the SMC sub-option and change SMC coverage to 80%.

Click Run again.

A third line will appear in the output graph showing the additional predicted impact

of adding SMC in the presence of high bed net coverage.

Output from these runs can be saved to a text file (which can be opened in Microsoft

Excel) by clicking the “save” icon. Further details of the columns in this file are given

in the Malaria Tools manual.

Using Malaria Tools for Elimination Scenario Planning · [email protected] 1 Using Malaria Tools for Elimination Scenario Planning 1. Getting Started ... Generate a third scenario

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