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Check the time needed to evaluate the model with one input set to random mode.

Execution time in various web browsers
?

This refers to the method whether or not to discard the sample generated previously and start over. Ticking the box means that the generated sample is discard and may be selected again for the next sampling.

This sampling method is especially useful for simulating possible results from a set of limited input, thus provide more certainty to the results.

Replace samples
?

This refers to the seed used in the random number generation.

Random number seed
?

This refers to how many samples the users want to base the simulation on. If the number of samples to generate is set at a large number, which will give a more precise result, the tool takes longer time to perform the calculation. The time length varies between different web browser. If it takes very long, it is advisable to empty the automatic calculation box on the front page and click the calculate button once the user finished entering all required inputs so the tool will not have to repeat running the simulation.

Number of samples to generate
?

This refers to the actual number of samples generated to calculate the output. Generally, the more samples generated, the more precise the result is.

Total number of samples
Print items shown on current page using a printing stylesheet optimised for monochrome printers. Print all items including output data distributions using a printing stylesheet optimised for monochrome printers.
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Save input parameters and outputs of the model to a file. Load input parameters of the model from a file.
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Copy the selected text (CTRL + C) and paste it in a text editor (CTRL + V).

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Copy the parameters' definition (CTRL + C) and paste it in this dialog (CTRL + V).
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Copy input parameters and outputs of the model to clipboard. Paste input parameters of the model from clipboard.
Shows the user manual (PDF file). Shows some worked-out outbreak analysis examples (PDF file).
EUFRAT presentation
Legal Notice

Disclaimer: ECDC accepts no responsibility or liability whatsoever (including but not limited to any direct or consequential loss or damage it might occur to you and/or any other third party) arising out of or in connection with the installation and/or usage of this software. Copyright © European Centre for Disease Prevention and Control, 2015.

http://ecdc.europa.eu/en/pages/legalnotice.aspx

Shows the slides of an introductory presentation of the EUFRAT tool (PDF file). Disclaimer
Show help

Quantification of the risk of infection transmission by blood transfusion in an outbreak-affected region,
or the risk from a stream of donors who have visited such a region

Please first select appropriate analysis setting:
?

If you select a specific disease, disease parameters are automatically provided whenever these were available from literature. You can also leave this field unchanged (‘Not specified’) if you don’t want to use pre-specified values. All input values can be specified by the user.

1. Select the disease for which the recipient risk will be calculated
?

If 'Yes' is selected, the number of recipients getting infected by donors who visited an outbreak region is calculated. Apart from outbreak and disease specific data additional information will be requested on travel (number of donors per year and duration of visit). If 'No' is selected, the number of recipients in the outbreak area getting infected by donors who reside in the outbreak-affected region is calculated.

2. Do you want to estimate the transmission risk from blood donors who have visited an outbreak-affected region? No
?

Information on either infected individuals in the general population or on infected donors can be used as input. If ‘Yes’ is selected, the requested input is the number of donors identified as infected. Identification of infected donors is possible either by testing donations or from the notification/surveillance system. If ‘No’ is selected, the requested input is the number of infections reported in the population of the outbreak-affected region.

3. Should the risk be calculated using data on infected donors? No
?

For some diseases, acute infected individuals might progress into an infectious chronic phase in which the infection remains transmissible by blood transfusion.

4. Does the infection considered have a chronic phase? No
?

This refers to the questions in the donor health questionnaire, which can either be introduced during the outbreak or be an existing questionnaire that potentially screens out donors with certain risk factors or symptoms related to the disease of concern before they donate blood. If the questions are not specific for the disease of concern but may partly work because of similar symptoms or exposures as other diseases included in the existing questionnaire, users should select ‘Yes’ and partial effectiveness should be considered.

5. Are there questions in the donor health questionnaire that potentially screen out the infected donors before donation? No
?

This refers to the test(s) implemented to screen the donated blood for the infection, in order to exclude donations that are reactive in the test. This test can either be introduced during the outbreak or be part of the existing safety measures.

6. Is the donated blood screened for the infection using a diagnostic test? No
?

The user can choose obtain estimates for the total number of infections expected beyond a certain point in time. If selected ‘Yes’, for each step future infections will be shown in addition to the total number of infections with a light blue background colour. In Step 1 ‘Disease and outbreak’ the user can specify the point in time that distinguishes past from future risks.

7. Do you want estimates for future infections? No
Always show results

Disease and outbreak

Expand
Population exposure & susceptibility
Value
Unit
Type
Cumulative infections reported (Ip)
 
 
[-]
Const.
 
The number of individuals in the population of the outbreak-affected region (or visiting donors) who are reported/notified as cases during the epidemic.
Duration of epidemic (D0)
days
Const.
 
The length of time between the first and the last day of reported cases (end of the observation period).
Population size (N)
 
 
[-]
Const.
 
Should reflect the number of individuals in the outbreak-affected region (smallest authority boundary) where the notified cases were observed.
Number of donors tested (Ndt)
 
 
[-]
Const.
 
Refers to those donors whose donations were tested for the presence of the disease considered.
Donor relative risk (RR)
%
Const.
 
This is related to donor predisposition (e.g. age, gender, cultural aspects) and behaviour that increases/decreases the risk of getting infected compared with the population risk. Relative risk of 100% should be considered for diseases that are transmitted ubiquitously in the general population (e.g. through mosquito bite).
Donor visits per day (tau)
per day
Const.
 
The (average) number of donors visiting the outbreak area per day.
Duration of stay (Dv)
days
Const.
 
The (average) length of stay of the donors in the outbreak area.
Disease characteristics
Value
Unit
Type
Proportion of undetected cases (pu)
%
Const.
 
Estimate of the proportion of infected individuals who were not identified as cases.
Duration of infectivity for acute infection (Da)
days
Const.
 
The length of the infectious period for acute infections.
Duration of latent period of acute infection (Dia)
days
Const.
 
Time interval between the donor getting infected and being able to transmit the infection
Proportion of chronic infection (pc)
%
Const.
 
Proportion of acute infected individuals who progress into a chronic infection.
Duration of infectivity for chronic infection (Dc)
days
Const.
 
The length of infectious period in chronic infected individuals.
Duration of latent period of chronic infection (Dic)
days
Const.
 
Time interval between the moment that the donor is no longer infectious from the acute infection and that the donor becomes infectious from the chronic infection.
Timepoint for risk evaluation
Value
Unit
Type
Time point for evaluation of the future risk (Tx)
 
 
days
Const.
 
This is the point in time for which the model will calculate the number of infected donations/products to expect beyond this time point, or the prevalence at this time point (Tx).
Value
Unit
Type
Estimated incidence rate in the donor population (I)
per day
Const.
 
The number of new infectious donors per donor per day.
Prevalence of infectious donors at the time of last observed infection (Pr)
[-]
Const.
 
The proportion of infectious donors at the end of the observation period (so at time point D0).
Prevalence of infection in the donor population at time Tx (Prx)
[-]
Const.
 
The proportion of infectious donors at the specified time point Tx.

Donor screening and donation testing

Expand
Donor screening
Value
Unit
Type
Proportion of symptomatic acute infections (pIa)
%
Const.
 
Out of all infected donors, the proportion of donors who develop symptoms throughout the course of infection, likely to be picked up by the screening questionnaire.
Proportion of symptomatic chronic infections (pIc)
%
Const.
 
Out of all chronically infected donors, the proportion of donors who develop symptoms throughout the course of their chronic infection, likely to be picked up by the screening questionnaire.
Effectiveness of donor health questionnaire (pQe)
%
Const.
 
Out of all symptomatically infected donors, the proportion of donors that is detected by the questionnaire.

If the questions are not specific but may still work due to similar symptoms or exposures with other diseases included in the existing questionnaire, partial effectiveness should be considered.
Donation testing
Value
Unit
Type
Test coverage (pTc)
%
Const.
 
Percentage of donations being tested for the infection.
Test effectiveness (test sensitivity, pTe)
%
Const.
 
The proportion of infected donations that are correctly detected by the test.
Value
Unit
Type
Prevalence of infectious donors after screening and/or testing (pRis)
[-]
Const.
 
The proportion of infectious donors who are not detected by the donor health questionnaire or screening tests.
Proportion of infectious donors after screening and/or testing at time point Tx (pRisx)
[-]
Const.
 
The proportion of infectious donors who are not detected by the donor health questionnaire or screening tests to be expected at time point Tx.

Blood component production and donor exposure

Expand
Number of products obtained from individual donations per year

The number of products from individual donations that have contributed to the production of end products for transfusion per year: for pooled products the number of donations that contribute should be counted here, not the number of end products administered to patients; for products that are split, the number of end products need to be counted, not the number of individual donations.

The names of the product types can be changed by the user by pressing <SHIFT> whilst clicking on the product type name.

Type of donation
The description of donation and product types can be changed by the user by pressing the <SHIFT> key whilst clicking on the name to be changed.
Number of donors
Red blood cells
Buffy coats
Plasma for transfusion
Apheresis platelets
Unit
Total number of donors/products per year
Total number of donors (tNdo)
Total number of donors
Total number of donors
Total number of donors
Total number of donors
[-]
Number of donors exposed. Specify as:
Value
Unit
Type
 
 
[-]
Const.
 
This refers to the proportion of infectious donors in the outbreak-affected region at the specified epidemic period. This instantaneous estimate may underestimate the true prevalence of infection at the peak of the outbreak.
%
Const.
 
Proportion of donors exposed.
[-]
Const.
 
Number of donors exposed to the infection.
Number of donors exposed (Ndo)
[-]
Const.
 
The number of donors actually exposed to the outbreak. Note that this number does not necessarily affect the number of transmissions.
Risk reduction
 
 
Total
Red blood cells
Buffy coats
Plasma for transfusion
Apheresis platelets
Unit
Remaining risk of transmission after processing (pit)
Proportion of the initial risk of transmission that remains per particular end product. The remaining risk might differ per type of product due to particular biological properties or risk reducing effects during production.
%
Number of infected products (Nip)
Total number of infected end products.
The number of infected end products for this product type.
The number of infected end products for this product type.
The number of infected end products for this product type.
The number of infected end products for this product type.
[-]
Number of infected products expected after time point Tx (Nipx)
This refers to the expected number of infected products after time point Tx. The presumption is made here is that products are delivered at the time of donation. Therefore if there is a delay in production this can be accounted for by changing the date of assessment.
This refers to the expected number of infected products after time point Tx. The presumption is made here is that products are delivered at the time of donation. Therefore if there is a delay in production this can be accounted for by changing the date of assessment.
This refers to the expected number of infected products after time point Tx. The presumption is made here is that products are delivered at the time of donation. Therefore if there is a delay in production this can be accounted for by changing the date of assessment.
This refers to the expected number of infected products after time point Tx. The presumption is made here is that products are delivered at the time of donation. Therefore if there is a delay in production this can be accounted for by changing the date of assessment.
This refers to the expected number of infected products after time point Tx. The presumption is made here is that products are delivered at the time of donation. Therefore if there is a delay in production this can be accounted for by changing the date of assessment.
[-]

Recipient population

Expand
Recipient susceptibility
 
 
Total
Red blood cells
Buffy coats
Plasma for transfusion
Apheresis platelets
Unit
Specific immunity in recipient population (pim)
Probability of recipients not getting infected when receiving the infected end product because of specific immunity, specified per product type.
%
Recipient risk categories
Value
Unit
Type
Proportion of other complications
%
Const.
 
Proportion of infected recipients who will develop complications other than severe infection or death.

The description can be changed by the user by pressing <SHIFT> whilst clicking on the parameter name.
Proportion of severe infections
%
Const.
 
Proportion of infected recipients who have a severe manifestation of the infection.

The description can be changed by the user by pressing <SHIFT> whilst clicking on the parameter name.
Proportion of deaths
%
Const.
 
Proportion of infected recipients who will die from the infection.

The description can be changed by the user by pressing <SHIFT> whilst clicking on the parameter name.
Recipient risk
 
 
Total
Red blood cells
Buffy coats
Plasma for transfusion
Apheresis platelets
Unit
Total number of recipient complications due to infected end products
Total number of infections in recipients due to infected end products.
Total number of infections in recipients due to infected end products.
Total number of infections in recipients due to infected end products.
Total number of infections in recipients due to infected end products.
Total number of infections in recipients due to infected end products.
[-]
Number of other complications
Total number of chronic infections.
Number of chronic infections.
Number of chronic infections.
Number of chronic infections.
Number of chronic infections.
[-]
Number of severe infections
Total number of severe infections.
Number of severe infections.
Number of severe infections.
Number of severe infections.
Number of severe infections.
[-]
Number of deaths
Total number of deaths.
Number of deaths.
Number of deaths.
Number of deaths.
Number of deaths.
[-]
Total number of infections in recipients due to infected end products expected after time point Tx
This refers to the expected number of infections from infected products after time point Tx. The presumption here is that products are transfused at the time of donation. The delay in processing this can be accounted for by changing the date of assessment.
This refers to the expected number of infections from infected products after time point Tx. The presumption here is that products are transfused at the time of donation. The delay in processing this can be accounted for by changing the date of assessment.
This refers to the expected number of infections from infected products after time point Tx. The presumption here is that products are transfused at the time of donation. The delay in processing this can be accounted for by changing the date of assessment.
This refers to the expected number of infections from infected products after time point Tx. The presumption here is that products are transfused at the time of donation. The delay in processing this can be accounted for by changing the date of assessment.
This refers to the expected number of infections from infected products after time point Tx. The presumption here is that products are transfused at the time of donation. The delay in processing this can be accounted for by changing the date of assessment.
[-]