New H1N1 Flu projections: worldwide report updated to May 16

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This report provides the current situation for the number of cases worldwide, and the projections for the expected number of cases for May 31. The projections are obtained from the most recent calibration of the model, with the available information as of May 16. The simulations consider the worst case scenario, where no intervention is implemented, and scenarios where antiviral treatment is considered, with varying rates of early detection treatment.

The official data coming from USA now represent more and more just a fraction of the actual cases. As of May 22 the CDC was stating “..more than 100,000 people probably have this virus now in the United States”. This number is obtained by applying a multiplying factor due to sampling and under reporting of 10 to 20 to the number of confirmed cases. We project a number of cases in the USA close or above to 100,000 by the 31st. Our numbers always refers only to the symptomatic cases.

In view of a decreased interest in short term projections we are shifting the focus of our modeling in the analysis of longer term scenarios considering seasonal effects. Next postings will therefore refer to these scenarios.

Current situation

The following map shows the confirmed number of cases worldwide for all infected countries, updated to May 19, 00:00 GMT. Click on the map to enlarge it.

Empirical data for the confirmed number of cases as of May 19, 00:00 GMT.

Empirical data for the confirmed number of cases as of May 19, 00:00 GMT.


Projections: Worst case scenario

The following maps report the predicted number of cases worldwide for  May 31. The color code corresponds to the maximum of the 95% confidence interval obtained by the stochastic runs of GLEaM. Numbers are also reported for the countries expected to experience the largest outbreak: the first value corresponds to the expected number of cases, and the value in brackets corresponds to the maximum of the 95% confidence interval.

Projections for May 31.

Worst case scenario, May 31. Number of cases.

Worst case scenario, May 31. Number of cases.

Projections: Antiviral treatment scenarios

Here we report the projections for a scenario in which some basic containment measure are considered. We implement early detection of cases and their treatment with antiviral drugs. The date of the interventions are set according to the time line of warning and threat level issued by national and international agencies. We assume a low level of efficacy in the early case detection and treatment, with a daily coverage of symptomatic case of 30% worldwide (top panel). These results are compared to a scenario in which in Europe we consider a different policy, with 90% daily rate of case detection and treatment delivery, thus providing a more optimistic scenario in the continent (bottom panel).

Projections for May 31.

Scenario with antiviral treatment, May 31. Number of cases. A 30% daily rate of case detection and treatment delivery is assumed worldwide.

Scenario with antiviral treatment, May 31. Number of cases. A 30% daily rate of case detection and treatment delivery is assumed worldwide.

Scenario with antiviral treatment, May 31. Number of cases. A 30% daily rate of case detection and treatment delivery is assumed worldwide, with the exception of Europe where a daily rate of 90% is considered.

Scenario with antiviral treatment, May 31. Number of cases. A 30% daily rate of case detection and treatment delivery is assumed worldwide, with the exception of Europe where a daily rate of 90% is considered.

New H1N1 flu projections: worldwide report updated to May 6

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This report provides the current situation for the number of cases worldwide, and the projections for May 17 and May 24 of the expected number of cases and of the likelihood of case occurrence. The projections are obtained from the most recent calibration of the model, with the available information as of May 6. The simulations consider the worst case scenario, where no intervention is implemented, and a scenario where antiviral treatment is considered.

Current situation

The following map shows the confirmed number of cases worldwide for all infected countries, updated to May 11, 11am EDT. Click on the map to enlarge it.

Actual number of cases, May 11, 12 am EDT.

Empirical data for the confirmed number of cases on May 11, 11 am EDT.

Projections: Worst case scenario

The following map reports the predicted number of cases worldwide (top panel) for the date of May 17. The color code corresponds to the maximum of the 90% confidence interval obtained by the stochastic runs of GLEaM. Numbers are also reported for the countries expected to experience the largest outbreak: the first value corresponds to the expected number of cases, and the value in brackets corresponds to the maximum of the 90% confidence interval.

The bottom panel reports the risk map at the worldwide level for May 17. The risk is quantified as the likelihood of the occurrence of cases in each country. All countries that as of May 11 00:00 CET already reported cases are colored in dark gray.

Worst case scenario, May 17. Top: number of cases; bottom: likelihood of occurrence of cases.

Worst case scenario, May 17. Top: number of cases; bottom: likelihood of occurrence of cases.

Projections for May 24.

Worst case scenario, May 14. Top: number of cases; bottom: likelihood of occurrence of cases.

Worst case scenario, May 24. Top: number of cases; bottom: likelihood of occurrence of cases.

Projections: Antiviral treatment scenario with 30% coverage

Here we report the projections for a scenario in which some basic containment measure are considered. We implement early detection of cases and their treatment with antiviral drugs. The date of the interventions are set according to the time line of warning and threat level issued by national and international agencies. We assume a low level of efficacy and early case detection, with a daily coverage of symptomatic case of 30%. results obtained with a higher level of coverage are reported in the next section.

Projections for May 17.

Best case scenario with antiviral treatment, May 17. Top: number of cases; bottom: likelihood of  occurrence of cases.

Best case scenario with antiviral treatment, May 17. Top: number of cases; bottom: likelihood of occurrence of cases.

Projections for May 24.

Best case scenario with antiviral treatment, May 24. Top: number of cases; bottom: likelihood of occurrence of cases.

Best case scenario with antiviral treatment, May 24. Top: number of cases; bottom: likelihood of occurrence of cases.

Projections: Antiviral treatment scenario with 50% coverage

Here we assume a higher level of efficacy and early case detection, with a daily coverage of symptomatic cases of 50%.

Projections for May 17.

Best case scenario with antiviral treatment, May 17. Top: number of cases; bottom: likelihood of  occurrence of cases.

Best case scenario with antiviral treatment, May 17. Top: number of cases; bottom: likelihood of occurrence of cases.

Projections for May 24.

Best case scenario with antiviral treatment, May 24. Top: number of cases; bottom: likelihood of  occurrence of cases.

Best case scenario with antiviral treatment, May 24. Top: number of cases; bottom: likelihood of occurrence of cases.

New H1N1 Flu projections: impact per country

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This report provides the current situation for the number of cases worldwide, and the projections for May 17 of the expected number of cases and of the likelihood of case occurrence. The projections are obtained from the most recent calibration of the model, with the available information as of May 3. The simulations consider the worst case scenario, where no intervention is implemented.

Impact per country: current situation

The following map shows the confirmed number of cases worldwide for all infected countries, updated to May 5, 11pm EDT.

Empirical data for the confirmed number of cases per country as of May 5.

Empirical data for the confirmed number of cases per country as of May 5.

Impact per country: projections for May 17

The following map reports the predicted number of cases worldwide for the date of May 17. The color code corresponds to the maximum of the 90% confidence interval obtained by the stochastic runs of GLEaM. Numbers are also reported for the countries expected to experience the largest outbreak: the first value corresponds to the expected number of cases, and the value in brackets corresponds to the maximum of the 90% confidence interval.

Projections for the number of cases per country, May 17.

Projections for the number of cases per country, May 17. Worst case scenario.

Here below we report the risk map at the worldwide level for May 17. The risk is quantified as the likelihood of the occurrence of cases in each country. All countries that as of May7 00:00 CET already reported cases are colored in dark gray.

Likelihood of occurrence of cases per country, May 17. Worst case scenario.

Likelihood of occurrence of cases per country, May 17. Worst case scenario.

Please note that we also provide reports that focus on the EU and the USA. Visit our homepage for an overview of what we have to offer.

WorldWide new H1N1 Flu prediction adjusted with data as of April 28: likelihood of occurrence of cases

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This report presents the new predictions concerning the likelihood of case detection worldwide at the country level. The new simulations are adjusted by considering data and reports as of April the 28th.

This report provides risk maps for the following dates:  May 10 and May 17.

The risk is quantified by the likelihood of the occurrence of case in a given zone according to our stochastic model.

The maps still refer to a high transmissibility (model calibration) and a worst case scenario with no effective containment measures implemented.

While most of the the likelihood of case detection as increased with respect to the projections obtained with the April the 26th data. We expect to see deviation from the predicted pattern in future updates as the result of WHO elevation in the pandemic threat level and the implementation of containment measures across the world.

World risk map May10

World risk map May10

World risk map May 17

World risk map May 17

Projections for new H1N1 Flu spread by computational modeling

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We use GLEaM, our GLobal Epidemic and Mobility modeler, to generate future projections on the global spreading of the unfolding Mexican flu epidemic. This first report presents some initial results of this ongoing effort. In the following days we will provide updated risks maps and future projections.

GLEaM is a computational modeler that integrates sociodemographic and population mobility data in spatially structured stochastic disease models to simulate the spread of epidemics at the worldwide scale. Read more about GLEaM…

Initialization and calibration of the model

We assume the epidemic originated in Mexico. We feed a first set of simulations with a cluster of infections on March 18th.  We then study the predicted infected areas as of the date of April the 26th. The disease is assumed to be an ILI like disease (with both symptomatic and asymptomatic). The reproductive number is tuned according to a high transmission scenario with more than 1000 infected individuals in Mexico and a low transmission scenario in which the number of cases is halved (assuming that most of the cases investigated at the moment will result in negative to H1N1 lab test).  For the sake of clarity we only provide the results for the high transmission scenario in this report. We here provide the data aggregated at the level of single countries. Finer resolution (major urban areas, states) can be provided upon request.

Model prediction as of April the 26th

The calibrated model provides the forecasts of the detection of infected cases in Mexico, USA, Canada, UK and Spain. In these countries, cases have been confirmed (as shown in red in the following figure).

The model also provide the likelihood of the occurrence of cases  in the following countries:

CountryOutbreak risk (%)CountryOutbreak risk (%)
France9Netherlands5
Germany9Brazil4
Costa-Rica7Chile4
Guatemala7El Salvador4
Cuba7Peru3
Colombia6Venezuela2
Panama5

In some of the listed countries there have been reports of infected individuals but they are not yet confirmed as H1N1 cases.

Model prediction April 26, 2009

Model prediction April 26, 2009

Risk maps three weeks ahead

This report provides risk maps for the following dates: May 3; May 10; and May 17.

The risk is quantified by the likelihood of a case detection in a given zone according to our stochastic model.

We are not pushing any anticipation beyond three weeks as the containment measures that will be put in place have to be considered (we plan to pull out new scenarios every 24/48 hours).

Worst case scenario

In the following figures we report the risk maps according to the model evolution in the worst case scenario, where no use of antivirals or other intervention measures is considered. It is important to stress once again that the evolution of the model is calibrated with the early evolution of the epidemics. Warnings and containment measures are likely to be effective and the model will have to be calibrated once more in the next days.

Outbreak probability May 3, 2009

Outbreak probability May 3, 2009

Outbreak probability May 10, 2009

Outbreak probability May 10, 2009

Outbreak probability May 17, 2009

Outbreak probability May 17, 2009

Countries colored in black have already reported confirmed cases. We report in the map only countries with more than 1% probability of having infected individuals as of the corresponding date.

The number of expected cases and relative confidence interval in each country can be provided upon request.

Disclaimers

While we think that this information might be useful to get possible scenarios for the spreading of the disease, we want to make clear a certain number of disclaimers which help framing the presented results in the right context.

  • Data  coming from different regions of the world have to be validated in most of the  cases. We feed the model with what appears plausible and confirmed at the moment but the scenarios are subject to changes depending on the available data.
  • We consider both a worse case and a best base scenario. Both are based on a certain number of assumptions on the data and what we find from the information gathered so far.
  • Containment measures as decided by health authorities will be integrated in futures updates.
  • The model is mostly used to provide first time arrival of infected individuals and provides risk maps telling the probability of infected case detection at a given date.  At this early stage of the disease, the number of predicted cases is a number with large fluctuations and as such the most sensitive outcome of the model.
  • The results are based on computational models and have to be considered only as an extra source of information and not as the reality of the epidemic unfolding.
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