Frequently asked questions about the Global Dengue Observatory, dengue, data interpretation, and how to use and cite our resources.
About the Global Dengue Observatory
What is the Global Dengue Observatory (GDO)?
GDO is an online dashboard that brings together dengue surveillance data reported by many countries, advanced modelling to help fill gaps, and historical data so users can track how dengue seasons are unfolding globally, regionally, and nationally. All case data is anonymised.
Who is it for?
The general public, journalists, public health practitioners, and decision-makers who want a clear, timely view of dengue trends—with appropriate context.
Is GDO a “real-time” case reporting system?
Not exactly. It uses the latest available official reporting and modelling to provide near real-time situational awareness, but these are estimates and may change with time.
What’s new or different compared to other dengue sites?
The focus is on real-time information, comparability across countries, seasonal context and gap-filling where reporting is delayed or incomplete, presented in a consistent visual format.
Who funds the GDO?
The GDO is supported by the AXA Research Fund, (title: “Pioneering a global observatory for dengue outbreak early warning”)
Dengue
What is dengue?
Dengue is a viral illness transmitted mainly by Aedes aegypti and Ae. Albopictus. It can cause fever and severe symptoms; a small proportion of infections can progress to severe dengue requiring urgent medical care.
Where is dengue found?
Dengue is endemic across much of the tropics and sub-tropics which is also emerging in across the globe with 5.66 billion people in over 120 countries at risk of infection
How does dengue spread?
Through mosquito bites, it does not typically spread person-to-person like respiratory viruses.
What are common symptoms?
Fever, headache, muscle/joint pain, nausea, rash—symptoms vary and can resemble other infections. Seek medical care for severe symptoms or warning signs. See the WHO Dengue and Severe Dengue page for more information.
What treatments are there for dengue?
There’s no specific medicine that cures dengue. Treatment is mainly supportive:
- Rest and drink plenty of fluids
- For fever and pain, use paracetamol/acetaminophen
- Seek medical care urgently if symptoms get worse or warning signs appear (your local health service can advise what to watch for)
For the best advice, talk to a doctor and follow local health guidance, especially for children, pregnancy, older adults, or anyone with other health conditions.
Is there a vaccine that protects against dengue?
Yes, dengue vaccines exist, but they are not recommended for everyone, and availability and eligibility vary by country. In some places, vaccination depends on age and whether someone has had dengue before.
For personal decisions, follow your national/local health guidance and speak with a doctor or travel clinic about whether a dengue vaccine is recommended for you.
How can people reduce risk?
By reducing and preventing mosquito bites: repellents, long sleeves, screens, eliminating standing water, and following local public health guidance. (CDC Prevention Guide)
Data, Methods, and Interpretation
Where do your numbers come from?
From dengue data reported by countries to regional (PAHO and SEARO) and global (WHO) databases and then integrated into a common pipeline. GDO also uses modelling to address missing data and delays in reporting.
Are the numbers “reported cases” or “estimated cases”?
The dashboard shows reported figures and model-based estimates. When you see language like “we estimate…”, that reflects modelled outputs rather than raw counts alone.
Why might your estimates differ from my ministry of health dashboard?
Differences can come from reporting cut-off dates, case definitions, backfilled updates, under-reporting, delayed reporting, and the modelling approach used to standardize and fill gaps.
Do you have a way to verify the accuracy of reporting, such as a common case definition supported by laboratory confirmation? Or does this vary from country to country?
Our goal is to reflect what countries are actually reporting, not to standardize case definition or compare data across countries. To confirm the case definition, please contact the relevant regional or country office directly.
What does “expected number of cases” mean?
It refers to the typical seasonal pattern based on historical data for that location. Comparing the current year to “expected” helps users understand whether the seasonal number of cases is unusually high or low for that time of year.
What does “× the expected number of cases” mean (e.g., 2.0×)?
It’s a ratio of current cumulative cases (or estimates) to the historical average for the same point in the year. For example, 2.0× means roughly double the usual level to date.
How should I interpret “High Severity Countries”?
It’s a spotlight list of places currently farthest above their own typical yearly average (based on cumulative ratios). It does not necessarily mean the highest absolute number of cases worldwide.
How often is the dashboard updated?
The site indicates a “data last updated” timestamp (e.g., shown on the global outlook). The dashboard is updated at the beginning of every month.
Do you show uncertainty?
While we do not currently visualise uncertainty all estimates should be considered approximate values.
Limitations and Responsible Use
A country is not included in the dashboard. Does that mean there is no Dengue there?
While this could mean that the country has no dengue cases, that is not the only reason a country is not included. Countries without a seasonal baseline or not present in the data sources are currently not included, but that doesn’t mean there are no cases of dengue. Seek further information from national authorities.
Can I use this to assess personal risk or make travel/medical decisions?
It’s designed for situational awareness, not individual medical guidance. For personal health decisions, follow advice from local public health agencies and clinicians.
Does a lower number mean dengue transmission is low?
Not always. Low reported/estimated values can also reflect under-diagnosis, reporting delays, changes in testing, or disruptions in surveillance.
Can I compare countries directly?
You can compare broad patterns, but direct comparisons can be misleading due to differences in surveillance systems, testing intensity, case definitions, healthcare access, and reporting practices.
Does GDO predict future outbreaks?
Currently, GDO is primarily a monitoring and context tool.
Using, Citing, and Contacting
Can I use your charts in an article or report?
Generally yes, with proper attribution. A good standard is: “Source: Global Dengue Observatory (accessed YYYY-MM-DD).”
Do you provide downloads or an API?
The data can be viewed and downloaded from the Data page.
Who do I contact for corrections?
If you believe a value is incorrect, contact us at contact@globaldengueobservatory.org. Please include the country, time period, screenshot, and link to the official source.
Who do I contact for press/media enquiries?
If you are a journalist with a media enquiry about GDO contact press@lshtm.ac.uk