A study led by the University of Malaga has shown that outbreaks of Ebola virus do not occur randomly over time; rather, their appearance is linked to specific large-scale meteorological patterns, even with oscillations occurring in regions thousands of miles away from Central Africa, where they are currently suffering from an epidemic of this disease, which can be fatal.

The scientific team, which also includes the Spanish Institute of Oceanography, the Manchester Metropolitan University and the Center for International Forestry Research, calls these links “teleconnections” and advocates their analysis as a “clue” to predict where and when the risk of Ebola increases.

According to the latest report from the National Institute of Public Health (INSP) of the Democratic Republic of the Congo, based on data collected through September 26, more than 8,000 confirmed infections have been recorded in the latest outbreak, which began in May, including 3,901 deaths, with a case fatality rate of nearly 50 percent.

This new finding, obtained after collecting data on 49 outbreaks in Africa between 1976 and 2025 and comparing them in a database with 26 climate oscillation indices, could be used as a means of epidemiological surveillance, capable of detecting early warning signals to identify periods and regions where weather conditions may be more favorable for the occurrence of new outbreaks. The paper has been published in the scientific journal Stochastic Environmental Research and Risk Assessment, from the prestigious publisher Springer Nature.

From the Pacific to Africa: following a climatic track
The scientists used this data until 2018 to build the models and dedicated the years 2019-2025 to seeing if they could forecast new outbreaks. They identified four climatic oscillation indices that were particularly associated with the distribution of outbreaks: the Caribbean Sea Surface Temperature Index (CAR) – no longer available since February 2020 – , the Dipole Mode Index (IMD), the Quasi-Biennial Oscillation (QBO) and the Pacific Decadal Oscillation (PDO), the latter being the most frequent indicator or “signal” and, therefore, the most important macroclimatic factor of the model.

“Our proposed interpretation is that these large oscillations modify meteorological patterns, for example, precipitation in the African continent, and these can alter ecological conditions that favor the occurrence of outbreaks”, explains the Zoology professor at UMA Raimundo Real, one of the authors of this paper.

In this sense, the Biogeography and Macroecology professor also at the University of Malaga Jesús Olivero, another of the authors of the paper, clarifies that this does not mean that these distant climate indicators directly cause Ebola, but they may serve as an early warning “clue” of environmental conditions more closely linked to the biological phenomenon.

“Early warning systems are essential for combating infectious diseases. To achieve this, it is not enough to detect cases of the disease early; we must anticipate them by monitoring risk factors, and our predictive tool could be key to this effort,” adds Olivero.

Surveillance tool
The researchers estimate that the “useful window” of these large climatic oscillations would be six to twelve months before a potential event, so their predictive capacity is still limited and further research along these lines would be needed before they could be considered an autonomous predictive system.

Nevertheless, the study represents an initial step as a surveillance tool that could help activate preparedness measures when climate conditions indicate an increased risk, identifying periods and locations that warrant closer epidemiological monitoring.

The study of the biogeography of Central African wildlife
This scientific team of the UMA, which includes researchers from the Faculty of Sciences Miguel Ángel Farfán and Ana L. Márquez, has been working for more than a decade on the study of the distribution of the Ebola virus in Africa, seeking to gain a better understanding of the transmission mechanisms of this disease, as well as on the analysis of the occurrence of new outbreaks.

Ebola is a zoonosis, that is, a disease transmitted from animals to humans. When the 2014 epidemic occurred, these researchers at the UMA had already been studying the biogeography of Central African wildlife for some time, as well as the human interaction with wildlife through hunting. “Since this same wildlife is part of the zoonotic cycle of Ebola, we decided to apply what we had learned to the study of this disease, and we discovered that we had a lot to contribute,” they explain.

This last project provides a new perspective on how outbreaks of infectious diseases do not depend on a single factor: the interaction between climate, ecosystems, species distribution, and local conditions can generate “temporary windows” during which an outbreak is more likely to occur. “Identifying these windows in advance could give healthcare systems additional time to prepare. Our goal is to build an ‘observatory’ capable of generating updated risk forecasts based on wildlife, deforestation, macroclimate, and local weather conditions”, they conclude.

The study is part of the project “Patogeografía espacio-temporal de las zoonosis mediadas por vertebrados voladores” [Spatial-temporal pathogeography of zoonoses mediated by flying vertebrates], co-financed by the European Regional Development Funds (ERDF) and managed by the Spanish Ministry of Science and Innovation and in the PPRO-RNM262-G-2023 project of the University of Malaga, financed by the Regional Government of Andalusia and the ERDF. It has also received support from the Center for International Forestry Research (CIFOR) through a Transfer of Research Results Contract.