"Zika virus is a clear example of how a viral disease spreads through mosquitoes. In 2013 it was detected in Tahiti and French Polynesia. In 2015 it appeared in Brazil, and from there it is spreading very rapidly through Latin America." In his new book, Viruses and Pandemics, Ignacio López-Goñi , professor and Full Professor of Microbiology at the University of Navarra, addresses the problems of viruses such as Ebola or HIV, and the factors that have made them true global crises. 

(Video of Ignacio López-Goñi's interview about his book in La aventura del Saber, TVE2. From minute 39.30 seconds to 41.52 seconds).

In the expert's opinion, the probability of a new virus generating a pandemic with thousands of infected people -like the 1918 flu that caused between 25 and 40 million deaths in a few months- is small, but not impossible. We must be prepared:"In nature there are pathogenic viruses that cause fatal diseases in almost 100% of cases - such as rabies -; others cause problems that are very difficult to cure - such as Ebola -; some are very infectious - influenza and measles are extremely easy to spread by air - and others have long incubation periods - such as the HIV virus, which causes AIDS".

The real concern, warns the author of the microBIO blog, "would be if a virus were to emerge that combined mortality with difficulty in treatment, that was easily transmitted and that had a long incubation period. In that case, the consequences would be extremely serious. There would be many people infected and many deaths".

According to what Full Professor predicts in this informative work, the next pandemic-causing virus will be transmitted through the air or by vectors, such as mosquitoes, which are very difficult to control: "This is what has happened with the Chikungunya virus, which has adapted to be transmitted by the Aedes albopictus -or tiger mosquito-, which has allowed it to spread from the Kenyan coasts, through the Pacific Ocean, to the Caribbean, where it already affects 50 countries and millions of people". This ability to adapt could also facilitate its spread throughout much of Europe and the rest of America, where it could mutate to adapt to common mosquitoes. There have already been some autochthonous cases of Chikungunya in Europe, and the same could happen with the Zika virus.

Ebola: under control?

In the case of the Ebola virus, the World Health Organization has brought the outbreak in West Africa under control. Despite this, the microbiologist warns that it will again cause outbreaks on the continent: "But Ebola will never be a global pandemic, as it does not meet the criterion of ease of transmission that we have just pointed out".

Among the factors that explain the periodic appearance of viral infections is the enormous adaptive capacity of the viruses themselves, as well as ecological and environmental factors or changes in temperature that can affect the distribution of vectors and mosquitoes, and turn a tropical disease into a global disease. However, the expert recalls that viruses have also influenced the history of mankind -as happened in the conquest of America or in the construction of the Panama Canal-: "Without them the Earth would be very different, it might not even exist", he concludes. 

Virus and pandemics is the first book of publishing house Naukas, the largest online platform of scientific knowledge dissemination in Spanish.