Brazil is at high risk of future epidemics, says expert in emerging infectious diseases

Publicação: 7 de November de 2017

To the Emerging Infectious Diseases program professor at Duke National University at Singapore Medical School, Mayaro and other viruses may emerge from the Amazon basin

For the first time we have found flaws in our thoughts and beliefs that, arboviruses require a vertebrate host to remain alive in nature

The recently published article “Vertebrate Reservoirs of Arboviruses: Myth, Synonym of Amplifier, or Reality?”, approaches controversial issues regarding vertebrate reservoirs and their role in arboviruses’ persistence in nature, examines the origins of the problem from a historical perspective, talks about multiple unsolved questions from several points of view, besides assessing the current status providing options to solve the problem. To Dr. Duane J Gubler, Emeritus Professor of the Emerging Infectious Diseases Program at Duke National University at Singapore Medical School, one of the paper’s authors, the article will become novel in the arboviral diseases field.  “For the first time it points flaws in our thoughts and beliefs that arboviruses require a vertebrate host to remain in nature. I also think this work will influence new currents of thought on how arboviruses evolve”, he says.

Asked about the current definition of host, if they really exist or if we are shifting our concepts of “temporary host” with time according to the infection and the transmission dynamics, i.e., the same events that last for weeks for Zika transmission, while these events for encephalitis virus transmitted by ticks could take years, Dr. Gubler – who was also head of the Asia-Pacific Tropical Medicine and Infectious Diseases Institute, John A Burns School of Medicine, Hawaii University in Manoa – stresses that since by definition, there are no documented hosts for any arbovirus stated in the paper. “This does not mean they do not exist, but that until now none has been documented. I believe we must begin thinking that arthropods may be the main hosts, and that vertebrates are amplifying hosts for some viruses, especially flaviviruses”, he observes.

Regarding how this concept links to epidemiology, emergency and recent arbovirus pandemics, as Zika and chikungunya, the researcher does not think it has great impact on how we approach prevention and control. “We still have to control arthropods and protect humans with vaccines and medications. I think we have to combine both approaches if we wish to succeed controlling them”, he adds.

Finally, Dr. Gubler talks about the risks of flaviviruses in Brazil. To him, as demonstrated by the recent dengue, chikungunya, Zika and yellow fever outbreaks, Brazil is at high risk of developing future epidemics, especially those where viruses are transmitted by Aedes aegypti in urban areas. “Besides this, the Country has many other viruses, as Mayaro and others that could emerge from the Amazon basin”, he adverts.