Infectious diseaseInfection outbreaks, unique diseases on the increase since 1980
Ebola has a lot of company. In a novel database now made publicly available, researchers found that since 1980 the world has seen an increasing number of infectious disease outbreaks from an increasing number of sources. The good news, however, is that they are affecting a shrinking proportion of the world population. The number of infectious disease outbreaks and the number of unique illnesses causing them appear to be increasing around the globe, with more than 12,000 outbreaks affecting forty-four million people worldwide over the last thirty-three years.
Ebola has a lot of company. In a novel database now made publicly available, Brown University researchers found that since 1980 the world has seen an increasing number of infectious disease outbreaks from an increasing number of sources. The good news, however, is that they are affecting a shrinking proportion of the world population.
Enterovirus. Tuberculosis. Cholera. Measles. Various strains of the flu and hepatitis. A Brown University release reports that the number of infectious disease outbreaks and the number of unique illnesses causing them appear to be increasing around the globe, according to a new Brown University analysis of more than 12,000 outbreaks affecting forty-four million people worldwide over the last thirty-three years.
Menacing as that may sound, these preliminary findings also reveal an encouraging trend. On a per capita basis, the impact of the outbreaks is declining. In other words, even though the globe faces more outbreaks from more pathogens, they tend to affect a shrinking proportion of the world population.
“We live in a world where human populations are increasingly interconnected with one another and with animals — both wildlife and livestock — that host novel pathogens,” said Katherine Smith, assistant professor of biology and co-lead author of the study, with Brown University colleagues Cici Bauer, assistant professor of biostatistics, and Sohini Ramachandran, assistant professor of biology, in the Journal of the Royal Society - Interface. “These connections create opportunities for pathogens to switch hosts, cross borders, and evolve new strains that are stronger than what we have seen in the past.”
Sure enough, animals are the major source of what ails us. The analysis revealed that 65 percent of diseases in the dataset were “zoonoses,” meaning they come from animals. Ebola, for instance, may have come from bats. In all, such diseases caused 56 percent of outbreaks since 1980.
Newly derived data
To perform the analysis, the team worked to derive quantifiable data from the prose reports of outbreaks stored in the Global Infectious Disease and Epidemiology Online Network (GIDEON). They developed a “bioinformatics pipeline” to automate the creation of a database comprising 12,102 outbreaks of 215 infectious diseases involving forty-four million cases in 219 countries between 1980 and 2013.
Brown’s Institute for the Study of Environment and Society funded the work. They are now making the database publicly available on Ramachandran’s server.
The raw numbers revealed a steep rise in the number of outbreaks globally.
“GIDEON defines an outbreak
