The Epidemiology of Unknown Disease Outbreak Reports Globally

Abstract

Disease outbreaks can adversely impact the health and economic status of the affected populations. The notification of disease outbreaks to public health authorities can take months, delaying efficient response to those outbreaks. However, disease outbreak data gathered from informal sources such as media reports prove to be a good, resource-light source of real-time data. This provides a faster option to conduct epidemiologic analyses on disease outbreaks globally. At the time this report was prepared, there was no epidemiological analysis of unknown disease outbreaks globally; outbreaks whose causes are not immediately known. EpiWATCH data is used to analyse the epidemiology of unknown disease outbreaks globally from 2016 to 2019. Descriptive analysis of EpiWATCH data was conducted. One hundred and nine reports of unknown outbreaks were found for analysis. Ninety-three reports were on human cases and 17 were on non-human populations (one report also included human cases). Unknown disease outbreaks resulted in 6714 human cases. India and USA were responsible for the greatest number of outbreak reports. The year 2017 saw the greatest number of reports on unknown diseases published. August, across all four years, produced the greatest number of reports. Fever and vomiting were the most common symptoms reported by human cases. Measles, Nipah virus, norovirus and influenza were the most common causes of unknown disease outbreaks. Seventy-six percent of unknown disease outbreaks remain undiagnosed.