ProMED-mail: 22 years of digital surveillance of emerging infectious diseases.

ProMED-mail (ProMED) was launched in 1994 as an email service to identify unusual health events related to emerging and re-emerging infectious diseases and toxins affecting humans, animals and plants. It is used daily by public health leaders, government officials at all levels, physicians, veterinarians and other healthcare workers, researchers, private companies, journalists and the general public. Reports are produced and commentary provided by a global team of subject matter experts in a variety of fields including virology, parasitology, epidemiology, entomology, veterinary and plant disease specialists. ProMED operates 24 hours a day, 7 days a week and has over 83 000 subscribers, representing every country in the world. Additionally, ProMED disseminates information via its website and through social media channels such as Twitter and Facebook as well as through RSS feeds. Over the last 22 years, it has been the first to report on numerous major and minor disease outbreaks including SARS, MERS, Ebola and the early spread of Zika. ProMED is transparent, apolitical, open to all and free of charge, making it an important and longstanding contributor to global health surveillance.