The cause is unknown. Commentators then and now have blamed the sewage, poor sanitation, and contaminated water supplies. The first confirmed outbreak was in August 1485 at the end of the Wars of the Roses, leading to speculation that it may have been brought from France by French mercenaries. However, an earlier outbreak may have affected the city of York in June 1485, before Tudor's army landed, although records of that disease's symptoms are not adequate to be certain. Regardless, the Croyland Chronicle mentions that Thomas Stanley, 1st Earl of Derby cited the<unk>  as reason not to join Richard III's army prior to the Battle of Bosworth. Relapsing fever, a disease spread by ticks and lice, has been proposed as a possible cause. It occurs most often during the summer months, as did the original<unk> . However, relapsing fever is marked by a prominent black scab at the site of the tick bite and a subsequent skin rash. The suggestion of ergot poisoning was ruled out due to England having much less rye (the main cause of ergotism) than the rest of Europe. Researchers have noted symptoms overlap with hantavirus pulmonary syndrome and have proposed an unknown hantavirus as the cause. Hantavirus species are zoonotic diseases carried by bats, rodents, and several insectivores. Sharing of similar trends (including seasonal occurrences, fluctuations multiple times a year, and occasional occurrences between major outbreaks) suggest the English<unk>  may have been rodent borne. The epidemiology of hantavirus correlates with the trends of the English<unk> . Hantavirus infections generally do not strike infants, children, or the elderly, and mostly affect middle-aged adults. In contrast to most epidemics of the medieval ages, the English<unk>  also predominantly affected the middle aged. A criticism of this hypothesis is that modern day hantaviruses, unlike the<unk> , do not randomly disappear and can be seen affecting isolated people. Another is that<unk>  was thought to have been transmitted from human to human, whereas hantaviruses are rarely spread that way. However, infection via human contact has been suggested in hantavirus outbreaks in Argentina. In 2004, microbiologist Edward McSweegan suggested the disease may have been an outbreak of anthrax poisoning. He hypothesized that the victims could have been infected with anthrax spores present in raw wool or infected animal carcasses, and suggested exhuming victims for testing. Numerous attempts have been made to define the disease origin by molecular biology methods, but have so far failed due to a lack of DNA or RNA.
Sweating sickness
Ski sickness
Altitude sickness
Morning sickness
Motion sickness
Decompression sickness
Caffeinism
Heat illness