Argentine hemorrhagic fever (AHF) or OHiggins disease, also known in Argentina as mal de los rastrojos (stubble disease) is a hemorrhagic fever and zoonotic infectious disease occurring in Argentina. It is caused by the Junín virus (an arenavirus, closely related to the Machupo virus, causative agent of Bolivian hemorrhagic fever). Its vector is the drylands vesper mouse, a rodent found in Argentina and Paraguay. Epidemiology
The disease was first reported in the town of OHiggins in Buenos Aires province, Argentina in 1958, giving it one of the names by which it is known. Various theories about its nature were proposed: it was Weils disease, leptospirosis, caused by chemical pollution. It was associated with fields containing stubble after the harvest, giving it another of its names. The endemic area of AHF covers approximately 150,000 km2, compromising the provinces of Buenos Aires, Córdoba, Santa Fe and La Pampa, with an estimated risk population of 5 million. The vector, a small rodent known locally as ratón maicero ("maize mouse"; Calomys musculinus), has chronic asymptomatic infection, and spreads the virus through its saliva and urine. Infection is produced through contact of skin or mucous membranes, or through inhalation of infected particles. It is found mostly in people who reside or work in rural areas; 80% of those infected are males between 15 and 60 years of age. Clinical aspects
AHF is a grave acute disease which may progress to recovery or death in 1 to 2 weeks.
An hour (symbol: h; also abbreviated hr) is a unit of time conventionally reckoned as 1⁄24 of a day and scientifically reckoned between 3,599 and 3,601 seconds, depending on the speed of Earths rotation. There are 60 minutes in an hour, and 24 hours in a day. The hour was initially established in the ancient Near East as a variable measure of 1⁄12 of the night or daytime. Such seasonal, temporal, or unequal hours varied by season and latitude. Equal or equinoctial hours were taken as 1⁄24 of the day as measured from noon to noon; the minor seasonal variations of this unit were eventually smoothed by making it 1⁄24 of the mean solar day. Since this unit was not constant due to long term variations in the Earths rotation, the hour was finally separated from the Earths rotation and defined in terms of the atomic or physical second. In the modern metric system, hours are an accepted unit of time defined as 3,600 atomic seconds. However, on rare occasions an hour may incorporate a positive or negative leap second, making it last 3,599 or 3,601 seconds, in order to keep it within 0.9 seconds of UT1, which is based on measurements of the mean solar day. Name
Hour is a development of the Anglo-Norman houre and Middle English ure, first attested in the 13th century.It displaced tide tīd, "time" and stound stund, span of time.