Stranger, when travelling to Argentina, make sure the rodents don't shit around....
Argentine (or Argentinian) haemorrhagic fever is one of the group of diseases commonly known as viral haemorrhagic fevers, the most notable of which is of course the dreaded Ebola. It is caused by the Junin virus, a member of the arena viri and was identified in 1958 . These little buggers are small (110-130 nanometers) RNA viri whose grainy protein particles give them their specific electron-microscopical characteristics and their name (arena means sandy in latin).
Local diseases like this used to be just medical footnotes, but in the age of international backpacking, some kid can be sleeping under the stars on the Argentinian pampa in rodent droppings one day and be on a flight to Pigsknuckle, Arkansas the next. In 2006 no diseases are local anymore.
AHF is being transmitted via the faeces and the urine of chronically infected small rodents, with a strong seasonal predominance for the fall, mainly to agricultural workers in the pampa (I presume that's because of increased activity on the fields at that time).
Pathophysiology is believed to be micro-haemorrhaging and necrosis with widespread tissue damage due to the increased permeability of small vessels. The symptoms are not particular distinctive for the disease, so it's easy to mistake the presentation of the patient for something else. The most common symptoms are
With significant, lifethreatening symptoms like that it's surprising that mortality is only 15-30 percent. That is of course mild compared to its more lethal cousins Ebola and Marburg virus. Diagnosis is by viral PCR, treatment is mainly supportive with iv fluids and plasma.
It is kinda obvious that a infectious diseases consultant, haematologist and a microbiologist should be consulted, although I doubt that you have them in the pampa.
Dion. R. Bell, Tropical Medicine, 4th edition, Blackwell Science, 2000