Bolivian hemorrhagic fever (BHF), also known as black typhus or Ordog Fever, is a hemorrhagic fever and zoonotic infectious disease originating in Bolivia after infection by Machupo mammarenavirus.BHF was first identified in 1963 as an ambisense RNA virus of the Arenaviridae family, by a research group led by Karl Johnson. The mortality rate is estimated at 5 to 30 percent. Due to its pathogenicity, Machupo virus requires Biosafety Level Four conditions, the highest level.During the period between February and March 2007, some 20 suspected BHF cases (3 fatal) were reported to the Servicio Departamental de Salud (SEDES) in Beni Department, Bolivia. In February 2008, at least 200 suspected new cases (12 fatal) were reported to SEDES. In November 2011, a second case was confirmed near the departmental capital of Trinidad, and a serosurvey was conducted to determine the extent of Machupo virus infections in the department. A SEDES expert involved in the survey expressed his concerns about the expansion of the virus to other provinces outside the endemic regions of Mamoré and Iténez provinces. Epidemiology
History
The disease was first encountered in 1962, in the Bolivian village of San Joaquín, hence the name "Bolivian" Hemorrhagic Fever. When initial investigations failed to find an arthropod carrier, other sources were sought before finally determining that the disease was carried by infected mice.
The presence of a positive pathergy reaction is not associated with an increased risk for specific mucocutaneous or systemic manifestations of the disease, and probably does not predict a more severe disease course.It is also important to note that, while a positive pathergy reaction helps to confirm a specific Behçets disease diagnosis, a negative reaction does not invalidate a BD diagnosis, because the disease process has to be active at the time of the skin prick test to produce a pathergy reaction. Differences in positive/negative pathergy and severity of the reaction depend on disease activity, ethnicity, type of needle used for the prick test, among other factors.Pathergy test is done both orally and cutaneous. Orally, the lower lip is the site of testing. Appearance of any ulcer or papule indicates a positive pathergy reaction. Cutaneous sites are the flexor forearm. Epidemiology
See also
Cutaneous conditions
List of cutaneous conditions


== References ==