A team of scientists from Bolivian Health authorities, the US Navy, and the CDC Special Pathogens Branch has characterized a new Hemorrhagic Arenavirus that they are calling Chapare virus. Although similar in its clinical presentation to the other New World Arenaviruses such as Junin and Machupo, Chapare demonstrates different genetics than both of these two viruses. The disease seems to be found only in a remote part of the Andean foothills of Bolivia and may carry a fatality rate of 30% if untreated. It has been suggested that recent human migration to the area may have brought about increased contact with the assumed rodent carriers of the virus. Read the Pro-Med Post Below:
ARENAVIRUS HEMORRHAGIC FEVER - BOLIVIA: (CHAPARE), NEW ARENAVIRUS
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A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
Date: Thu 17 Apr 2008
Source: EurekAlert! Public News, PLoS [Public Library of Science] Pathogens report [edited] <http://www.eurekalert.org/pub_releases/2008-04/plos-sdn041508.php>
A team of Bolivian health authorities, US Navy health experts based
in Lima, Peru, and the US Centers for Disease Control and Prevention
(CDC) has characterized "Chapare arenavirus," a previously
unrecognized arenavirus, discovered in serum samples from a patient
in rural Bolivia who eventually died of the infection. A full report
of the study is published 18 Apr [2008] in the open-access journal
PLoS Pathogens.
Named after the Chapare River in the eastern foothills of the Andes,
the new Chapare arenavirus produces clinical hemorrhagic symptoms
similar to those associated with other New World arenaviruses, such
as the Junin, Machupo, Guanarito, and Sabia viruses. Genetically,
however, Chapare is different from each.
Junin, Machupo, and Guanarito viruses have been associated with large
outbreaks of hemorrhagic fever. Initial symptoms often include fever,
malaise, muscle aches, nausea, vomiting, and anorexia, followed later
by hemorrhagic symptoms. Untreated, more severe neurologic and/or
hemorrhagic symptoms may develop, and death occurs in up to 30
percent.
In this study, the authors first tested for yellow fever and dengue
hemorrhagic fevers, but results were negative. Tests for Machupo and
other related viruses also were negative. Sequence analysis of
specific segments of the virus later confirmed it as a unique member
of the clade B New World arenaviruses.
Due to the remote nature of the region where the case occurred, only
a limited description of a possible cluster of cases in the area was
determined.
"Further surveillance and ecological investigations should clarify
the nature of the health threat posed by the Chapare virus, and give
us better information on the source of human infection," says CDC
virologist Tom Ksiazek of the Special Pathogens Branch.
"We need to learn more about this virus: how it is related to the
other arenaviruses, how it causes disease, where it lives in nature,"
says Ksiazek. "Together with our colleagues in Bolivia and Peru,
we're anticipating a more intensive investigation that improves our
understanding of the virus, the disease it causes, and its ecology."
[Byline: Craig Manning
Health Communications Specialist
Special Pathogens Branch
Centers for Disease Control and Prevention]
Reference
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Delgado S, Erickson BR, Agudo R, Blair PJ, Vallejo E, et al. 2008:
Chapare Virus, a Newly Discovered Arenavirus Isolated from a Fatal
Hemorrhagic Fever Case in Bolivia. PLoS Pathog 4(4): e1000047.
doi:10.1371/journal.ppat.1000047 [available at
[PLoS Pathogens (<http://www.plospathogens.org/>) is an open-access
journal that focuses on pathogens and their interactions with hosts.
- Mod.TY]
--
Communicated by:
ProMED-mail Rapporteur A-Lan Banks
[One hopes that this interesting report of a new Bolivian arenavirus
that causes human hemorrhagic disease will prompt timely follow-up
studies on its pathogenesis, epidemiology, and its natural hosts
(presumably wild rodents). The relationship of Chapare virus to other
South American arenaviruses, and especially Machupo virus found in
lowland Bolivia, will be of considerable interest. The Chapare region
is ecologically varied, transitioning from higher elevation foothills
to lower tropical forest. Over the past 20 years, this region has
been the site of considerable human migration from the high plateau
(Altiplano) and inter-Andean valleys into the Chapare for
agricultural development.
Jon Dyal
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