Monday, April 21, 2008

New Hemorrhagic Arenavirus found!

Hey everyone, sorry I didn't get to see you at class last week! I'll post my make-up article soon. But first, big news!

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:



A ProMED-mail post


ProMED-mail is a program of the

International Society for Infectious Diseases <>

Date: Thu 17 Apr 2008

Source: EurekAlert! Public News, PLoS [Public Library of Science] Pathogens report [edited] <>

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


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


"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]



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 (<>) 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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