Bats and zoonotic viruses: can we confidently link bats with emerging deadly viruses?

An increasingly asked question is 'can we confidently link bats with emerging viruses?'. No, or not yet, is the qualified answer based on the evidence available. Although more than 200 viruses - some of them deadly zoonotic viruses - have been isolated from or otherwise detected in bats, the supposed connections between bats, bat viruses and human diseases have been raised more on speculation than on evidence supporting their direct or indirect roles in the epidemiology of diseases (except for rabies). However, we are convinced that the evidence points in that direction and that at some point it will be proved that bats are competent hosts for at least a few zoonotic viruses. In this review, we cover aspects of bat biology, ecology and evolution that might be relevant in medical investigations and we provide a historical synthesis of some disease outbreaks causally linked to bats. We provide evolutionary-based hypotheses to tentatively explain the viral transmission route through mammalian intermediate hosts and to explain the geographic concentration of most outbreaks, but both are no more than speculations that still require formal assessment.

Evolutionary, ecological and taxonomic relationship between anboviruses of Florida, U.S.A. and Brazil

A few arbovirus and related viruses genotypic and phenotypic corollaries in both subtropical south Florida and tropical Brazil. Their occurrences in these areas may to intercontinental movement by circumstances or, most likely, to divergent virus evolution in divergently evolving hosts. It is counterintuitive that ecologic similarities and the presence of rodents and certain genera of mosquitoes alone would be sufficient to bring about convergent evolution and account for nucleotide similarities of such close order. Although relatively few, pairings such as these may indicate common ancestry and subsequent evolution

Foco permanente de fiebre amarilla en el Valle del Río Apurímac, Ayacucho, Perú, y primer aislamiento del virus de la fiebre amarilla en ese país / A continuing focus of yellow fever in the Apurimac River Valley, Ayacucho, Peru, and the first isolation of yellow fever virus in that country

En 1977 ocurrió en el sur de Perú un extenso brote de una enfermedad hemorrágica que correspondía a la fiebre amarilla, y a pesar de uma amplia campaña de vacunación hubieron brotes recurrentes en años posteriores. Las circunstacias epidemiológicas en que acaecieron estos brotes indican que un importante factor determinante fue el ingreso, repetido anualmente, de trabajadores migratorios susceptibles en un foco enzootico de esta enfermedad. Durante el estudio de dichos brotes los autores intentaron aislar el virus de la fiebre amarilla de muestras de sangre obtenidas de seis pacientes en 1977, cuatro en 1978 y cuatro en 1981, en la zona endémica. Con este propósito se inyectó sangre entera de los pacientes a ratones lactantes (por via intracraneal), y se inocularon ademas cultivos de celulas C6/36 (Aedes albopictus), ratones lactantes, LLCMK2 y Vero. Las cepas del virus aisladas de seis de estos pacientes se identificaron posteriormente como agentes causales de la fiebre amarilla, y es esta la primera vez que se logra aislar el virus en Perú

Relaciones antigenicas entre virus del complejo Tacaiuma del serogrupo Anopheles A (Bunyaviridae). / Antigenic relations between Tacaiuma complex viruses of the Anopheles A serogroup (Bunyaviridae)

En investigaciones de campo realizadas en forma independiente sobre la ecologia de los arbovirus en Arizona, EUA, y Sao Paulo Brasil, se aislaron dos virus del grupo Anopheles A. El virus aislado en Arizona (743-366), obtenido de mosquitos Anopheles freeborni, para el que se propone el nombre de virus Virgin River y el virus aislado en Sao Paulo (H-32580, obtenido de un ser humano) estaban vinculados serologicamente con el complejo Tacaiuma (TCM). Asimismo, se determino que los virus 743-366 y H-32580 son variantes de un subtipo del TCM (SPAr 2317). Sin embargo, es posible distinguir uno del otro. Se describen las circunstancias en que se hicieron estas observaciones y se resalta su significado en la epidemiologia, la genetica y la nomenclatura de la familia virica Bunyaviridae.

Durante pesquisas de campo não relacionadas sobre a ecologia dos arbovírus no Arizona, Estados Unidos, e em São Paulo, no Brasil, isolaram-se dois vírus dos Anopheles, grupo A. 0 vírus isolado no Arizona (743-366 tirado de mosquitos Anopheles freebornz) para o qual se propóe dar o nome de vírus Virgin River e o vírus isolado em São Paulo (H-32580 tirado de um ser humano), estavam serologicamente relacionados no âmbito do complex Tacaiuma (TCM). Determinou-se também que o 743-366 e o H- 32580 são variantes de um subtipo (SPAr2317) do TCM. Contudo, o 743-366 e o H-32580 diferenciam-se um do outro. Este artigo descreve as circunstancias em que se fueram essas observações e a sua significacão epidemiológica, terminológica e genética em relacão com a família dos Bunyaviridae.

Encefalitis equina del este en la Republica Dominicana, 1978. / Eastern equine encephalitis in Dominican Republic, 1978

En 1978, se presento en la Republica Dominicana un brote epizootico de EEE de proporciones aparentemente considerables. Este articulo describe las medidas tomadas para investigarlo y combatirlo