Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela

Mary L. Milazzo, Maria N.B. Cajimat, Gloria Duno, Freddy Duno, Antonio Utrera, and Charles F. Fulhorst

Author affiliations: University of Texas Medical Branch, Galveston, Texas, USA (M.L. Milazzo, M.N.B. Cajimat, C.F. Fulhorst); Ministerio de Sanidad y Asistencia Social, Region Sanitaria del Estado Portuguesa, Guanare, Venezuela (G. Duno, F. Duno); Universidad Nacional Experimental de Los Llanos Occidentales “Ezequiel Zamora,” Guanare (A. Utrera)

Abstract

Samples from rodents captured on a farm in Venezuela in February 1997 were tested for arenavirus, antibody against Guanarito virus (GTOV), and antibody against Pirital virus (PIRV). Thirty-one (48.4%) of 64 short-tailed cane mice (Zygodontomys brevicauda) were infected with GTOV, 1 Alston’s cotton rat (Sigmodon alstoni) was infected with GTOV, and 36 (64.3%) of 56 other Alston’s cotton rats were infected with PIRV. The results of analyses of field and laboratory data suggested that horizontal transmission is the dominant mode of GTOV transmission in Z. brevicauda mice and that vertical transmission is an important mode of PIRV transmission in S. alstoni rats. The results also suggested that bodily secretions and excretions from most GTOV-infected short-tailed cane mice and most PIRV-infected Alston’s cotton rats may transmit the viruses to humans.

The Tacaribe serocomplex viruses (family Arenaviridae, genus Arenavirus) known to occur in Venezuela are Guanarito virus (GTOV) and Pirital virus (PIRV) (1,2). GTOV is the etiologic agent of Venezuelan hemorrhagic fever (VHF) (1). The human health significance of PIRV has not been rigorously investigated (3).

Specific members of the rodent family Cricetidae (4) are the principal hosts of the Tacaribe complex viruses for which natural host relationships have been well characterized. It is generally accepted that humans usually become infected with arenaviruses by inhalation of virus in aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents or by inhalation of virus-contaminated dust particles.

The results of published studies (2,5) indicated that the short-tailed cane mouse (Zygodontomys brevicauda) is the principal host of GTOV and that the Alston’s cotton rat (Sigmodon alstoni) is the principal host of PIRV. The objective of our study was to extend knowledge of the natural host relationships of these arenaviruses, particularly the relative importance of various modes of intraspecies virus transmission and the prevalence of virus shedding among naturally infected rodents.

Suggested citation for this article: Milazzo ML, Cajimat MNB, Duno G, Duno F, Utrera A, Fulhorst CF. Transmission of Guanarito and Pirital viruses among wild rodents, Venezuela. Emerg Infect Dis [serial on the Internet]. 2011 Dec [date cited]. http://dx.doi.org/10.3201/eid1712.110393