Publication: Life-long shedding of Puumala hantavirus
Researchers have found evidence of the life-long shedding of Puumala hantavirus (PUUV) by its host, following a monthly capture-mark-recapture study analysing 18 wild bank voles for the presence and relative quantity of PUUV RNA in excreta and blood. Their findings contradict current views of a decline in shedding, suggesting pathogen kinetics in wild hosts may differ considerably from those found in the lab.
Writing in the Journal of Virology, they report: “The knowledge of viral shedding patterns and viremia in the reservoir host species is a key factor in assessing the human risk of zoonotic viruses. The shedding of hantaviruses (family Bunyaviridae) by their host rodents has widely been studied experimentally, but rarely in natural settings. Here we present the dynamics of Puumala (PUUV) hantavirus shedding and viremia in naturally infected, wild bank voles (Myodes glareolus). In a monthly capture-mark-recapture study, we analyzed 18 bank voles for the presence and relative quantity of PUUV RNA in the excreta and blood from 2 months before up to 8 months after seroconversion.
“The proportion of animals shedding PUUV RNA in saliva, urine, and feces peaked during the first month after seroconversion, but continued throughout the study period with only a slight decline. The quantity of shed PUUV in RT-PCR positive excreta was constant over time. In blood, PUUV RNA was present for up to 7 months but both the probability of viremia and the virus load declined by time.
“Our findings contradict the current view of a decline in virus shedding after the acute phase and a short viremic period in hantavirus infection - an assumption widely adopted into current epidemiological models. We suggest the life-long shedding as a means of hantaviruses to survive over host population bottlenecks, and to disperse in fragmented habitats where local host and/or virus populations face temporary extinctions. Our results indicate that the kinetics of pathogens in wild hosts may considerably differ from those observed in laboratory settings.”
Taken from: Liina Voutilainen, Tarja Sironen, Elina Tonteri, Anne Tuiskunen Bäck, Maria Razzauti, Malin Karlsson, Maria Wahlström, Jukka Niemimaa, Heikki Henttonen and Åke Lundkvist. Life-Long Shedding of Puumala Hantavirus in Wild Bank Voles (Myodes glareolus). Journal of General Virology, February 2015. Doi: 10.1099/vir.0.000076 (EDENext132)
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