Bats host major mammalian paramyxoviruses

Drexler, Jan Felix; Corman, Victor Max; Müller, Marcel Alexander; Maganga, Gael Darren; Vallo, Peter; Binger, Tabea; Gloza-Rausch, Florian; Rasche, Andrea; Yordanov, Stoian; Seebens, Antje; Oppong, Samuel; Sarkodie, Yaw Adu; Pongombo, Célestin; Lukashev, Alexander N.; Schmidt-Chanasit, Jonas; Stöcker, Andreas; Carneiro, Aroldo José Borges; Erbar, Stephanie; Maisner, Andrea; Fronhoffs, Florian; Buettner, Reinhard; Kalko, Elisabeth K.V.; Kruppa, Thomas; Franke, Carlos Roberto; Kallies, René; Yandoko, Emmanuel R.N.; Herrler, Georg; Reusken, Chantal; Hassanin, Alexandre; Krüger, Detlev H.; Matthee, Sonja; Ulrich, Rainer G.; Leroy, Eric M.; Drosten, Christian

theoretical task. The current limitation, however, is in the sparse and incomplete biological sampling of habitat. Beyond phylogenetic analysis, we have identified traits of the natural history of infection that suggest a specific connection between PV and bats. The epidemiology of a morbilli-related virus was fundamentally different from that of measles virus in humans, or that of Rinderpest in cattle. Human measles is the prototype of viruses depending on steady transmission in sufficiently large social groups, potentially absent from isolated and remote populations 41 . Black 41 has defined this pattern of pathogen prevalence as the 'introduced disease' pattern, based on observations in isolated human tribes. Strikingly, in bats, the morbilli-related virus was excreted by adult animals at similar rates as by young animals, which is very untypical of morbilliviruses in other mammals. This pattern of prevalence was classified by Black 41 as 'endemic-high incidence, low morbidity' , as exemplified in humans by hepatitis B virus or herpes viruses. Some researchers have argued that bats in general might deal with viral infections differently than other mammals 42 . However, we have recently described a variance of viral persistence patterns in bats that is congruent with observations in other mammals, with a typical 'introduced disease' pattern for astro-and coronaviruses, although a bat adenovirus in the same group of animals showed Black's 'endemic' pattern 41, 43 . Adenoviruses provide a good template to explain the shedding pattern of the morbilli-related virus found in the present study, as they are known to persist in tissue and to be shed without signs beyond the acute phase of disease-a property determining the ability of viruses to persist in small populations 41, 44 . Accordingly, the morbilli-related virus in our study was detected in a species of bats forming small-to medium-sized social groups (M. myotis), possibly requiring long-term excretion for virus maintenance on group level. This is rather untypical for morbilliviruses in other mammals that depend heavily on efficient transmission and sufficient group size to be maintained 30, 41, 45 . In this light, the difference in organ association between bats and rodents was quite interesting. Although PVs in rodents were associated with the kidney, favouring excretion, their highest concentrations and prevalences in bats were seen in the spleen. Although we have no further direct proof, this matches the concept that bat-borne PV might not as much depend on highly efficient transmission, but might routinely employ mechanisms of persistence to follow Black's 'endemic' pattern of prevalence 41 . This anomality might indeed identify bats as AR of these viruses. Moreover, the morbilli-related bat virus was detected in Europe, but also in an unrelated species forming rather small social groups in sub-Saharan Africa. Even though we have not been able to conduct longitudinal investigations of excretion in other PV genera, detection in groups without social connection as well as re-detection in subsequent years was seen also for rubulaand henipaviruses in this study. Detection of these viruses was not associated with changes in serum chemistry parameters, suggesting symptomless infection despite virus replication in internal organs, which may be regarded as typical for a virus in its natural host context that is not dependent on efficient horizontal transmission 4, 7, 46 .