Serological evidence of influenza A viruses in frugivorous bats from Africa.

Gudrun Stephanie Freidl,Janko Van Beek,Jan Felix Drexler,Marion Koopmans,Marcel Alexander Müller,Samuel K Oppong,Andrea Rasche,Erwin De Bruin,Christian Drosten,Augustina Sylverken,Tabea Binger,Yaw Adu-Sarkodie,Veronika M Cottontail,Victor Max Corman,Marco Tschapka

doi:10.1371/journal.pone.0127035

Abstract

Bats are likely natural hosts for a range of zoonotic viruses such as Marburg, Ebola, Rabies, as well as for various Corona- and Paramyxoviruses. In 2009/10, researchers discovered RNA of two novel influenza virus subtypes – H17N10 and H18N11 – in Central and South American fruit bats. The identification of bats as possible additional reservoir for influenza A viruses raises questions about the role of this mammalian taxon in influenza A virus ecology and possible public health relevance. As molecular testing can be limited by a short time window in which the virus is present, serological testing provides information about past infections and virus spread in populations after the virus has been cleared. This study aimed at screening available sera from 100 free-ranging, frugivorous bats (Eidolon helvum) sampled in 2009/10 in Ghana, for the presence of antibodies against the complete panel of influenza A haemagglutinin (HA) types ranging from H1 to H18 by means of a protein microarray platform. This technique enables simultaneous serological testing against multiple recombinant HA-types in 5μl of serum. Preliminary results indicate serological evidence against avian influenza subtype H9 in about 30% of the animals screened, with low-level cross-reactivity to phylogenetically closely related subtypes H8 and H12. To our knowledge, this is the first report of serological evidence of influenza A viruses other than H17 and H18 in bats. As avian influenza subtype H9 is associated with human infections, the implications of our findings from a public health context remain to be investigated.

Highlights

IntroductionBats are likely reservoirs for a range of zoonotic viruses, such as rabies and other lyssaviruses (family Rhabdoviridae), Ebola- and Marburg viruses (Filoviridae), Hendra- and Nipah viruses (Paramyxoviridae), as well as severe acute respiratory syndrome (SARS) virus (Coronaviridae) [1]
Bats are likely reservoirs for a range of zoonotic viruses, such as rabies and other lyssaviruses, Ebola- and Marburg viruses (Filoviridae), Hendra- and Nipah viruses (Paramyxoviridae), as well as severe acute respiratory syndrome (SARS) virus (Coronaviridae) [1]
In 2009/10, influenza A expanded the list of viral pathogens found in bats, when RNA of two novel influenza A virus (IAV) subtypes (Orthomyxoviridae), H17N10 and H18N11, was discovered in frugivorous bats from Guatemala and Peru, respectively [2,3]

Summary

Introduction

Bats are likely reservoirs for a range of zoonotic viruses, such as rabies and other lyssaviruses (family Rhabdoviridae), Ebola- and Marburg viruses (Filoviridae), Hendra- and Nipah viruses (Paramyxoviridae), as well as severe acute respiratory syndrome (SARS) virus (Coronaviridae) [1]. In 2009/10, influenza A expanded the list of viral pathogens found in bats, when RNA of two novel influenza A virus (IAV) subtypes (Orthomyxoviridae), H17N10 and H18N11, was discovered in frugivorous bats from Guatemala and Peru, respectively [2,3]. Sixteen hemagglutinin (HA)- and nine neuraminidase (NA) types, two surface proteins utilized to classify IAV into subtypes, had been previously described. Water- and shore birds have been known to be the only relevant reservoir hosts for IAV [4]. Several IAV subtypes originating from birds have established stable lineages in birds, pigs and humans. Other avian (e.g., H5N1, H6N2, H7N9, H10N8) and swine influenza virus subtypes (e.g., most recently H3N2v) occasionally cause human infection, resulting in mild- to severe disease and occasional death [5]

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