Viral zoonotic encephalitis: Australian Bat Lyssavirus and Hendra Bev Paterson Hunter© by Medicalauthor Research Institute University of Newcastle Australia ESCMID OnlineEmail: [email protected] Library Encephalitis in Australia Causes substantial morbidity and mortality Herpes simplex virus is the most commonly identified causative pathogen 70% of adult encephalitis hospitalisations no pathogen identified 57% of deaths no pathogen identified (Reference: Huppatz et al. CDI,© 2009; by Huppatzauthor et al. EID, 2009) ESCMID Online Lecture Library Viral zoonotic encphalitis Several recently emerged or resurging pathogens are known to cause an encephalitis syndrome Vectorborne and transmitted flaviviruses – MVEV, WNEV-KUN and JEV © by author Bat-borne viruses – Australian Bat Lyssavirus (ABLV) and Hendra virus ESCMID Online Lecture Library Impact of climatic conditions © by author ESCMID Online Lecture Library Australian Bat Lyssavirus Australia has no endemic rabies ABLV is a member of the family Rhabdoviridae, genus Lyssavirus ABLV is very closely related to rabies (genotype 7 of the Lyssavirus genus) Reservoir is bats © by author Two deaths from ABLV ESCMID Online Lecture Library Human exposure © by author ESCMID Online Lecture Library Epidemiology of human disease Two fatal human cases – coastal Qld – encephalitis indistinguishable from classic rabies 1996 – 39yr female, a few weeks after scratches from bat 1998 – 37yr female, 27 months after bite from bat © by author References (Samaratunga et al 1998, Hanna et al 2000). ESCMID Online Lecture Library Australian Public Health responses All bat exposures managed similarly (flying foxes or microbats) Importance of immediate rigorous wound cleaning – reduce mortality by 50% Immunoglobulin (HRIG) 20 IU/kg – max. into wound; multiple wounds dilute with normal saline Rabies human diploid cell vaccine (HDCV) – 2.5 IU/IM dose – Essen© schedule by author – 0,3,7,14,28 Omit HRIG where > 7 days has elapsed since the first vaccine dose ESCMID Online Lecture Library Hendra (Family Paramyxoviridae) Related but not identical to Nipah virus Newcastle disease © by author ESCMID Online Lecture Library Hendra (HeV) Reservoir in fruit bats, Pteropus First isolated in 1994 One of the world’s rarest diseases Fatality rate of close to 60% Seven confirmed human HeV infections Four deaths All human infections epidemiologically linked to horses © by author ESCMID Online Lecture Library Transmission Not very contagious, luckily Bat to horse Bat to person Horse to horse Horse to person Person to person © by author ESCMID Online Lecture Library Infections in humans – 7 cases Self limiting ILI (2 cases) IlI complicated by severe pneumonic illness contributing to death (1 case) Aseptic meningitis with apparent recovery then death from encephalitis 13 months later (1 case) Acute ILI followed© byby encephalitisauthor at seroconversion, followed by recovery (1 case) and death (2 cases) ESCMID Online Lecture Library Treatment No known specific treatment for Hendra Antivirals haven’t been found to be effective Three people have recovered with general medical support Research into the use of monoclonal antibodies © by author ESCMID Online Lecture Library Vaccine Vaccine still in the clinical trial stage Preliminary work on cats and ferrets looks promising © by author ESCMID Online Lecture Library What are we missing? What does cause viral encephalitis in Australia? Are we missing cases of ABLV or Hendra (or did we miss them in the past)? Are there other highly pathogenic viruses out there, that we just don’t know about yet? © by author ESCMID Online Lecture Library Acknowledgements David Durrheim Nigel Perkins Ben Ewald © by author ESCMID Online Lecture Library © by author Questions? ESCMID Online Lecture Library .