Reverse Zoonoses: An Assessment of the Risk to Weddell Seals at Scott Base from Clyptosporidium in Human Sewage Effluent

• Main Author: Weinstein, Phil
• Format: Other/Unknown Material
• Language: English
• Published: 1999
• Subjects: Scott Base; Weddell; Antarc*; Antarctica; Weddell Seal; Weddell Seals
• Online Access: http://hdl.handle.net/10092/14294

Cryptosporidiosis is a disease generally considered in the context of humans being exposed to animal faeces, but the converse route Of infection is also theoretically possible. In summer at Scott Base (Antarctica), about 8,000 litres of effluent per 24 hours is discharged untreated into the ocean. Levels of viable Cryptosporidium oocysts in the resultant effluent plume could reach about one oocyst per litre. A 200-300kg Weddell seal is unlikely to Ingest more than about 500ml of sea water per day, and is therefore can not receive an infective dose of Cryptosporidium (about 10 oocysts). Because the combination of this pathogen and host constitute a worst case scenario for mammals exposed to human effluent from Scott Base, it is unlikely that base effluent poses a microbiological risk to any Organisms in the area. However, there are many other examples of situations in which 'reverse zoonoses' might pose a threat to fauna in sensitive environments, and both scientific research and 'ecotourism' should be managed with this in mind. Cryptosporidiosis is a disease generally considered in the context of humans being exposed to animal faeces, but the converse route Of infection is also theoretically possible. In summer at Scott Base (Antarctica), about 8,000 litres of effluent per 24 hours is discharged untreated into the ocean. Levels of viable Cryptosporidium oocysts in the resultant effluent plume could reach about one oocyst per litre. A 200-300kg Weddell seal is unlikely to Ingest more than about 500ml of sea water per day, and is therefore can not receive an infective dose of Cryptosporidium (about 10 oocysts). Because the combination of this pathogen and host constitute a worst case scenario for mammals exposed to human effluent from Scott Base, it is unlikely that base effluent poses a microbiological risk to any Organisms in the area. However, there are many other examples of situations in which 'reverse zoonoses' might pose a threat to fauna in sensitive environments, and both scientific research and ...