b'MeningitisWhat is it? farmers and meat industry workers 117 .The bacterium Streptococcus suis (S. suis) isRoutes of transmissiona zoonotic agent causing severe infectionsAmong pigs, the bacteria can be spread by to people in close contact with infecteddirect and indirect contact. It is present in pigs or pork-derived products 109 . It hasthe faeces and nasal secretions of carriers, been linked to various diseases, includingand transmission may be through ingestion, meningitis, septicaemia, and endocarditis,inhalation or through nose-to-nose contact. in both pigs and people 110 .The bacteria can survive on flies for at The bacteria are carried in the tonsilsleast five days 118and, unsurprisingly, are more prevalent when pigs are crowded and nasal cavities of apparently healthytogether 119 . pigs allowing infection to spread before symptoms are spotted 111 . It is most commonly found in 4-8-week-old piglets, 112and particularly in intensive, indoor units 113 . The bacteria can be passed to people in whom meningitis can develop. HistoryStreptococcus suis has been a recognised zoonosis (infectious disease that can beHuman infection is usually through close transmitted from animals to humans)contact with infected pigs or with raw or since 1968. An editorial in the Journalundercooked pig meat and is thought to of Infectious Diseases described it asoccur through cuts or abrasions on the skin emerging as an important threat to humanwhen handling infected pig carcasses 120 .health 114 .Symptoms in animalsThe largest outbreak was in China in 2005,Typical symptoms include involuntary where 215 people were infected and 39eye movement, convulsions, paddling, died 115 .shivering, pain and discomfort, raised hair and grinding teeth 121 . In untreated pigs, the In 2017 there were just four reportedmortality rate is 20 per cent 122 . cases in the UK 116but it is a recognised occupational hazard to veterinary surgeons, 20'