The Islands of St Kilda and the 8-Day Sickness Day
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1/26/2010 The Islands of St Kilda and the 8-day Sickness Neonatal tetanus, evacuation and was it all because of the Fulmar? How I got involved Ian Poxton Centre for Infectious Diseases University of Edinburgh The culprit? The northern fulmar (Fulmarus gracialis) Plan of presentation • Summary of problem • What is tetanus, including the neonatal form? • The St Kilda problem in 19th Century • How we investigated the theory • Conclusions Neonatal tetanus and St Kilda What is tetanus? – a summary • Latter part of 19th Century • Spastic paralysis as a result of the • Most babies born on the island action of tetanospasmin – a neurotoxin developed tetanus and died at the age produced following infection of a wound of 8 days – the “sickness of eight days” with Clostridium tetani • Mysterious midwifery procedures • In the developed world it is easily • Theory put forward in 1928 that the preventable by administration of the source of the infection was the fulmar tetanus toxoid vaccine. oil – supposedly used to anoint the umbilicus 1 1/26/2010 Tetanus Current picture of neonatal tetanus (from World Health Organisation) • Neonatal tetanus kills more than 450 000 infants each year between 3 and 10 days (8- day sickness on St Kilda) – in rural areas of the Third World • (If mother is not immunised nearly 40 000 mothers die from tetanus infection acquired during delivery: immunisation of mother protects baby). • Only 5% of cases of neonatal tetanus are actually reported • Referred to as “the silent killer”. Sir Charles Bell's portrait of a man with generalized tetanus (Original in the Royal College of Surgeons of Edinburgh, Scotland) Symptoms Prevention of Neonatal Tetanus Initially the baby feeds Neonatal tetanus can be prevented if: normally, then after 3 days it cannot suckle and becomes • Women are immunized with at least two irritable. doses of tetanus toxoid vaccine before Convulsions occur that increase childbirth, and in intensity and frequency. From CDC • Clean practices are used during delivery Progresses to difficult and in the care of the infant’s umbilical breathing, exhaustion, starvation cord. and in most cases death. Clostridium Clostridium tetani • Anaerobic, Gram-positive, straight, slender rod with • Gram-positive rounded ends. • Rod-shaped • Spore-forming with terminal ‘Drumstick’ spores • Anaerobic – highly resistant. • Peritrichous flagella allowing motility – swarms on • Spore-forming blood agar • Saprophytic in the environment • Commensal in the GI tract Occurrence • Found in intestine of Man and animals. • Pathogenic for man and animals • Primary source is animals faeces and soil, especially • Virulence factors = exotoxins clay (alkaline). Spores widespread • Animal species – variable susceptibility. 2 1/26/2010 C. tetani spores Clostridium tetani Pathogenesis • Spores contaminate a wound (the umbilical cord after cutting) • Spores germinate in wound – low O2 tension and non-vital tissue • C. tetani is not an invasive organism – stays at site of initial infection • Toxin production and release • Toxin absorbed from site and moves via peripheral motor neurons within axon to CNS. Tetanus toxin St Kilda • The islands of St • Acts by preventing the release of inhibitory Kilda, the remotest neurotransmitters resulting in over-stimulation part of the British Isles, lie 66 km west of motor neurons in CNS. of the Outer Hebrides. • Prevents relaxation of muscle fibres - • The economy of the interferes with normal inhibition of motor islands was based on impulses leading to tonic spasm seabirds. • The one inhabited • Affects voluntary muscle. Head and neck usually island was evacuated in 1930 – due largely first areas to be affected (lockjaw) to a decline in the population • Now a World Heritage Site 3 1/26/2010 Living conditions The aetiology of neonatal tetanus on St Kilda: theories and suppositions • Quotes from Captain Henry Otter • Houses in St Kilda: “worse than any I have • In many parts of the world the cut seen in the Highlands, no aperture for smoke umbilical cord was/is wrapped with rag to escape, soot lies 2-3 inches on rafters and soaked in salt butter, ghee, or other oils everything is impregnated” • (Custom still used in parts of the Indian • “To each house is attached a barn of stones sub-continent) which is erected opposite the door to defend • In St Kilda “fulmar oil” used?? them from the wind – and is deposited their manure, ashes and pickled birds” 4 1/26/2010 Between 1855 and 1876 • Accurate infant death records were kept by Mr Duncan Kennedy: 41 infant deaths out of 56 births; most of these deaths were ascribed to “sickness of eight days” In 1885 1890 Rev Angus Fiddes • He was convinced that tetanus was due Robert Connell (Glasgow Herald) noted to birth practices that “a great gun of the Free Church….. • Perhaps first to blame the fulmar oil was not ashamed to say that this lockjaw was a wise device of the • Decided to act Almighty for keeping the population • Recruited help of nurses from Glasgow within the resources of the island” to change the midwifery procedures • Last case of tetanus recorded on 18th August 1891 Fulmar oil • Naturally produced as a smelly, sticky “vomit”: a defence mechanism to deter predators • Harvested by St Kildans and stored in flasks made from the stomach of a “solan goose” – the gannet (refilled over years) • Used for lighting • Had medicinal properties • and was exported 5 1/26/2010 Opportunity to test the theory April 2004 • Visited St Kilda and collected environmental samples Summer 2004 • Collected 40 samples of fulmar “vomit” from nesting birds in Firth of Forth (thanks to Lothian Ringing Group) Methods • Culture. – Environmental Samples • 1g added to pre-reduced CMB • Initial and 5 day samples plated out onto Blood Agar to form single colonies • 1ml culture supernate removed at 0 and 5 days, spun down and the pellet stored. Methods • Culture. – Fulmar vomit • Samples plated out onto blood agar to form single colonies • CMB inoculated with 1 ml samples and incubated anaerobically for 5 days then sub-cultured onto agar as before • 1ml culture supernate removed at 0 and 5 days, cetrifuged and the pellet stored. 6 1/26/2010 Detection of tetanus toxin genes Methods cont. • DNA extracted from pellet using “bead beating” and phenol/chloroform method with Amplification of nucleic acid (DNA) by CTAB. the polymerase chain reaction (PCR) • PCR performed for the detection of the C fragment of the C. tetani neurotoxin gene 1 copy Target gene Melt DNA at 94C Polymerase Chain Reaction 1st cycle Cool to 60C, add primers and bases, heat stable polymerase and incubate few mins 2 copies melt, cool, incubate 2nd cycle 4 copies 8 copies 3rd cycle > 1 million copies in 2-3 hours Results Antimicrobial properties of fulmar oil • All soil samples by culture and subsequent • Due to lack of viable organisms found in oil microscopy were found to contain C. tetani- samples, a filter paper disc coated in a sample like organisms of fulmar oil was placed in the centre of an • All soil samples were positive by PCR for the agar plate inoculated with a lab strain of C. C. tetani neurotoxin gene tetani. • All fulmar samples were found to be negative by PCR for the C. tetani neurotoxin gene • Growth of the organism was not affected by • and when cultured contained no viable the presence of the oil – therefore no organisms at all! antibacterial action against C. tetani 7 1/26/2010 Conclusions Acknowledgements • There is no doubt that neonatal tetanus occurred on St Kilda in the latter half of the 19th Century – • Annemarie Gibson (Circa Media) and had a serious consequence for the population • Ann Heffron • Tom Pennycott (SAC) • The fulmar oil appears to be ‘innocent’ as the • Bernie Zonfrillo (U of Glasgow) source of the infection and it is unlikely that storage conditions may have affected the content • John Davies and members of the Lothian of the oil Ringing Group • Louise Dalziel and Hermione Cockburn (BBC • But in the squalid surroundings - it is possible that Radio 4) the oil helped to seal in any infection and created an anaerobic environment within the wound site, and/or create a sticky site for bacteria to bind. 8.