JM Cowden
SCIEH, Glasgow, Scotland

On the afternoon of Friday 22 November 1996, Lanarkshire Health Board’s Public Health Department became aware of 15 cases of possible Escherichia coli O157 infection (five of which had been confirmed microbiologically) in residents of the town of Wishaw in central Scotland. All the cases had either eaten cold cooked meats or meat sandwiches from a local butcher, or had eaten cooked steak in gravy at a church lunch on 17 November 1996 supplied by the same butcher. At this stage it was possible that the association between the cases and meat from the butcher could have been coincidental. Indeed, the butcher had recently won the award for Best Scottish Beef Butcher of the Year. Nevertheless, because of the seriousness of the infection, the butcher was asked to stop selling cooked meat products from the morning of 23 November 1996.

To date (9 December 1996) Lanarkshire Health Board has identified 303 people with symptoms compatible with infection with E. coli O157, 137 whose infections have been confirmed by various laboratory tests. Over a hundred isolates have been typed by the E. coli Reference Laboratory at Aberdeen as phage type 2, VT1 negative, VT2 positive. All the isolates tested so far are indistinguishable on pulsed field gel electrophoresis (PFGE) fingerprinting.

E. coli O157 of the same phage type, VT, and PFGE pattern as the epidemic strain was isolated from gravy served with the meat supplied to the church lunch. E. coli O157 was also isolated from an unopened, vacuum-packed, 2.7kg piece of cooked beef prepared by the same butcher, but retrieved from a shop in Glasgow. This was traced and withdrawn from sale.

In addition to the 303 Lanarkshire cases, 87 suspected or confirmed cases have been reported from the rest of Scotland; 85 from Forth Valley, one from Greater Glasgow, and one from Lothian. Almost all have been linked to the butcher in Wishaw, or with outlets supplied by him, whose shop is now thought to be the principal and probably only source of the infection. The case in Glasgow is thought to be a secondary case; the case in Lothian ate meat from the suspect butcher's shop. Forty-three of the cases in Forth Valley and both of the other cases have been confirmed. All isolates tested so far from Forth Valley are PT2 VT2 with the same PFGE pattern as the Lanarkshire cases, as is the Lothian case. An epidemic curve of all the cases whose dates of onset are known is shown as figure 1.

Ten cases (all adults) have died. Forty-nine cases are currently in hospital (42 adults and seven children). The clinical condition of 25 is reported as giving cause for concern (19 adults and six children). This is the largest outbreak of E. coli O157 infection yet reported in the United Kingdom, and Scotland's most serious food poisoning event since 512 cases arose in an outbreak of typhoid in 1964, which was caused by contaminated can of corned beef (1).

Reference

1. Scottish Home and Health Department. The Aberdeen typhoid outbreak 1964: report of the department committee of enquiry. Milne D (Chairman). Edinburgh: HMSO, 1964