a1 Department of Bacteriology, University of Edinburgh, Edinburgh
a2 Infectious Diseases Unit, Monklands District General Hospital, Airdrie
a3 Department of Community Medicine, Monklands Cumbernauld District, Lanarkshire Health Board, Airdrie
a4 Microbiology Laboratory, Monklands District General Hospital, Airdrie
a5 Meningococcus (Scotland) Reference Laboratory, Ruchill Hospital, Glasgow
A survey of ABO blood groups, secretor status and smoking habits among 389 students and staff of a school in which there was an outbreak of meningococcal disease found no difference in the distribution of the ABO blood groups but a significantly higher proportion of non-secretors (37·6%) in the population examined compared with that reported for previous surveys of the neighbouring population in Glasgow (26·2%) (P < 0·0005). There was also a significantly higher proportion of non-secretors among carriers of meningococci (47%) compared with non-carriers (32%). Increased carriage of meningococci among non-secretors might contribute to the increased susceptibility of individuals with this genetic characteristic to meningococcal disease observed in previous studies. Although passive exposure to cigarette smoke has been associated with meningococcal disease, there was no association between passive smoking and carriage. There was, however, a significant association between active smoking and carriage.
(Accepted November 20 1989)