Meningococcal carriage in close contacts of cases

Abstract

SUMMARYBetween 1 October 1986 and 31 March 1987, 55 cases of meningococcal disease were identified in the South-West of England, an attack rate of 1-54 per 100000 during the study period. Antibiotics used in the treatment of the disease successfully eliminated nasopharyngeal carriage of meningococci in 13 out of 14 cases without use of rifampicin. The overall meningococcal carriage rate in 384 close contacts was 18-2 % and the carriage rate of strains indistinguishable from the associated case strain was 11 1 %. The carriage rate of indistinguishable strains in household contacts (16-0 %) was higher than the carriage rate in contacts living at other addresses (7 0 %, P < 0-05). A 2-day course of rifampicin successfully eradicated meningococci from 46 (98 %) of 47 colonized contacts.In one third of cases groupable meningococci were isolated from at least one household contact; 92 % of these isolates were of the same serogroup as the associated case strain. When a meningococcus is not isolated from a deep site in a clinical case of meningococcal disease, culture of serogroup A or C strains from nasopharyngeal swabs of the case or of household contacts is an indication that the close contact group should be offered meningococcal A + C vaccine in addition to chemoprophylaxis. The failure in this and other studies to isolate meningococci from any household contact in the majority of cases may be due either to the relative insensitivity of nasopharyngeal swabbing in detecting meningococcal carriage or to the acquisition of meningococci by most index cases from sources outside the household.

Smoking, the environment and meningococcal disease: a case control study

“…The ages of the cases ranged from 2 months to 53 years, with slightly more males (38) than females (36). Thirty-eight cases (51 %) were aged under 5 years; there were 16 teenagers but no cases aged 9-14 years.…”

“…Geographical variation in disease incidence [36,37] may be due to underlying differences in the prevalence of virulent strains circulating, the level of population immunity and differences in exposure. Historically, increases in MD have been associated with periods of high population mobility, such as in Britain and the USA during World War II and in Brazil in the 1970s [38].…”

Transmission ofNeisseria meningitidisamong asymptomatic military recruits and antibody analysis

“…Close contacts of meningococcal cases are much more likely than control populations to harbour pathogenic strains in their throat and are at considerably increased risk of developing systemic meningococcal infection [20][21][22]. The carriage rate of N. meningitidis in a troop of military recruits, in which a case due to a B: 15:P1.7, 16 strain of ET-5 had occurred, was higher than 70 %, but none of the asymptomatic recruits carried N. meningitidis of the same clone as the patient.…”

“…The sensitivity of single swabbing in identifying meningococcal carriers has been questioned [21]. Together with a carriage rate of about 70%., the fact that no new carriers were detected by additional samples indicated that the tonsillopharyngeal swab procedure employed was adequate.…”

Should University Students Be Vaccinated against Meningococcal Disease in Canada?

“…For any individual, IMD risk is associated with the probability of exposure to a virulent strain of Neisseria meningitidis, and exposure is determined by the frequency, duration and closeness of interpersonal contacts, and by the prevalence of asymptomatic carriers among contacts (5). Bringing together groups of young adults in a university setting is a recipe for the transmission of meningococci.…”