[Analysis of the epidemiological characteristics and prognostic factors in probable or confirmed invasive meningococcal disease in a cohort of adolescents and adults during an epidemic outbreak].

Objective: To describe the profile of people suffering Invasive Meningococcal Disease in Andalusia and the Canary Islands, and identify the risk factors for death.

Material And Methods: A retrospective study was designed, recruiting cases from week 41 of 1995 to week 40 2000. Cases were probable or definite, and were extracted from the databases of the hospital by examining diagnosis at discharge or death.

Results: 167 cases were identified, with a mortality rate of 7.2%. Mean age was 28.88 years, this being greater in those who died (p = 0.041). There was no previous contact with the Health System before the diagnosis in 56.3% of the cases, this being associated with death (p = 0.017). The more frequent reason for contact was a low level of consciousness, and it was the only one associated to death (p = 0.036). Pharyngotonsilitis was associated with a lower incidence of death. About 24% of patients received antibiotics as out-patients and their use was associated to a lower incidence of death (p = 0.07). Temperature over 40 degrees C (p = 0.003) and heart rate lower than 60 beats per minute (p < 0.0005) were associated with death. Leucocytes in peripheral blood less than 4.500 cells/ microliter, or platelets less than 100.000 cells/microliter were associated with a greater proportion of deaths. In Cerebrospinal fluid, less than 5 leucocytes per microliter, or proteins less than 50 mg/dl were associated with more deaths. Neisseria meningitidis B was isolated in 47 patients (28.1%), and C in 77 cases (46.1%). Sepsis was significantly associated with death (p < 0.0005).

Conclusions: The absence of previous contacts with the Health System reveals an abrupt onset of Meningococcal disease, with less inflammatory response and very severe. Out of hospital antibiotic treatment and pharyngoamygdalitis are associated with a better prognosis.