[Meningococcal infection: changes in serogroups and penicillin resistance]

There has been an increasing number of strains of meningococcus with reduced susceptibility to penicillin in Spain during the past few years. The serogroup distribution has also changed during this period. The objective of this study was to estimate the incidence of different N. meningitidis serogroups, the penicillin susceptibility and the clinical and laboratory data from the patients with meningococcal disease in our hospital.

A retrospective study of the patients admitted to the hospital during a 4 year period (1993-1996) with bacteriological data of meningococcal sepsis/meningitis was performed. Serogroup and penicillin minimum inhibitory concentration (MIC) were determined. Analysis of the clinical data from the patients with disease due to serogroups B or C was also performed.

The incidence of serogroups C and B was 47% and 51.6%, respectively. There were 5 cases of decreased susceptivility to penicillin (MIC 0 0.25 microgram/ml). There were no clinical differences between the two groups of patients.

There was a progressive increase in the incidence of serogroup C, while the incidence of serogroup B remained stable, as did the cases of meningococci with reduced susceptibility to penicillin. Although this study did not suggest a modification in the initial treatment, every strain of meningococci must be studied to show penicillin MIC to avoid treatment failure.