Long-term predominance of a rare meningococcal phenotype in a small geographical area.
Reported here is a predominant clone of Neisseria meningitidis B:14:P1.13 that persisted over a 6-year period in the northernmost province of Italy, where it was responsible for a higher incidence of meningococcal disease compared to the rest of the country. Genetic relatedness of isolates was confirmed by multilocus sequence typing, pulsed-field gel electrophoresis and PorA variable region typing. All strains examined belonged to the ST44 complex/lineage III. Risk factors for infection were evaluated through a case-control study conducted with 21 cases and 63 age- and sex-matched controls. Risk factors for infection in the seven patients younger than 13 years were (i) residence in a rural area, (ii) exposure to passive smoke, and (iii) living in a home with rooms rented to tourists (all odds ratios infinite). The only risk factor for the older patients was previous influenza-like illness (odds ratio, 41.9; 95% confidence interval, 1.6-1068.9). Guidelines for the early treatment of patients and public information campaigns were successfully implemented to reduce disease transmission and the case fatality rate in the region.
Stefanelli
P
P
Laboratory of Bacteriology and Medical Mycology, Viale Regina Elena, 299, 00161 Rome, Italy.
Fazio
C
C
Neri
A
A
Sofia
T
T
Kreidl
P
P
Salmaso
S
S
Mastrantonio
P
P
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008297:Male; D008589:Meningococcal Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000235:genetics* / Q000302:isolation & purification*; D016017:Odds Ratio; D010641:Phenotype; D011336:Probability; D018570:Risk Assessment; D017678:Sex Distribution; D013997:Time Factors