Invasive meningococcal disease in Malta: an epidemiological overview, 1994-2007.
Since 1996, Malta has experienced an upsurge of invasive meningococcal disease (IMD) following an almost 30 year period with a negligible number of annually reported cases. We reviewed the 233 IMD cases notified during a 14 year period (1994-2007), and analysed epidemiological and laboratory surveillance data. The crude incidence per 100,000 inhabitants peaked in 2000 at 8.1 [95 % confidence interval (CI) 5.7-11.6] and again in 2006 at 8.9 (95 % CI 6.4-12.4), thereby placing Malta amongst the countries with the highest incidence of the disease in Europe. Of the total cases, 137 (59 %) were confirmed and 30 (13 %) were classified as probable. However, 66 cases (28 %) had no laboratory evidence of the disease and were classified as possible. Information on the serogroup was available for 114 cases. Serogroup B formed the largest proportion (76 %, n=87) followed by serogroup C (16 %, n=18). B : 4 : P1.19,15 strains (n=46) predominated throughout the study period since their first identification in 1998. With 28 deaths attributed to IMD, the overall case fatality rate was 12 %. Apart from stressing the importance of maintaining high vigilance for IMD, our findings underscore the importance of enhancing laboratory surveillance of the disease, including characterization of the meningococci. Until vaccines against a broad range of serogroup B meningococci become available for universal use, the main methods of control remain the early treatment of cases and the prevention of secondary cases.
Muscat
Mark
M
Department of Epidemiology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
Spiteri
Gianfranco
G
Infectious Disease Prevention and Control Unit, Department of Health Promotion and Disease Prevention, 5B The Emporium, C. de Brocktorff Street, Msida MSD 1421, Malta.
Calleja
Neville
N
Directorate of Health Information and Research, 95 G'Mangia Hill, G'Mangia PTA 1313, Malta.
Haider
Julie
J
Bacteriology Laboratory, Department of Pathology, Mater Dei Hospital, Msida MSD 2090, Malta.
Gray
Stephen J
SJ
Meningococcal Reference Unit, Health Protection Agency, Manchester Medical Microbiology Partnership, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WZ, UK.
Melillo
Jackie Maistre
JM
Infectious Disease Prevention and Control Unit, Department of Health Promotion and Disease Prevention, 5B The Emporium, C. de Brocktorff Street, Msida MSD 1421, Malta.
Mamo
Julian
J
Department of Public Health, Mater Dei Hospital, Medical School, University of Malta, Msida MSD 2090, Malta.
Cuschieri
Paul
P
Bacteriology Laboratory, Department of Pathology, Mater Dei Hospital, Msida MSD 2090, Malta.
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008319:Malta / Q000453:epidemiology; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000503:physiopathology / Q000517:prevention & control; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000145:classification* / Q000302:isolation & purification; D012621:Seasons; D012703:Serotyping; D017678:Sex Distribution; D055815:Young Adult