Table 2.
Burden of IMD-related deaths, reported to the VSD, adjusted by diagnostic methods, by year
| Number of IMD-related deaths per year (MRs; per 100 000 inhabitants per year) | Year | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | Mean | ||
| Reporteda | 26 (0.065) | 25 (0.062) | 31 (0.076) | 14 (0.034) | 15 (0.036) | 22 (0.052) | 15 (0.035) | 24 (0.056) | 20 (0.046) | 21 (0.051) | |
| CFRs (%)b | 11.0% | 9.7% | 19.2% | 6.1% | 4.4% | 8.9% | 4.9% | 8.2% | 10.3% | 9.2% | |
| Adjusted by improved bacterial culture methodsc | 35 (0.088) | 34 (0.084) | 46 (0.112) | 18 (0.044) | 16 (0.039) | 29 (0.068) | 16 (0.037) | 27 (0.062) | 29 (0.066) | 28 (0.067) | |
| Adjusted by improved bacterial culture + PCR diagnosisc | 52 (0.130) | 50 (0.123) | 67 (0.165) | 27 (0.065) | 24 (0.058) | 42 (0.100) | 23 (0.055) | 39 (0.091) | 42 (0.098) | 41 (0.098) | |
CFRs, case fatality ratios; IMD, invasive meningococcal disease; IRs, incidence rates; PCR, polymerase chain reaction; SNVS, National Clinical Surveillance System; VSD, Vital Statistics Database.
Reported deaths are related to ICD-10 code A39 (meningitis and other invasive forms due to N. meningitidis); the system coverage for the reporting of death certificates was assumed to be 100%.
Case fatality ratios (CFR) were calculated with the IMD-related deaths ((A39 code) reported to the VSD [24] and the number of IMD cases (A39 code) reported to the SNVS database [22], adjusted by coverage).
To adjust the number of IMD-related (A39) deaths to account for the diagnostic methods, the number of diagnosis-adjusted IMD cases previously calculated (Table 1) was multiplied by the CFR, by year.