Table 1.
Epidemiological parameters of influenza epidemics in Russia for the period 2005–2012 according to the primary data on morbidity, hospitalization and death cases reported by collaborating Regional Bases and analyzed at Research Institute of Influenza
| Indices | Epidemic Seasons
|
|||||||
|---|---|---|---|---|---|---|---|---|
| 2005–2006 | 2006–2007 | 2007–2008 | 2008–2009 | 2009–2010 | 2010–11 | 2011–12 | ||
| Week of start - end of the epidemic in Russia | 05 - 22 | 04 - 17 | 03 - 17 | 04 - 17 | 40 - 03 | 01-14 | 05-12 | |
| Duration of the epidemic in weeks | 18 | 14 | 15 | 14 | 17 | 14 | 16 | |
| Number of week when epidemic peaked | 13 | 9 | 8 | 10 | 47 | 8 | 10 | |
| Average for cities duration of influenza epidemic (weeks) by age groups | Total population | 5,6 | 5,1 | 5,4 | 5,3 | 6,8 | 5,2 | 6,2 |
| 0–2 years | 6,1 | 6,6 | 6,7 | 7,4 | 4,4 | 4,7 | 6,9 | |
| 3–6 years | 7,5 | 7,7 | 8,2 | 8,2 | 5,0 | 4,7 | 6,4 | |
| 7–14 years | 7,3 | 6,5 | 5,8 | 6,6 | 6,7 | 4,9 | 6,4 | |
| 15 years & older | 5,5 | 4,6 | 5,1 | 4,7 | 6,7 | 4,7 | 4,0 | |
| Percent of cities involved in the epidemic by age group | In total | 77,9 | 77,9 | 84,7 | 93,2 | 98,3 | 96,6 | 28,8 |
| 0–2 years | 61,0 | 77,9 | 71,2 | 86,4 | 89,8 | 76,3 | 22,0 | |
| 3–6 years | 84,7 | 86,4 | 88,1 | 86,4 | 91,5 | 93,2 | 54,2 | |
| 7–14 years | 88,1 | 77,9 | 86,4 | 89,8 | 100 | 96,6 | 52,5 | |
| 15 years & older | 59,3 | 61,0 | 69,5 | 74,6 | 98,3 | 94,9 | 11,9 | |
| Percent of ILI and ARI morbidity at the peak of the epidemic | 0,85 | 1,04 | 0,87 | 0,95 | 1,38 | 1,43 | 0,76 | |
| Average ILI & ARI morbidity (percent of population in each age group) for the epidemic period (M ± 2m) | Total population | 4,9 ±0,6 | 5,0±0,6 | 5,2±0,7 | 5,3±0,8 | 8,5±0,7 | 7,1±0,7 | 5,9±0,4 |
| 0–2 years | 27,7±3,7 | 32,4±5,1 | 34,2±6,0 | 39,7±5,8 | 32,6±8,0 | 32,9±4,5 | 40,2±4,4 | |
| 3–6 years | 34,1±4,2 | 37,1±4,3 | 41,9±4,9 | 44,6±5,7 | 36,0±3,7 | 33,4±4,2 | 36,9±4,6 | |
| 7–14 years | 19,7±2,9 | 17,8±1,9 | 13,7±1,9 | 17,5±2,8 | 29,0±2,5 | 21,0±2,6 | 15,8±1,8 | |
| 15 years & older | 2,7±0,4 | 2,6±0,4 | 2,6±0,4 | 2,6±0,4 | 4,3±0,4 | 3,4±0,4 | 1,7±0,1 | |
| Number of hospitalized patients | Influenza | 1 023 | 3 318 | 3 314 | 4656 | 21319 | 15742 | 2619 |
| Influenza & ARI | 77 344 | 69 617 | 71 214 | 86 710 | 150 924 | 122 082 | 101 429 | |
| Percent of hospitalized patients with ILI clinical diagnosis | For the epidemic period * | 1,3 | 4,8 | 4,7 | 5,4 | 14,1 | 12,9 | 2,6 |
| On the peak of epidemic | 2,9 | 8,4 | 6,8 | 8,5 | 23,0 | 18,5 | 5,9 | |
| Number of laboratory confirmed influenza deaths cases | 3 | 4 | 6 | 4 | 622 | 264 | 7 | |
| The direction of the epidemic spread in the country | From East to West | From East to West | In both directions | In both directions | From East to West | In both directions | In both directions | |
*
beginning from the start to the end of epidemic on the territory of 59 cities under surveillance with population number of 48.5 millions of people