Four epidemics of Influenza in London, 1890-94.
1890
| Week ending | Annual death-rate per 1000 living | Deaths from all causes | Influenza | Bronchitis | Pneumonia | ||||||
| Jan. | 4 | 28·0 | 2371 | 4 | 530 | 215 | |||||
| 11 | 32·4 | 2747 | 67 | 715 | 253 | ||||||
| 18 | 32·1 | 2720 | 127 | 630 | 281 | ||||||
| 25 | 26·3 | 2227 | 105 | 468 | 193 | ||||||
| Feb. | 1 | 21·8 | 1849 | 75 | 339 | 145 | |||||
| 8 | 20·6 | 1749 | 38 | 369 | 117 | ||||||
1891
| Week ending | Annual death-rate per 1000 living | Deaths from all causes | Influenza | Bronchitis | Pneumonia | ||||||
| April | 25 | 21·0 | 1809 | 10 | 240 | 179 | |||||
| May | 2 | 23·3 | 2006 | 37 | 280 | 241 | |||||
| 9 | 25·6 | 2069 | 148 | 302 | 230 | ||||||
| 16 | 27·7 | 2245 | 266 | 352 | 207 | ||||||
| 23 | 27·6 | 2235 | 319 | 337 | 219 | ||||||
| 30 | 28·9 | 2337 | 310 | 353 | 189 | ||||||
| June | 6 | 27·0 | 2189 | 303 | 320 | 176 | |||||
| 13 | 23·3 | 1886 | 249 | 255 | 166 | ||||||
| 20 | 23·0 | 1865 | 182 | 248 | 159 | ||||||
| 27 | 19·0 | 1538 | 117 | 151 | 113 | ||||||
| July | 4 | 16·8 | 1363 | 56 | 108 | 103 | |||||
1891-92
| Week ending | Annual death-rate per 1000 living | Deaths from all causes | Influenza | Bronchitis | Pneumonia | ||||||
| Dec. | 26 | 21·9 | 1771 | 19 | 355 | 131 | |||||
| Jan. | 2 | 42·0 | 3399 | 37 | 927 | 256 | |||||
| 9 | 32·8 | 2679 | 95 | 740 | 246 | ||||||
| 16 | 40·0 | 3271 | 271 | 867 | 285 | ||||||
| 23 | 46·0 | 3761 | 506 | 1035 | 317 | ||||||
| 30 | 41·0 | 3355 | 436 | 844 | 255 | ||||||
| Feb. | 6 | 30·6 | 2500 | 314 | 492 | 215 | |||||
| 13 | 24·6 | 2010 | 183 | 368 | 140 | ||||||
| 20 | 20·7 | 1693 | 79 | 259 | 137 | ||||||
1893-94
| Week ending | Annual death-rate per 1000 living | Deaths from all causes | Influenza | Bronchitis | Pneumonia | ||||||
| Nov. | 4 | 20·2 | 1695 | 8 | 191 | 125 | |||||
| 11 | 21·4 | 1679 | 20 | 220 | 137 | ||||||
| 18 | 24·4 | 2016 | 22 | 318 | 228 | ||||||
| 25 | 26·5 | 2190 | 36 | 384 | 215 | ||||||
| Dec. | 2 | 27·1 | 2235 | 74 | 426 | 248 | |||||
| 9 | 31·0 | 2556 | 127 | 491 | 266 | ||||||
| 16 | 29·1 | 2401 | 164 | 421 | 232 | ||||||
| 23 | 26·3 | 2170 | 147 | 387 | 203 | ||||||
| 30 | 23·3 | 1920 | 108 | 306 | 157 | ||||||
| Jan. | 6 | 24·5 | 2040 | 87 | 342 | 169 | |||||
| 13 | 29·5 | 2462 | 75 | 490 | 211 | ||||||
| 20 | 23·7 | 1975 | 69 | 320 | 172 | ||||||
| 27 | 19·8 | 1655 | 41 | 232 | 152 | ||||||
It will be seen that the third epidemic, that of Jan.-Feb. 1892, had the highest maximum weekly mortality from influenza (506) as well as the highest maxima from bronchitis and pneumonia not specially associated in the certificates with influenza; that the second epidemic, of 1891, had the next highest maxima, and that the first and last of the four outbreaks were both milder than the two intermediate ones. All but the second, which fell in early summer, are strictly comparable as regards season (mid-winter). But although the second, in 1891, had the advantage of falling in some of the healthiest weeks of the year, it was more protracted than the original outbreak, much more fatal than it in the article influenza, more fatal also in the article pneumonia, and less fatal only in the article bronchitis. The third outbreak was not only more protracted than the first, in the same season of the year, but much more fatal in all the associated articles. As to the deaths referred to influenza (whether as primary or secondary cause), the numbers are not strictly comparable in all the outbreaks; they are probably too few in the first table, more nearly exact in the second, third, and fourth, the diagnosis having at length become familiar and the fashion of nomenclature established. It is undoubted that many of the deaths from bronchitis and pneumonia in January, 1890, were due to the epidemic; for, “while the ordinary rise of mortality in cold seasons is mainly among the very aged, the increased mortality in this fatal month was mainly among persons between 20 and 60 years” (Ogle).