Pneumonia epidemiology and demographics

Pneumonia Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Pneumonia from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Diagnostic Criteria
Diagnostic Algorithm
History and Symptoms
Physical Examination
Laboratory Findings
Chest X Ray
CT
Other Imaging Findings
Treatment
Medical Therapy
Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Pneumonia epidemiology and demographics On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Pneumonia epidemiology and demographics All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Pneumonia epidemiology and demographics
CDC onPneumonia epidemiology and demographics
Pneumonia epidemiology and demographics in the news
Blogs on Pneumonia epidemiology and demographics
Directions to Hospitals Treating Pneumonia
Risk calculators and risk factors for Pneumonia epidemiology and demographics

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Priyamvada Singh, M.D. [2]; Alejandro Lemor, M.D. [3]

Overview

Pneumonia is a common illness in all parts of the world. It is a major cause of death among all age groups. Mortality from pneumonia generally decreases with age until late adulthood. Elderly individuals, however, are at particular risk for pneumonia and associated mortality. More cases of pneumonia occur during the winter months than during other times of the year. Pneumonia occurs more commonly in males than females, and more often in African Americans than caucasians. People who are hospitalized for any reason are also at high risk for pneumonia. Following urinary tract infections, pneumonia is the second most common cause of nosocomial infections, and its prevalence is 15-20% of the total number.

Epidemiology and Demographics

Table 1. Incidence of pneumococcal infections in the United States.

Age (years)	Disease Incidence Cases/100,000 (number of cases)	Death Rate Deaths/100,000 (number of deaths)
<1	31.4 (142)	0.22 (1)
1	24.6 (112)	0.22 (1)
2-4	12.6 (171)	0.15 (2)
5-17	2.2. (111)	0.02 (1)
18-34	3.7 (261)	0.26 (18)
35-49	10.3 (670)	0.65 (42)
50-64	19.5 (1,068)	1.86 (102)
≥ 65	37.0 (1,291)	5.61 (196)
Total	12.9 (3,828)	1.22 (363)
Adapted from CDC[4]

United States of America

• It is the seventh most common cause of death in the United States
• It causes around 500,000 hospitalizations and 65,000 deaths annually.

International

• It is a common illness in all parts of the world.

Age

• It is a major cause of death among all age groups.
• In children, the majority of deaths occur in the newborn period, with over two million worldwide deaths a year.
• In fact, the WHO estimates that one in three newborn infant deaths are due to pneumonia.
• Mortality decreases with age until late adulthood; elderly individuals are particularly at risk for CAP and associated mortality.

Seasonal

• More common during winter months than during other times of the year.

Gender

• CAP occurs more commonly in males than females

Race

• More common in African Americans than caucasians.

Mortality

• Patients hospitalized with pneumonia have a mortality rate of 12-14%.

Special Considerations

• Individuals with underlying illnesses such as Alzheimer's disease, cystic fibrosis, emphysema, tobacco smoking, alcoholism, or immune system problems are at increased risk for pneumonia.

Invasive Pneumococcal Disease Incidence by Age Group, 1998 and 2008. Obtained from CDC

Countries with the highest estimated absolute number of new cases of clinical pneumonia in children

Country	Predicted no. of new cases (millions)	Estimated incidence(e/cy)
India	43.0	0.37
China	21.1	0.22
Pakistan	9.8	0.41
Bangladesh	6.4	0.41
Nigeria	6.1	0.34
Indonesia	6.0	0.28
Ethiopia	3.9	0.35
Democratic Republic of the Congo	3.9	0.39
Viet Nam	2.9	0.35
Philippines	2.7	0.27
Sudan	2.0	0.48
Afghanistan	2.0	0.45
United Republic of Tanzania	1.9	0.33
Myanmar	1.8	0.43
Brazil	1.8	0.11
Table adapted from WHO

Incidence of Community–Acquired Pneumonia in 2010 in Children 0–4 Years of Age in 192 Countries

▸ Click on the following regions to expand the data.

Africa

Country WHO Region Population 0–4 years New episodes (incidence) New severe episodes (severe morbidity) Deaths (mortality) All ALRI SP Hib RSV FLU All ALRI SP Hib RSV FLU All ALRI SP Hib Algeria AfroD 3446548 470713 34251 4697 135754 80351 53790 10297 783 7315 2251 2440 804 148 Angola AfroD 3377576 856794 62241 9674 247099 146255 97936 18712 1613 13293 4090 20429 6733 1398 Benin AfroD 1506408 424074 30705 5895 122303 72389 48501 9231 983 6558 2018 6281 2070 522 Burkina Faso AfroD 2955148 1047365 76085 11826 302060 178785 119719 22874 1972 16250 5000 17933 5911 1227 Cameroon AfroD 3054802 790160 56858 14815 227882 134880 90462 17094 2470 12143 3736 13341 4397 1463 Cape Verde AfroD 50634 9874 691 395 2848 1686 1136 208 66 148 45 39 13 8 Chad AfroD 2006165 678297 48155 19812 195621 115785 77827 14477 3304 10285 3164 14683 4840 2390 Comoros AfroD 122296 38380 2769 645 11069 6552 4392 832 108 591 182 377 124 37 Equ. Guinea AfroD 107207 16341 1144 654 4713 2789 1879 344 109 244 75 402 132 85 Gabon AfroD 185179 36186 2579 943 10436 6177 4149 775 157 551 170 291 96 43 Gambia AfroD 287078 79805 2667 802 23016 13623 8746 802 134 1338 412 987 171 56 Ghana AfroD 3532887 795448 57857 8199 229407 135783 90905 17394 1367 12357 3802 7808 2573 490 Guinea AfroD 1657883 546525 39262 10948 157618 93292 62586 11804 1826 8385 2580 7689 2534 895 Guin.–Bissau AfroD 240350 75199 5429 1216 21687 12836 8605 1632 203 1159 357 1592 525 152 Liberia AfroD 680701 212990 15195 5418 61426 36357 24419 4568 903 3245 999 1611 531 232 Madagascar AfroD 3305278 1051407 76189 13932 303226 179475 120231 22906 2323 16272 5007 8004 2638 637 Mali AfroD 2911668 932894 67350 15086 269047 159245 106745 20248 2516 14384 4426 23947 7893 2292 Mauritania AfroD 513267 144982 10415 2904 41813 24748 16603 3131 484 2224 684 2099 692 244 Mauritius AfroD 84433 13518 985 117 3899 2307 1544 296 20 210 65 20 7 1 Niger AfroD 3084517 1127652 81210 20418 325215 192490 129082 24415 3405 17344 5337 19004 6264 2018 Nigeria AfroD 26568927 7339761 513783 293590 2116787 1252897 844072 154465 48956 109729 33763 121201 39948 25767 S. Tome & P'e AfroD 23490 5118 373 46 1476 874 585 112 8 80 25 79 26 4 Senegal AfroD 2081483 591373 42853 7836 170552 100947 67625 12883 1307 9152 2816 4612 1520 367 Seychelles AfroD 5623 862 63 7 248 147 98 19 1 13 4 2 1 0 Sierra Leone AfroD 969597 315676 22866 4286 91041 53886 36101 6874 715 4883 1503 7262 2393 591 Togo AfroD 862745 280487 20292 4082 80893 47879 32083 6101 681 4334 1333 3321 1095 288 Zimbabwe AfroD 1692247 349031 25271 4852 100661 59580 39918 7598 809 5397 1661 2461 811 205 Botswana AfroE 225120 47818 3347 1913 13791 8162 5499 1006 319 715 220 159 52 34 Burundi AfroE 1184632 349477 25440 3373 100789 59656 39933 7648 562 5433 1672 7259 2393 428 Cen. Afr. Rep. AfroE 651222 195417 13981 4538 56358 33358 22394 4203 757 2986 919 3911 1289 520 Congo AfroE 623244 168619 12244 1959 48630 28783 19275 3681 327 2615 805 2001 659 141 Cote d'Ivoire AfroE 2969425 985611 71421 13060 284250 168244 112707 21472 2178 15253 4693 11003 3626 875 D. Rep. Congo AfroE 11848026 3671614 263117 80589 1058894 626745 420631 79104 13438 56194 17291 86897 28641 10986 Eritrea AfroE 861496 208035 15163 1802 59997 35512 23766 4559 301 3238 996 2419 797 129 Ethiopia AfroE 11931668 3367561 240540 82471 971205 574843 386005 72317 13752 51372 15807 37269 12284 5196 Kenya AfroE 6664323 1645189 119118 22871 474473 280834 188157 35812 3814 25440 7828 17064 5624 1419 Lesotho AfroE 274307 58335 4224 811 16824 9958 6672 1270 135 902 278 607 200 50 Malawi AfroE 2714859 658512 47877 7004 189915 112408 75261 14394 1168 10225 3146 6932 2285 448 Mozambique AfroE 3876419 1155781 83373 19438 333327 197292 132266 25065 3241 17806 5479 13167 4340 1307 Namibia AfroE 286374 63796 4619 887 18399 10890 7296 1389 148 987 304 287 95 24 Rwanda AfroE 1830654 397910 13638 3991 114757 67923 43646 4100 666 6659 2049 4145 734 236 South Africa AfroE 5041132 705554 33436 14342 203482 120438 78749 10052 2392 11357 3494 5156 1218 583 Swaziland AfroE 156715 28802 2091 344 8306 4916 3293 629 57 446 137 471 155 34 Uganda AfroE 6465275 1745727 126241 25969 503468 297996 199697 37953 4330 26961 8296 21181 6981 1876 U. R. Tanzania AfroE 8009544 2151379 156285 24291 620458 367240 245913 46986 4051 33378 10270 17467 5757 1195 Zambia AfroE 2412190 576056 41709 8008 166135 98333 65882 12539 1335 8908 2741 6141 2024 511 ALRI – acute lower respiratory infection, SP – Streptococcus pneumoniae, Hib – Haemophilus influenzae type B, RSV – respiratory syncytial virus, FLU – influenza virus

America

Country WHO Region Population 0–4 years New episodes (incidence) New severe episodes (severe morbidity) Deaths (mortality) All ALRI SP Hib RSV FLU All ALRI SP Hib RSV FLU All ALRI SP Hib Canada AmroA 1884546 25275 866 271 13709 8032 6438 604 105 3774 755 27 5 2 Cuba AmroA 569056 8208 598 79 4452 2609 2178 417 31 1140 228 63 21 4 USA AmroA 21650217 313322 22733 3845 169946 99574 83169 15868 1489 43355 8671 799 263 59 Antigua & B'a AmroB 7756 686 50 6 198 117 78 15 1 41 8 0 0 0 Argentina AmroB 3385831 311588 22663 3212 89862 53188 35609 6814 536 18616 3723 952 314 60 Bahamas AmroB 25507 2514 182 23 725 429 287 55 4 151 30 25 8 1 Barbados AmroB 14562 1377 60 19 397 235 153 18 3 87 17 4 1 0 Belize AmroB 36599 4795 349 46 1383 819 548 105 8 287 57 9 3 1 Brazil AmroB 15156449 1497706 95518 14711 431938 255658 169535 28717 2453 91150 18230 3079 916 181 Chile AmroB 1219437 88722 6448 973 25588 15145 10141 1938 162 5296 1059 145 48 10 Colombia AmroB 4497661 488486 31421 6092 140879 83385 55372 9446 1016 29585 5917 1530 459 113 Costa Rica AmroB 362979 37185 1272 425 10724 6348 4080 382 71 2389 478 24 4 2 Dominica AmroB 5924 703 51 6 203 120 80 15 1 42 8 0 0 0 ALRI – acute lower respiratory infection, SP – Streptococcus pneumoniae, Hib – Haemophilus influenzae type B, RSV – respiratory syncytial virus, FLU – influenza virus

Europe

Country WHO Region Population 0–4 years New episodes (incidence) New severe episodes (severe morbidity) Deaths (mortality) All ALRI SP Hib RSV FLU All ALRI SP Hib RSV FLU All ALRI SP Hib Andorra EuroA 4001 58 4 1 31 18 15 3 0 9 2 0 0 0 Austria EuroA 386431 5604 406 78 3040 1781 1488 283 30 913 186 5 2 0 Belgium EuroA 616259 8882 647 80 4817 2823 2356 452 31 1456 296 7 2 0 Croatia EuroA 389100 5610 409 52 3043 1783 1488 285 20 919 187 8 2 0 Czech Rep. EuroA 547804 7892 575 68 4280 2508 2093 401 26 1294 263 23 7 1 Denmark EuroA 326007 4413 168 55 2394 1402 1129 117 21 770 157 5 1 0 Estonia EuroA 78229 1129 82 12 613 359 300 57 5 185 38 2 1 0 Finland EuroA 299477 4314 314 37 2340 1371 1144 219 14 708 144 7 2 0 France EuroA 3974436 53589 2019 534 29067 17031 13698 1409 207 9391 1910 61 12 3 Germany EuroA 3466740 49718 3450 516 26967 15800 13146 2408 200 8192 1666 67 21 4 Greece EuroA 586137 8500 615 118 4610 2701 2257 430 46 1385 282 35 12 3 Hungary EuroA 490804 7071 515 61 3835 2247 1875 360 24 1160 236 27 9 1 Iceland EuroA 23511 339 25 3 184 108 90 17 1 56 11 0 0 0 Ireland EuroA 358318 5011 282 53 2718 1592 1307 197 21 847 172 4 1 0 Israel EuroA 735243 10618 772 113 5759 3375 2818 539 44 1737 353 13 4 1 Italy EuroA 2901653 41871 3047 418 22711 13307 11109 2127 162 6856 1395 30 10 2 Luxembourg EuroA 28783 389 15 4 211 124 100 11 1 68 14 0 0 0 Malta EuroA 19130 278 20 4 151 88 74 14 2 45 9 0 0 0 Monaco EuroA 2001 29 2 0 16 9 8 1 0 5 1 0 0 0 Netherlands EuroA 934218 12528 435 126 6795 3981 3192 303 49 2208 449 18 3 1 Norway EuroA 303047 4085 150 45 2216 1298 1044 105 17 716 146 3 1 0 Poland EuroA 1933388 27852 2030 241 15107 8851 7388 1417 93 4568 929 126 41 7 Portugal EuroA 516604 7448 542 69 4040 2367 1976 379 27 1221 248 3 1 0 San Marino EuroA 1401 20 1 0 11 6 5 1 0 3 1 0 0 0 Serbia & Montenegro EuroA 604144 8747 634 110 4744 2780 2322 443 43 1428 290 30 10 2 Slovakia EuroA 275895 3688 123 34 2000 1172 938 86 13 652 133 35 6 2 Slovenia EuroA 99368 1433 104 14 777 455 380 73 5 235 48 2 1 0 Spain EuroA 2521375 36353 2647 339 19718 11553 9644 1848 131 5958 1212 50 16 3 Sweden EuroA 557426 7682 382 72 4167 2441 1989 266 28 1317 268 10 2 1 Switzerland EuroA 376228 5431 395 56 2946 1726 1441 276 22 889 181 3 1 0 UK EuroA 3765820 50844 1913 560 27578 16158 13000 1335 217 8898 1810 165 32 10 Albania EuroB 207681 6230 436 249 3379 1980 1664 304 96 981 200 66 22 14 Bosnia & Herzegovina EuroB 164958 4784 346 67 2595 1520 1270 242 26 780 159 24 8 2 Bulgaria EuroB 373095 10245 470 122 5557 3256 2643 328 47 1763 359 219 50 15 Georgia EuroB 256459 7488 539 143 4061 2380 1990 376 55 1212 247 108 36 12 Romania EuroB 1079244 32377 2266 1295 17561 10290 8645 1582 501 5100 1037 807 266 172 FYR Macedonia EuroB 111863 3236 235 39 1755 1029 859 164 15 529 108 10 3 1 Turkey EuroB 6412702 172393 6203 1724 93506 54786 43984 4330 667 30306 6164 2212 408 126 Armenia EuroB 226376 6661 475 167 3613 2117 1773 332 65 1070 218 80 26 11 Azerbaijan EuroB 795163 23855 1670 954 12939 7581 6369 1166 369 3758 764 1448 477 308 Kyrgyzstan EuroB 595111 17168 1250 166 9312 5456 4555 872 64 2812 572 599 197 35 Tajikistan EuroB 870519 25144 1828 267 13638 7991 6672 1276 104 4114 837 2097 691 136 Turkmenistan EuroB 505844 14823 1062 325 8040 4711 3943 741 126 2391 486 824 271 104 Uzbekistan EuroB 2737750 82133 5749 3285 44549 26102 21929 4013 1272 12938 2632 4970 1638 1057 Belarus EuroC 514996 30900 2163 1236 16760 9820 8250 1510 479 4868 990 51 17 11 Kazakhstan EuroC 1640953 94676 6892 914 51352 30088 25117 4811 354 15510 3155 1408 464 83 Latvia EuroC 115275 6673 484 82 3619 2121 1771 338 32 1090 222 19 6 1 Lithuania EuroC 166177 9592 698 96 5203 3048 2545 487 37 1571 319 19 6 1 R. of Moldova EuroC 214693 12557 902 256 6811 3991 3339 629 99 2029 413 161 53 19 Russian Federation EuroC 8117113 487027 34092 19481 264163 154777 130036 23797 7542 76721 15604 1618 533 344 Ukraine EuroC 2376293 139669 9980 3376 75756 44387 37167 6966 1307 22460 4568 629 207 87 ALRI – acute lower respiratory infection, SP – Streptococcus pneumoniae, Hib – Haemophilus influenzae type B, RSV – respiratory syncytial virus, FLU – influenza virus

South-East Asia Region

Country WHO Region Population 0–4 years New episodes (incidence) New severe episodes (severe morbidity) Deaths (mortality) All ALRI SP Hib RSV FLU All ALRI SP Hib RSV FLU All ALRI SP Hib Indonesia SearoB 21578876 3918360 274285 156734 1130055 668864 450611 82462 26135 99135 22531 19147 6311 4071 Sri Lanka SearoB 1892699 433688 31610 3757 125076 74030 49545 9503 626 11425 2597 298 98 16 Thailand SearoB 4360687 648021 45361 25921 186889 110617 74522 13638 4322 16395 3726 903 298 192 Timor Leste SearoB 192839 67370 4716 2695 19429 11500 7748 1418 449 1704 387 489 161 104 Bangladesh SearoD 14707333 4484527 326317 44752 1293338 765509 512461 98105 7462 117940 26805 18310 6035 1114 Bhutan SearoD 70891 12773 894 511 3684 2180 1469 269 85 323 73 152 50 32 DPR of Korea SearoD 1704446 393494 27545 15740 113484 67169 45252 8281 2625 9955 2263 1744 575 371 India SearoD 127960004 35361230 2475286 1414449 10198179 6036162 4066541 744177 235859 894639 203327 388144 127932 82519 Maldives SearoD 25984 4061 284 162 1171 693 467 85 27 103 23 6 2 1 Myanmar SearoD 3956305 1213300 84931 48532 349916 207110 139530 25534 8093 30697 6976 9129 3009 1941 Nepal SearoD 3506023 832451 58272 33298 240079 142099 95732 17519 5552 21061 4787 5501 1813 1170 ALRI – acute lower respiratory infection, SP – Streptococcus pneumoniae, Hib – Haemophilus influenzae type B, RSV – respiratory syncytial virus, FLU – influenza virus

Western Pacific Region

Country WHO Region Population 0–4 years New episodes (incidence) New severe episodes (severe morbidity) Deaths (mortality) All ALRI SP Hib RSV FLU All ALRI SP Hib RSV FLU All ALRI SP Hib Australia WproA 1457527 32776 1204 385 17778 10416 8374 841 149 2724 1654 38 7 3 Brunei D'lam WproA 37385 899 65 9 488 286 239 46 3 70 42 3 1 0 Japan WproA 5430793 135770 9504 5431 73642 43148 36251 6634 2103 10150 6163 231 76 49 New Zealand WproA 311974 7036 264 90 3816 2236 1800 184 35 583 354 31 6 2 Singapore WproA 230550 5764 403 231 3126 1832 1539 282 89 431 262 9 3 2 Cambodia WproB 1491690 373583 27150 4096 107741 63771 42699 8162 683 12489 7583 2101 693 140 China WproB 81595595 6488544 454198 259542 1871296 1107594 746183 136551 43279 208931 126851 43089 14202 9161 Cook Islands WproB 2096 210 15 2 61 36 24 5 0 7 4 0 0 0 Fiji WproB 89552 14426 1051 125 4161 2463 1648 316 21 484 294 30 10 2 Kiribati WproB 9948 1625 118 18 469 277 186 35 3 54 33 19 6 1 Lao Peop's DR WproB 682861 212441 15325 3573 61268 36264 24312 4607 596 7049 4280 1076 355 107 Malaysia WproB 2828151 285716 20781 2945 82400 48772 32652 6248 491 9559 5804 199 66 12 Marshall Isl. WproB 5400 934 59 10 269 159 106 18 2 32 19 5 2 0 Micronesia WproB 13237 2620 118 50 756 447 292 35 8 91 55 23 5 2 Mongolia WproB 296799 60292 4389 582 17388 10292 6889 1320 97 2019 1226 332 109 20 Nauru WproB 1025 97 7 1 28 16 11 2 0 3 2 1 0 0 Niue WproB 152 15 1 0 4 3 2 0 0 1 0 0 0 0 Palau WproB 2046 211 12 4 61 36 24 3 1 7 4 0 0 0 Papua N. G. WproB 962437 166267 11905 3755 47951 28382 19051 3579 626 5476 3325 2038 672 264 Philippines WproB 11254421 2428448 170059 96399 700364 414536 279254 51127 16075 78227 47495 8974 2958 1896 R. of Korea WproB 2371820 249811 17487 9992 72045 42643 28728 5257 1666 8044 4884 56 18 12 Samoa WproB 22338 3377 245 43 974 576 386 74 7 113 68 7 2 1 Solomon Isl. WproB 79962 19101 1381 290 5509 3261 2185 415 48 635 386 59 20 5 Tonga WproB 13792 2223 162 19 641 379 254 49 3 75 45 4 1 0 Tuvalu WproB 1015 126 9 2 36 22 14 3 0 4 3 0 0 0 Vanuatu WproB 33152 8344 584 334 2406 1424 960 176 56 269 163 9 3 2 Viet Nam WproB 7185862 1728193 124101 35174 498411 295003 197920 37310 5865 57086 34660 3553 1171 420 ALRI – acute lower respiratory infection, SP – Streptococcus pneumoniae, Hib – Haemophilus influenzae type B, RSV – respiratory syncytial virus, FLU – influenza virus

Eastern Mediterranean

Country WHO Region Population 0–4 years New episodes (incidence) New severe episodes (severe morbidity) Deaths (mortality) All ALRI SP Hib RSV FLU All ALRI SP Hib RSV FLU All ALRI SP Hib ALRI – acute lower respiratory infection, SP – Streptococcus pneumoniae, Hib – Haemophilus influenzae type B, RSV – respiratory syncytial virus, FLU – influenza virus

Guidelines for the Management of Adults with Hospital-Acquired, Ventilator-Associated, and Healthcare-Associated Pneumonia (DO NOT EDIT)

“

Many patients with HAP, VAP, and HCAP are at increased risk for colonization and infection with MDR pathogens (Level II) It is often difficult to define the exact incidence of HAP and VAP, because there may be an overlap with other lower respiratory tract infections, such as tracheobronchitis, especially in mechanically ventilated patients (Level III). The exact incidence of HAP is usually between 5 and 15 cases per 1,000 hospital admissions depending on the case definition and study population; the exact incidence of VAP is 6- to 20-fold greater than in nonventilated patients (Level II). HAP and VAP are a frequent cause of nosocomial infection that is associated with a higher crude mortality than other hospital-acquired infections (Level II). Patients with late-onset HAP and VAP are more likely to be infected with MDR pathogens and have higher crude mortality than patients with early-onset disease; patients with early-onset HAP who have recently received antibiotics or had an admission to a healthcare facility are at risk for colonization and infection with MDR pathogens (Level II). An increase in crude and attributable mortality for HAP and VAP is associated with the presence of MDR pathogens (Level II). Bacteria cause most cases of HAP, VAP, and HCAP and many infections are polymicrobial; rates are especially high in patients with ARDS (Level I). HAP, VAP, and HCAP are commonly caused by aerobic gram-negative bacilli, such as P. aeruginosa, K. pneumoniae, and Acinetobacter species, or by gram-positive cocci, such as S. aureus, much of which is MRSA; anaerobes are an uncommon cause of VAP (Level II). Rates of L. pneumophila vary considerably between hospitals and disease occurs more commonly with serogroup 1 when the water supply is colonized or there is ongoing construction (Level II). Nosocomial virus and fungal infections are uncommon causes of HAP and VAP in immunocompetent patients. Outbreaks of influenza have occurred sporadically and risk of infection can be substantially reduced with widespread effective infection control, vaccination, and use of antiinfluenza agents (Level I). The prevalence of MDR pathogens varies by patient population, hospital, and type of ICU, which underscores the need for local surveillance data (Level II). MDR pathogens are more commonly isolated from patients with severe, chronic underlying disease, those with risk factors for HCAP, and patients with late-onset HAP or VAP (Level II)

”

For Level of evidence and classes click here.