Reading_05 - WATURES Food-Related Illness and Death in the...

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Unformatted text preview: WATURES Food-Related Illness and Death in the United States To better quantily the impact of loodbome diseases on health in the l'nited States. we compiled and analyzed information from multiple surveillance systems and other sources. We estimate that loodhorne diseases cause approximately 76 million illnesses. 323.000 hospitalizations. and 3,000 deaths in the United States each year. Known pathogens account for an estimated 14 million ill- nesses, 60,000 hospitalizations. and IBM deaths. Three pathogens, Salmonella, listaia, and Toxoplasnia, are responsible for 1,500 deaths each year, more than 75% of those caused by ltnown pathogens while unknown agents account for the remaining 62 million illnesses. 265.000 hospitalizations. and 3.200 deaths. Overall. loodborne diseases appear to cause more illnesses but fewer deaths than previously estimated. Editor‘s note This paper \tth otigiiitillt pith- lished in imaging Infectious Diseases till)! lM‘ National ( enter [or lrllt‘tllt'lh Dixetixes of the (enters {or Dixetiset ontiol tllltl l'tt'tt'niioii The format of the pupa theretoie mites iioni "tnmill lotiinal ol l‘lH‘ll‘ttnlltt‘llldl llealtli stile in [7.10. ovei itlt‘ references tittonipuninl the paper. as did (l \i'\ err-page tippentht tlest tih- ing the methods and assumptions hehind the ctuthois' pathogen-speciln t'\lHllillt'\ these soiitees were not reprinted In lllh l.\\lti' of the Joumal because of sprite limitations l'pon request. however. thev me tiittiluhle iioni NHM Sc'nttt' te'piesetttitlivi's in tin” oi niittl Introduction “me than 200 known diseases are transmit- ted through food tlt. lhe cattses of food- horne illness include viruses. bacteria. para- sites. toxtns. metals. and prions. and the svinptoins ol loodhorne illness range from nuld gastroenteritis to hie—threatening nett- iologic. hepatic. and renalsvndromes. In the l'inted States. loodliorne diseases have been estimated to cause 6 million to Hi million illnesses and up to 9.000 deaths each year (2- 5). However. ongoing changes in the food supply. the identilieatioti ol new loodhorne diseases. and the availability of new surveil- ’aul 5. .\lead Laurence Slutsker \'ante Diet] Linda [3. MtCaig Joseph S. lll’t‘St‘t‘ Craig Shapiro Patricia M. (iriffin and Robert V. Tauxe lance data have made these ligures obsolete. New. more accurate estimates are needed to gutde prevention ellorts and assess the dice- tivenes’s’ ol lood saletv regulations. Surveillance ol loodhorne illness is coni- plicated by several lactors. The first is under- reporting. Although loodhorne illness-es can be severe or even fatal. milder cases are olten not detected through routine surveillance Second. many pathogens transmitted through food are also spread through water or from person to person. thtts obscuring the role of loodborne transmission Finallv. some proportion of ioodhorne illness is caused hv pathogens or agents that have not yet been tdeiitilied and thus cannot be diagnosed. The importance of this final factor cannot he overstated. Many oi the pathogens ol greatest concern today (e.g.. (Tunipvlohattei ieiuni. Fscherichia mli OISHIT. Listeria nionoevto- genes, (fytlosponi ttiH'ldnt‘llslsl were not ret- ognizecl as causes ol loodhorne illness iust 20 vears ago. in this article. we report new estimates ol illnesses. hospitalizations. and deaths due to loodbomc diseases in the l'nited States To ensure their validity. these estimates have been derived by ustng data from multiple sources. including the neva established Foodhorne Diseases .'\Clt\‘(‘ Surveillance Network tFoodNet). The figures presented Manh 2000 - Environmental Health 9 include estimates for specific known pathogens. as well as overall estimates for all causes of foodborne illness. known. unknown. infectious. and noninfectious. Data Sources Data sources for this analysis include the 00' Foodborne Diseases Active Surveillance wz Network (Foothetl (oi, the National 003 Notiliable Disease Surveillance System (7). W the Public Health laboratory lnfonnation “5.0 W M System t8). the Gulf Coast States Vibrio “5' B i Surveillance System (9*. the Foodborne ' , . Disease Outbreak Surveillance System (10}. MRI-“5’3 W m the National Ambulatory Medical Care 005.0 Survey ill). the National Hospital 00$...”53 Ambulatory Medical Care Survey (ll-H). m M the National Hospital Discharge Survey US), the National Vllfll Statistics System ( lb). and selected published studies. [Established In [9%, FoodNet is a collabo- rative effort by the Centers for Disease Control and Prevention. the US. Department of Agriculture. the CS Food and Drug Administration. and selected state health departments. Foodth conducts active stir- veillance for seven bacterial and two parasitic foodbome diseases within a defined popula- tion of 20.5 million Americans to), Additional surveys conducted within the FoodNet catchment area provide informa- tion on the frequency of diarrhea in the gen- cral population. the proportion of ill persons seeking care. and the frequency of stool cul- turing by physicians and laboratories for selected foodbome pathogens. The National Notifiable Disease Surveillance System (7) and the Public M07 Health laboratory Information System (8) “69,000,. collect passive national surveillance data for a m, wide range of diseases reported by physicians s” 9 and laboratones. The Gulf Coast States V'ibrio ' Surveillance System collects reports of Vibno infections from selected states (9). and the 00” (Sindhi: 007.0. 0011-0073 000.00. 000.09 Other Protozoa! Intestinal Infections ttise. Botandiia' ' mli int:ka E. at Enterotaiguk E. «if Emmian E. (of Enmhemrrtiagk E. ali We»! l'em'tu'a Misc. Bacterial loath: 000.0l 000.01 000.03 000.04 000.43 000.64 000.4l-2. W01”. 000.5 000.“ 000.62 000.63 000.64 000.65 000.66 Foodborne Disease Outbreak Surveillance System receives data from all states on recog- nized foodborne illness outbreaks (defined as two or more cases of a similar Illness result- ing from ingestion of a common food) (10). As components of the National Health Care Survey. the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey measure health care use in various clinical settings. including physician offices and hos- pital emergency and outpatient departments (ll-l4). These surveys collect information 10 Environmental Health ' March Ml) on patient characteristics. patient symptoms or reasons for visit. provider diagnosis. and whether the patient was hospitalized. Up to three symptoms are recorded usrng a stan- dard classification (17). and up to three provider diagnoses are recorded according to the lntemational Classification of Diseases. 9th Revision. Clinical Modifications thD-9- CM) (18) (Table l). The National Hospital Discharge Survey. another component of the National Health Care Survey. is a representative annual sam- ple of discharge records from approximately 475 nonfederal short-stay hospitals ( l 5). The information collected includes up to seven princtpal discharge diagnoses classified by ICI).9-(IM codes (18). Because these data include information on condition at dis. charge, they can be used as a source of infor- mation on in-hospital deaths, Additional information on food—related deaths was obtained from the National Vital Statistics System. which collects death cenificate data on causes of death classified by 3- or 'i-dlgll lCD-9 codes (16). lti addition to information front these for- mal surveillance systems, we used data from two pttblished population-based studies. The Tecumseh study was conducted from 1965 through 1971 in 850 households in Tecumseh. Michigan. with an emphasis on households with young children (19). Households were telephoned weekly to iden- tify incident cases of self-defined diarrhea. vomiting. nausa. or stomach upset. The Cleveland study was conducted among a selected group of 86 families followed from 1948 through 1957 (20). A family member recorded occunences of gastrointestinal ill- nesses and associated symptoms on a month- ly tally sheet. Both studies also collected information on extraintestinal illnesses (e.g.. respiratory illness). Other studies with simi- lar designs were not included in our analysis. either because they were relatively small or because they did not provide information on the desired endpoints. The Study Food-Related Illness and Death from Known Pathogens Total Cases To estimate the total number of foodbome illnesses caused by known pathogens. we determined the number of reported cases for each pathogen. adjusted the figures to account for underreponing. and estimated the proportion of illnesses specifically attrib- utable to foodbome transmission. Although data from various periods were used. adjust- ments for changes in population size had minimal effect on the final estimates and were therefore omitted. Cases may be reported in association with documented foodbome outbreaks. through passive surveillance systems (e.g.. the National Notifiable Disease Surveillance System. the Public Health Laboratory lnforrnation System). or through active sur- veillance systems (e.g.. FoodNet). Sporadic illness caused by some pathogens (e.g.. Bacillus ccretts. Clostridium perjringens. Staphylococcus auretts) is not reportable through passive or active systems; hence. the only cases reported are those related to out- breaks. For these pathogens. we have assumed that if diagnosed sporadic cases were reported. the total number would be 10 times the number of outbreak-related cases. This multiplier is based on experience with pathogens for which data are available on both sporadic and outbreak-associated cases (e.g.. reported cases of Salmonella or Shigella. Table 2). For all pathogens. the number of outbreak-related cases was calculated as the average annual number of such cases report- ed to CDC from 1983 to 1992. the most recent years for which published outbreak data are available. For pathogens also under passive surveillance. we used the average number of cases reported to CDC from 1992 through 1997. and for pathogens under active surveillance through FoodNet. we used the average rate observed for the sur- veillance population from l996'to 1997 and applied this to the total 1997 U.S. population (with some modification for E. coli 0157:H7; Appendix). Irrespective of the surveillance system. many cases of foodbome illness are not reported because the ill person does not seek medical care. the health-care provider does not obtain a specimen for diagnosis. the lair oratory does not perform the necessary diag- nostic test. or the illness or laboratory find- ings are not communicated to public health officials. Therefore. to calculate the total number of illnesses caused by each pathogen. it is necessary to account for underreponing. i.e.. the difference between the number of reported cases and the num- ber of cases that actually occur in the com- munity. For Salmonella. a pathogen that typ« ically causes nonbloody diarrhea. the degree of underreponing has been estimated at ~38 fold (Voetsch. manuscript in preparation) (21). For E. coli 01572H7. a pathogen that typically causes bloody diarrhea. the degree of underreponing has been estimated at ~20 fold (22). Because similar information is not available for most other pathogens. we used a factor of 38 for pathogens that cause pri- marily nonbloody diarrhea (e.g.. Salmonella. Campylobacter) and 20 for pathogens that cause bloody diarrhea (e.g.. E. coli OlS7:H7. Shigella). For pathogens that typically cause severe illness (i.e.. Clostridium botulinum. Listeria monocytogerrcs). we arbitrarily used a far lower multiplier of 2. on the assumption that most cases come to medical attention. Details of the calculations for each specific pathogen and rationale are provided in the Appendix. Where information from both active and passive reporting was available. we used the figure from active surveillance when estimating the total number of cases. Having estimated the number of cases caused by each pathogen. the final step was to estimate for each the percentage of illness attributable to foodbome transmission. The total number of cases was then multiplied by this percentage to derive the total number of illnesses attributable to foodbome transmis- sion. The rationale for each estimate is pre- sented in the Appendix; although precise percentages are generally difficult to justify. in most instances there is ample support for the approximate value used. Results are presented in Tables 2 and 3. Known pathogens account for an estimated 38.6 million illnesses each year. including 5.2 million (13%) due to bacteria. 2.5 mil- lion (7%) due to parasites. and 30.9 million (80%) due to viruses (Table 2). Overall. foodbome transmission accounts for 13.8 million of the 38.6 million illnesses (Table 3). Excluding illness caused by Listeria. Toxoplasma. and hepatitis A virus (three pathogens that typically cause nongastroin- teStinal illness). 38.3 million cases of acute gastroenteritis are caused by known pathogens. and 13.6 million (36%) of these are attributable to foodbome transmission. Among all illnesses attributable to foodbome transmission. 30% are caused by bacteria. 3% by parasites. and 67% by viruses. Hospitalizations To estimate the number of hospitalizations due to foodbome transmission. we calculat- ed for each pathogen the expected number of hospitalizations among reported cues by multiplying the number of reported cases by pathogen-specific hospitalization rates from FoodNet data (23.24). reported outbreaks (10.25). or other published studies (Appendix). Not all illnesses resulting in hospitalization are diagnosed or reported. Health-care providers may not order the nec- essary diagnostic tests. patients may have already taken antibiotics that interfere with diagnostic testing. or the condition leading to hospitalization may be a sequela that develops well after resolution of the actual infection (e.g.. Campylobacter-associated Guillain-Barré syndrome). Therefore. to account for underreponing. we doubled the number of hospitalizations among reported cases to derive for each pathogen an estimate of the total number of hospitalizations. Finally. we multiplied this figure by the pro- portion of infections attributable to food- bome transmission. Because of gaps in the available data. this approach could not be used for some parasitic.and viral diseases (Appendix). Overall. the pathogens listed in Table 2 cause an estimated 181.177 hospitalizations each year. of which 60.854 are attributable to foodbome transmission (Table 3). Excluding hospitalizations for infection with Listeria. March 2000 - Environmental Health 1 1 Reported and Estimateda Illnesses. Frequency of Foodborne Transmission, and Hospitalization ‘ and Case-Fatality Rates for Known Foodborne Pathogens, United States 1 Estimated RWWW“ C3595 °/o Case Total by SU'Veillance TYPE Foodborne Hospitalization Fatality 1 Disease or Agent Cases Active PJSSiVe Outbreak Transmission Rate Rate ‘ Bacterial i Baal/us (mus 27.360 720 72 IM 0.006 0.0000 \ Botulism. Foodbome 58 29 I00 0.800 0.0769 Brute/la spp. [.554 Ill 50 0.550 0.0500 Campy/abort" spp. 2.453. 926 64.5 77 37.496 I46 80 0. l 02 0.00 I 0 (lasmdium perfringent 248.520 6.540 654 I00 0.003 0.0005 Escherichia coll 0|57:ll7 73.480 3.674 2.725 500 85 0.295 0.0083 5. coll. Non-0l57 STE( 36.740 [.837 85 0.295 0.0083 E. (all. Entetotoxigenic 79.420 2.090 209 70 0.005 0.000l E. (oli. Other Diarrheogenit 79.420 2,090 30 0.005 0.000l ; Listeria monocyrogenes 2.5/8 [.259 373 99 0.922 0.2000 ‘ Salmonella Typhib 824 4l2 80 0.750 0.0040 Salmonella. Nontyphoidal /.4IZ.498 37,I7I 37.842 3.640 95 MN 0.0078 ‘ Shigella spp. 448.240 22.4/2 l7.324 L476 20 0.l39 0.00I6 3 Staphylococcus Food Poisoning l85.060 4.870 487 [00 0.l80 0.0002 i Streptotottus. Foodborne 50, 920 l. 340 I 34 [00 0| 33 0.0000 1 l’ibn‘o cholene. loxigenit 54 27 90 0.340 0.0060 9. vulnilicus 94 47 50 MW 0.3900 Vibn'o. Othei 7.880 393 I ll 65 0. I 26 0.0250 lemma enterotolilia 96.368 2.536 90 0.242 0.0005 1 Subtotal 5.204.934 ’ Parasitic Cryptospofidium parvum 300.000 6.630 2.788 M 0.l50 0.005 ‘ [ydospora ayennemi: 10,204 420 90 90 0.020 0.0005 Glardi'a lamb/i: 2.000.000 707.000 22.907 I0 n/a n/a loxoplaima gondii 225.000 |5.000 50 n/a n/a Iridiinella spiral/'5 52 26 |00 0.08I 0.003 . Subtotal 2.54l.3l6 } Viral Norwalk-lilte Viruses 23,000,000 40 n/a n/a Rouvirus 3,900,000 I nla n/a Astrovirus 3,900,000 7 n/a 01: l Hepatitis A 83.397 27.797 5 0| 30 0.0030 i Subtotal 30,003,391 Grand Total 38,629.64! 1Number; In «talus in estimates; others are measured. b>707. ol (am atqmred abmd. 12 lm lini‘nu'l‘ln. lit-.allh - \ltinlt Ill" WBLE if* i—_' ‘ Estimated Illnesses. Hospitalizations. and Deaths Caused by Known Foodborne Pathogens, United States Illnesses Hospitalizations °/. 0! Total ' °/. 0! Total ' 7 ' 73/; of Total ' Disease or Agent Total Foodbome FOOdbOI'M 1 Total Foodborne FOOdbON‘Ie Total Foodborne FOOdbOme Bacterial Baal/u: (mus 27.360 27.360 0.2 8 8 0.0 0 0 0.0 Botulism. loodborne 58 58 0.0 46 46 0| 4 4 0.2 Brucella spp. L554 777 0.0 I22 6| 0| || 6 0.3 | Campy/063cm spp. 2.453.926 |.963.|4l l4.2 l3.|74 |0.539 I73 I24 99 5.5 1 (lostnd/um perfiingem 248.520 248.520 |.8 4| 4| 0| 7 7 0.4 ‘ [schen'rhia (all 0|571||7 73.480 62.458 0.5 2.l68 L843 3.0 6| 52 2.9 6. (all. Non-0|57 STEC 36.740 3|.229 0.2 L084 92| |.5 30 26 l.4 [. (all. Enterotoxigenic 79.420 55.594 0.4 2| l5 0.0 0 0 0.0 E. (all; Other Dianlieogenic 79.420 23.826 0.2 2| 6 0.0 0 0 0.0 ‘ listed: monoqtogene: 2.5l8 2.493 0.0 2.322 2.298 3.8 504 499 27.6 1 Salmoner Typhi 824 659 0.0 6|8 494 0.8 3 3 0| Salmonella. Nontyphoidal |.4l2.498 |.34l.873 9.7 l6.430 l5.608 25.6 582 553 30.6 | Shigella spp. 448.240 89.648 0.6 6.23l L246 2.0 70 I4 0.8 ‘ Stair/locum: Food Pointing |85.060 |85.060 L3 L753 L753 2.9 2 2 0| Streptococcus. Foodborne 50.920 50.920 0.4 358 358 0.6 0 0 0.0 l’lbrlo (ho/em. Toxigenic 54 49 0.0 l8 l7 0.0 0 0 0.0 1 V. vulnificus 94 47 0.0 86 43 0| 37 I8 |.0 Vibn'o. Othet 7.880 5.|22 0.0 99 65 0| 20 I3 0.7 1 ‘ Yminia enterwolirita 96.368 86.73l 0.6 L228 |.|05 L8 3 2 0| Subtotal 5.204.934 4.|75.565 30.2 45.826 36.466 59.9 L458 L297 7|.7 Parasitic Cryptosporidium panum 300.000 30.000 0.2 L989 I99 0.3 66 7 0.4 (ydospora (ayeranensis l6.264 H.638 0.| I7 l5 0.0 0 0 0.0 Giardia lamb/i2 2.000.000 200.000 H 5.000 500 0.8 W | 0.l Iaxoplasma gondii 225.000 “2.500 0.8 5.000 2.500 4.| 750 375 20.7 i lrkhinella spin/is 52 52 0.0 4 4 0.0 0 0 0.0 ‘ Subtotal 2.54l.3l6 357.|90 2.6 |2.0|0 3.2l9 5.3 827 383 2|.2 Viral Norwalk-like Viruses 23.000.000 9.200.000 66.6 50.000 20.000 32.9 3l0 |24 6.9 Rouvirus 3.900000 39.000 0.3 50.000 500 0.8 30 0 0.0 Astwvirus 3.900.000 39.000 0.3 |2.500 |25 0.2 l0 0 0.0 Hepatitis A 83.39l 4.|70 0.0 |0.84| 90 0.9 83 4 0.2 Subtotal 30.833.39l 9.282.|70 67.2 |23.34| 2|.l67 34.8 433 I29 7.l Grand Total 38,619.64I I3,8|4.924 |00.0 I8l.|77 60.854 l00.0 2.7I8 |.809 l00.0 lovopliisiittr and hepatitis .1\ virus. “8013 hospitalizations for acute gastroenteritis are caused bv ktiowii pathogens. of which 33.3l.’ 04%) are attributable to loodborne transmission Overall, bacterial pathogens account for 60“» of hospitalizations attribut- able to loodborne transmission. parasites for 3%. and viruses for 34%. Deaths like illnesses and hospitalizations. deaths are also underreported. l’recise information on food-related deallis Is espectallv dilliciill to ohtain because pathogen-specilic surveil- lance svstems rarelv collect inlorinatioii on illness outcome. and outcome-specilie stir- veillance systems leg. death certilieatesl grosslv underreport manv pathogen-specific conditions. To estimate the number of deaths due to bac terial pathogens. we used the same approach described for hospitalizations: first calculating the iitiiiiber ol deaths among reported cases. then doubling this figure to account lor unreported deaths. and liiiall) niiiltiplving bv the percentage ol infections attributable to loodboriie transmission. :\s with hospitalization. this approach could not be Used lor some parasitic and viral diseases. Overall. the specilied pathogens cause an estimated 2.718 deaths each vear, of which 1.809 are attributable to loodborne transmis- sion i'lable 3i [Excluding death due to l.l\lt'lltl. lilulpltlwlltl. and hepatitis A virus. the number of deaths due to pathogens that cause acute gastroenteritis is 1.381, ol which 03] IoT‘XVi are attributable to loodborne transmission Bacteria account lor 72‘?» of deaths associated witli loodhorne transmis- sion. parasites lor ll‘To. and viruses [or 7% l‘l\‘t‘ pathogens account lor over 90“,“ of esti- mated food-related deaths: Salmonella 01‘7an l,l,\l(‘lltl (28%|. lovoplusmu (ll‘lol. Norwalk-like viruses tT‘i‘M. (ttnipvlohiittei [Skill and F ioli 0137,”? I. B‘va. Food-Related Illness and Death from Unknown Pathogens Some proportion ol gastrointestinal illness is caused bv loodboriie agents not yet identi- lied. This conclusion is supported hv well- documented loodborne outbreaks of distinc- tive illness lor which the causative agent remains unknown keg. Braiiierd diarrhea) not. by the large percentage of loodborne outbreaks reported to (DC lor which no pathogen is identified 123). and hv the large number of new loodboriie pathogens identi- lied in recent vears To estimate food-related illness and death lroiii unknown pathogens. we used svmp- tom-based data to estimate the total number of acute gastrointestinal illnesses and then subtracted from this total the nutnber ol cases accounted for bv known pathogens: this dillereiice represents the illness due to acute gastroenteritis of unknown etiology lo determine how much of this illness was due to loodhorne transmission. we used the per— centages of loodhorne transmission as deter- mined above [or acute gastroenteritis caused by known pathogens. Total (mes To determine the rate ol acute gastroenteritis in the general population. we used data on the frequency of diarrhea from the [9% to 1097 lioodNet population survev lhis sur- vev did not collect data on the rate of vomit- ing among persons without diarrhea, howev- cr. so we relied on the 'lecumseh and (level-and studies lor inlorinaiion on the he— qiiencv ol this svinptoin. Because voting chil- dreii were overrepresented iii the leciimseh .iiid (‘leveland studies relative to the current [25. population. rates of illness for these studies were age-adiusted l'or the leciiiiiseh data. we Used the reported age- and svmps tom-specilic rates lor the ('leveland studv. we itsed the method described bv (varthright (-7! to derive an overall age-adjusted rate of gastrointestinal illness. we then multiplied this rate by the relative lrequeiicv of s_\nip- totiis to derive age-adjusted rates lor specilic svmptoms. In the two-«)7 lioodNet population sur- vey; the overall rate ol diarrhea was l-l episodes per person per vear. and the rate of diarrheal illness delined as diarrhea l 3 loose stools per 24-hour periodl Listing >l do or interfering with normal activities, was 073 episodes per person per year lll lleriksiad, manuscript in preparationi. We used the lower 0.73 rate lor our analysis To this we added the average age-adiusted rate of win iting without diarrhea lrom the Tecumseh and Cleveland studies (0.30. l'alile 4" to deriie an overall estitiiate ol 1 05 episodes per person per year ol acute gastrointestinal illness characterized bv diarrhea. vomiting. or both Previous studies have shown that some cases of acute gastrointestinal illness are accompanied bv respiratorv suitptoms: although the catises ol these illnesses are generally unknown. such cases have tradi- tionall) been attributed to respiraton pathogens 0.0.27] Data on the lrequencv ol concomitant respiratorv svniptoiiis were not collected in the 1990-07 lioothet stirvev but were 20% to 27% among patients with acute gastroenteritis in the 'l‘ecuniseh and ('leveland studies 'llierelore. we adiustcd downward our estimate of acute gastroen- teritis hv 23% \‘telding a final estimate of 0.70 HUS X 0 73) episodes ol acute gas- troenteritis per person per vear lixtrapolated Frequency of Gastrointestinal Illness in the General Population. in Episodes per Person per Year, as Determined by Three Studies FoodNet Population Survey Symptom Diarrhea or Vomiting Diarrhea. Any Diarrhea Mthout Vomiting Diarrhea With Vomiting Vomiting Without Diarrhea 7 14 lm ironmental lletilth - .\l.irrli lull) {cite Actuated Tecumseh Study (rude Age Admired Cleveland Study (rude Age ,lditisted c to a population of 267.7 million persons. the US. resident population in 1997 (28). this rate is equivalent to 211 million episodes each year in the United States. As determined previoust 38.3 million of these 211 million episodes of acute gastroen- teritis are attributable to known pathogens. A small proportion of the remaining 173 mil- lion episodes can be accounted for by known. noninfectious agents (e.g.. mycotox- ins. marine biotoxins); however. most are attributable to unknown agents. Because we cannot directly ascertain how many of these illnesses of unknown etiology are due to foodbome transmission. we used the relative frequency of foodbome transmission for known pathogens as a guide. For illnesses of known etiology. foodbome transmission accounts for 36% of total cases. Applying this percentage yields an estimate of 62 million cases of acute gastroenteritis of unknown eti- ology (36% of 173 million) due to foodbome transmission each year. Hospitalizations The National Ambulatory Medical Care Survey/National Hospital Ambulatory Medical Care Survey data were searched for visits due to symptoms of diarrhea, vomiting. or gastrointestinal infection (reason for visit classification (RVC) codes 1595. 1530. 1540) (17) and for visits resulting in a diagnosis of infectious enteritis (lCD-9-CM codes 001- 0093; Table 1). Visits associated with respi- ratory symptoms (RVC codes 1400-1499) or a diagnosis of influenza (lCD-9-CM code 487) were excluded. Data for the years 1992 to 1996 were combined before analysis. Overall. these criteria yielded an average of 15810905 visits annually from 1992 through 1996. of which an average of 1.246.763. or 7.9%. resulted in hospitaliza- tion. This figure is equivalent to a rate of 4.7 hospitalizations per 1000 person-years. The National Hospital Discharge Survey data were searched by using diagnostic codes for infectious gastroenteritis of known cause (1CD-9-CM codes 001-008; Table l), with the exception of the code for Clostridium dif- ficilc colitis (ICD9 008.45), a common form of nosocomially acquired diarrhea. In addi- tion. we included the nonspecific lCD-9-CM diagnosis codes 009 (infectious gastroenteri- tis) and 558.9 (other and unspecified nonin- fectious gastroenteritis and colitis). Despite the description. many of the illnesses attrib- uted to lCD-9-CM code 558.9 are likely to be either infectious or due to agents possibly transmitted by food. For example. in the absence of laboratory testing. sporadic cases of viral gastroenteritis may be coded as 558.9. Under the previous [CD-8 classifica- tion. these same cases would have been assumed to be infectious and coded % 009 (29.30). Data for the years 1992 to 1996 were weighted according to National Center for Health Statistics criteria and averaged to derive national estimates of annual hospital- izations. Records with a diagnosis of respira- tory illness were not excluded because of the high incidence of respiratory infections among hospitalized patients. Considering all listed diagnoses. the National Hospital Discharge Survey data for the years 1992 to 1996 yielded an annual average of 616.337 hospital discharges with a diagnosis of gastrointestinal illness. Included in this figure are 193.084 cases of gastroen- teritis with an identified pathogen and an additional 423.293 cases of gastroenteritis of unknown etiology (Table 5). Converted to a rate. the total number is equivalent to 2.3 hospitalizations per 1.000 person-years. Because these data depend on the recording of a diagnosis and not just a symptom. it is likely that they underestimate the rate of hospitalization for acute gastroenteritis. This view is supported by FoodNet population survey data indicating a rate of approximate- ly 7.2 hospitalizations per 1.000 person- years for diarrheal illness (H. Herilcstad. manuscript in preparation). These data were not included here because they omit hospi- talizations for vomiting alone and are not easily adjusted for concomitant respiratory symptoms. Averaging the rates from the National Ambulatory Medical Care Survey/National Hospital Ambulatory Medical Care Survey and National Hospital Discharge Survey yields a final estimate of 3.5 hospitalizations per 1.000 person-years. equivalent to 936.726 hospitalizations annu- ally for acute gasuoenteritis. As noted previ- ously. 163.153 of these hospitalizations can be attributed to known causes of acute gas troenteritis. yielding an estimated 773,573 hospitalizations for acute gastroenteritis caused by unknown agents. Applying the rel- ative frequency of foodbome transmission as determined for known pathogens yields an estimated 263.015 hospitalizations (34% of 773.573) for acute gastroenteritis due to foodbome transmission of unknown agents. Deaths Multiple-cause-of-death data (16) and infor- mation on in-hospital~death data (National Hospital Discharge Survey) were used. lCD- 9-CM codes 001-008 were employed to iden- tify deaths due to diagnosed infectious gas- troenteritis and 1CD-9-CM codes 009 and 558 to identify deaths due to gastroenteritis of unknown etiology. Death certificate data for the years 1992 to 1996 yielded an annual average of 6.195 total deaths. of which 1.432 (23%) were due to specific causes of gastroenteritis and 4.763 (77%) to undiagnosed causes of gastroenteri- tis. For the same years and 1CD-9-CM codes. the average annual in-hospital deaths for all- listed diagnoses totaled 6.608. of which 1.460 were due to specific and 5.148 (77%) undiagnosed causes of gastroenteritis (Table 5). Averaging the totals for all causes from death certificate and National Hospital Discharge Survey data and adjusting to the 1997 US. census estimates. we estimated that gastroenteritis contributed to the death of 6.402 persons in the United States in 1997. A total of 1.386 of these deaths can be explained by known causes of acute gas- troenteritis (see above). Thus an estimated 5.016 deaths from acute gastroenteritis are caused by unknown agents. Applying the rel- ative frequency of foodbome transmission as determined for known pathogens yields an estimated 3.360 deaths (67% of 5.016) due to acute gastroenteritis caused by foodbome transmission of unknown agents. Overall Food-Related Illness and Death We summed illness attributable to foodbome gastroenteritis caused by known and unknown pathogens. yielding an estimate of 76 million illnesses. 318.574 hospitaliza- tions. and 4.316 deaths. Adding to these fig- ures the nongastrointestinal illness caused by Listeria. Toxoplasma. and hepatitis A virus. we arrived at a final national estimate of 76 million illnesses. 323.914 hospitalizations. and 5.194 deaths each year (Figure 1). Conclusions The nature of food and foodbome illness has changed dramatically in the United States over the last century. While technological advances such as pasteurization and proper canning have all but eliminated some dis- use. new causes of foodbome illness have been identified. Researchers have used vari- ous methods to estimate the illnesses and deaths due to foodbome diseases in the United States. in 1985. Archer and Kvenberg coupled information on underreponing of salmonellosis with data on other foodbome pathogens to derive estimates of 8.9 million Marth 2M) ° Environmental Health BLE 5 Average Annual Hospitalizations and Deaths for Gastrointestinal Illness by Diagnostic Category, National Hospital Discharge Survey, 19924996 (ause of Ento‘illls‘] Bacterial (Dill-005. moon) Viral (008.6-008.8) Parasitic (mom Urian Etiology (009. 558.9) Total Irma Code “txmuummmsuwtiu illnesses due to known pathogens and 24 million to 81 million illnesses dtte to all ioodborne agents (2) In 1087, Bennett et a1. computed incidence iigures ior all known infectious diseases and determined the pro- portion oi each dtie to various modes of transmission. Summing these iigures, they concluded that ioodborne transmission oi known pathogens caused it 5 tiiillioii illness- es and up to 0.000 deaths each year t3]. in 1030. Todd used a coiiihinatioii oi methods. including extrapolation iroiii (Zanadian stir- \eill.ince data. to derive an estimate oi 12 3 million ioodborne illnesses and 522 related deaths each vear‘ Ht l‘inally. in 1994. a task ( (Louneil ior .\gl‘l\lllllll’dl Science and lechnology t( A51 1 lorie com cited bv the rev iew ed available studies and estimated the overall number oi food-related illnesses at 35 million cases per year t3". lliese various esti- niates oiteii reicr to diiierent entities. The estimates oi 0.3 million and 8.0 million reier to illness caused by known pathogens. w hercas the estimate oi 33 million reiers to all causes oi ioodborne illnesses. known and unknown. inieciious and noniniectious. Our estimates are based on data iroiii a wide variety oi sources and dtiier iroiii previ. ous estimates in several respects. For known pathogens. our estimate oi 13.8 million lll' nesses per vear is substantially higher titan the previous estimates oi b 3 million and 8 \) million (2.3). an increase attributable largely to our inclusion oi ioodborne illness caused by Norwalk-like viruses l‘or ioodborne ill- ness oi all etiologies. otir estimate oi 7b inil- hon illnesses is within the range proposed by lni imnrnental Ilealth ° \larth am 16 First Diagnosis Hosptalizaticrii Deaths 21,931 m" 32m tih 2.806 021’ mm m" 299.419 um .\rclter and Kvenberg ill but considerably higher than the point estimate oi 33 million presented in the (A81 report t5]. Both our estimate and the ('.-\.\T estimate assume that ioodborne transmission accounts ior ~33‘.‘~ oi acute gastroenteritis cases caused by unknown agents. The disparity between the two stems irorii diiierences iii the estimated annual frequency oi acute gastroenteritis overall: 211 million cases for otir estimate. W million ior the (A51 estitnate Whereas otir estimates oi illness are gener- ally higher than those oi previous studies, otir estimates oi death are generally lower. \\'e estimate that ioodborne illness causes 3020 deaths annually t 1.810 deaths due to known pathogens and 3.210 deaths dtie to unknown agents]. a total that is slightly more than hall the 0.000 deaths estimated by Bennett et a1, (3). lhe Bennett estimate includes 2.100 deaths due to cainpylobaete- iiosis, 1.200 deaths due to staphylococcal iood poisoning. and 1.000 deaths due to trichinosis our total ior all three oi these dis— eases is 101 deaths, Our estimated case-iatal- ity rates ior several other diseases are also lower than those used in the Bennett report. either because better data are available or perhaps because treatment has improved. Our analysis suggests that unknown agents account ior approximately 81% oi ioodborne illnesses and hospitalizations and h‘i‘kr oi deaths. Among cases oi ioodborne ill- ness dtte to known agents. Norwalk-like viruses account ior over 67‘?" oi all cases. 33% oi hospitalizations. and 7‘?“ oi deaths '1 he assumptions underlying the Norwalk- Hciizitalizatci'is Deatl‘s $4.953 i.l39 32.332 mb 5.199 in" 423.29} 5.148 616.37? All Diagnoses 6.608 . like viruses ligures are among the most diiii» cult to veriiy. and these percentages should be interpreted with caution t.-\ppendi.vZ-. Other important causes oi severe illness are Salmonella and (“nip-\it'iltlllt‘l. accounting ior 20% and 17“» oi hospitalizations, respec- tively lhe leading causes oi death are salmonella. i.l\lt'lltl, and loxopltisniu. which together account ior 1.427. or more than 75% oi ioodborne deaths caused by known pathogens. Many oi the deaths due to tow- plasmosis occtir in Hi\'—iniected patients; recent advances in HIV treatment may greab 1y reduce deaths dtic to toxoplasinosis. 0| necessity. our analysis entails a number oi assumptions. The iirst maior assumption concerns the degree oi underi‘elmrting Well- docuineiited estimates of underreporting are not available ior most pathogens; tiiereiore. we relied on multipliers derived ior salmo- nellosis and other diseases For salmonel- losis, the multiplier oi 38 has been indepen- dently derived by investigators in the [tilted Slates using diiierent data sources. The L5. l'igure is ll\'t‘ to teniold higher titan multipli- ers ior .Salmoiiellu and Ctinipilolxuter recent- ly derived in Great Britain (31'! However. this diiierence is nearly or w holly oiiset by far higher per capita rates of reported inieetions in (-reai Britain, Nevertheless, when extrapo~ lated to other pathogens. these multipliers may result iii under- or overestimates, and clearly studies such as those conducted ior Salmonella are needed to develop better niul- tipliers ior these other diseases. However. in our analysis, changing the multipliers ior individual diseases has a minimal eileet on the overall estimate of foodborne illness. Our second set of assumptions concerns the frequency of foodbome transmission for individual pathogens. We have used pub- lished studies when available. but these are rare. As with underreporting multipliers. errors affect estitnates for individual pathogens but have minimal effect on the estimate of overall illness and death froin foodbome diseases. The one notable excep- tion is the estimate for Norwalk-like viruses. Because these viruses account for an espe- cially large number of illnesses. changes in the percentage attributed to foodbome trans- mission have a major effect on our overall estimates. For example. if the actual number of infections due to foodborne transmission were 30% rather than 40%. the overall esti- mate would decrease from 76 million to 63 million illnesses per year. Interestingly. our overall estimate is influenced far less by the Norwalk-like virus case estimate itself. It would require a lOO-fold reduction in the estimated number of Norwalk-like virus cases to reduce the overall estimate from 76 million to 63 million. A third assumption concerns the frequen- cy ofacute gastroenteritis in the general pop- ulation. The rate we used is based in part on recent data from the FoodNet population survey. a retrospective survey involving more than 9000 households. The overall rate of diarrhea as recorded by the survey was 1.4 episodes per person per year; however. we used the survey's far lower rate of 075 episodes of diarrheal illness per person per year. Furthermore, we limited our definition of acute gastroenteritis to symptoms of diar- rhea or vomiting and reduced the rate to account for concomitant respiratory symp- toms. As a result. our final assumed rate of 0.79 episodes of acute gastroenteritis per person per year is very similar to respiratory- adjusted estimates derived from the prospec- tively conducted Tecumseh (0.74) and Cleveland (0.71) studies (27). All three stud- ies are based on household sun‘eys, and thus the rates of illness are not influenced by Estimated Froquency of Foodborne Illness In the United Sum km W 2|l.000.000 than: changes in health-care delivery. Compared with rates of diarrheal illness from studies conducted in Great Britain. our estimated rate is higher than in one recent study (31) but lower than another (32). In addition to these assumptions. our analysis has several limitations Differences in available surveillance information pre- vented us from using the same method to estimate illness and death from bacterial, parasitic. and viral pathogens. Furthermore. because of a paucny of surveillance informa- tion. we did not include specific estimates for some known. occasionally foodhorne pathogens (e.g.. Plesiomomts, Aeromonus, or Edwardsiella). nor did we develop speCIfic estimates for known noninfectious agents. such as mushroom or marine biotoxins. met- als. and other inorganic toxins. However. many of these agents cause gastroenteritis and are therefore captured iii our overall estimate of foodhorne illness. With the exception of a few important pathogens (Appendix). we have not estimated the num- uupiuiimim 931.000 0min 6.400 .\lanh 2000 - Environmental Health her ol cases ol chronic sequelae. although these may he part ol the overall burden ol loodhorne diseases l'inalh: future research “'1” reline our assumptions aitd allow lor more precise estimates Methodologic dillerences between our aiialtsis and prt‘\‘l(tltsl_\' piihlished studies make it dilltcult to dra“ ltrm conclusions regarding overall trends in the incidence ol loodhorne illness In general, the dillerences hetueeii our estimates and previouin pub- lished ligures appear to he dtie primarily to the availahiliu ol hettei‘ information and new anal\ scs rather than real changes in disease lrequencv over time. lior example. If (Ull 0137:”? “as estimated to cause [0.000 to 20.000 illnesses annually. based on studies ol patients \isitiitg a physician lor diarrhea, Recent l‘ood\et data have allowed a more detailed estimation ol mild illnesses itot resulting in ph_\ sician consultation, Our esti- inate ol iiearh 74,000 illnesses per year incorporates these milder illnesses and should not he iinseonstrued as demonstrat- ing a recent increase in If. (Ull OISTVHT llllk'kllolls, \Vhatever the limitations on ret- rospective L'Olnparhnlts. the estimates pre» sented here pionde a more reliable hench- niaik \s‘ith “'lllt‘ll to ludge the ellecliveness ol ongoing and luture prevention ellorts. l’urther relinements ol loodhorne disease estimates \\lll require continued and improved active slll‘H’lll'Jllt't‘ Beginning iii NOS. the t-oodNet population sur\'e\ was modilied to capture cases ol vomiting not associated “till diarrhea; lunher enhance- ment to capture concomitant respiratory symptoms should reline the l'oodXet survey data. lixpansion ol laboratory diagnostic capacity could lead to better detection ol cer- tain pathogens. estimates ol tlte degree ol underreporting lor additional diseases. and estimates ol the proportion of specilic dis- eases transnntted throuin lood. lleightened surveillance lor acute. noninfectious lood- horne diseases. such as mushroom pms‘oinng and otlter illnesses caused by hiotoxrns. could lurther improve estimates ol illness and death from loodhorne llllls‘ss, Emergency department-hased surveillance systems l Bl or poison control center-based suneillance might provide such inlormation, l‘llmll)’. identifying llL‘\\ causes of enteric lll‘ ness and delining the public health impor- tance ol known agents leg” enteroaggrega» live l? iolil would improve loodhorne dis— ease prevention ellorts. a 18 liuiroiinieiital lIi-altli ' \lartli lllll Acknowledgements: 'i‘. :l:.:i:l: .' ml legal tit-ti: flail litumm l-I':':i.‘v li' Pentium: i'x' igri l-Lm .' \lzt't; \ti a. ': Min ‘5 MJHh Path 1, .'\.‘.:il \i-.:".li -i-. lr'ri‘ la" i'ilcdt" and tn 'ti"."l‘.'l1i'tt\ maxi. ix :5 1 .i ,i’ll"l7i l’fx Corresponding Author: llaal \ ‘rl-.;.l Donut": ' l‘idtfr,"‘...'i tiv:.l ‘dzr In ."N l.ti‘i'!\ f." {Inner (t’llc'lt‘tl ital l’lyi. 'Ili tr ‘.i’a'.i my US, 31-.‘0 t lz'r'or: ll. .ia’, ,iti'..r:_'.., (Ll. ic‘iil l \l. 'at Ji‘érri‘l 3.1“. rental y'Wa‘lw‘dti To save valuable resources, please notify us even in the event that you do not wish to renew your membership. This will allow us to cancel your automatic expiration and renewal reminders, conserve resources, and spare you the annoyance of mail you do not wish to receive! Iokes Needed! Original humorous stories, jokes, quotes or cartoons concerning food protection are needed for publication in the F000 emionnlenl news dodges! !! (Please be sure to note the source so that proper credit may be given.) ltanything made you laugh today, please write it down and send it in! Submission should be sent to the attention of Julie Collins via fax at (303) 69l»9490, email at <jcol|ins@neha.org>, or regular mail at NEHA, 720 S. Colorado Blvd, Suite 970 South Taster, Denver, CO 30246-1925. lt‘you received a transfusion or organ transplant before july 1992, you should he tested For hepatitis (I. a disease that can damage your liver and cause it to tail. ~uara-A'h5- K'Z. "NA\‘|..£ 5.\!.‘>L‘"r'...' '. .' (:all l-888-4lllil’ (ll)(‘. (l-888—443-7232). or visit: www.cdc. gov/ he pat i t i s Ask your doctor if you or your loved ones should be tested for hepatitis C. CDC ...
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Reading_05 - WATURES Food-Related Illness and Death in the...

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