1	Should “Cook it, Boil it, Peel it, or forget it!” be forgotten? David Boulware, M.D. Medicine-Pediatrics Resident University of Minnesota
2	Should “Cook it, Boil it, Peel it, or forget it!” be forgotten?
3	Etiologic Agents of Traveler’s Diarrhea
4	Standard Recommendations “Cook it, Boil it, Peel it, or forget it!” 1692 Dutch East India Company warned colonists not to eat salads. Good Common Sense Standard pre-travel advice
5	CDC Recs Travelers can minimize their risk for TD by practicing the following effective preventive measures: Avoid eating foods or drinking beverages purchased from street vendors or other establishments where unhygienic conditions are present Avoid eating raw or undercooked meat and seafood Avoid eating raw fruits and vegetables unless the traveler peels them. Tap water, ice, unpasteurized milk, and dairy products are associated with increased risk for TD.
6	But does it work?
7	Why does this matter? 714 million people were tourists in 2002.¹ 54 million Americans in 2002 traveled abroad. ² Avg. trip duration 15.2 days in 2002. ²
8	Destinations 18 million Americans to Mexico. 24 million outside of North America Caribbean 18% Asia 13% (excluding Japan) South America 8% Central America 7% Middle East 4% Eastern Europe 3% Africa 2%
9	Who gets it? Approximately 40% of travelers in first 2 weeks of travel. 2002 Avg Trip duration = 15.2 days 90% resolve within 1 week. Good news – 98% resolve within 1 month
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11	Basis for this recommendation
12	Basis for this recommendation Single Prospective Case-Control Study among Swiss tourists (n=2240) on charter flights in 1982. 10 page survey on outbound flight Recorded food for first 3 days Recorded diarrhea for first 5 days
13	Dietary Mistakes 98% made dietary mistakes in first 3 days All but 13 people. (36 people made 1 mistake). Salads / uncooked vegetables 71% Fruit, unpeeled 70% Ice cubes 53% 13 foods considered high-risk (raw oysters, steak tartar, salads, ice cubes, unpeeled fruit, cold sandwiches, etc)
14	Incidence of Diarrhea Diarrhea: 19.5% in first 5 days.
15	Influence of TD on Diet
16	(Continued)
17	Study Limitations Response rate 29.6% (n=662). “A response rate of 30% is not representative” Why not? If you had 8 more cases of diarrhea (out of the 1552 surveys not returned… non-significant).
18	Study Limitations Only recorded first 5 days of diarrhea. Missing 40% of diarrhea cases, as… Mean onset of TD is 3.8 to 4.0 days^1,2 “Vast majority of the interviewed travelers always ate at the hotel”
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20	Historical Context
21	Turista – 1973 – Round 1
22	Incidence of Turista Symptom onset Median 3-4 days after entry into Mexico Incidence of Diarrhea North Americans 55% Northern Europeans 48% “Lower attack areas” 18% (Mediterranean, Africa, Latin American, Asia)
23	Turista - Data
24	Turista Conclusions “Turista is a problem of N. Americans and N. Europeans entering Mexico.” “The apparent inability of non-medicinal precautionary measures to prevent turista was surprising and disconcerting…. <pathogens may be> so omnipresent as to make such precautionary actions worthless.” “Since drinking bottled water does not prevent turista, water may not be an important vehicle, or the water may not have been purified.”
25	Merson et al. NEJM 1976
26	Am GI Assoc World Congress 1976 Incidence of: diarrhea 49%, loose stools 11% Of those with diarrhea: Confined to bed 19% Changed Activities 39% Median Onset 6.5 days in Mexico 8% ill after return home. Duration 4.5 days.
27	And Dietary Protection?
28	Merson et al. Conclusions “Illness was not associated with consumption of water or iced beverages” “Illness was similarly not associated with consumption of vendor food, salads containing raw vegetables, other raw vegetables, or other unpeeled fruits.”
29	Association with ETEC
30	Stool Samples
31	Epidemiology of Diarrhea in Travelers Steffen, R. et al JAMA 1983 Swiss or German charter flights (flights n=162) Dec 1975 to Mar 1977 N=16,568 Response Rate 60% (fair) Retrospective survey completed on return flight
32	Onset of Diarrhea (days)
33	Onset of Diarrhea (days)
34	Duration of Diarrhea
35	Onset / Duration of Diarrhea
36	Preventative Measures
37	CDC Recs Avoid street vendors and/or unhygienic conditions Avoid eating raw or undercooked meat and seafood Avoid eating raw fruits and vegetables unless peeled. Avoid tap water, ice, unpasteurized milk, and dairy products.
38	Expatriates in Nepal
39	CIWEC Clinic Katmandu, Nepal CIWEC Clinic Yak & Yeti Road, Durbar Marg Kathmandu, Nepal Tel: 977-1-228531, 241732 travmed@ciwec-clinic.com website: www.ciwec-clinic.com
40	Risks factors for Diarrhea (Nepal)
41	#1 Activity of Tourists Survey says: Dining in Restaurants 86%
42	Pathogen presence in Stool
43	Develop Immunity with time
44	Hoge, Shlim Conclusions: “High level of exposure to enteric pathogens” Mucosal immunity acquired with time OR @ 1yr 0.36 (95% 0.18 to 0.74) Similar to DuPont Am J Epidem 1977 study of college students in Mexico at 1 year. Risks: restaurants, lasagna, fruit drinks, age “Our study failed to confirm as risk factors certain foods widely believed to be associated with TD, such as leafy vegetables, unpeeled fruits, untreated water, and ice.”
45	Examination in Children Pitzinger B, Steffen R, Tschopp A. Incidence and clinical features of traveler’s diarrhea in infants and children. Pediatr infect Dis J 1991; 10: 719-23. Prospective recruitment from a Zurich travel clinic 1987-88. Retrospective surveys upon return. 81% response rate (Very good) n = 363
46	Diarrhea v. Age
47	Impact of type of Travel
48	Diarrhea Risks Type of Travel Destination “No significant differences between those who did and did not adhere to dietary rules below age 15.” Dietary measures followed consistently by 38% Adolescents’ diet did have a statistically difference (P <0.05), but RR, 95% CI not listed.
49	So what about hygiene? Small children (<2yo) most likely to have followed dietary advice (60%) Highest rate of diarrhea (40%) Mean duration 29.5 days (median 17.5 d).
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51	Diarrhea rates in tourists visiting Jamaica
52	Food Consumption <3% Avoided all high risk Food 95% had ice cubes 90% ate salads 80% ate dairy products 55% ate ice cream, undercooked meat, uncooked seafood 24% bought food from street vendors
53	Did it Matter? No individual food statistically significant. “Risky food score” No difference for classic TD. Street Vendor: diarrhea 25.6% v. 24.7% controls.
54	Other Significant Results Age 16-35 : OR 1.1 ?Greater appetite and food/pathogen consumption Country of Origin (Odds Ratio) UK 3.4 Canada 3.1 USA 2.6 Italy 1.2 Japan 1.0 Latin America 0.5 Diarrhea cost per patient $116.50 per international traveler $27.50 Mean duration of incapacitation 17.1 hours for TD
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56	Review of the Data Loewenstein [Mexico, The Lancet, 1973] “ Drinking bottled liquids, and avoiding salads, raw vegetables, and unpeeled fruits failed to prevent illness” Merson [Mexico, NEJM 1976] “Illness was not associated with consumption of water or iced beverages. Illness was similarly not associated with consumption of vendor food, salads containing raw vegetables, other raw vegetables, or unpeeled fruits.” Steffen [World, JAMA 1983] “Thus, diarrhea seemed to occur more frequently the more a person tried to elude it!”
57	Review of the Data Pitzinger [World, JAMA 1991] “No significant differences between those who did and did not observe the rules were observed in children below the age of 15 years.” Mattila [Morocco, J Trav Med 1995] “The incidence of TD was not associated with the presence or absence of any specific dietary errors or the number of them committed. The rate of TD among people who reported no errors was 33%.” Hoge, Shlim [Nepal, JAMA 1996] “Our study failed to confirm as risk factors certain foods widely believed to be associated with TD, such as leafy vegetables, unpeeled fruits, untreated water, and ice.” Steffen [Jamaica, JAMA 1999] “Consumption of high risk food was a weak predictor of all diarrhea and no predictor for classic TD. The rules of dietary discipline could not be shown to have relevant value.”
58	Is something missing?
59	Yes – obviously… but what is it? Fecal-oral transmission is the premise. Via food, water, or hands. In a study of NYC housewives, 87% had entero-pathogens cultured from their hands.[i] Not only a problem in the developing world. How important is hand hygiene?
60	What about Hand Hygiene? In wilderness settings, wilderness diarrhea is traditionally thought to be caused by contaminated water. Is this true? What role does hygiene play?
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62	Appalachian Trail Backpackers Prospective Cohort Survey 334 Hikers in 1997. Response Rate 85% Diarrhea Occurrence 56% (n=156) Incidence Rate: 0.78 days (95% C.I = 0.60 to 0.95) per 30 days Inquiry Method of water disinfection Consistency of disinfection Water sources Hygiene
63	Consistency Of those reporting consistent treatment of their water (n=67) 45% ever suffered from diarrhea whereas 69% of those who inconsistently treated their water experienced diarrhea (RR 0.652, p=0.001)
64	Consistency of Disinfection v. Diarrhea
65	Hygiene Behavior RR v. Diarrhea
66	Hand washing with soap and water After defecation [36%] (RR 0.61; 95% CI: 0.39 to 0.93, P=0.006). After both urination and defecation [7%] (RR 0.11 ; 95% CI: 0.04 to 0.31, P<0.001). Comparison: always disinfecting water [43%] (RR 0.65, 95% CI 0.53 to 0.81, P=0.001).
67	Incidence Rate v. Behavior Freq.
68	Negative Behaviors : Increase rate of Diarrhea
69	Hygiene is important Mother’s are always right, Wash your hands! Where else has this been shown via EBM?
70	Alcohol based hand sanitizers Reduce school absence due to gastrointestinal illness by 25-50%.[i],[ii] In hospital settings, 30-36% reduction in UTIs, respiratory tract, and wound infections. [iii],[iv] [i] Guinan M, McGuckin M, Ali Y. The effect of a comprehensive hand washing program on absenteeism in elementary schools. Am J Inf Contr. 2002; 30: 217-20. [ii] White CG, Shinder FS, Shinder AL, Dyer DL. Reduction of illness absenteeism in elementary schools using an alcohol-free instant hand sanitizer J School Nursing. 2001 ;17: 258-65. [iii] Hilburn J, Hammond BS, Fendler EJ, Groziak PA. Use of alcohol hand sanitizer as an infection control strategy in an acute care facility. Am J Inf Contr 2003; 31: 109-16. [iv] Fendler EJ, Ali Y, Hammond BS, Lyons MK, Kelley MB, Vowell NA. The impact of alcohol hand sanitizer use on infection rates in an extended care facility. Am J Inf Contr 2002; 30:226-33.
71	What role does hand hygiene play in traveler’s diarrhea? Unknown Ideally a Prospective randomized controlled trial to investigate. 80% Power, assuming 20% difference -> need 1000-3000 people for adequate trial. -> And Funding. Will it be done?
72	Acknowledgements David Shlim, M.D.- Jackson Hole, WY. William Martin, M.D. – Univ. of Cincinnati