Abstract

Background

Gastrointestinal illness is a common risk for wilderness travelers, even among those who consistently disinfect their water, yet the importance of hygiene has not been characterized.

Methods

In a prospective surveillance study, 334 Appalachian Trail backpackers who hiked for at least 7 days in 1997 were interviewed. Upon completion of their hike, a written questionnaire was sent, addressing illnesses, water disinfection methods, and hygiene. Hygiene inquiries focused on the frequency of behaviors concerning handwashing and cleaning cookware.

Results

Two hundred and eighty backpackers compiled 38, 940 wilderness exposure days, with 56% (n= 156) experiencing diarrhea. Diarrhea correlated with the frequency of drinking untreated surface water (relative risk (RR) 2.4, 95% confidence interval (CI) 1.0–4.7%, p =.03). Of those who consistently treated water, 45% suffered from diarrhea, whereas 69% of those who inconsistently treated water experienced diarrhea (RR 0.65, 95% CI 0.53–0.81%, p =.001). Hikers practicing “good hygiene”, defined as handwashing postdefecation and cleaning cookware routinely, were less likely to ever experience diarrhea (RR 0.47, 95% CI 0.22–0.99, p =.04). Routine handwashing with soap and water after both urination and defecation reduced the risk of diarrhea (RR 0.11, 95% CI 0.04–0.31%, p <.001). In a case-control analysis of those experiencing diarrhea, decreased diarrhea was associated with routine consumption of multivitamins (RR 0.50, 95% CI 0.37–0.66%, p <.001), routine cleaning of utensils with warm, soapy water (RR 0.38, 95% CI 0.20–0.74%, p <.01), and postdefecation handwashing with soap and water (RR 0.61, 95% CI 0.39–0.93%, p =.006).

Conclusions

Lack of hygiene, specifically handwashing and cleaning of cookware, should be recognized as a significant contributor to wilderness gastrointestinal illness. Hikers should routinely disinfect water and avoid untreated surface water.

References

1
Boulware
DB
Forgey
WW
Martin
W
.
Medical risks of wilderness backpacking
.
Am J Med
 
2003
;
114
:
288
293
. 12681456
2
Gentile
DA
Morris
JA
Schimelpfenig
T
et al.
Wilderness injuries and illnesses
.
Ann Emerg Med
 
1992
;
21
:
853
861
. 1376973
3
Crouse
BJ
Josephs
D
.
Health care needs of Appalachian trail hikers
.
J Fam Pract
 
1993
;
36
:
521
525
. 8482936
4
Gorter
AC
Sandiford
P
Pauw
J
et al.
Hygiene behaviour in rural Nicaragua in relation to diarrhoea
.
Int J Epidemiol
 
1998
;
27
:
1090
1100
. 10024209
5
Shahid
NS
Greenough
WB
Samadi
AR
et al.
Hand washing with soap reduces diarrhoea and spread of bacterial pathogens in a Bangladesh village
.
J Diarrhoeal Dis Res
 
1996
;
14
:
85
89
. 8870400
6
Cao
X
Rawalai
K
Thompson
AJ
et al.
Relationship between feeding practices and weanling diarrhoea in northeast Thailand
.
J Health Population Nutr
 
2000
;
18
:
85
92
.
7
Saidi
SM
Iijima
Y
Sang
WK
et al.
Epidemiological study on infectious diarrheal diseases in children in a coastal rural area of Kenya
.
Microbiol Immunol
 
1997
;
41
:
773
778
. 9403500
8
Waner
S
Durrheim
DN
Leggat
PA
Ross
MH
.
Preventing infectious diseases in long-term travelers to rural Africa
.
J Travel Med
 
2001
;
8
:
304
. 11726295
9
Hoque
BA
Briend
A
.
A comparison of local hand-washing agents in Bangladesh
.
J Trop Med Hyg
 
1991
;
94
:
61
64
. 1995938
10
Hoque
BA
Mahalanabis
D
Alam
MJ
Islam
MS
.
Post-defecation hand-washing in Bangladesh: practice and efficiency perspectives
.
Public Health
 
1995
;
109
:
15
24
. 7871142
11
Forgey
WW
.
Wilderness medicine: beyond first aid
5th edn.
1999
Guilford, CT
Globe Press
.
12
Backer
HD
. In:
Auerbach
PS
,
Geehr
EC
eds.. Field water disinfection.
Management of wilderness and environmental emergencies
2nd edn.
1989
St Louis, MO
Mosby
;
805
827
.
13
Backer
H
.
Water disinfection for international and wilderness travelers
.
Clin Infect Dis
 
2002
;
34
:
355
364
. 11774083
14
Ladegaard
MB
Stage
V
.
Hand-hygiene and sickness among small children attending day care centers. An intervention study
.
Ugeskr Laeger
 
1999
;
161
:
4396
4400
. 10487104
15
Wilson
JM
Chandler
GN
Muslihatun
J
.
Hand-washing reduces diarrhoea episodes: a study in Lombok, Indonesia
.
Trans R Soc Trop Med Hyg
 
1991
;
85
:
819
821
. 1801364
16
Velema
JP
van Wijnen
G
Bult
P
et al.
Typhoid fever in Ujung Pandang, Indonesia—high-risk groups and high-risk behaviours
.
Trop Med Int Health
 
1997
;
2
:
1088
1094
. 9391512
17
Rudland
S
Little
M
Kemp
P
et al.
The enemy within: diarrheal rates among British and Australian troops in Iraq
.
Mil Med
 
1996
;
161
:
728
731
. 8990829
18
Manun'Ebo
M
Cousens
S
Haggerty
P
et al.
Measuring hygiene practices: a comparison of questionnaires with direct observations in rural Zaire
.
Trop Med Int Health
 
1997
;
2
:
1015
1021
. 9391503
19
Rose
JB
Cerba
CP
Jablonski
W
.
Survey of potable water supplies for Cryptosporidium and giardia
.
Environ Sci Technol
 
1991
;
25
:
1393
1400
.
20
Fawzi
WW
Herrera
MG
Willett
WC
et al.
Dietary vitamin A intake and the incidence of diarrhea and respiratory infection among Sudanese children
.
J Nutr
 
1995
;
125
:
1211
1221
. 7738681
21
Bhandari
N
Bahl
R
Taneja
S
et al.
Substantial reduction in severe diarrheal morbidity by daily zinc supplementation in young north Indian children
.
Pediatrics
 
2002
;
109
:
e86
. 12042580
22
Black
RE
Sazawal
S
.
Zinc and childhood infectious disease morbidity and mortality
.
Br J Nutr
 
2001
;
85
:
S125
S129
. 11509100
23
Boyum
A
Wiik
P
Gustavsson
E
et al.
The effect of strenuous exercise, calorie deficiency and sleep deprivation on white blood cells, plasma immunoglobulins and cytokines
.
Scand J Immunol
 
1996
;
43
:
228
235
. 8633203
24
Rowbottom
DG
Green
KJ
.
Acute exercise effects on the immune system
.
Med Sci Sports Exerc
 
2000
;
32
:
S396
S405
. 10910296
25
Steffen
R
.
Epidemiologic studies of traveler's diarrhea, severe gastrointestinal infections, and cholera
.
Rev Infect Dis
 
1986
;
8
:
S122
S130
. 3523708
26
Kean
BH
Waters
SR
.
Intestinal protozoa of American travelers returning to the United States from Mexico
.
AMA Arch Indust Health
 
1958
;
18
:
148
.
27
Peltola
H
Gorbach
SL
. In:
Dupont
HL
,
Steffen
R
eds.. Traveler's diarrhea.
Textbook of travel medicine and health
2nd edn.
2001
Hamilton
BC Decker
;
155
.
This work was financially supported by William Fogey, MD. Apart from this, the authors had no financial or other conflicts of interest to disclose.