OUTLINE
Introduction
Conceptual Framework
Why travel?
Infectious diseases and travel
CASES: TYPHOID MARY: CHOLERA:
MALARIA: SARS; EBOLA
How is this issue handled?
CONCLUSIONS
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INTRODUCTION
Today, there is growing recognition that an outbreak anywhere can potentially
represent an emergency of international public health concern.
“The movement of populations shapes the patterns and distribution of
infectious diseases globally” (Wilson, 2003).
During travel, humans carry their genetic makeup, immunologic sequelae of
past infections, cultural preferences, customs, and behavioral patterns
(Wilson, 1995).
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GLOBAL TRAVEL
Geographical location
Route of Transmission
- Foodborne and waterborne diseases
- Vector-borne diseases
- Zoonoses (diseases transmitted by animals)
- Sexually transmitted diseases
- Blood borne diseases
- Airborne diseases
- Diseases transmitted via soil / formites
Economic Tourism Social
NON-INFECTIOUS DISEASES
-NCDs/Genetics
-Toxins (chemical and biological))
INFECTIOUS DISEASES
-Virus
-Bacteria
-Fungi
-Protozoa
How do we handle this problem?
-Sensitization
-Prevention
-Vaccination
-Quarantine
ConflictsNatural Disasters
Figure 1: Conceptual flow of ideas (with inspiration from WHO’s International Travel and Health guide, 2012 )
ENVIRONMENTAL RISKS-Altitude-Heat/humidity-UV radiation
INJURY AND VIOLENCE-Road traffic injuries-Recreational waters-Interpersonal violence
PSYCHOLOGICAL HEALTHStress
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Why do we travel?
Social
Natural disasters
Conflicts
Figure 2: Tourism and commerce: cornerstones for “A World of Movement.”
Figure 3: Tourism is the fastest growing industry worldwide, and the number of in-country arrivals is projected to double by the year 2020 (Source: Hurley and Friend, 2006)
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Selected pecific infectious diseases involving potential health risks for travellers(WHO, 2007)Disease Agent Risk
ANTHRAX Bacillus anthracis Very low for most travellers.
BRUCELLOSIS Brucella bacteria Generally low, but higher in rural/agricultural areas
LISTERIOSIS Listeria monocytogenes Low. consumption of unpasteurized milk and milk products and prepared meat products
VIRUSES
Chikungunya Chikungunya virus Risk in endemic areas/those affected by epidemics
Yellow fever virus Yellow fever virus Risk in endemic area; greater for visitors who enter forest and jungle areas
DENGUE Dengue virus Significant risk in endemic areas/those affected by epidemics
PROTOZOA
GIARDIASIS Giardia intestinalis Significant risk in recreational waters
Parasitic
LEISHMANIASIS Leishmania sp Visitors to rural and forested areas in endemic countries are at risk.
TRYPANOSOMIASIS Trypanosoma brucei sp Risk in endemic regions if they visit rural areas for hunting, fishing, safari trips, sailing or other activities in endemic areas.
Risk varies geographically and with lifestyle (Toovey et al., 2007a)
Routes of transmission
Figure 4: Common routes for potential transmission of infectious diseases between animals and humans and vice versa (Hurley and Friend, 2006).
Waterborne diseases
Sexually transmitted diseases
Bloodborne diseases
Diseases transmitted via soil
• MRSA lives for a week on seat-back
pockets in Airplanes; E. coli O157:H7
persisted for 96 hours on armrests
and 72 hours on tray tables (ASM,
2014).
• Windshield washer fluid as potential
source of Legionella pneumophila; 84%
of samples at a high concentration of
8.1×104 CFU/mL (Schwake, 2015).
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Typhoid Mary: Mary Mallon~ Cook: 1900-1907
Asymptomatic carrier of typhoid fever
The work of a chronic typhoid germ distributor (SOPER, 1907).
First quarantine (1907–10); Mary Brown
Release and second quarantine (1915–38)
Death 1938 (68 years)
Blamed for 51 Cases and 3 Deaths
(The New York Times, 1938). http://upload.wikimedia.org/wikipedia/
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CHOLERA: Haiti 2010
-START: October 21,
2010
-Nov. 16: + cases in the
neighboring Dominican
Republic and in Florida.
-Nov. 19: had reached
every department of
the country
-Several confirmed
cases in the Dominican
Republic (3) and all
confirmed U.S. cases
(5) were among
travelers from Haiti
(CDC, 2010).
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MalariaPopulation movement
contributes to the spread of
malaria (Martens and Hall,
2000)
Risk is dependent upon the
entomological inoculation
rate faced by the long-term
traveler.
Risk is cumulative,
increasing with duration of
exposure, greatest in rural
and periurban areas, and
least in urban centers (Toovey
et al., 2007b).
SARS
(Source: Hurley and Friend, 2006)
-February 2003, a Canadian and a US
resident were both infected when they and
the index SARS patient stayed at the same
hotel in Hong Kong
--The US (symptomatic) resident returned
as a suspect case; was treated with caution;
so, she did not cause a SARS outbreak.
--The Canadian resident returned to Canada
as an asymptomatic case and caused a
SARS outbreak in Toronto (Ruin et al.,
2003).
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Global Outbreak Alert and Response Network-(GOARN)
-Creation: April 2000. W.H.O
-Presently monitoring:
Middle East respiratory syndrome coronavirus (MERS-CoV) -United Arab
Emirates, Qatar, Saudi Arabia, Korea, Germany and The Philippines: 1118
laboratory-confirmed cases of infection with MERS-CoV, including at least 423
related deaths
Meningococcal disease -Niger: 6,179 suspected cases of meningococcal
meningitis, including 423 deaths (WHO, 2015).
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CREATING AWARENESS!!!
-Infographics-News-Communiques-SMS (Senegal)…
Creating
awareness
particularly
strengthens
PREVENTIO
N
CAMPAIGNS
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Prevention/control of spread
The most effective measure and needs to be prompt
Hygiene (Faecal-Orally Transmitted Diseases)
Prophylaxis (Malaria)
Cure all disease humans and/animals
Quarantine (Ebola, Swine and bird flu,)
Vaccination (Yellow fever, Polio,)
Due to better hygienic standards at travel destination, Faeco-orally transmitted diseases among travellers is decreasing (Baaten et al., 2010)
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CONCLUSIONS Travel is very much linked to infectious diseases???
Knowledge of transmission routes and putting in place of proper disinfection protocols, and personal hygiene is invaluable to keeping travelers safe.
Rapid response in case of outbreaks, to establish source and transmission mechanism(s), so as to prevent spread and thus control the disease.
Are we doing enough? (Ebola outbreak 2014).
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