Travel Health – Risk assessment and prevention Dr Peter Tay MBBS; DTM RCPS(Glasg); MMed (OM); AFTM (Glasg); FAMS
Summary International Travel Travel health Accidents & Injuries Health hazards associated with flying Travel related illness Fitness to travel Preventing ill health during travel
International Travel The WTO (World Tourism Organization) reports that international tourist arrivals in the year 2006 exceeded 840 million 1 The majority of international travel was for : – Leisure, recreation and holiday (51%) – Business travel (16%) – 27% (225 million) represented travel for other reasons such as visiting friends and relatives (VFR), religious purposes/pilgrimages and health treatment – For the remaining 8% of arrivals, the purpose of visit was not specified
Travel Health People in their home environment live in a state of equilibrium with the physical environment and with the local strains of micro-organisms. Exposure of the traveller to the different health risks of the visited area is determined by destination, duration of visit, purpose of visit, behaviour of the traveller and physical and biological status of the traveller. Dr Hussein A Gezairy, Regional Director, WHO Eastern Mediterranean Region
A Scottish study 2 of 952 travellers who died abroad found that cardio-vascular disease was the major cause of death in the older age group whereas in the younger group, traumatic deaths were commonest. Among business travellers and expatriates, studies 3,4 have reported a higher incidence of injuries, especially back injuries compared to non-travelling employees and up to 20% of reported health events were found to be due to accidents with sprains, strains and fractures accounting for 74% of those cases. Sports activity accounted for 51% of accidents and 12% were due to road traffic accidents (MVCs).
Humidity, Radiation & Motion sickness Humidity of cabin air is usually low (< 20%) due to frequent air exchanges. Giving rise to skin dryness and discomfort to the eye and upper respiratory tract Cosmic radiation comes from the sun and outer space. It is more intense over the polar regions. However, health risks to the occasional traveller is extremely small. Air travellers seldom develop motion sickness except in the case of severe turbulence. Susceptible individuals are advised to sit in the middle sections of the plane, avoid spicy, fatty, gas-forming foods.
Chemical Exposures On the ground, pollutants associated with most airports are volatile organic compounds, carbon monoxide, oxides of nitrogen, particulates and ozone. During flight, at higher altitudes, Ozone is the main pollutant and can lead to airway irritation and reduced lung function. Most modern aircraft are fitted with catalytic converters to remove ozone from cabin air 6. Disinsection is a requirement in a number of countries. The pesticide group in most common use are pyrethroids and the WHO found no evidence of harmful effects if the insecticides were used as prescribed.
Deep Vein Thrombosis (DVT) Misnomer : economy class syndrome Due to relative immobility therefore associated with travelling in general. WHO : risk of thromboembolism approx. 2X after travel lasting 4 hours. Passengers taking multiple flights over a short period are also at risk 7. Risk of developing DVT associated with 8 : Travelling in general, with the risk associated with flying similar to that of travelling by car, bus or train A Body Mass Index (BMI) of more than 30 kg/m 2 Very tall individuals (above 1.90 m in height) Those who use Oral Contraceptives, and Those who are below 1.60 m in height (for air travel specifically) Prevention : moving around the cabin to reduce immobility; calf exercises to stimulate circulation; avoidance of alcohol (dehydration & promotes immobility) and keeping well hydrated during the flight.
Jet Lag May lead to – Indigestion & bowel disturbance, – general malaise, – daytime sleepiness, – reduced physical and mental performance 9. – chronic exposure may lead to cognitive deficits 10 Prevention : – getting adequate sleep in the destination country – use of short acting sedatives – use of melatonin : recommendation that it be taken by adult travellers flying across five or more time zones, particularly in the easterly direction 11 Disruption of the bodys internal clock and its circadian rhythms Occurs especially when crossing multiple time zones
Psychological Aspects For biz travel, a World Bank study 13 found that almost 75% of employees and 50% of spouses reported high or very high stress levels associated with business travel. Concerns were with : – negative impact on their family – inability to refuse travel – personal health concerns – lack of control over travel – interference from last minute changes in itinerary Main problems encountered are stress and fear of flying. One study of 238 travellers 12 found that flight delays were perceived as a source of anxiety for 50% of respondents, take-off and landing by 40% and customs and baggage reclaim for 1/3.
Communicable Diseases Commercial aircraft designed after 1980 recycle up to 50% of cabin air through HEPA filters Risk of ID transmission passenger is confined in close quarters for a prolonged period of time The CDC 14 found that 4 passengers were infected with TB during a 9-hour flight and the WHO 15 concluded that TB transmission was possible especially during long flights (e.g. 8 hr duration). Most important factors in disease spread were infectiousness of the patient, proximity to the source, ventilation and degree of crowding. Indeed, any disease that is spread via droplets (e.g. influenza, meningococcal disease & measles) may be spread in this way. In 2003, SARS 16 very quickly spread from Hong Kong to Viet Nam, Singapore, Canada and Germany.
Review of literature shows that the overall incidence of TRI ranges from 37.0% to a high of 65.5% 17-21 Prevalence of specific diseases : – Travellers diarrhoea (TD) was the commonest reported illness, ranging from 26.3% to 59.0% Prevalence of TRI – The second most commonly reported illness was respiratory tract infection which ranged from 12% to 29% – Skin problems (sun burn, dermatophytosis, allergic rash) made up the third most common illness reported – other illnesses reported were jet lag, insomnia, constipation, acute mountain sickness, headache and myalgia
Fitness to Fly 22 At this altitude, there is 25% less oxygen (SaO 2 90 - 93%) - caution in coronary, cerebrovascular, pulmonary & anaemic patients Gases in cavities expand (Boyles law : v 1/p) Cabin Humidity 10 – 20 % Medical Clearance may be needed : – After recent illness, injury, surgery or hospitalization – With existing unstable medical conditions – If oxygen or other medical equipment on board is required – If travelling for medical reasons Cruising altitude 30,000 – 40,000 ft but cabin pressurized to 5000 - 8000 ft (1524 - 2438m)
Medical Guidelines for Flying 23 Aerospace Medical Association Medical Guidelines Task Force : Medical Guidelines for Airline Travel 2 nd Ed. Aviation, Space and Environmental Medicine 2003; 74 (5)
Prevention (1) – Destination – Duration and season – Purpose and activity – Mode of travel – Accommodation – Food & water hygiene – Behaviour of traveller – Underlying health of traveller Pre-travel risk assessment InternetTrvl Agent Booking Travel Risk Assmt ? See doctor ? NATAS
Immunizations Is malaria prophylaxis required ? Travel Health Advice – Sources of information Travel Health kit Travel Insurance Prevention (2)
Immunizations What is recommended ? Give 4 – 6 weeks
Anti-malarials To take or not to take ? – Do a risk assessment Is there chloroquine-resistance ? Season of travel Availability of medical facilities Age, sex, pregnancy, personal medical history Bite prevention – Long-sleeved shirts, long pants, socks – Avoid being outdoors during dusk & dawn – Use of insect repellent (DEET; Neem tree; Citronella) – Air-conditioned rooms – Screened windows & doors – Mosquito nets (pyrethroid-impregnated) – Use of pyrethroid coils/electrical burners Emergency stand-by medication
Advice regarding potential risks and risk-taking behaviour is essential. These cover : – Personal hygiene – Food & water hygiene (e.g. filtration, boiling) – Sunburn avoidance (e.g. sunglasses, sunscreen, hat) – Motion sickness – Altitude sickness – Heat disorders – Insect/Animal avoidance – Safe sex – Accident & crime avoidance Driving, motorcycles, scooters etc. Hazardous pursuits e.g. bungee jumping, scuba diving, caving, skiing – Alcohol usage – Substance use/abuse – When to self-treat (e.g. diarrhoea, skin infections, malaria) – When and where to seek acute medical care while overseas
Sources of Information On-line, up-to-date sources preferable International Travel and Health 2008 ed. WHO : http://www.who.int/ith/en/index.html http://www.who.int/ith/en/index.html Travellers Health. CDC : http://wwwn.cdc.gov/travel/default.aspx http://wwwn.cdc.gov/travel/default.aspx Travax – The A to Z of Healthy Travel. NHS Scotland : http://www.travax.nhs.uk/http://www.travax.nhs.uk/ Fit For Travel. NHS Scotland : http://www.fitfortravel.nhs.uk/ http://www.fitfortravel.nhs.uk/
Travel Insurance Cost of medical care overseas can be prohibitive Huge costs associated with medical evacuation, ranging from commercial flights to chartered aircraft
Conclusion International travel volume is on the increase with travel for leisure/pleasure, business and VFR being the top 3 reasons Travel related health risks have to do with factors such as destination, duration, purpose of travel, activity, standards of accommodation, behaviour of the traveller and the underlying health condition of the traveller On-line databases are excellent sources of travel health information A pre-travel risk assessment is essential in reducing the risks associated with travel A health consultation is recommended 4 – 6 weeks prior to travel Do not forget travel insurance
References (1) 1.UNWTO Tourism highlights, 2007. http://www.unwto.org/facts/eng/highlights.htmhttp://www.unwto.org/facts/eng/highlights.htm 2.Paixao ML, Dewar RD, Cossar JH et al. What do Scots die of when abroad ? Scottish Medical Journal 1991; 36 (4) : 114 – 116 3.Liese B, Mundt KA, Dell LD et al. Medical insurance claims associated with international business travel. Occupational and Environmental Medicine 1997; 54 (7) : 499 – 503 4.Patel D, Easmon C, Seed P et al. Morbidity in expatriates – a prospective cohort study. Occupational Medicine 2006; 56 : 345 - 352 5.Barish RJ. In-flight radiation : Counselling patients about risk. Journal of the American Board of Family Practice 1999; 12 (3) : 195 - 199 6.United States Environmental Protection Agency. Evaluation of air pollutant emissions from sub-sonic commercial jet aircraft. http://www.epa.gov/otaq/regs/nonroad/aviation/r99013.pdf http://www.epa.gov/otaq/regs/nonroad/aviation/r99013.pdf 7.World Health Organization. News release : Study results released on travel and blood clots, 29 June 2007. Available from : http://www.who.int/mediacentre/news/releases/2007/pr35/en http://www.who.int/mediacentre/news/releases/2007/pr35/en 8.Cannegieter SC, Doggen CJ, van Houwelingen HC et al. Travel-related venous thrombosis : results from a large population-based case control study (MEGA study). PLoS Medicine / Public Library of Science 2006; 3 (8) : e307 9.Nicholson AN, Pascoe PA, Spencer MB et al. Jet lag and motion sickness (Review). British Medical Bulletin 1993; 49 (2) : 285 – 304 10.Cho K, Ennaceur A, Cole JC et al. Chronic jet lag produces cognitive effects. Journal of Neuroscience 2000; 20 (6) : RC 66
References (2) 11.Herxheimer A, Petrie KJ. Review : Oral melatonin reduces jet lag in our travellers. Cochrane Database of Sytematic Reviews 2001; (1) : CD001520 12.McIntosh IB, Swanson V, Power KG et al. Anxiety and health problems related to air travel. Journal of Travel Medicine 1998; 5 (4) : 198 – 204 13.Espino CM, Sundstrom SM, Frick HL et al. International business travel : impact on families and travellers. Occupational and Environmental Medicine 2002; 59 (5) : 309 - 322 14.Centres for Disease Control and Prevention. Exposure of passengers and flight crew to mycobacterium tuberculosis on commercial aircraft, 1992 – 1995. Morbidity and Mortality Weekly Report 1995; 55 (8) : 137 - 140 15.World Health Organization. Tuberculosis and Air Travel : Guidelines for prevention and control (Second edition, 2006). Available from : http://whqlibdoc.who.int/hq/2006/WHO_HTM_TB_2006.363_eng.pdf http://whqlibdoc.who.int/hq/2006/WHO_HTM_TB_2006.363_eng.pdf 16.World Health Organization. Severe Acute Respiratory Tract Infection (SARS). Available from : http://www.wpro.who.int/health_topics/sars/http://www.wpro.who.int/health_topics/sars/ 17.Kemmerer TP, Cetron M, Harper L et al. Health problems of corporate travellers :. Risk factors and management. Journal of Travel Medicine 1998; 5 (4) : 184 – 185 18.Rack J, Wichmann O, Kamara B et al. Risk and spectrum of diseases in travellers to popular tourist destinations. Journal of Travel Medicine 2005; 23 (5) : 248 - 253
References (3) 19.Bruni M, Steffen R. Impact of travel-related health impairments. Journal of Travel Medicine 1997; 4 (2) : 61 – 64 20.Hill DR. Health problems in a large cohort of Americans travelling to developing countries. Journal of Travel Medicine 2000; 7 ((5) : 259 – 266 21.Redman CA, MacLennan A, Wilson E et al. Diarrhoea ad respiratory symptoms among travellers to Asia, Africa, and South and Central America from Scotland. Journal of Travel Medicine 2006; 13 (4) : 203 - 211 22.The World Health Organization. International Travel and Health (2007 edition). Available from : http://www.who.int/ith/en/ (Accessed 18 October 2007).http://www.who.int/ith/en/ 23.Aerospace Medical Association Medical Guidelines Task Force : Medical Guidelines for Airline Travel 2 nd Ed. Aviation, Space and Environmental Medicine 2003; 74 (5) 24.Centres for Disease Control and Prevention. Travellers Health Kit. Available from : http://wwwn.cdc.gov/travel/yellowBookCh2-HealthKit.aspxhttp://wwwn.cdc.gov/travel/yellowBookCh2-HealthKit.aspx 25.Health Risks and Precautions : general considerations. In : International Travel and Health 2008 Edition. WHO. Available from : http://www.who.int/ith/chapter_1_2008.pdf http://www.who.int/ith/chapter_1_2008.pdf 26.Harper LA, Bettinger J, Desmukes R et al. Evaluation of the Coca-Cola company travel health kit. Journal of Travel Medicine 2002; 9 (5) : 244 - 246