- Email: [email protected]
Advising the traveller
SPECIAL SITUATIONS
Advising the traveller
What’s new?
Joanna S Herman C
David R Hill
C C
C
Abstract
C
Nearly 70 million visits are made from the UK to foreign countries each year. Over the past decade there has been a large increase in travel to tropical destinations that have different health risks from those encountered closer to home. Seeking pre-travel advice should be an essential part of any trip for a traveller, but is often omitted. The key elements of pre-travel advice are health risk assessment and health promotion, which involves advice on prevention of malaria, travellers’ diarrhoea, sexually transmitted infections and accidents, as well as appropriate vaccinations. High-risk groups of travellers, such as those visiting friends and relatives, need to be particularly targeted.
Decrease in incidence of P. vivax in travellers Change in timing of BCG vaccination New understanding of adverse events associated with yellow fever vaccine New oral cholera vaccine New Japanese encephalitis vaccine
primary care setting or at specialized travel clinics, and is usually nurse-led.
Access to pre-travel healthcare A survey of European travellers visiting countries in the developing world found that only 50% had sought pre-travel health advice.4 Of these, the majority had been to their general practice surgery, and about 30% consulted a specialist travel medicine clinic. The likelihood of seeking pre-travel advice varies in different groups of travellers, with migrants who return to their country of origin to visit friends and relatives (VFRs) being the least likely to seek advice or take precautionary measures. This group has a disproportionately increased risk of acquiring the more common tropical infections, when compared to the other travellers, and they should be targeted specifically for pre-travel advice.5,6
Keywords health risk assessment; health promotion; malaria prevention; pre-travel advice; travel medicine; travellers’ diarrhoea; vaccinations; yellow fever
Introduction The travel clinic consultation
International travel has increased at a dramatic rate over the past decade, with an estimated 800 million travellers worldwide now crossing international borders, and 70 million visits made from the UK each year. Although many travellers from the UK visit Europe, there has been a marked increase in travel to more tropical destinations that carry particular health risks. Travel to such places brings exposure to a broad range of pathogens rarely, if ever, encountered at home, with the risk of morbidity varying between 20 and 70%.1 While the majority of illnesses tend to be self-limiting, approximately 5% of travellers will require a doctor’s attention and 1% will require hospitalization whilst abroad, and many travellers will require medical care on return home. However, the most likely causes of mortality in travellers are accidental injury (e.g. road traffic accident or drowning) or a cardiovascular event, rather than an infectious disease, which accounts for only 1e2% of deaths.2,3 Many travel-related illnesses are preventable by taking sensible precautionary measures, and, for some diseases, by having the appropriate vaccinations and taking chemoprophylactic medications. In the UK pre-travel advice is given in the
The key features of a pre-travel consultation are health risk assessment, and health promotion with risk management (Table 1). Risk assessment Risk of infection varies according to the area to be visited, endemicity of diseases, nature of travel (holiday, business, backpacker, VFR), type of accommodation, anticipated activities,
Key elements of travel medicine Health risk assessment C
C
Health promotion and risk management C C C C C
Joanna S Herman MBBS MSc MRCP is a Specialist Registrar in Infectious Diseases and Tropical Medicine at the Hospital for Tropical Diseases, London, UK. Competing interests: none declared.
C
Responsible personal behaviour and safety Vaccine-preventable illness Vector avoidance Malaria prevention Travellers’ diarrhoea prevention and self-treatment Environmental illness e altitude, heat, swimming, jet lag, prevention of deep-vein thrombosis
Travel insurance and access to medical care overseas Post-travel screening, care and triage of illness (e.g. fever, diarrhoea, rash)
David R Hill MD DTM&H FRCP FFTM is Director of the National Travel Health Network and Centre and Honorary Professor, London School of Hygiene and Tropical Medicine, London, UK. Competing interests: none declared.
MEDICINE 38:1
Health status of traveller e medical conditions, medications and allergies, immunization history Health risk of travel e itinerary (rural, urban), accommodation, duration of trip, anticipated activities
Table 1
56
Ó 2009 Elsevier Ltd. All rights reserved.
SPECIAL SITUATIONS
and duration of trip. It will also vary according to the health status of the traveller: their medical conditions, current medications, allergies and immunization history. The majority (80e95%) of travellers to the tropics undertake short-term visits (<1 month), with the other 5e20% spending long periods abroad, either travelling or working (e.g. backpackers, missionaries, volunteer workers, placements with the armed forces), or on repeated short-term visits (e.g. businessmen, airline crews). The risks and exposure these groups incur are different, and depend on both individual behaviour and environment, with the long-term group at greater risk of acquiring infections endemic in the local population they are visiting. There is also a risk difference between the sexes, with male travellers being at greater risk of disease acquisition.7 Risk varies according to the geographical area visited. Travellers to Africa have the highest rate of all-cause morbidity and account for the greatest number of cases of Plasmodium falciparum malaria.8 The highest risk of P. vivax and diarrhoeal illness is in travellers to South Asia, while cutaneous leishmaniasis is most common in visitors to Latin America. Risk within a country may also differ; for example, malaria risk in Nairobi is negligible compared with a significant risk on the Kenyan coast. Information about the regional prevalence of specific diseases can be difficult to obtain, but some websites offer valuable information, particularly in relation to recent outbreaks or vaccine recommendations, e.g. the World Health Organization, the National Travel Health Network and Centre (NaTHNaC), and the Centers for Disease Control and Prevention (see Box 1 for web addresses). However, it is important to remember that non-tropical infections account for many of the infections that present in returned travellers.5
serious or potentially fatal. These include malaria, travellers’ diarrhoea, sexually transmitted infections, and road traffic accidents (RTAs). Health hazards that are rare (e.g. cholera, Japanese encephalitis, parasitic infections) take a lower priority. The travel medicine practitioner must balance the need for prophylaxis against the realistic risk of infection and the likelihood of adherence by the traveller. However, travellers should be aware that no intervention is fully protective. Malaria (Table 2) Malaria is one of the most serious causes of fever in travellers, either while abroad or on return (see the article on malaria, pp. 41e46). The risk of malaria is greatest in sub-Saharan Africa (particularly West Africa), to a lesser extent in South Asia (India), and lowest in Central and South America and South East Asia. However, the risk can vary widely within countries depending on location. In the UK each year there are 1500e1750 cases of malaria reported and 5e10 deaths; almost all deaths are caused by P. falciparum. Prevention of infection involves understanding of the disease process and the ‘ABCD of malaria’:9 Awareness of risk Bite prevention from nocturnal Anopheles spp. mosquitoes Chemoprophylaxis prompt Diagnosis of infection Bite prevention measures include use of insect repellent such as DEET, covering up at the appropriate time of day (dusk to dawn), and sleeping under an insecticide-impregnated mosquito net. The choice of chemoprophylaxis depends on what type of malaria is endemic in the region being visited, and the presence of drug resistance. It will also depend on individual factors and preferences for the different drug regimens, such as dosing frequency (e.g. weekly for mefloquine or daily for doxycycline or atovaquoneeproguanil), and affordability. For detailed advice, including side effects and special cases such as pregnancy see the continually updated UK
Health promotion and risk management Many travel consultations focus on vaccinations, but these may be among the least cost-effective preventative measures in travellers, as vaccine-preventable diseases account for less than 5% of travel-associated morbidity e a figure similar to that for accidents and injuries. The main priorities should be given to health problems that are common, preventable/treatable, and
Prevention of malaria Vector avoidance C
Useful websites
C C
National Travel Health Network and Centre (www.nathnac.org)a Health Protection Scotland (http://www.hps.scot.nhs.uk/)a UK Foreign and Commonwealth Office (www.fco.gov.uk) ‘Know Before You Go’ site provides information on travel insurance and safety (www.fco.gov.uk/en/travelling-and-livingoverseas/about-kbyg-campaign/) WHO Travellers’ Health section (www.who.int/ith/)a US Centers for Disease Control and Prevention (www.cdc.gov/ travel/)a International Society of Travel Medicine (www.istm.org)a,b
C
Protective clothing Repellents e either with DEET a or picaridin are the most effective. Netting e impregnated with a residual insecticide such as permethrin Limiting exposure during transmission time (dusk to dawn) b
Antimalarial chemoprophylaxis C C
C C C
Chloroquine (only where there is no resistant P. falciparum) Chloroquine plus proguanil (only where there is little resistant P. falciparum, or where P. vivax predominates) Atovaquone plus proguanil Doxycycline Mefloquine
a
20e50% Is usually recommended and is safe for all travellers >2 months of age; the manufacturer’s guidelines for use should be followed. b Before prescribing an antimalarial agent, the prevalence and species of malaria found in the travel destination as well as potential resistance must be determined, as should any medical contraindications.
a
These organizations aim to improve travellers’ health by providing guidance and setting standards for health professionals in settings ranging from primary care to specialized travel clinics
b
Publishes the Journal of Travel Medicine
Box 1
MEDICINE 38:1
Table 2
57
Ó 2009 Elsevier Ltd. All rights reserved.
SPECIAL SITUATIONS
travellers who seek pre-travel advice, as the risk can be virtually eliminated by practising safer sex. Raising awareness of these sensitive issues is an important part of the travel health consultation, although some practitioners may find them difficult to address. Less common risk factors for HIV infection include invasive medical treatment and transfusion with contaminated blood, which are of particular importance in sub-Saharan Africa where the seroprevalence of HIV can be as high as 30%.
malaria advice at http://www.hpa.org.uk/web/HPAweb&HPAweb Standard/HPAweb_C/1195733823080. For countries with a high prevalence of chloroquine-resistant P. falciparum, mefloquine, doxycycline or atovaquoneeproguanil can be taken. For areas with little chloroquine resistance, chloroquine plus proguanil should be taken, and in areas without resistance, chloroquine or proguanil can be used.10 Practitioners need to be aware of the adverse effects and contraindications to all the antimalarials; for example, mefloquine is contraindicated in those with a neuropsychiatric history (e.g. depression, seizures), or a cardiac conduction abnormality. Fever secondary to malaria can be difficult to differentiate clinically from other causes of fever, and any traveller who develops fever within a year of return from the tropics should have malaria excluded by blood film.
Vaccinations (Table 3) There are three main reasons for vaccinating travellers: recommended as part of routine healthcare required by destination country recommended because of travel-related risk.
Gastrointestinal illness Diarrhoea is the most common illness affecting travellers to developing countries, and can affect 20e60% of travellers; 11 see the article on pp. 26e29. The most common causal organisms are bacteria, particularly enterotoxigenic Escherichia coli, enteroaggregative E. coli, Salmonella spp., Shigella and Campylobacter, but viruses (rotavirus and noroviruses) and protozoa (Giardia lamblia and Cryptosporidium spp.) can also be the cause. Rarer, but more serious, are the enteric fevers, typhoid and paratyphoid, which have the same risk factors. Advice on food and water hygiene should be given, and it is useful to emphasize the ‘boil it, cook it, peel it or forget it’ approach to eating while abroad, although this advice is difficult to follow and symptoms can still occur in those that do adhere to it. Travellers should be given guidelines on self-treatment that must stress the importance of maintaining hydration and the consideration of a short course of antibiotic. Self-administered fluoroquinolone antibiotics significantly reduce the duration and severity of symptoms in acute watery diarrhoea. A single dose of ciprofloxacin (500 mg) or levofloxacin may be sufficient in many cases, but treatment can be continued for up to three days if symptoms persist. In areas where fluoroquinolone-resistant Campylobacter is present (South and South East Asia) a macrolide, such as azithromycin, may be a more effective choice. It can also be useful to carry a supply of the anti-motility agent loperamide, which can be used if symptoms are interfering with essential plans. However, this should not be taken if the diarrhoea is dysenteric or if the person is febrile. Packaged oral rehydration salts can also be of use, and are a particular advantage in infants, young children and the elderly. Medical advice should be sought abroad if symptoms continue, or if the diarrhoea is dysenteric. Travellers with persistent diarrhoea on return from their trip should have further investigations, particularly looking for protozoan infection with Giardia intestinalis or Cryptosporidium.
Vaccines used for international travel Vaccines administered in the UK for age-specific routine health carea b C Diphtheria b C Tetanus b C Pertussis b C Poliomyelitis (also recommended when there is a risk of disease during travel) b C Haemophilus influenzae C Measles, mumps and rubella (MMR combination vaccine) c C BCG C Influenza C Pneumococcal C Meningococcal C conjugate C HPV Vaccines that may be required for entry into a destination country C Yellow fever (required under International Health Regulations (2005)) C Neisseria meningitidis (serotypes A, C, Y, W 135; required by Saudi Arabia for pilgrims) Vaccines that may be recommended because of risk during travel C Hepatitis A C Hepatitis B C Salmonella enterica serotype Typhi C Japanese encephalitis C Tick-borne encephalitis C Rabies C Cholera Before administering any vaccine, the manufacturer’s complete prescribing information should be consulted a
UK standards for childhood, adolescent and adult immunization, and updates to the ‘Green Book’ are available from the Department of Health immunization website (www.immunisation.nhs.uk). b Usually provided as part of multivalent vaccine products; since autumn 2004, only inactivated polio vaccine has been available in the UK. c BCG is now administered only to high-risk children in the UK, and for travellers under the age of 16 going to high-risk destinations for 3 months (areas with an annual incidence of tuberculosis 40 cases/100,000), or healthcare workers <35 years of age going to same destinations.
Sexually transmitted infections (STIs) Travellers and tourists are often more relaxed about behaviour when abroad, and may have unprotected intercourse with other travellers or locals from high-risk populations. One study found that 25% of people with an STI who attended a genitourinary medicine clinic reported a new partner while away, with almost 70% not using or inconsistently using condoms.12 The risk of transmission of STIs and HIV should be discussed with all
MEDICINE 38:1
Table 3
58
Ó 2009 Elsevier Ltd. All rights reserved.
SPECIAL SITUATIONS
Routine vaccinations e Most travellers born or brought up in high-income countries will have had routine vaccinations against measles, mumps, rubella, tetanus, diphtheria, pertussis and polio. However, this is often not the case in those from lowincome countries, and a vaccination record should be checked for all travellers.
high-risk groups are targeted for pre-travel advice. However it should be emphasized to the traveller that some tropical infections may become manifest only months after return home, and that if they develop a febrile illness at any time up to a year after return malaria must be excluded, even if prophylaxis was taken. A
Required vaccinations e yellow fever is currently the only vaccine that may be required under International Health Regulations (2005). Yellow fever vaccine should be given to those travelling to areas where there is a risk of yellow fever transmission (equatorial Africa and the Amazon basin of South America). Before administering yellow fever vaccination, consideration must be given to recently recognized severe adverse events associated with the vaccine.13 For pilgrims travelling to Saudi Arabia for the Hajj and Umra, the quadrivalent meningococcal vaccine is required by Saudi Arabia as a condition of granting a visa.
REFERENCES 1 Steffen R, Amitirigala I, Mutsch M. Health risks among travellers e need for regular updates. J Travel Med 2008; 15: 145e6. 2 Hargarten SW, Barker TD, Guptill K. Overseas fatalities of United States citizen travellers: an analysis of deaths related to international travel. Ann Emerg Med 1991; 20: 622e6. 3 MacPherson DW, Gushulak BD, Sandhu J. Death and international travelethe Canadian experience: 1996 to 2004. J Travel Med 2007; 14: 77e84. 4 Van Herck K, Van Damme P, Castelli F, et al. Knowledge, attitudes and practices in travel-related infectious diseases: the European airport survey. J Travel Med 2004; 11: 3e8. 5 Ansart S, Perez L, Vergely O, Danis M, Bricaire F, Caumes E. Illnesses in travellers returning from the tropics: a prospective study of 622 patients. J Travel Med 2005; 12: 312e18. 6 Leder K, Tong S, Weld L, et al. Illness in travelers visiting friends and relatives: a review of the GeoSentinel Surveillance Network. Clin Infect Dis 2006; 43: 1185e93. 7 Steinlau S, Segal G, Sidi Y, Schwartz E. Epidemiology of travel-related hospitalization. J Travel Med 2005; 12: 136e41. 8 Freedman DO, Weld LH, Kozarsky PE, et al. for the GeoSentinel Surveillance Network Spectrum of disease and relation to place of exposure among ill travellers. N Eng J Med 2006; 354: 119e30. 9 Lalloo DG, Hill DR. Preventing malaria in travellers. BMJ 2008; 336: 1362e6. 10 Chiodini P, Hill D, Lalloo D, et al. Guidelines for Malaria Prevention in Travellers from the United Kingdom. London: Health Protection Agency, January 2007. Also available at: http://www.hpa.org.uk/webw/ HPAweb&HPAwebStandard/HPAweb_C/1195733823080?p¼ 1191942128258 (accessed 23.09.09). 11 Hill DR, Ryan ET. Management of travellers’ diarrhoea. BMJ 2008; 337: 863e7. 12 Gilles P. HIV related risk behaviour in UK holiday makers. AIDS 1992; 6: 339e40. 13 Lindsey NP, Schroeder BA, Miller ER, et al. Adverse event reports following yellow fever vaccination. Vaccine 2008; 26: 6077e82. 14 Rogstad KE. Sex, sun, sea and STIs: sexually transmitted infections acquired in holiday. BMJ 2004; 329: 214e17.
Immunization for risk e the practitioner must understand the epidemiology of disease in the destination region, the mode of acquisition (e.g. food-borne, vector-borne, water-borne) and non-vaccine preventive measures available, and then determine whether the traveller is likely to be at risk during his or her trip. Other factors for consideration are the potential adverse effects, cost and efficacy of the vaccine. If the risk is deemed high enough, the vaccine should be given. Travellers should be informed that no vaccine is 100% effective and appropriate precautionary measures should still be taken.
Accidents Accidents are an important cause of serious morbidity and mortality during travel, and travellers should be aware of the risks of RTAs and driving in foreign countries, particularly when unfamiliar with different road systems. The need for moderation of alcohol consumption must be addressed because of its tendency to promote risk-taking behaviour, including unsafe sexual practices, or accidents.14 All travellers should have comprehensive travel insurance that will cover illness or underlying medical conditions, in addition to their expected activities. They should also know how to access safe medical care in the event of an accident or illness. Travellers from the UK should consult the Foreign and Commonwealth Office country page to determine if there are any safety or travel restrictions for their destination. In summary, most travel-related illness is avoidable if the necessary preventative measures are taken, and the appropriate
MEDICINE 38:1
59
Ó 2009 Elsevier Ltd. All rights reserved.
Advising the traveller
What’s new?
Joanna S Herman C
David R Hill
C C
C
Abstract
C
Nearly 70 million visits are made from the UK to foreign countries each year. Over the past decade there has been a large increase in travel to tropical destinations that have different health risks from those encountered closer to home. Seeking pre-travel advice should be an essential part of any trip for a traveller, but is often omitted. The key elements of pre-travel advice are health risk assessment and health promotion, which involves advice on prevention of malaria, travellers’ diarrhoea, sexually transmitted infections and accidents, as well as appropriate vaccinations. High-risk groups of travellers, such as those visiting friends and relatives, need to be particularly targeted.
Decrease in incidence of P. vivax in travellers Change in timing of BCG vaccination New understanding of adverse events associated with yellow fever vaccine New oral cholera vaccine New Japanese encephalitis vaccine
primary care setting or at specialized travel clinics, and is usually nurse-led.
Access to pre-travel healthcare A survey of European travellers visiting countries in the developing world found that only 50% had sought pre-travel health advice.4 Of these, the majority had been to their general practice surgery, and about 30% consulted a specialist travel medicine clinic. The likelihood of seeking pre-travel advice varies in different groups of travellers, with migrants who return to their country of origin to visit friends and relatives (VFRs) being the least likely to seek advice or take precautionary measures. This group has a disproportionately increased risk of acquiring the more common tropical infections, when compared to the other travellers, and they should be targeted specifically for pre-travel advice.5,6
Keywords health risk assessment; health promotion; malaria prevention; pre-travel advice; travel medicine; travellers’ diarrhoea; vaccinations; yellow fever
Introduction The travel clinic consultation
International travel has increased at a dramatic rate over the past decade, with an estimated 800 million travellers worldwide now crossing international borders, and 70 million visits made from the UK each year. Although many travellers from the UK visit Europe, there has been a marked increase in travel to more tropical destinations that carry particular health risks. Travel to such places brings exposure to a broad range of pathogens rarely, if ever, encountered at home, with the risk of morbidity varying between 20 and 70%.1 While the majority of illnesses tend to be self-limiting, approximately 5% of travellers will require a doctor’s attention and 1% will require hospitalization whilst abroad, and many travellers will require medical care on return home. However, the most likely causes of mortality in travellers are accidental injury (e.g. road traffic accident or drowning) or a cardiovascular event, rather than an infectious disease, which accounts for only 1e2% of deaths.2,3 Many travel-related illnesses are preventable by taking sensible precautionary measures, and, for some diseases, by having the appropriate vaccinations and taking chemoprophylactic medications. In the UK pre-travel advice is given in the
The key features of a pre-travel consultation are health risk assessment, and health promotion with risk management (Table 1). Risk assessment Risk of infection varies according to the area to be visited, endemicity of diseases, nature of travel (holiday, business, backpacker, VFR), type of accommodation, anticipated activities,
Key elements of travel medicine Health risk assessment C
C
Health promotion and risk management C C C C C
Joanna S Herman MBBS MSc MRCP is a Specialist Registrar in Infectious Diseases and Tropical Medicine at the Hospital for Tropical Diseases, London, UK. Competing interests: none declared.
C
Responsible personal behaviour and safety Vaccine-preventable illness Vector avoidance Malaria prevention Travellers’ diarrhoea prevention and self-treatment Environmental illness e altitude, heat, swimming, jet lag, prevention of deep-vein thrombosis
Travel insurance and access to medical care overseas Post-travel screening, care and triage of illness (e.g. fever, diarrhoea, rash)
David R Hill MD DTM&H FRCP FFTM is Director of the National Travel Health Network and Centre and Honorary Professor, London School of Hygiene and Tropical Medicine, London, UK. Competing interests: none declared.
MEDICINE 38:1
Health status of traveller e medical conditions, medications and allergies, immunization history Health risk of travel e itinerary (rural, urban), accommodation, duration of trip, anticipated activities
Table 1
56
Ó 2009 Elsevier Ltd. All rights reserved.
SPECIAL SITUATIONS
and duration of trip. It will also vary according to the health status of the traveller: their medical conditions, current medications, allergies and immunization history. The majority (80e95%) of travellers to the tropics undertake short-term visits (<1 month), with the other 5e20% spending long periods abroad, either travelling or working (e.g. backpackers, missionaries, volunteer workers, placements with the armed forces), or on repeated short-term visits (e.g. businessmen, airline crews). The risks and exposure these groups incur are different, and depend on both individual behaviour and environment, with the long-term group at greater risk of acquiring infections endemic in the local population they are visiting. There is also a risk difference between the sexes, with male travellers being at greater risk of disease acquisition.7 Risk varies according to the geographical area visited. Travellers to Africa have the highest rate of all-cause morbidity and account for the greatest number of cases of Plasmodium falciparum malaria.8 The highest risk of P. vivax and diarrhoeal illness is in travellers to South Asia, while cutaneous leishmaniasis is most common in visitors to Latin America. Risk within a country may also differ; for example, malaria risk in Nairobi is negligible compared with a significant risk on the Kenyan coast. Information about the regional prevalence of specific diseases can be difficult to obtain, but some websites offer valuable information, particularly in relation to recent outbreaks or vaccine recommendations, e.g. the World Health Organization, the National Travel Health Network and Centre (NaTHNaC), and the Centers for Disease Control and Prevention (see Box 1 for web addresses). However, it is important to remember that non-tropical infections account for many of the infections that present in returned travellers.5
serious or potentially fatal. These include malaria, travellers’ diarrhoea, sexually transmitted infections, and road traffic accidents (RTAs). Health hazards that are rare (e.g. cholera, Japanese encephalitis, parasitic infections) take a lower priority. The travel medicine practitioner must balance the need for prophylaxis against the realistic risk of infection and the likelihood of adherence by the traveller. However, travellers should be aware that no intervention is fully protective. Malaria (Table 2) Malaria is one of the most serious causes of fever in travellers, either while abroad or on return (see the article on malaria, pp. 41e46). The risk of malaria is greatest in sub-Saharan Africa (particularly West Africa), to a lesser extent in South Asia (India), and lowest in Central and South America and South East Asia. However, the risk can vary widely within countries depending on location. In the UK each year there are 1500e1750 cases of malaria reported and 5e10 deaths; almost all deaths are caused by P. falciparum. Prevention of infection involves understanding of the disease process and the ‘ABCD of malaria’:9 Awareness of risk Bite prevention from nocturnal Anopheles spp. mosquitoes Chemoprophylaxis prompt Diagnosis of infection Bite prevention measures include use of insect repellent such as DEET, covering up at the appropriate time of day (dusk to dawn), and sleeping under an insecticide-impregnated mosquito net. The choice of chemoprophylaxis depends on what type of malaria is endemic in the region being visited, and the presence of drug resistance. It will also depend on individual factors and preferences for the different drug regimens, such as dosing frequency (e.g. weekly for mefloquine or daily for doxycycline or atovaquoneeproguanil), and affordability. For detailed advice, including side effects and special cases such as pregnancy see the continually updated UK
Health promotion and risk management Many travel consultations focus on vaccinations, but these may be among the least cost-effective preventative measures in travellers, as vaccine-preventable diseases account for less than 5% of travel-associated morbidity e a figure similar to that for accidents and injuries. The main priorities should be given to health problems that are common, preventable/treatable, and
Prevention of malaria Vector avoidance C
Useful websites
C C
National Travel Health Network and Centre (www.nathnac.org)a Health Protection Scotland (http://www.hps.scot.nhs.uk/)a UK Foreign and Commonwealth Office (www.fco.gov.uk) ‘Know Before You Go’ site provides information on travel insurance and safety (www.fco.gov.uk/en/travelling-and-livingoverseas/about-kbyg-campaign/) WHO Travellers’ Health section (www.who.int/ith/)a US Centers for Disease Control and Prevention (www.cdc.gov/ travel/)a International Society of Travel Medicine (www.istm.org)a,b
C
Protective clothing Repellents e either with DEET a or picaridin are the most effective. Netting e impregnated with a residual insecticide such as permethrin Limiting exposure during transmission time (dusk to dawn) b
Antimalarial chemoprophylaxis C C
C C C
Chloroquine (only where there is no resistant P. falciparum) Chloroquine plus proguanil (only where there is little resistant P. falciparum, or where P. vivax predominates) Atovaquone plus proguanil Doxycycline Mefloquine
a
20e50% Is usually recommended and is safe for all travellers >2 months of age; the manufacturer’s guidelines for use should be followed. b Before prescribing an antimalarial agent, the prevalence and species of malaria found in the travel destination as well as potential resistance must be determined, as should any medical contraindications.
a
These organizations aim to improve travellers’ health by providing guidance and setting standards for health professionals in settings ranging from primary care to specialized travel clinics
b
Publishes the Journal of Travel Medicine
Box 1
MEDICINE 38:1
Table 2
57
Ó 2009 Elsevier Ltd. All rights reserved.
SPECIAL SITUATIONS
travellers who seek pre-travel advice, as the risk can be virtually eliminated by practising safer sex. Raising awareness of these sensitive issues is an important part of the travel health consultation, although some practitioners may find them difficult to address. Less common risk factors for HIV infection include invasive medical treatment and transfusion with contaminated blood, which are of particular importance in sub-Saharan Africa where the seroprevalence of HIV can be as high as 30%.
malaria advice at http://www.hpa.org.uk/web/HPAweb&HPAweb Standard/HPAweb_C/1195733823080. For countries with a high prevalence of chloroquine-resistant P. falciparum, mefloquine, doxycycline or atovaquoneeproguanil can be taken. For areas with little chloroquine resistance, chloroquine plus proguanil should be taken, and in areas without resistance, chloroquine or proguanil can be used.10 Practitioners need to be aware of the adverse effects and contraindications to all the antimalarials; for example, mefloquine is contraindicated in those with a neuropsychiatric history (e.g. depression, seizures), or a cardiac conduction abnormality. Fever secondary to malaria can be difficult to differentiate clinically from other causes of fever, and any traveller who develops fever within a year of return from the tropics should have malaria excluded by blood film.
Vaccinations (Table 3) There are three main reasons for vaccinating travellers: recommended as part of routine healthcare required by destination country recommended because of travel-related risk.
Gastrointestinal illness Diarrhoea is the most common illness affecting travellers to developing countries, and can affect 20e60% of travellers; 11 see the article on pp. 26e29. The most common causal organisms are bacteria, particularly enterotoxigenic Escherichia coli, enteroaggregative E. coli, Salmonella spp., Shigella and Campylobacter, but viruses (rotavirus and noroviruses) and protozoa (Giardia lamblia and Cryptosporidium spp.) can also be the cause. Rarer, but more serious, are the enteric fevers, typhoid and paratyphoid, which have the same risk factors. Advice on food and water hygiene should be given, and it is useful to emphasize the ‘boil it, cook it, peel it or forget it’ approach to eating while abroad, although this advice is difficult to follow and symptoms can still occur in those that do adhere to it. Travellers should be given guidelines on self-treatment that must stress the importance of maintaining hydration and the consideration of a short course of antibiotic. Self-administered fluoroquinolone antibiotics significantly reduce the duration and severity of symptoms in acute watery diarrhoea. A single dose of ciprofloxacin (500 mg) or levofloxacin may be sufficient in many cases, but treatment can be continued for up to three days if symptoms persist. In areas where fluoroquinolone-resistant Campylobacter is present (South and South East Asia) a macrolide, such as azithromycin, may be a more effective choice. It can also be useful to carry a supply of the anti-motility agent loperamide, which can be used if symptoms are interfering with essential plans. However, this should not be taken if the diarrhoea is dysenteric or if the person is febrile. Packaged oral rehydration salts can also be of use, and are a particular advantage in infants, young children and the elderly. Medical advice should be sought abroad if symptoms continue, or if the diarrhoea is dysenteric. Travellers with persistent diarrhoea on return from their trip should have further investigations, particularly looking for protozoan infection with Giardia intestinalis or Cryptosporidium.
Vaccines used for international travel Vaccines administered in the UK for age-specific routine health carea b C Diphtheria b C Tetanus b C Pertussis b C Poliomyelitis (also recommended when there is a risk of disease during travel) b C Haemophilus influenzae C Measles, mumps and rubella (MMR combination vaccine) c C BCG C Influenza C Pneumococcal C Meningococcal C conjugate C HPV Vaccines that may be required for entry into a destination country C Yellow fever (required under International Health Regulations (2005)) C Neisseria meningitidis (serotypes A, C, Y, W 135; required by Saudi Arabia for pilgrims) Vaccines that may be recommended because of risk during travel C Hepatitis A C Hepatitis B C Salmonella enterica serotype Typhi C Japanese encephalitis C Tick-borne encephalitis C Rabies C Cholera Before administering any vaccine, the manufacturer’s complete prescribing information should be consulted a
UK standards for childhood, adolescent and adult immunization, and updates to the ‘Green Book’ are available from the Department of Health immunization website (www.immunisation.nhs.uk). b Usually provided as part of multivalent vaccine products; since autumn 2004, only inactivated polio vaccine has been available in the UK. c BCG is now administered only to high-risk children in the UK, and for travellers under the age of 16 going to high-risk destinations for 3 months (areas with an annual incidence of tuberculosis 40 cases/100,000), or healthcare workers <35 years of age going to same destinations.
Sexually transmitted infections (STIs) Travellers and tourists are often more relaxed about behaviour when abroad, and may have unprotected intercourse with other travellers or locals from high-risk populations. One study found that 25% of people with an STI who attended a genitourinary medicine clinic reported a new partner while away, with almost 70% not using or inconsistently using condoms.12 The risk of transmission of STIs and HIV should be discussed with all
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SPECIAL SITUATIONS
Routine vaccinations e Most travellers born or brought up in high-income countries will have had routine vaccinations against measles, mumps, rubella, tetanus, diphtheria, pertussis and polio. However, this is often not the case in those from lowincome countries, and a vaccination record should be checked for all travellers.
high-risk groups are targeted for pre-travel advice. However it should be emphasized to the traveller that some tropical infections may become manifest only months after return home, and that if they develop a febrile illness at any time up to a year after return malaria must be excluded, even if prophylaxis was taken. A
Required vaccinations e yellow fever is currently the only vaccine that may be required under International Health Regulations (2005). Yellow fever vaccine should be given to those travelling to areas where there is a risk of yellow fever transmission (equatorial Africa and the Amazon basin of South America). Before administering yellow fever vaccination, consideration must be given to recently recognized severe adverse events associated with the vaccine.13 For pilgrims travelling to Saudi Arabia for the Hajj and Umra, the quadrivalent meningococcal vaccine is required by Saudi Arabia as a condition of granting a visa.
REFERENCES 1 Steffen R, Amitirigala I, Mutsch M. Health risks among travellers e need for regular updates. J Travel Med 2008; 15: 145e6. 2 Hargarten SW, Barker TD, Guptill K. Overseas fatalities of United States citizen travellers: an analysis of deaths related to international travel. Ann Emerg Med 1991; 20: 622e6. 3 MacPherson DW, Gushulak BD, Sandhu J. Death and international travelethe Canadian experience: 1996 to 2004. J Travel Med 2007; 14: 77e84. 4 Van Herck K, Van Damme P, Castelli F, et al. Knowledge, attitudes and practices in travel-related infectious diseases: the European airport survey. J Travel Med 2004; 11: 3e8. 5 Ansart S, Perez L, Vergely O, Danis M, Bricaire F, Caumes E. Illnesses in travellers returning from the tropics: a prospective study of 622 patients. J Travel Med 2005; 12: 312e18. 6 Leder K, Tong S, Weld L, et al. Illness in travelers visiting friends and relatives: a review of the GeoSentinel Surveillance Network. Clin Infect Dis 2006; 43: 1185e93. 7 Steinlau S, Segal G, Sidi Y, Schwartz E. Epidemiology of travel-related hospitalization. J Travel Med 2005; 12: 136e41. 8 Freedman DO, Weld LH, Kozarsky PE, et al. for the GeoSentinel Surveillance Network Spectrum of disease and relation to place of exposure among ill travellers. N Eng J Med 2006; 354: 119e30. 9 Lalloo DG, Hill DR. Preventing malaria in travellers. BMJ 2008; 336: 1362e6. 10 Chiodini P, Hill D, Lalloo D, et al. Guidelines for Malaria Prevention in Travellers from the United Kingdom. London: Health Protection Agency, January 2007. Also available at: http://www.hpa.org.uk/webw/ HPAweb&HPAwebStandard/HPAweb_C/1195733823080?p¼ 1191942128258 (accessed 23.09.09). 11 Hill DR, Ryan ET. Management of travellers’ diarrhoea. BMJ 2008; 337: 863e7. 12 Gilles P. HIV related risk behaviour in UK holiday makers. AIDS 1992; 6: 339e40. 13 Lindsey NP, Schroeder BA, Miller ER, et al. Adverse event reports following yellow fever vaccination. Vaccine 2008; 26: 6077e82. 14 Rogstad KE. Sex, sun, sea and STIs: sexually transmitted infections acquired in holiday. BMJ 2004; 329: 214e17.
Immunization for risk e the practitioner must understand the epidemiology of disease in the destination region, the mode of acquisition (e.g. food-borne, vector-borne, water-borne) and non-vaccine preventive measures available, and then determine whether the traveller is likely to be at risk during his or her trip. Other factors for consideration are the potential adverse effects, cost and efficacy of the vaccine. If the risk is deemed high enough, the vaccine should be given. Travellers should be informed that no vaccine is 100% effective and appropriate precautionary measures should still be taken.
Accidents Accidents are an important cause of serious morbidity and mortality during travel, and travellers should be aware of the risks of RTAs and driving in foreign countries, particularly when unfamiliar with different road systems. The need for moderation of alcohol consumption must be addressed because of its tendency to promote risk-taking behaviour, including unsafe sexual practices, or accidents.14 All travellers should have comprehensive travel insurance that will cover illness or underlying medical conditions, in addition to their expected activities. They should also know how to access safe medical care in the event of an accident or illness. Travellers from the UK should consult the Foreign and Commonwealth Office country page to determine if there are any safety or travel restrictions for their destination. In summary, most travel-related illness is avoidable if the necessary preventative measures are taken, and the appropriate
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Ó 2009 Elsevier Ltd. All rights reserved.