Preventive measures for overseas travel or residence
Preventive measures for overseas travel or residence
The question that is most commonly asked prior to overseastravel to or residence in the tropics or subtropics is'what vaccines are needed?' In fact, the main diseasethreats do not come from vaccine-preventable conditions,but from trauma, alcohol-related illness, sun exposure,unprotected sexual contacts and infectious diarrhoealdisease. Malaria is the main threat that is amenable topreventive measures.Protection of skinThe skin must be protected against biting insects. This isimportant not only for the prevention of malaria, but alsofor protection against viral, rickettsial, protozoal andfilarial diseases transmitted by insect vectors.Exposure to ticks occurs mainly in rural bush areas andso appropriate clothing and footwear is needed to preventticks getting on to the skin. Evening and night hours aretimes for maximum frequency of biting by many insects,and at these times the skin should be covered as much aspossible wearing shirts with long sleeves and long trousersor skirts. Insect repellent (diethyltoluamide (DEET)-containing compounds with formulations designed to havea long retention time on the skin) is applied to exposedareas, including the forearms, lower legs, ankles and feet,and face and neck. Elasticated wrist and ankle bands canbe impregnated with DEET and worn for the samepurpose. Mosquito nets should be used in malarial areas ifdoors and windows are not screened. Impregnation of bednets and curtains with permethrin enhances protectionthrough its residual insecticidal action. It is also useful tospray bedrooms with insecticide last thing at night.Schistosomiasis is acquired by contact between skin andslow-flowing or still water containing cercariae. Swimmingand paddling in fresh water are best avoided in endemicareas.Protection against malariaMeasures to prevent mosquito bites (see above) andchemoprophylaxis against malaria are the sole means ofpreventing malaria in the traveller. The traveller must betold that there is no vaccine against malaria and that noneof the vaccines received prior to travel is of any benefit inthis regard. Details of chemoprophylaxis against malariaare given in Table 9.36, p. 352.Immunization for travellers oroverseas residentsA range of vaccines is available and the commonly usedones are listed in Table 9.10. Poliomyelitis is still commonin many areas of the world, and so adequate vaccinationshould be assured in all travellers. Meningococcal vaccineis most often recommended for backpackers in sub-Saharan Africa. It is occasionally a requirement for travelto specified countries, e.g. Saudi Arabia for the Hajjpilgrimage. Yellow fever vaccination is essential for thosevisiting tropical Africa, the Caribbean and South America.Oral poliomyelitis and yellow fever vaccines should begiven either together or separated by an interval of 3weeks. Active hepatitis A vaccination is available and isusually used in preference to passive immunization,although it is more expensive. Hepatitis B vaccination isparticularly recommended for those at particular risk,i.e. healthcare and hospital laboratory workers, althoughincreasingly backpacking travellers are having this vaccine.Pre-exposure rabies vaccination is needed by those whomay have any contact with animals, but again increasingnumbers of tourists undertaking overland travels arehaving pre-exposure vaccination. The intradermal routeallows more economical use of the vaccine. Tetanusvaccination is needed for any who may be at particular riskof trauma, e.g. military personnel, construction workers etc.Typhoid vaccination is a sensible precaution for manyareas, but those vaccinated should be told that having thevaccine does not mean that they are 100% protected andcan be careless about sources of water and food. Althoughthe whole-cell killed vaccine has the greatest efficacy it alsohas the greatest incidence of side-effects and is not nowobtainable. The choice lies between two vaccines: (a) theTy21a oral vaccine containing the epimerase-deficientstrain of S. typhi, which has the appeal of stimulating animmune response at the site of entry of the naturalpathogen, and (b) the vaccine based on the Vi antigen ofS. typhi. Cholera vaccination is not effective.Protection of the gutGastrointestinal infection is the most common afflictionfaced by the traveller. Boiled water used to make tea andcoffee or left to cool in a covered, clean container is safeto drink. Bottled drinks are safe. Water from the tap orwater used to make ice cubes may not be safe. Tincture ofiodine (2%) can be used to sterilize water, adding 0.5mLper litre and allowing it to stand for 30 minutes. Iodine ismore potent than chlorine-based sterilizing tablets. How to Save Big on Your Next Trip with an Expedia Coupon Code The Advantages of Discount Travel Services No More Incredible City In The World Than Sydney, Australia Travelling with a Medical Condition Architecture Of Africa Relaxing at Fascinating Toledo Holiday Wreaths Decorating Ideas Watch The Office Season 7 Episode 11 - Classy Christmas Touring Lanzarote by Bike Halong Bay Vietnam Cruise Tour Overnight on Junk China, US Cooperate to Fight Taiwan Referendum Plan Franchise Royalties - Finding a Win-Win Are You Travelling to the World Cup This Year?