General | July 6, 2014 | Author: The Super Pharmacist
Travel is an enjoyable or essential part of life for many people however particular diseases or illnesses may be associated with one or more regions of the world. Contracting one can be particularly unpleasant for travellers, especially if they may not have access to adequate medical care. This may be avoided by immunisation against the viruses or bacteria that cause disease.
Vaccinations are inactive (i.e. dead or chemically inactivated) or attenuated (live but weakened) forms of these micro-organisms. They may also be individual parts or components of the micro-organism, e.g. a toxin. Vaccination programmes are common worldwide to prevent the spread of common diseases (e.g. rubella) but can also be given in advance of a journey abroad, to prevent an individual becoming infected.
Some of the most prevalent, disease-causing bacteria or viruses are listed below, so you may decide whether or not to be vaccinated against these if travelling to any of the countries or regions affected.
This bacterium causes a disease known as typhoid fever.
Symptoms may include progressive fever, headache, sleep disturbances, loss of appetite, constipation and possible diarrhoea.
Untreated typhoid can cause irregular heartbeat, neurological abnormalities and gastrointestinal damage, which may lead to death.
Salmonella typhi is contracted through consumption of contaminated food or water.
Typhoid vaccines are available as live-attenuated cells, or those containing specific molecules found on the surface of this bacterium.
Typhoid fever is particularly prevalent in:
This is a leading cause of bacterial meningitis, a condition that involves inflammation of the linings of the brain. Bacterial meningitis causes death in approximately 10% of all cases. One in ten survivors experience permanent neurological damage or live with amputated extremities (a common medical procedure to halt the spread of Neisseria meningitides). There are also rare cases of meningococcal septicaemia (blood poisoning) which are often fatal. There are six main subtypes of the bacterium associated with meningitis: A, B, C, W-135, X and Y. Vaccines may contain a combination of two or more of these.
Neisseria meningitides infection is endemic in sub-Saharan Africa. An extensive region, spreading roughly from Senegal in the west to Ethiopia in the east, encompassing every country in it, is associated with a high rate of meningitis development. Travellers to this region are not thought to be at high risk of infection, unless their stay is prolonged and/or they are in consistent close proximity to individuals who may be affected. However, vaccination is mandatory for entry into certain countries such as Saudi Arabia.
Yellow fever is particularly prevalent in central African countries, and in most of South America. The virus may cause headache, chills, fever, loss of appetite and nausea, which may be accompanied by heart rate abnormalities. This may progress to renewed fever, abdominal pain and haemorrhaging. Death occurs in 7.5% of symptomatic yellow fever cases. The yellow fever virus vaccine, 17D, is a live-attenuated form intended for injection.
Yellow fever incidence has decreased, possibly due to effective vaccination programmes. Travellers are at high risk of infection if their plans include activities with an increased probability of mosquito exposure, e.g. 'jungle treks'.
Travellers coming from regions associated with a high prevalence of yellow fever are required to have proof of vaccination for entry into many countries.
Three main subtypes of this virus are associated with poliomyelitis, or infantile paralysis. Poliomyelitis may cause permanent loss or significant decrease of motor function in children under five, if the virus reaches the spinal cord. This occurs in approximately 1% of cases. Polio had been largely eradicated in many countries, but is reported to have caused recent outbreaks and pandemics in some countries. This is associated with both 'wild' and vaccine-derived polio virus. Vaccination for polio is an oral form of either inactivated or live-attenuated viral particles. This is recommended for all travellers intending to visit the following countries:
This is a bacterium that causes tetanus, via a neurotoxin released once in the body. Tetanus presents as a spasming of the jaw muscles ('trismus') and/or spasms of the back muscles ('opisthotonus'). Tetanus is easily treated, but may result in death if medical attention is not readily available. Tetanus may be contracted anywhere on earth. This is normally due to infection of open wounds with Clostridium tetani spores. Tetanus vaccination (inactive toxin) is not recommended by authorities, unless the traveller intends to engage in activities such as hiking; however, the WHO advises that all travellers are immunised.
This virus causes the form of acute encephalomyelitis know as rabies which is transmitted via animal bite or scratch. Mammals are the main carriers of rabies, and may be found nearly everywhere on earth.
The first signs of rabies infection in humans are usually malaise, headache and fever, progressing to excitability, hallucinations and oesophageal muscle spasms, culminating in convulsions, delirium and fatality. Lyssavirus may alternatively cause paralysis and pain.
The risk of rabies is increased for travellers who are planning extensive outdoor activities and/or activities which may take them into close proximity to wild or stray animals. There is a moderate to high risk of rabies in:
The rabies vaccine is recommended for high-risk travellers, and is also part of conventional treatment for acute infection.
There are two types of the hepatitis A vaccine: inactivated virus and live attenuated virus. The inactivated form is recommended for travellers, although the live-virus version has also demonstrated efficacy in providing immunity.
There is a moderate to severe risk of Hepatitis A contraction in nearly every country, with the exception of the following nations or regions:
Either form of Hepatitis A vaccine should be administered two to four weeks before travel. This vaccine is not always mandatory for travel, but is recommended for every individual of one year old or more.
This is a separate form of hepatitis, caused by a different class of virus to that responsible for hepatitis A.
This virus may cause loss of appetite, abdominal pains, nausea, vomiting, rash and possible jaundice. Hepatitis B may also be asymptomatic. Approximately 1% of hepatitis B cases in adults result in death. Chronic infection may result in severe liver damage.
Contraction of this virus is associated with the exchange of body fluids, e.g. unprotected sex or receiving an unscreened blood transfusion, or skin breaks caused by unsterilized needles.
The hepatitis B vaccine is produced in yeast by genetic recombination. Two doses are usually given one month apart, with a third up to twelve months later. This vaccine is not usually required for travel, but is strongly recommended for all travellers with a destination in a moderate to high risk of hepatitis B infection. These include:
This viral condition may cause fever, headache and symptoms of meningitis. Approximately 25% of severe cases are fatal. This disease is most prevalent in:
Travellers to these regions are not at high risk, unless they are in more non-urban areas for longer periods of time, e.g. in the course of hiking trips and other outdoor activities. The Japanese encephalitis vaccine is an inactivated form of the virus. Immunisation is not required, unless the traveller intends to take part in a high volume of outdoor activities, where there is more risk of exposure to the virus' insect vector (a type of mosquito). The incidence of Japanese encephalitis has been reduced considerably due to regular immunisation programmes, but this has not affected the high rate of infection.
Cholera is caused by the O1 and O139 subtypes of the bacterium Vibrio cholerae. These can cause moderate to severe diarrhoea. Death from cholera mostly occurs through extreme dehydration. Cholera is no longer considered prevalent or endemic, but still persists in many nations and regions, including:
The risk of cholera to travellers is considered to be low, and immunisation is only strongly required for health, aid and disaster relief workers4. Cholera is best protected against by avoiding potentially contaminated food and water. Vaccines consist of either inactive O1 bacterial cells with a subunit of the cholera toxin (in order to elicit immune system recognition of both) or a combination of dead O1 and O139 bacteria. Travellers at risk of cholera should take two doses by mouth one or two weeks4. All at-risk travellers of two years or more should be immunised4.
Some diseases, which are endemic in many popular destination areas, unfortunately do not have corresponding vaccines. In many cases, these are still in development or at the clinical trial stage. They also cause illness and discomfort for many travellers.
Preventative measures are based on chemical prophylaxis, i.e. drugs that can halt or treat an infection if the pathogen in question comes into contact with them.
These are micro-organisms of a class called protozoans. Certain subtypes of these, particularly Plasmodium falciparum and Plasmodium vivax, are responsible for the widespread disease malaria. The protozoans are spread by mosquitos (Anaphales).
Malaria is characterised by fever, headache, vomiting, arthalgia, shivering or convulsions, jaundice and retinal damage. Malaria may also cause pnuemonia-like symptoms and anaemia.
Some estimates put the number of people infected with malaria at between 300 to 500 million worldwide, with approximately 1.2 million deaths (based on estimates from 2010). Malarial transmission reduction is based on drug therapy. Malarone, doxycycline, mefloquine or chloroquine tablets are recommended just before and during travel in an affected country or region. These are:
As 65% of malaria cases occur in people under 15, prophylaxis for children is particularly important. Acute infection is mainly treated with artemisinins, primaquine and 8-aminoquinolines.
This disease is also spread by a type of mosquito (Aedes). It is thought to affect nearly a hundred million people worldwide, but as dengue infection is often asymptomatic (or goes unreported), this number may in fact be much higher.
Dengue may present as mild fever, headache, rash, joint pain, gastrointestinal disturbances, or severe signs such as shock or haemorrhagic fever. The less serious symptoms are more common, but the disease may also be fatal.
Dengue may be prevented by reducing the risk of mosquito bites through suitable clothing, the use of nets while resting and using insect repellent.
Unfortunately, there are no vaccines or specific antiviral drugs for dengue.
Treatment for this disease is mainly based on combating the symptoms; e.g. paracetamol for fever, analgesics for joint pain, platelet transfusion for haemorrhaging. Corticosteroids are also used to treat dengue-related shock. Dengue is prevalent in the following regions or countries:
This is a common gut bacterium which may cause diarrhoea and gastrointestinal discomfort. In these cases, it is termed enterotoxigenic E. coli (ETEC), which is associated with the common condition of "traveller's diarrhoea". Currently, there are no specific treatments or vaccines for ETEC. Some vaccine candidates, mainly targeting molecules called adhesins and/or the ETEC heat-labile toxin, are currently in development. ETEC is particularly prevalent in:
Langley JM, Carmona Martinez A, Chatterjee A, et al. Immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate: a phase III randomized controlled trial in children. The Journal of infectious diseases.2013;208(4):544-553.
Ambuel Y, Young G, Brewoo JN, et al. A rapid immunization strategy with a live-attenuated tetravalent dengue vaccine elicits protective neutralizing antibody responses in non-human primates. Frontiers in immunology.2014;5:263.
Deen J, Ali M, Sack D. Methods to assess the impact of mass oral cholera vaccination campaigns under real field conditions. PloS one.2014;9(2):e88139.
World Health Organization. International travel and health : situation as on 1 January 2012. Geneva: World Health Organization; 2012.
Barrett FC, Knudsen JD, Johansen IS. Cases of typhoid fever in Copenhagen region: a retrospective study of presentation and relapse. BMC research notes.2013;6:315.
Agu K, Nzegwu M, Obi E. Prevalence, Morbidity, and Mortality Patterns of Typhoid Ileal Perforation as Seen at the University of Nigeria Teaching Hospital Enugu Nigeria: An 8-year Review. World journal of surgery.2014.
Anwar E, Goldberg E, Fraser A, Acosta CJ, Paul M, Leibovici L. Vaccines for preventing typhoid fever. The Cochrane database of systematic reviews.2014;1:Cd001261.
Gallego V, Berberian G, Lloveras S, et al. The 2014 FIFA World Cup: Communicable disease risks and advice for visitors to Brazil - A review from the Latin American Society for Travel Medicine (SLAMVI). Travel medicine and infectious disease.2014;12(3):208-218.
Darton TC, Blohmke CJ, Pollard AJ. Typhoid epidemiology, diagnostics and the human challenge model. Current opinion in gastroenterology.2014;30(1):7-17.
Ying S, He J, Yu M, et al. Recombinant Neisseria surface protein A is a potential vaccine candidate against Neisseria meningitides serogroup B. Molecular medicine reports.2014.
Gudlavalleti SK, Crawford EN, Harder JD, Reddy JR. Quantification of each Serogroup Polysaccharide of Neisseria meningitidis in A/C/Y/W-135-DT Conjugate Vaccine by High-Performance Anion-Exchange Chromatography-Pulsed Amperometric Detection Analysis. Analytical chemistry.2014;86(11):5383-5390.
Serie C, Lindrec A, Poirier A, Andral L, Neri P. [Studies on yellow fever in Ethiopia. I. Introduction- clinical symptoms of yellow fever]. Bulletin of the World Health Organization.1968;38(6):835-841.
Wiwanitkit V. Vaccination against mosquito borne viral infections: current status. Iranian journal of immunology : IJI.2007;4(4):186-196.
Muyanja E, Ssemaganda A, P NG, et al. Immune activation alters cellular and humoral responses to yellow fever 17D vaccine. The Journal of clinical investigation.2014.
Hovi T, Paananen A, Blomqvist S, et al. Characteristics of an environmentally monitored prolonged type 2 vaccine derived poliovirus shedding episode that stopped without intervention. PloS one.2013;8(7):e66849.
Sutter RW, John TJ, Jain H, et al. Immunogenicity of bivalent types 1 and 3 oral poliovirus vaccine: a randomised, double-blind, controlled trial. Lancet.2010;376(9753):1682-1688.
Serie C, Lindrec A, Poirier A, Andral L, Neri P. [Studies on yellow fever in Ethiopia. I. Introduction- clinical symptoms of yellow fever]. Bulletin of the World Health Organization.1968;38(6):835-841.
Terenzio M, Golding M, Schiavo G. siRNA screen of ES cell-derived motor neurons identifies novel regulators of tetanus toxin and neurotrophin receptor trafficking. Frontiers in cellular neuroscience.2014;8:140.
Matthews CC, Fishman PS, Wittenberg GF. Tetanus toxin reduces local and descending regulation of the H-reflex. Muscle & nerve.2014;49(4):495-501.
Herrman H, Braekhus A, Aaserud O, Aukrust P, Stubhaug A, Hassel B. Early treatment of tetanus-induced trismus with botulinum toxin A. Anesthesia and analgesia.2008;106(5):1591.
Vandelaer J, Birmingham M, Gasse F, Kurian M, Shaw C, Garnier S. Tetanus in developing countries: an update on the Maternal and Neonatal Tetanus Elimination Initiative. Vaccine.2003;21(24):3442-3445.
Oie S, Obayashi A, Yamasaki H, et al. Disinfection methods for spores of Bacillus atrophaeus, B. anthracis, Clostridium tetani, C. botulinum and C. difficile. Biological & pharmaceutical bulletin.2011;34(8):1325-1329.
Brook I. Current concepts in the management of Clostridium tetani infection. Expert review of anti-infective therapy.2008;6(3):327-336.
Wilcox ME, Poutanen SM, Krajden S, Agid R, Kiehl TR, Tang-Wai DF. A case of rabies encephalitis: new dog, old tricks. Neurology.2014;82(12):1101.
Pye J. Rabies: prevention strategies for overseas travellers. Nursing standard (Royal College of Nursing (Great Britain) : 1987).2014;28(40):54-58.
Leung AK, Davies HD, Hon KL. Rabies: epidemiology, pathogenesis, and prophylaxis. Advances in therapy.2007;24(6):1340-1347.
Takayama N. Rabies: a preventable but incurable disease. Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy.2008;14(1):8-14.
Cui F, Liang X, Wang F, Zheng H, Hutin YJ, Yang W. Development, production, and postmarketing surveillance of hepatitis A vaccines in China. Journal of epidemiology / Japan Epidemiological Association.2014;24(3):169-177.
Pearse J. Infection control. Nursing management of a patient with hepatitis A and B. Nursing RSA = Verpleging RSA.1992;7(5):28-29.
Iwasaki E, Takita M, Kishino R, Izumiya M, Nakazawa A, Tsukada N. [Adult Gianotti-Crosti syndrome caused by hepatitis B]. Nihon Shokakibyo Gakkai zasshi = The Japanese journal of gastro-enterology.2013;110(9):1657-1662.
Geier MR, Geier DA, Zahalsky AC. A review of hepatitis B vaccination. Expert opinion on drug safety.2003;2(2):113-122.
Li X, Gao X, Ren Z, Cao Y, Wang J, Liang G. A Spatial and Temporal Analysis of Japanese Encephalitis in Mainland China, 1963-1975: A Period without Japanese Encephalitis Vaccination. PloS one.2014;9(6):e99183.
Hills S, Martin R, Marfin A, Fischer M. Control of Japanese encephalitis in Asia: the time is now. Expert review of anti-infective therapy.2014:1-4.
Nadjm B, Behrens RH. Malaria: an update for physicians. Infectious disease clinics of North America.2012;26(2):243-259.
Kavanaugh M, Bavaro M. Malaria in a returning traveler from Jamaica. Military medicine.2014;179(6):e697-698.
Spottiswoode N, Duffy PE, Drakesmith H. Iron, anemia and hepcidin in malaria. Frontiers in pharmacology.2014;5:125.
Murray CJ, Rosenfeld LC, Lim SS, et al. Global malaria mortality between 1980 and 2010: a systematic analysis. Lancet.2012;379(9814):413-431.
Bijker EM, Bastiaens GJ, Teirlinck AC, et al. Protection against malaria after immunization by chloroquine prophylaxis and sporozoites is mediated by preerythrocytic immunity. Proceedings of the National Academy of Sciences of the United States of America.2013;110(19):7862-7867.
Looareesuwan S, Chulay JD, Canfield CJ, Hutchinson DB. Malarone (atovaquone and proguanil hydrochloride): a review of its clinical development for treatment of malaria. Malarone Clinical Trials Study Group. The American journal of tropical medicine and hygiene.1999;60(4):533-541.
Bloechliger M, Schlagenhauf P, Toovey S, et al. Malaria chemoprophylaxis regimens: A descriptive drug utilization study. Travel medicine and infectious disease.2014.
World Health Organization. World malaria report 2012. Geneva: World Health Organization; 2012.
White NJ. The role of anti-malarial drugs in eliminating malaria. Malaria journal.2008;7 Suppl 1:S8.
Bhatt S, Gething PW, Brady OJ, et al. The global distribution and burden of dengue. Nature.2013;496(7446):504-507.
Simmons CP, Farrar JJ, Nguyen v V, Wills B. Dengue. The New England journal of medicine.2012;366(15):1423-1432.
World Health Organization. Dengue guidelines for diagnosis, treatment, prevention and control : new edition. Geneva: World Health Organization; 2009.
Idrees S, Ashfaq UA. A brief review on dengue molecular virology, diagnosis, treatment and prevalence in Pakistan. Genetic vaccines and therapy.2012;10(1):6.
Rajapakse S, Rodrigo C, Maduranga S, Rajapakse AC. Corticosteroids in the treatment of dengue shock syndrome. Infection and drug resistance.2014;7:137-143.
Lamberti LM, Bourgeois AL, Fischer Walker CL, Black RE, Sack D. Estimating diarrheal illness and deaths attributable to Shigellae and enterotoxigenic Escherichia coli among older children, adolescents, and adults in South Asia and Africa. PLoS neglected tropical diseases.2014;8(2):e2705.
Lamberti LM, Fischer Walker CL, Black RE. Systematic review of diarrhea duration and severity in children and adults in low- and middle-income countries. BMC public health.2012;12:276.