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RMIT Travel Health Briefing July 2007 Destination: Shanghai Ho Chi Minh City Dr Tony Gherardin
Speaker: Dr Tony Gherardin • National Medical Adviser for Travel Doctor Group • Background in General Practice • 17 years in Travel Medicine • 9 years living in Asia
Travel Doctor Group • Started in 1987 • Network of clinics, largest travel med practices in Australia • Network in NZ, South Africa, Singapore • 100,000 travellers each year, • 40% corporate work, Govt and Private Co.
Objectives • Pre-travel preparation • Vaccinations • Health checks • General issues • Medical support while away • Questions
General preparation • Appropriate clothing, luggage • Care with travel documents • Seek travel medical advice early • Document medications • Have travel insurance
Health Preparation • Try to be fit • Stabilise any chronic medical conditions • Have a medical checkup if health has been poor or symptoms present • Consider vaccines • Take required medicines and useful personal supplies • Be aware of health risks
Health Risks in Indochina • Communicable diseases via air, food and water, body fluids or contact with animals • Non-communicable problems such as motor vehicle accidents • For short trips, 1-4 weeks, the risks are low, and simple prevention is all that is required
Incidence of specific illnesses while staying in developing countries (Steffen and DuPont, 1994) Incidence rate / month 100% 100,000 Traveller’s diarrhoea 30 -80% 10,000 10% Malaria (West Africa,not taking malaria tablets) Acute respiratory infection 1% 1,000 Hepatitis A Gonorrhoea 0.1% 100 Animal bite with risk of rabies Typhoid (India, North andNorth-West Africa, Peru) HIV infection 0.01% 10 Typhoid (other regions) Asymptomatic polio 0.001% 1 Cholera Paralytic polio
Incidence of vaccine-preventable diseases among travellers 10,000 Hepatitis A 1000 Hepatitis B Typhoid fever 100 Morbidity/ 100,000 travellers/mo Polio- myelitis 10 Cholera 1 0.1 Expatriate Tramper Hotel tourist India, NW Africa, Peru Other destinations Steffen & Gyurech J Med Virol 1994;44:460-462
Communicable DiseasesNo vaccines • Dengue - Mosquito avoidance • HIV and other STDs - Safe sex • Avian Influenza - Avoid contact with birds
Communicable DiseasesVaccine Preventable • Hep A and B • Typhoid • Diphtheria/tetanus/pertussis • MMR Varicella • Influenza • Polio • Japanese Encephalitis • Rabies • Tuberculosis
Special Risk Groups • Current medical problems or chronic conditions • Pregnancy • Children • Elderly • Cardiac or Lung disease • Diabetes • HIV infections • Immunocompromised
Traveller’s Mortality • Many more travellers have been killed or maimed by road traffic accidents than by all infectious diseases combined worldwide • Common medical diseases => death • IHD • trauma • drug overdose (mainly narcotics)
Cause of death - Australians travelling (n=421) 92/93 • I.H.D. 35.0% • all accidents 18.0% (m.v.crashes 7.4%) • cancer 4.3% • suicide & m/s 3.8% • homicide 3.8% • infect/parasitic 1.9% Prociv P. Med J Aust 1995; 163: 27-30
Vaccines • Update your routine vaccinations, ADT, polio, MMR, influenza, (Chicken Pox) • Consider Hep-B • Food and water - Hep A and Typhoid • Be aware of other risks: • Rabies, dengue fever, JEV, MVA, STDs • No malaria risk
Changing Epidemiology of Polio • By 2003, only 7 countries remained endemic for polio : • India, Nigeria, Pakistan, Egypt, Afghanistan, Niger & Somalia (listed from highest to lowest burden of disease) • 99% of the world polio cases concentrated in the India, Nigeria & Pakistan • 6 other countries considered at high risk of polio reinfection - Angola, Bangladesh, the Democratic Republic of the Congo, Ethiopia, Nepal & Sudan • Recent resurgence in Java, Yemen, Nigeria 2005
Diphtheria and Tetanus • Travellers to countries where health services are difficult to access… should receive a booster of dT (or dTPa) if more than 10 years have elapsed since the last dose. NH&MRC 2003
MMR • more severe disease as an adult • if in doubt, check antibodies • MMR available free of charge for 17 - 37 years old in Australia (born in or before 1966) • Chickenpox vaccine available • Can also check antibodies
Influenza • Several inactivated vaccines available • Designed around a “best match” based of WHO surveillance • Usually 2 A strains, 1B, maybe different in Nth and Sth hemispheres • No protection against H5 N3 Avian strains
Avian Influenza • Outbreaks of H5 N1 avian subtypes over last few years across whole of Asia • Recent outbreaks in Vietnam, Thailand and Indonesia, with spread to humans in close contact, 57 deaths in 112 cases. • Massive culling to prevent pandemic • No vaccine yet, antivirals useful • Avoid birds, bird markets. • Cooked chicken, eggs safe
Hepatitis-A • Syn Infectious hepatitis, epidemic hepatitis, yellow jaundice, very common • Picornavirus, ( single stranded small RNA virus) • Humans are only reservoir, other primates can be infected • Worldwide distribution with decreasing incidence associated with higher sanitation and development • Faecal-oral spread mainly. Contaminated hands, food, water and sex. Transplacental and via transfusion has occurred
Hep-A Epidemiology • In developing world, infection occurs in early childhood, > 90% children infected by 5 years • In well developed countries, sporadic cases are associated with contact with cases, child-care centres, homosexuality, overseas travel • As social development occurs, local epidemiology moves from endemic to epidemic to sporadic • Disease more severe as age rises
Typhoid Fever - Geographic distribution Ref :Caumes E. Health and travel. 1999: 37–56
Typhoid • Cosmopolitan in distribution, but commonest where standards of personal hygeine are low • Mode of infection is by ingestion, water, food, and is largely dose-related • Can multiply in suitable food at favourable temperature, so food-handlers are important transmitters • Most important reservoir is asymptomatic human carriers • Estimated about 12.5 million cases per year globally. In Australia, 5-20 cases per year, mostly in returned travellers
Typhoid Vaccines • Typhim Vi, capsular antigen, injectable +70% , last 2-3 years, 2+y • Oral Typh-vax/ Vivotif, Ty21a live strain, 50-80%, 3 caps lasts 3 y, 4 caps lasts 5 years, 4 is more effective (est 40%) • Swallowed whole away from food. • Lasts 5 days outside fridge • Delays of 10-21 days OK
TRAVELLER’S DIARRHOEA “Travelling is the ruin of all happiness”Fanny BurneyCecilia Book 4, 1762
TRAVELLER’S DIARRHOEA • Bali belly • Montezuma’s revenge • Cleopatra’s curse • Delhi belly • Mexican two step • Rangoon runs • Tokyo trots • Ho Chi Minhs
TRAVELLER’S DIARRHOEA • Affects between 30 – 50% of people in a 2 week stay • Onset usually during stay • - 62% in first week • - day 3 the highest rate of onset • Mean duration 3.2 + 0.2 days (treated) • Mean duration 4.1 + 0.2 days (untreated) • Duration less in older travellers • Correlation between dietary indiscretions
Traveller’s diarrhoea • Cause: Ingestion of contaminated FOOD AND WATER; • High risk foods • Seafood, Salads, Cold meat, Peeled fruit, Local water and ice Single most important message- WASH YOUR HANDS!!!
Traveller’s diarrhoea- treatment • Rehydration salts, fluids • Anti-nauseant • Loperamide • Antibiotic, eg norfloxacin • Consider tinidazole if suspect giardia • Consider Dukoral vaccine for risk reduction
Hepatitis-B • HBV is a DNA virus, hepadnavirus with 4 major subtypes • Worldwide distribution, with variation in rates of infection and chronic carriage. • 300 million chronic carriers worldwide • Virus enters via mucous membranes or breaks in the skin, contaminated needles, transfusion of blood products, sexual and other intimate contact, transplacentally and at birth
Hepatitis-B • In high endemic areas, >90% of adults have antibodies or carry antigen. Up to 20% chronic carriage in Indochina, SEAsia, Oceania, Africa and Amazonia • In Middle East/India 5% chronic carriage, in Western countries >1% • Main modes are perinatal, child to child, Unsafe injections or transfusions, and sexual contact. • 50-100 X more infectious than HIV
Malaria risk • No significant risk in Shanghai or in Jiangsu and Zhejiang provinces • No significant risk in HCMC, the coastal plains, or the Mekong delta • Antimalarial drugs are not indicated!
Dengue Fever • Common viral disease spread by mosquitoes, spreading widely • Unpleasant illness of high fever, muscle and joint pains for 2 weeks, rash • May lead to DHF, which is a significant killer of children in many parts of the world • No vaccine to date
Insect Avoidance • Dengue Fever- bite of the Aedes mosquito • rise in urban populations and poor sanitation • poor water storage and waste disposal • increase in urban mosquito breeding • no current vaccine Japanese Encephalitis- bite of the Culex mosquito • prevalent in rural areas of Asia and Indonesia • summer seasonal risk in temperate areas • rural agricultural areas such as flooded terraces • swine and wild birds amplify risk • vaccine available!
JEV - Transmission • Humans are an incidental host rather than part of the enzootic cycle • Prolific breeding of vectors (mosquitoes) in flooded rice fields of rural areas • High level of transmission to humans when pigs are kept near residential areas Ref: NHMRC. Australian immunisation handbook. 7th ed. 2000: 148
Personal Protection from Mosquitoes • Avoid outdoor exposure, dawn to dusk • Wear long sleeved loose clothing after dusk, light colours • Avoid perfumes and colognes • Use repellent with 20-40% DEET • Use knockdown sprays, coils, vapours, etc indoors • Sleep in air-con, under fans or under nets impregnated with permethrin
Rabies - epidemiology • Major problem in developing countries. 40-50,000 deaths per year in India, 500,000 get PEP • 3% dogs in BKK are positive for virus • Risk of disease after a bite of infected animal is 30-50% • Risk falls to > 5% if PEP administered • Availability of PEP variable
Rabies Vaccines • HDCV – inactivated virus, 1.0ml is only current available vaccine in Australia • Others available internationally, all are considered interchangeable • Pre-exposure immunisation involves 3 injections over a month, and is very expensive. Not generally for trips of less than 3 months
Post-Exposure Prophylaxis- PEP • Important treatment for persons exposed to virus • Should commence ASAP. No PEP vaccine failures in developed countries • RIG + 5 X cell-culture vaccine on D 0,3,7,14,28 • Shortage of RIG/ vaccine supply problems
Personal Medical Kit • Iodine and bandaids • Paracetamol • Loperamide • Sudafed • General antibiotic • Prochlorperazine ( stemetil) for nausea • Condoms, insect repellent, handwash