Travel Vaccines & Yellow Fever By: CHARLES N. CHUNGE MB ChB MSc, CNM, PhD, MSc, DLSHTM, FRCPS(Glasg) Consultant Microbiologist, & Specialist in Tropical & Travel Medicine. Director of the Centre for Tropical &Travel Medicine – Nairobi, Kenya. MAIN OBJECTIVE TODAY To make you medical people aware that excellent vaccines are available to prevent many serious/deadly diseases, so that you will take appropriate action to protect yourself & others. What your objectives should not be!! • To sleep here (This is not Parliament) • To get to the TEA BREAK area very fast before others. • To stare at other guests • To ask political questions • To sit next to her/him A TRAVELLER IS A PERSON WHO:(Yes/No) GOES ON SAFARI IS A TOURIST EATS IN A RESTAURANT OR HOTEL TRAVELS OVERSEAS CATCHES A BUS, AEROPLANE, TRAIN etc? INGESTS FOOD PREPARED OUTSIDE HIS HOME Which are the common diseases that afflict travellers? • • • • • • • • • • Yellow Fever AIDS? Cholera Travellers Diarrhoea Hepatitis A Hepatitis B Influenza = Flu Japanese encephalitis Malaria? Measles/Mumps/Rubella* • • • • • • • • • • Meningitis Pneumonia Rabies Diphtheria Tetanus Polio Tuberculosis Typhoid fever Cancer of CERVIX Food-poisoning As you can see from this list of diseases: • Many of these diseases can be prevented by vaccines. • Many cannot be cured easily. • With the increase in travel, serious diseases are literally only a plane-ride away. Vulnerable groups • Infants, because their immune systems cannot easily fight off disease. • Children & workers in crowded situations • The Immuno-depressed/compromised • Those pregnant • Malnourished individuals • Old people (? Over 65yrs) • Professional groups (medical, military, students, nurseries, orphanages, prisoners) • All Travellers CHRONIC CONDITIONS WORSENED BY FAILURE TO VACCINATE • • • • • • • HEART DISEASES LUNG DISEASES LIVER DISEASES KIDNEY DISEASES MENTAL DISEASES - ? Where? Kisii? JOINT DISEASES DIABETES, HIV, etc Available Vaccines for travellers • • • • • • • • • • • • • • Yellow Fever – Mandatory Meningitis – sometimes mandatory (during Hajj) Diphtheria-Tetanus (dT) Typhoid, Travellers diarrh, Cholera, Hepatitis A Hepatitis B Rabies Polio Measles-Mumps-Rubella Influenza Pneumococcal Japanese encephalitis Human Papilloma Virus (Cervical cancer) Tuberculosis*** Malaria****HIV**** TRAVEL VACCINES: Classification Divided into 3 categories: • Mandatory (M): International Certificate required – Yellow fever vaccine • Recommended (R) for all travellers to certain countries – Meningo ACYW135 (Saudia Arabia) for Hajj travellers – dTPolio to North and South America • Recommended (r) for travellers to certain areas – Influenza and Pneumococcal vaccines for at risk subjects: >65 yrs – Varicella for travellers to USA who do not have antibodies – Rabies in Latin America Vaccines for healthcare workers • Hepatitis B • Influenza vaccine (annually for the flu) • Measles-Mumps-Rubella (MMR) vaccine • Varicella (chickenpox) vaccine • Typhoid • Meningitis Vaccines for Students Recommended or Mandatory (depending on who?) dT-Polio (diphtheriaTetanusPolio) Pneumococcal, Flu, Meningitis Hepatitis A Hepatitis B Measles,mumps,Rubella(MMR)-Susceptible/without antibodies Varicella (chicken pox) Typhoid ETEC travellers diarrhoea & Cholera There are no vaccines for: Malaria (current efficacy =35-45%) HIV (current efficacy <31%) Rift Valley Fever Bird Flu = Avian influenza Gonorrhoea or Syphilis Swine Flu H1N1 – remarkable efforts Anthrax Most STIs The Value of Vaccination Produces two Types of Protection OR Immunity among clients: -Individual immunity -Community Immunity (Herd Immunity) ! Impact of vaccination: Benefits 1. Immunisation saves 3Million lives/year (WHO) 2. Immunisation is second to provision of clean water and third are antibiotics in saving lives 3. In addition to preventing disease, it reduces mortality, morbidity and medical/travel costs 4. It costs less than treatment 5. It is easily explained Impact of vaccination: Successful eradication • Smallpox was eradicated 1978 Vaccination costs less than treatment (this is excellent for a traveller) For example typhoid: Vaccine Ksh 500-1000 every 3 years Treatment of disease Ksh >12000 twice a year? Man hrs lost on off duties School HRS lost on absenteeism Cost of death = is too large to calculate The Wise choice • Choosing to avoid vaccines is simply a choice to take a different risk – usually much worse: =>the disease & its complications. e.g. meningitis, pneumonia, Yellow fever, paralysis, deafness caused by mumps, liver cancer (by hepatitis B virus), heart failure, kidney failure, peritonitis (typhoid) and of course DEATH. Therefore: When you compare the side effects/benefits of vaccines and the risk of the actual diseases, vaccines are the safer choice." WHICH DOCTORS ARE LIKELY TO ADVISE PATIENTS ON PREVENTIVE MEASURES? • PAEDIATRICIANS&Travel Medicine Specialists • PUBLIC HEALTH SPECIALISTS • GYNAECOLOGISTS • PHYSICIANS & General Practitioners • DERMATOLOGISTS • SURGEONS Why these differences? Who consults prior to travel? (In descending order) »AMERICANS »JAPANESE= very nice people »GERMANS & FRENCH »SCANDINAVIANS »OTHER EUROPEANS »THE BRITISH »INDIANS,CHINESE RUSSIANS, AFRICANS etc What about Kenyans? • Kenyan people and medical insurance companies want to treat the illnesses once it occurs; they tend to react only when a crisis occurs. • They always try to skip mandatory vaccines (even doctors!) • We need to teach them the truth: “Prevention is better than cure” Yellow Fever Yellow and feverish He is Yellow Yellow Fever • Why the name? • The arbovirus is called Flavivirus • The vector: Aedes, Haemagogus mosquitoes • Prevalence = Variable (Africa & Americas) • India & Asia/Far East = Nil (but very suitable) • A zoonosis = Primates reservoirs Yellow Fever • Endemic areas: Africa and C.&S. America • Urban YF seen in South America • Sub clinical cases may occur = 15% • Kills over 60-80% of its victims • Why is it the only compulsory vaccine? Because: The vectors, the primates & humans exist in Asia But the disease does not. VEGETATION MAP OF AFRICA Yellow fever belt JUNGLE TYPE YELLOW FEVER • This enzootic cycle is essentially animal and keeps the virus alive in the tropical forest of Africa and South America • In Africa, Monkeys do not die once infected, they become and remain immune. • Monkeys don’t act as virus hosts, as their viremia is short but rather as amplifiers & indicators of virus circulation EPIDEMIC YELLOW FEVER • Transmission from man to man => epidemic • Main vector : Aedes Aegypti Aedes aegypti Yellow Fever Yellow Fever DIAGNOSIS / TREATMENT • Incubation period: lasts 3 to 6 days • Evolution : -Acute forms are fatal in 2-7 days, -Severe forms are fatal > 80% of cases. -Milder forms similar to flu-like syndrome or viral hepatitis. Mortality: Upto 80 % despite treatment Diagnosis: Serology Yellow Fever: TREATMENT • There is no specific anti-viral Yellow fever therapy • The mortality rate for acute forms of the disease is 80%, despite any treatment • The only efficient prevention is the routine vaccination of all persons exposed to the disease risk • Vaccination for international travellers is aimed at preventing travellers from getting infected abroad and taking the disease back home. Side effects: Viscerotropic and Neurotropic Disease Age >60 years •Risk of Viscerotropic Disease: ≈ 20/106 or 1/50,000 • Risk of Neurotropic Disease: ≈ 15/106 or 1/65,000 VACCINE EXEMPTIONS allowed: ESPECIALLY IN THOSE >65YRS Where to go for the vaccination Vaccination Centres Travel Health clinics Hospitals Medical Clinics (with enlightened providers) ? Pharmacies Airports/entry/exit points LASTLY:Do not get involved with any of the following attractions GOING TO MECCA TO WORSHIP Allah using fake vaccine certificates “MY BOOKLET IS LOST SYNDROME” (ladies) ACQUIRING/issuing of FAKE BOOKS & STAMPS COMING LATE FOR VACCINATION! Then demanding a backdating.