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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.
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Travel Vaccines & Yellow Fever By: CHARLES N. CHUNGEMB ChBMSc, 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
Yellow Fever AIDS? Cholera TravellersDiarrhoea 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 Which are the common diseases that afflict travellers?
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 • Immunisation saves 3Million lives/year (WHO) • Immunisation is second to provision of clean water and third are antibiotics in saving lives • In addition to preventing disease, it reduces mortality, morbidity and medical/travel costs • It costs less than treatment • 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
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 • Transovarial transmission in the mosquito keeps the virus alive
EPIDEMIC YELLOW FEVER • Transmission from man to man => epidemic • Main vector : Aedes Aegypti
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.