Transcript Travel Vaccines & Yellow Fever By

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)
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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?
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Yellow Fever
AIDS?
Cholera
Travellers Diarrhoea
Hepatitis A
Hepatitis B
Influenza = Flu
Japanese encephalitis
Malaria?
Measles/Mumps/Rubella*
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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
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HEART DISEASES
LUNG DISEASES
LIVER DISEASES
KIDNEY DISEASES
MENTAL DISEASES - ? Where? Kisii?
JOINT DISEASES
DIABETES, HIV, etc
Available Vaccines for travellers
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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?)
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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:
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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)
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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
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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
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GOING TO MECCA TO WORSHIP Allah
using fake vaccine certificates
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“MY BOOKLET IS LOST
SYNDROME” (ladies)
ACQUIRING/issuing of FAKE
BOOKS & STAMPS
COMING LATE FOR VACCINATION!
Then demanding a backdating.