Transcript Dr.I.Selvaraj,I.R.M.S B.SC.,M.B.B.S.,(M.D Community medicine).,D.P.H.,D.I.H.,P.G.C.H&FW(NIHFW,New delhi) Sr.D.M.O(ON STUDY LEAVE) INDIAN RAILWAYS MEDICAL SERVICE In 1881, Carlos Juan Finlay, a physician in Havana, first proposed that.

Dr.I.Selvaraj,I.R.M.S
B.SC.,M.B.B.S.,(M.D Community medicine).,D.P.H.,D.I.H.,P.G.C.H&FW(NIHFW,New delhi)
Sr.D.M.O(ON STUDY LEAVE)
INDIAN RAILWAYS MEDICAL SERVICE
In 1881, Carlos Juan Finlay, a physician in Havana, first
proposed that yellow fever was a mosquito-borne illness,
which subsequently was proven by Walter Reed and
colleagues.
U.S. Army doctor
Discovered the
Cause of Yellow
Fever
August 27, 1900
Research and Walter Reed
Walter Reed, M.D., (1851-1902) was an American
Army surgeon who led the team which proved the
theory first set forth in 1881 by the Cuban doctor and
scientist Dr. Carlos Finlay that yellow fever is
transmitted by mosquitoes rather than direct contact.
The risky but fruitful research work was done with
human volunteers, including some of the medical
personnel such as Clara Maass and surgeon Jesse W.
Lazear Walter Reed Medal winner who allowed
themselves to be deliberately infected and died of the
virus. All this lead to the elimination of Yellow Fever
from Cuba and allowed the final construction of the
Panama Canal.
Clara Maass
On August 14, 1901, Maass allowed herself to be
bitten by infected mosquitoes for the seventh
time. Maass once again became ill with yellow
fever on August 18 and died on August 24. Her
death roused public sentiment and put an end to
yellow fever experiments on humans.
•Thirty-three countries, with a combined
population of 508 million, are at risk in
Africa. These lie within a band from 15°N
to 10°S of the equator.
• In the Americas, yellow fever is endemic
in nine South American countries and in
several Caribbean islands. Bolivia, Brazil,
Colombia, Ecuador and Peru are
considered at greatest risk.
•There are 200,000 estimated cases of
yellow fever (with 30,000 deaths) per year.
Countries regarded as yellow fever infected
Africa:
Angola, Benin, Burkina Faso, Burundi, Cameroon, Central
African Republic, Chad, Congo, Democratic Republic of
Congo (Zaire), Equatorial Guinea, Ethiopia, Gabon,
Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast
(Cote D'Ivoire), Kenya, Liberia, Mali, Niger, Nigeria,
Rwanda, Sao Tome and Principe, Senegal, Sierra Leone,
Somalia, Sudan (South of 15° N), Togo, Uganda,
Tanzania, Zambia.
America:
Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana,
Peru, Suriname, Trinidad and Tobago, Venezuela, Panama.
•As of 6 December 2005, the Federal
Ministry of Health,SUDAN reported to
WHO a total of 565 cases, including
143 deaths, with a case fatality rate of
25.3%.
•As of 19 December2005, the Ministry
of Health, Guinea has reported a total
of 114 suspected cases of yellow fever
with 26 deaths, Twenty-three of these
cases have been laboratory confirmed.
There are no reported cases of yellow fever in
Asia. It is suspected that the high incidence of
dengue fever helps confer protection against
yellow fever, and that the Asian mosquito strains
are not as competent as vectors of the disease.
AGENT
• Genus :Flavivirus fibricus,
Group B Arbovirus
Family : Toga virus
• The yellow fever virus is 35-40 nm in
• size. It consists of a single strand of
RNA virus
The photomicrograph shows multiple virions of the
yellow fever virus at a magnification of 234,000x
VECTORS
Aedes mosquitoes, including
A. aegypti,
A. africanus,
A. simpsoni,
A. furcifer,
B. luteocephalus,
and A. albopictus (Asian tiger mosquito).
Urban yellow fever is transmitted by the Aedes aegypti
mosquito. Jungle, or sylvatic, yellow fever is
transmitted by Haemagogus and other mosquitoes
(such as Masoni africana) of the forest canopy (treehole breeding mosquitoes).
• Reservoir: Monkey, Human, Mosquito
• Incubation period: Intrinsic IP:3to 6 Days
Extrinsic IP: 1to 2 weeks
.Period of communicability: First 4 days of
illness
Mode of Transmission : 1.Sylvan cycle
2. Urban cycle
Race: No known racial predilection exists.
Sex: Both sexes are infected equally
Age: All ages are suceptible to yellow fever.
Jungle yellow fever primarily affects nonimmunized adults
who work as foresters,wood cutters & hunters in endemic
areas and persons residing on the edge of the jungle.
Infants born of immune mothers have antibodies up to 6
months of life
ENVIRONMENTAL
FACTORS
•
•
•
•
TROPICAL CLIMATE
HUMIDITY (60%)
TEMPERATURE ( 24ºC)
SOCIAL FACTORS : URBANISATION ,
TRAVEL &EXCESSIVE RAINS
• The natural host for the yellow fever virus in
forest areas is non-human primates (usually
monkeys and chimpanzees).
• The vectors of yellow fever in forest areas in
Africa are Aedes africanus . In South America,
the primary vector is the Haemagogus species.
• In urban areas of both Africa and South
America, the vector is Aedes aegypti.
The natural yellow-fever cycle is mosquitomonkey-mosquito.
The shift from jungle yellow fever to urban yellow
fever is thought to be the result of humans entering
the sylvan setting and becoming part of the yellowfever cycle:
Initially, wood cutters and other forest workers
were bitten by forest-canopy mosquitoes carrying
the yellow-fever virus. The humans then returned
to the urban settings.
Clinical features of yellow fever
Yellow fever presents with a variety of clinical signs and
outcomes ranging from mild to severe and fatal cases. Yellow
fever in human beings has the following characteristics:
· An acute phase lasting for four to five days and presenting
with:
- a sudden onset of fever
- headache or backache
- muscle pain
- nausea
- vomiting
- red eyes (infected conjunctiva).
The diagnosis can be
strongly suspected when
Faget's sign is present.
Faget's sign: The
simultaneous occurrence of a
high fever with a slowed
heart rate.
This phase of yellow fever can be confused with
other diseases that also present with fever,
headache, nausea and vomiting because jaundice
may not be present in less severe (or mild) cases of
yellow fever. The less severe cases are often nonfatal.
· A temporary period of remission follows the
acute phase in 5% to 20% of cases. The period of
remission lasts for up to 24 hours.
A toxic phase can follow the period of
remission and presents with:
- jaundice
- dark urine
- reduced amounts of urine production
- bleeding from the gums, nose or in the stool
- vomiting blood
- hiccups
- diarrhoea
- slow pulse in relation to fever
No specific treatment is available for yellow
fever. In the toxic phase, supportive treatment
includes therapies for treating dehydration and
fever. In severe cases, death can occur between
the seventh and tenth days after onset of the
first symptoms.
CONTROL OF YELLOW
FEVER
Theiler won Nobel Prize in 1951 for his
accomplishments
YELLOW FEVER VACCINE
• The virus first isolated in 1927 by
inoculating rhesus monkeys with the blood
of an African patient (Asibi).
• Edward Hindle developed inactivated
vaccine 1928.Theilar and Smith developed
17D vaccine from the Asibi strain in cell
cultures from embryonated chicken eggs.
• It is a safe & effective vaccine.
• Yellow Fever Vaccine, Live (17D Strain Live, Freeze Dried).
Each 0,5 mL contains Yellow Fever Virus 104.1 pfu.
• Vaccine must be maintained continuously at temperatures between 5 and -30°C
• The vial of diluent should not be allowed to freeze.
• The reconstituted vaccine must be kept cool and used within 60 minutes
following reconstitution.
• The product appears slightly opalescent and light orange in color after
reconstitution.
• Vials of 5 doses with vials of diluent.
• Reconstitute the vaccine using only the diluent supplied (Sodium Chloride
Injection).
• Slowly inject the diluent into the vial containing the vaccine, let stand for
one or two minutes and then carefully swirl mixture until a uniform
suspension is achieved. Avoid vigorous shaking as this tends to cause
foaming of the suspension.
• Administer the vaccine subcutaneously.
The yellow fever vaccine has a long record of safety, but
clinicians should be aware of two severe complications
from the vaccine.
1. Yellow fever-associated neurotropic disease (previously
known as post vaccine encephalitis), occurs 7–21 days
after vaccination. Of the 1/8 000 000 people who contract
this disease, full recovery is typical.
2. Yellow fever-associated viscerotropic disease occurs 2–5
days after vaccination. It is characterized by fever,
myalgia, arthralgia, increased liver enzymes and
bilirubin, lymphopenia, thrombocytopenia, disseminated
intravascular coagulation, hypotension, oliguria and
rhabdomyolysis. There have been 13 cases reported out of
over 100 million doses administered worldwide.
Persons exempted from production of
vaccination
1.Infants below the age of six months.
2. Crew and passengers of an aircraft transiting
through an airport located in yellow fever infected
area provided the Health Officer is satisfied that such
persons remained within the airport premises during
the period of stay.
•The validity period of international certificate of
vaccination or re-vaccination against yellow fever is
10 years, beginning 10 days after vaccination.
REFERENCE CENTRES INDIA
• 1. National Institute of Virology,
Pune
• 2. Central Research Institute,
Kasauli
Aedes aegypti index
It is a house index.It is defined as “the
percentage of houses and their premises
showing actual breeding of Aedes aegypti
larvae. This index should not be more than
1% in airports and seaports in endemic
areas at least 400 meters around their
perimeters to ensure freedom from
yellow fever
MosquiTRAP. is a novel, simple, easy, low cost, and efficient trap
especially developed to catch Aedes mosquitoes. MosquiTRAP. allows the
identification of the mosquito species in the field, thus saving time and
avoiding laboratory routine such as counting eggs and larval
identification. Trapped mosquitoes can also be used for virus diagnosis.
New entomological indices are
(a) the Positive MosquiTRAP Index
(PMI), the percentage of positive traps,
and (b) the Adult Density Index for A. aegypti and for A. albopictus. Field
data can be collected using hand-held PDAs and then loaded directly into
a Geographical Information System (GIS), for an efficient determination
of local entomological indices.
YELLOW FEVER RECEPTIVE AREA
• An area in which yellow fever does
not exist, but where conditions
would permit its development if
introduced
• The population of India is unvaccinated
• The vector Aedes aegypti is found in
abundance
• The climactic conditions are favourable for
its transmission
• The common monkey of India is more
susceptible for yellow fever
• The missing link is in the chain of
transmission is the virus of yellow fever
INTERNATIONAL
MEASURES
• A valid international certificate of
vaccination
• Aerosol spraying of prescribed insecticides
on the arrival of aircrafts and ships from
endemic areas
• Airports and seaports are kept free from the
breeding of insect vectors at least 400
meters around their perimeters
• Clinical surveillance, entomological
surveillance, epidemiological surveillance
• A) For entry into India:- Any person, Foreigner or Indian,
(excluding infants below six months) arriving by air or sea
without a vaccination certificate of yellow fever will be kept in
quarantine isolation for a period up to 6 days if:
• He arrives in India within 6 days of departure from an
infected area.
• Has come on a ship which has started from or transited at any
port in a yellow fever affected country within 30 days of its
arrival in India provided such ship has not been disinfected in
accordance with the procedure laid down by WHO.
• (B) For leaving India:There is no health check requirement by
Indian Government on passengers leaving India.
• The Government of Guyana requires that all persons
including diplomats traveling to that country from India to
possess valid yellow fever and cholera inoculation certificates
before they leave India.
GUIDELINES FOR YELLOW FEVER SURVEILLANCE
•
Make sure that personnel at health facilities
in the district know how to identify suspected
cases of yellow fever.
•
Make sure that health facilities use a
standard case definition to report suspected
cases of yellow fever.
•
Assist health facilities with investigation of
suspected cases.
•
Collect samples for diagnostic testing and
laboratory confirmation. If necessary,
transport samples to a drop-off point or
specified laboratory.
•
Notify the national level about the suspected
case. Alert other health facilities in nearby
areas about the potential for additional cases.
• Receive and report laboratory results about
confirmed cases.
• Coordinate the response to the confirmed case
with a district emergency response committee.
• Carry out intensified surveillance activities to
identify additional cases in areas where the
patient lived, worked or travelled. Collect
diagnostic specimens from any new suspected
cases.
•
Monitor and supervise routine disease
surveillance activities. Analyse data for trends
suggesting a yellow fever outbreak. Report data
from routine activities to the national level on
time.
• Assist and support health facilities with the
integration of yellow fever vaccine into the routine
childhood immunization schedule. Make sure
vaccine and immunization supplies are available
for routine yellow fever activities.
• Ref : Monitoring the mosquito Aedes aegypti: A novel surveillance
method and newentomological indices using the gravid trap
MosquiTRAP. and a synthetic oviposition attractant (AtrAedes.)
• Ref: Aedes aegypti survey of Chennai* Port/Airport, India
• PREVENTIVE &SOCIAL MEDICINE 18th edition
• TEXT OF COMMUNITY MEDICINE –T. BHASKAR RAO
• Manson’s tropical disease – 21st edition
• http://www.who.int/vaccines-documents/DocsPDF/www9834.pdf
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