Time Required - 90 minutes
The following slides were used.
MM; Glass; Guarda
49; mounted; Aa eradication indices, Sao Luis and Maranhao
21; unmounted; Vale Canaan, 1932
xx; mounted color; YF in Southern Brazil 1934-1940
53; mounted; Aa Paraguay DDT
43; mounted; Aa eradication Brazil 1943-52, influence of DDT
xxx; mounted color; Aa in Americas 1957
unmounted; Jungle at Tocumen
x1; mounted; JYF Cent. Am. 1948-57
unmounted; Tree Ferns
unmounted; Colorado Indians
unmounted; Jungle YF and Plague, Caracas
71; mounted; YF in Americas 1946-53
137; mounted; YF in Americas, 1954-56
Yellow Fever Problem
A. Tropical Public Health
B. International Health
Reality of Problem
Present: America - Man - Monkeys
Present: Africa - Man - Primates
Present: Asia Potential - Man - Monkeys
Present: Temperate Zones - Seasonal Man.
Most difficult problem for International Quarantine Committee
Most fearsome disease
Most emotional reaction
Most severe restrictions on travel to Asia
Yellow Fever
Zoonosis -
Man and Other Primates
Virus - Acute Infection
Death or Immunity
No Carrier State
Transmission
Aa - urban maritime
Haemogogus - Aedes - Sabeites
Aedes africanus, Aedes simpsoni
No Trans-Ovarian persistence
Continued Existence of Virus
Requires series of acute mammalian infections - not further spaced than life time of infected mosquito
Clinically - short incubation - rapid onset -
A. infection
B. lull
C. intoxication
albuminuria
hemorrhage
anuria
Diagnosis
A. Time schedule
albuminuria
B. Isolation virus
C. Repeated neutralization
Pathology - Liver
Immunology - complement fixation
neutralization - 2B Viruses
haemogglutination
Immunization -
1. Natural - maternal antibodies + early infection
2. Vaccination
a. killed virus
b. virus plus serum
c. cultured virus plus serum
d. Fch neurotropic virus
e. 17D
Duration of immunity!
(Comment on Polio Vaccination - YF vaccine viruses are neutropic - Fch. kills 100% mice and 100% + monkeys - Fch gives 60% viremia 17D gives 5% viremia)
Today's lecture on YF is in the course on Ecology and Epidemiology of Infectious Diseases in Department of Microbiology and Tropical Public Health.
Tropical Public Health
Tropical Medicine - successes always in preventive medicine -
YF in 1900 - VF only after Columbus
RF in 1913 - Rose to Asia
1915 - Gorgas studied a decade and a half of results.
R.F. embarked on Eradication of YF based on reduction of Aa in key centers of infection
Spontaneous Disappearance
Early victories
Ecuador, Peru, Central America, Mexico
Failures
Brazil - 1919-20 Federal Commissao
R.F. - 1923-46
R.F. - 1926-28
Rio outbreak - 1928-29
Recife cases in control area 1929
Colombia - Socorro 1929
Venezuela - Guasapati 1929
Bolivia - Sta Crux 1932
Personal experience on becoming responsible for YF in North Brazil.
Belem to Maceio
Reorganization - Manual - Maps
FA 52 - Detailed Records
Larvicide to all foci
Adult captures; Threshold of Visibility
Viscerotomy; YF = Aa
Results =
a. unrecognized Aa breeding - Local eradication in several cities.
2 slides - Light.
b. unrecognized endemic Aa transmitted
YF in rural areas of NE Brazil - attack on
Aa in rural areas ended endemic in Aug, 1934
2 slides lights C. unrecognized jungle yf very widespread in many areas where yf had never been recorded
Became clear that Socorro, Guasapati and Santa Cruz were secondary to Jungle yf
yf virus not eradicable - program changed to eradicate Aa -  give story of expansion to 1960 - DDT helped
3 slides lights
Jungle YF - clinically identical
Depends on animal infections and on forest mosquitoes
(Wave phenomenon in Aa and Jungle Fever)
America: Man is incidental, often dead-end infection unless Aa is present in domicile - Transmission by day time biting mosquitoes
Africa: Man not so frequently infected in forest - vector is night biting A. africanus - monkey brings virus to Aedes simpsoni which transmits man to man.
Protection against jungle yf requires individual vaccination -
Endemic Aa, yf travels with man along human routes of travel
Jungle yf travels through forests.
Recent yf history
Under - reporting Africa, Americas
Africa - virus widespread, but few recognized cases
Panama - Mexico - 2 slides
Pacific Coast - Ecuador 2 slides
Trinidad - Caracas 1954 1 slide
YF 1946 - 1956 2 slides
Eradication of Aa led to eradication of Ag Brazil - Egypt
Rehabilitation of Eradication Concept
Eradication must expand -
International cooperation Essential
WHO, PAHO, UNICEF, TCA
But, complete coverage in individual countries needed - USA not entirely ready.
small pox, tuberculosis, leprosy, typhoid, yaws, syphilis
Local general unit vs Unilateral Campaigns