﻿576 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  in 
  South 
  America. 
  The 
  tendency 
  was 
  to 
  consider 
  the 
  disease 
  in 
  these 
  

   areas 
  as 
  more 
  or 
  less 
  static 
  although 
  the 
  first 
  observation 
  of 
  proved 
  

   jungle 
  yellow 
  fever 
  was 
  made 
  during 
  a 
  sharp 
  epidemic 
  in 
  the 
  Valle 
  do 
  

   Chanaan 
  in 
  Brazil 
  (Soper 
  et 
  ah, 
  1933). 
  The 
  very 
  fact 
  that 
  jungle 
  

   yellow 
  fever 
  was 
  transmitted 
  only 
  under 
  biological 
  conditions 
  pecu- 
  

   liar 
  to 
  a 
  forest 
  environment 
  with 
  its 
  special 
  insects 
  and 
  animals 
  would 
  

   seem 
  also 
  to 
  limit 
  the 
  spread 
  as 
  jungle 
  yellow 
  fever. 
  It 
  has, 
  however, 
  

   become 
  increasingly 
  clear 
  that 
  jungle 
  yellow 
  fever 
  may 
  sweep 
  as 
  an 
  

   epidemic 
  through 
  a 
  wide 
  extent 
  of 
  the 
  favorable 
  environment 
  and 
  then 
  

   become 
  urban, 
  aegypti-tr&nsmitted 
  yellow 
  fever 
  when 
  it 
  reaches 
  a 
  

   community 
  in 
  which 
  that 
  mosquito 
  abounds. 
  That 
  such 
  spread 
  of 
  

   yellow 
  fever 
  from 
  jungle 
  to 
  city 
  has 
  not 
  been 
  observed 
  to 
  occur 
  re- 
  

   cently 
  needs 
  special 
  comment. 
  

  

  THE 
  ABSENCE 
  OF 
  AEGYPTI-TRANSMITTED 
  EPIDEMICS 
  AND 
  

   THE 
  DANGER 
  OF 
  THEIR 
  REAPPEARANCE 
  

  

  A 
  striking 
  and 
  reassuring 
  feature 
  of 
  the 
  present 
  situation 
  in 
  the 
  

   Western 
  Hemisphere 
  is 
  the 
  absence 
  of 
  the 
  classical 
  type 
  of 
  yellow 
  

   fever 
  outbreak, 
  in 
  which 
  the 
  disease 
  is 
  transmitted 
  by 
  the 
  long- 
  

   recognized 
  mosquito 
  vector 
  Aedes 
  aegypti 
  and 
  tends 
  to 
  be 
  localized 
  in 
  

   cities 
  and 
  to 
  invade 
  the 
  channels 
  of 
  commerce. 
  For 
  3 
  years 
  no 
  reports 
  

   of 
  such 
  outbreaks 
  have 
  been 
  confirmed 
  in 
  the 
  Americas. 
  The 
  credit 
  

   must 
  rest 
  largely 
  with 
  those 
  who 
  have 
  continued 
  and 
  perfected 
  the 
  

   control 
  of 
  Aedes 
  aegypti, 
  so 
  successfully 
  begun 
  by 
  Gorgas 
  and 
  Oswaldo 
  

   Cruz, 
  for 
  the 
  threat 
  of 
  infection 
  from 
  areas 
  of 
  endemic 
  and 
  epidemic 
  

   jungle 
  yellow 
  fever 
  in 
  the 
  interior 
  of 
  South 
  America 
  appears 
  to 
  have 
  

   been 
  continuous 
  for 
  an 
  undetermined 
  period 
  extending 
  far 
  into 
  the 
  

   past. 
  Were 
  it 
  not 
  for 
  the 
  noninfectibility 
  of 
  Rio 
  de 
  Janeiro 
  in 
  1938, 
  

   owing 
  to 
  well-organized 
  aegypti 
  control, 
  we 
  might 
  have 
  seen 
  another 
  

   serious 
  epidemic 
  in 
  that 
  city, 
  with 
  spread 
  to 
  other 
  communities 
  and 
  

   shipping, 
  for 
  Soper 
  (1938) 
  has 
  reported 
  that 
  four 
  persons 
  infected 
  in 
  

   a 
  nearby 
  epidemic 
  of 
  jungle 
  yellow 
  fever 
  were 
  known 
  to 
  have 
  come 
  

   into 
  the 
  city 
  without 
  causing 
  any 
  local 
  infections. 
  

  

  That 
  jungle 
  yellow 
  fever 
  is 
  the 
  same 
  disease 
  as 
  urban 
  yellow 
  fever 
  

   is 
  well 
  established. 
  That 
  it 
  may 
  be 
  transmitted 
  by 
  Aedes 
  aegypti 
  

   has 
  been 
  repeatedly 
  demonstrated 
  in 
  the 
  laboratory 
  (Whitman 
  and 
  

   Antunes, 
  1938), 
  and 
  on 
  one 
  occasion 
  the 
  establishment 
  of 
  yellow 
  fever 
  

   of 
  jungle 
  origin 
  in 
  a 
  Brazilian 
  town 
  and 
  its 
  transmission 
  there 
  by 
  

   Aedes 
  aegypti 
  were 
  observed 
  (Walcott 
  et 
  al., 
  1937). 
  Some 
  risk 
  of 
  

   urban 
  yellow 
  fever 
  epidemics 
  will 
  remain 
  as 
  long 
  as 
  jungle 
  yellow 
  

   fever 
  persists. 
  Inasmuch 
  as 
  the 
  possibility 
  of 
  complete 
  extermination 
  

   of 
  the 
  disease 
  now 
  seems 
  remote 
  if 
  not 
  impossible, 
  the 
  health 
  author- 
  

   ities 
  are 
  faced 
  with 
  the 
  problem 
  of 
  choosing 
  wisely 
  between 
  the 
  avail- 
  

   able 
  methods 
  of 
  confining 
  jungle 
  yellow 
  fever 
  to 
  the 
  areas 
  in 
  which 
  

   it 
  is 
  endemic, 
  reducing 
  the 
  human 
  involvement 
  within 
  these 
  areas, 
  

  

  