﻿578 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  to 
  suspect 
  yellow 
  fever 
  or 
  disagreement 
  as 
  to 
  the 
  diagnosis 
  have 
  caused 
  

   the 
  loss 
  of 
  valuable 
  time. 
  No 
  longer 
  is 
  it 
  sufficient 
  to 
  accept 
  as 
  final 
  

   the 
  weighed 
  opinion 
  of 
  the 
  experienced 
  clinician, 
  although 
  a 
  decision 
  

   on 
  the 
  basis 
  of 
  symptoms 
  may 
  be 
  all 
  that 
  is 
  possible 
  before 
  the 
  first 
  pre- 
  

   cautionary 
  measures 
  have 
  to 
  be 
  taken. 
  For 
  the 
  final 
  decision 
  as 
  to 
  

   the 
  nature 
  of 
  a 
  case 
  or 
  outbreak, 
  the 
  laboratory 
  is 
  now 
  giving 
  con- 
  

   clusive 
  information 
  even 
  when 
  the 
  cases 
  are 
  clinically 
  mild 
  and 
  lack 
  

   nearly 
  all 
  the 
  well-known 
  classical 
  symptoms 
  (Sawyer, 
  1939). 
  In 
  

   such 
  cases 
  blood 
  specimens 
  are 
  drawn 
  aseptically 
  as 
  early 
  as 
  possible 
  

   during 
  the 
  acute 
  disease 
  and 
  again 
  3 
  weeks 
  after 
  the 
  onset. 
  If 
  the 
  

   serum 
  from 
  both 
  specimens 
  is 
  examined 
  by 
  means 
  of 
  the 
  mouse- 
  

   protection 
  test 
  in 
  a 
  yellow 
  fever 
  laboratory, 
  and 
  the 
  first 
  specimen 
  

   gives 
  no 
  protection 
  against 
  yellow 
  fever 
  virus 
  while 
  the 
  second 
  protects 
  

   definitely, 
  the 
  case 
  is 
  one 
  of 
  yellow 
  fever. 
  If 
  neither 
  or 
  both 
  speci- 
  

   mens 
  give 
  definite 
  protection, 
  the 
  illness 
  must 
  be 
  some 
  other 
  disease. 
  

   Where 
  a 
  more 
  serious 
  investigation 
  is 
  required, 
  the 
  attempt 
  is 
  made 
  to 
  

   isolate 
  the 
  virus 
  itself 
  from 
  cases 
  during 
  the 
  first 
  3 
  days 
  of 
  illness 
  

   by 
  injecting 
  blood 
  serum 
  from 
  the 
  sick 
  person 
  intracerebrally 
  in 
  

   amounts 
  of 
  0.03 
  cc. 
  into 
  six 
  susceptible 
  mice. 
  Any 
  virus 
  thus 
  isolated 
  

   may 
  be 
  studied 
  in 
  detail 
  in 
  the 
  laboratory. 
  Great 
  care 
  must 
  be 
  exer- 
  

   cised 
  to 
  prevent 
  infectious 
  blood 
  from 
  coming 
  into 
  contact 
  with 
  the 
  

   hands 
  of 
  a 
  nonimmune 
  investigator. 
  These 
  methods 
  establish 
  the 
  

   diagnosis 
  beyond 
  dispute 
  whenever 
  the 
  case 
  has 
  been 
  seen 
  early. 
  If 
  

   there 
  are 
  fatal 
  cases, 
  it 
  is 
  important 
  to 
  obtain 
  at 
  least 
  a 
  specimen 
  of 
  

   liver 
  by 
  autopsy 
  or 
  puncture 
  with 
  the 
  viscerotome 
  and 
  to 
  send 
  it 
  in 
  

   10 
  percent 
  formalin 
  to 
  a 
  pathologist 
  acquainted 
  with 
  the 
  lesions 
  of 
  

   yellow 
  fever. 
  The 
  determination 
  of 
  the 
  nature 
  of 
  the 
  disease 
  in 
  the 
  

   individual 
  case 
  is, 
  however, 
  only 
  one 
  step 
  in 
  the 
  thorough 
  epidemio- 
  

   logic 
  investigation 
  necessary 
  for 
  the 
  adequate 
  study 
  of 
  an 
  outbreak 
  

   of 
  yellow 
  fever. 
  

  

  THE 
  PROBABLE 
  ABSENCE 
  OF 
  YELLOW 
  FEVER 
  OUTSIDE 
  

   SOUTH 
  AMERICA 
  

  

  When 
  adequate 
  in 
  number, 
  sufficiently 
  representative, 
  and 
  com- 
  

   pletely 
  negative, 
  protection 
  tests 
  give 
  the 
  strongest 
  possible 
  evidence 
  

   of 
  the 
  absence 
  of 
  yellow 
  fever, 
  whether 
  transmitted 
  by 
  aegypti 
  or 
  

   the 
  unknown 
  jungle 
  vectors. 
  The 
  results 
  of 
  protection 
  tests 
  of 
  sera 
  

   from 
  North 
  America, 
  Central 
  America, 
  and 
  the 
  West 
  Indies 
  were 
  

   published 
  by 
  Sawyer, 
  Bauer, 
  and 
  Whitman 
  early 
  in 
  1937. 
  The 
  speci- 
  

   mens 
  had 
  been 
  collected 
  by 
  many 
  cooperating 
  persons 
  from 
  1932 
  

   through 
  the 
  early 
  part 
  of 
  1936. 
  When 
  the 
  collection 
  began, 
  jungle 
  

   yellow 
  fever 
  had 
  not 
  been 
  discovered 
  or 
  defined, 
  and 
  fewer 
  specimens 
  

   were 
  taken 
  in 
  rural 
  or 
  forest 
  environment 
  than 
  would 
  otherwise 
  have 
  

   been 
  the 
  case. 
  Moreover, 
  a 
  brief 
  survey 
  with 
  completely 
  negative 
  

  

  