﻿RESEARCH 
  ON 
  THE 
  GOLD 
  COAST. 
  31 
  

  

  V. 
  Insect-Borne 
  Diseases 
  of 
  Man 
  and 
  Other 
  Animals. 
  

  

  (l.) 
  Malaria. 
  

  

  This 
  disease 
  is 
  still 
  one 
  which 
  has 
  to 
  be 
  reckoned 
  with 
  in 
  the 
  Gold 
  Coast. 
  In 
  1910, 
  

   of 
  the 
  official 
  population 
  six 
  were 
  invalided 
  with 
  this 
  disease 
  and 
  three 
  died 
  of 
  it 
  ; 
  

   of 
  the 
  non-official 
  population, 
  twelve 
  were 
  invalided 
  and 
  twelve 
  died 
  from 
  malaria. 
  

   In 
  1911, 
  three 
  officials 
  and 
  twenty-one 
  non-officials 
  were 
  invalided 
  with 
  malaria 
  ; 
  

   the 
  deaths 
  I 
  have 
  been 
  unable 
  to 
  ascertain. 
  

  

  In 
  the 
  Medical 
  and 
  Sanitary 
  Report 
  for 
  the 
  Gold 
  Coast 
  for 
  1910, 
  the 
  following 
  

   appears 
  : 
  — 
  " 
  The 
  curve 
  (seasonal 
  prevalence) 
  for 
  malaria 
  begins 
  to 
  rise 
  slowly 
  soon 
  

   after 
  the 
  rains 
  set 
  in, 
  and 
  reaches 
  its 
  greatest 
  height 
  in 
  August. 
  There 
  is 
  then 
  a 
  fall 
  

   and 
  a 
  second, 
  but 
  small, 
  rise 
  in 
  October, 
  followed 
  by 
  another 
  fall. 
  The 
  prevalence 
  of 
  

   this 
  disease 
  is, 
  of 
  course, 
  in 
  direct 
  proportion 
  to 
  the 
  Anopheline 
  rate. 
  It 
  does 
  not 
  

   begin 
  to 
  rise 
  until 
  some 
  time 
  after 
  the 
  commen 
  cement 
  of 
  the 
  rains, 
  because 
  there 
  

   has 
  not 
  yet 
  been 
  time 
  for 
  any 
  great 
  number 
  of 
  mosquitoes 
  to 
  be 
  bred 
  and 
  become 
  

   infected. 
  During 
  the 
  heavy 
  rains, 
  moreover, 
  stagnant 
  pools 
  suited 
  to 
  the 
  habits 
  of 
  

   the 
  Anophelines 
  are 
  less 
  numerous 
  and 
  are 
  constantly 
  being 
  flushed 
  out 
  by 
  flood 
  water, 
  

   and 
  it 
  is 
  therefore 
  only 
  when 
  the 
  rainfall 
  is 
  decreasing 
  and 
  these 
  pools 
  remain 
  for 
  

   longer 
  periods 
  that 
  the 
  great 
  rise 
  in 
  the 
  malarial 
  rate 
  takes 
  place. 
  The 
  small 
  

   secondary 
  rise 
  ... 
  is 
  possibly 
  due 
  to 
  the 
  nearly 
  equal 
  rainfall 
  from 
  August 
  to 
  

   October, 
  which 
  would 
  be 
  sufficient 
  to 
  maintain 
  many 
  suitable 
  pools 
  at 
  a 
  fairly 
  

   constant 
  level." 
  

  

  This 
  is 
  very 
  suggestive, 
  and 
  shows 
  the 
  time 
  at 
  which 
  most 
  effective 
  control 
  could 
  

   be 
  instituted 
  in 
  the 
  way 
  of 
  draining 
  and 
  oiling. 
  

  

  Dr. 
  J. 
  M. 
  O'Brien, 
  when 
  in 
  charge 
  of 
  the 
  Accra 
  Laboratory 
  in 
  1911, 
  in 
  investi- 
  

   gating 
  the 
  malarial 
  index 
  of 
  the 
  school 
  children 
  of 
  ages 
  ranging 
  from 
  four 
  to 
  fifteen 
  

   in 
  Accra, 
  found 
  that 
  about 
  twenty 
  per 
  cent, 
  of 
  the 
  children 
  harboured 
  parasites, 
  mostly 
  

   malignant 
  tertian, 
  a 
  few 
  quartan 
  and 
  rarely 
  benign 
  tertian. 
  He 
  states 
  also 
  that 
  

   more 
  than 
  half 
  had 
  recently 
  suffered 
  from 
  malaria. 
  

  

  (2.) 
  YeHow 
  Fever. 
  

  

  This 
  insect-borne 
  disease 
  is 
  still 
  far 
  from 
  uncommon 
  in 
  West 
  Africa. 
  In 
  the 
  early 
  

   part 
  of 
  1910 
  ten 
  cases 
  of 
  yellow 
  fever, 
  nine 
  of 
  which 
  proved 
  fatal, 
  occurred 
  amongst 
  

   the 
  European 
  population 
  in 
  Sekondi. 
  Three 
  deaths 
  are 
  also 
  known 
  to 
  have 
  occurred 
  

   amongst 
  natives. 
  In 
  1911 
  there 
  were 
  six 
  cases 
  of 
  this 
  disease 
  in 
  Europeans 
  in 
  Accra 
  

   and 
  Axim, 
  all 
  of 
  which 
  proved 
  fatal. 
  Cases 
  have 
  also 
  occurred 
  in 
  Kwitta, 
  

   Cape 
  Coast 
  and 
  elsewhere 
  along 
  the 
  coast, 
  and 
  quite 
  recently 
  two 
  cases 
  in 
  Europeans 
  

   occurred 
  at 
  Bole 
  in 
  the 
  Northern 
  Territories. 
  

  

  It 
  will 
  be 
  seen 
  from 
  the 
  narrative 
  that 
  Stegomyia 
  fasciata 
  is 
  by 
  no 
  means 
  limited 
  

   in 
  its 
  distribution, 
  although 
  it 
  is 
  most 
  common 
  along 
  the 
  coast 
  towns. 
  When 
  

   dealing 
  above 
  with 
  Shama, 
  Saltpond, 
  Winniba, 
  etc., 
  I 
  pointed 
  out 
  the 
  main 
  source 
  of 
  

   the 
  mosquito 
  supply, 
  and 
  one 
  cannot 
  advocate 
  too 
  strongly 
  the 
  adoption 
  of 
  some 
  

   measure 
  to 
  mitigate 
  the 
  prevalence 
  of 
  this 
  pest. 
  

  

  (3.) 
  Sleeping 
  Sickness. 
  

  

  The 
  Gold 
  Coast 
  suffers 
  more 
  from 
  sleeping 
  sickness 
  than 
  any 
  other 
  British 
  Colony 
  

   in 
  West 
  Africa. 
  The 
  accompanying 
  map 
  shows 
  the 
  distribution 
  of 
  this 
  disease, 
  so 
  

   far 
  as 
  can 
  be 
  definitely 
  ascertained, 
  but 
  cases 
  from 
  widely 
  diverse 
  localities 
  have 
  been 
  

  

  