Bettridge, Judy M.

Christley, Robert M.

Collins, M.

Macleod, M.

Walker, A.R.

CGSpace

M.	  Collins1,	  R.	  Christley1,	  J.M.	  Be4ridge1,	  A.R.	  Walker2,	  E.	  MacLeod3	  	  1The	  University	  of	  Liverpool,	  InsFtute	  of	  InfecFon	  and	  Global	  Health,	  Department	  of	  Epidemiology	  and	  PopulaFon	  Health	  2Honorary	  Fellow,	  The	  University	  of	  Edinburgh,	  Royal	  (Dick)	  School	  of	  Veterinary	  Studies	  3The	  University	  of	  Edinburgh,	  School	  of	  Biomedical	  Sciences,	  Division	  of	  Pathway	  Medicine	  A	  new	  look	  at	  ectoparasites	  aﬀec1ng	  indigenous	  village	  poultry	  in	  Ethiopia	  	  Introduc1on	  	  	  •  Small	  scale	  poultry	  producFon	  in	  Ethiopia	  is	  a	  signiﬁcant	  contributor	  to	  the	  livelihoods	  of	  poor	  rural	  subsistence	  farmers.	  •  Research	  shows	  that	  ectoparasites,	  parFcularly	  lice,	  mites	  and	  ﬂeas	  are	  common	  in	  scavenging	  ﬂocks	  in	  Ethiopia.	  •  InfestaFon	  is	  perceived	  by	  farmers	  to	  be	  a	  major	  cause	  of	  bird	  morbidity	  and	  mortality,	  parFcularly	  in	  young	  stock	  (Fig.1).	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  •  The	  role	  of	  ectoparasites	  within	  the	  wider	  context	  of	  infecFous	  disease	  constraints	  in	  village	  chicken	  producFon	  remains	  poorly	  understood,	  in	  part	  due	  to	  the	  complexity	  of	  correctly	  speciaFng	  ectoparasite	  specimens.	  	  •  This	  study	  focuses	  on	  the	  idenFﬁcaFon	  and	  prevalence	  of	  ectoparasites	  in	  scavenging	  chickens	  and	  forms	  part	  of	  a	  large	  collaboraFve	  project	  invesFgaFng	  the	  disease	  epidemiology,	  socio-­‐economic	  dimensions	  and	  geneFc	  diversity	  of	  indigenous	  poultry	  in	  Ethiopia.	  	  	  Methodology	  	  	  •  A	  mulF-­‐stage	  cross-­‐secFonal	  study	  was	  conducted	  over	  4	  sampling	  periods	  between	  May	  2011	  and	  October	  2012.	  •  A	  total	  of	  1266	  healthy	  adult	  birds	  in	  640	  households	  were	  examined	  in	  the	  western	  region	  of	  Horro	  (n=635)	  and	  eastern	  region	  of	  Jarso	  (n=631),	  and	  a	  further	  30	  birds	  in	  in	  15	  households	  in	  the	  central	  village	  of	  Godino.	  	  •  Visual	  examinaFon	  and	  Fmed	  counts	  were	  conducted	  at	  predilecFon	  sites	  for	  ectoparasites	  on	  the	  bird’s	  body	  (Fig.2).	  Specimens	  were	  collected	  and	  stored	  in	  70%	  ethanol	  for	  idenFﬁcaFon	  by	  light	  microscopy	  at	  x100	  and	  x400	  magniﬁcaFon,	  using	  10%	  potassium	  hydroxide	  soluFon	  to	  clarify	  samples	  where	  necessary.	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  Fig.2.	  Sites	  of	  visual	  and	  3med	  ectoparasite	  examina3on	  and	  the	  parasite	  genera	  	  	  	  	  expected	  to	  be	  found	  at	  the	  predilec3on	  sites	  on	  the	  body.	  	  A C 	  Results	  	  •  One	  or	  more	  species	  of	  ectoparasite	  were	  idenFﬁed	  in	  777/1296	  (60%)	  of	  the	  birds	  in	  the	  study,	  with	  426/635	  (67%)	  of	  birds	  in	  Horro,	  325/631	  (52%)	  in	  Jarso	  and	  26/30	  (87%)	  in	  Godino	  showing	  infestaFon	  with	  at	  least	  one	  ectoparasite	  species.	  •  Within	  720	  specimens	  collected,	  16	  ectoparasite	  types	  were	  idenFﬁed,	  all	  known	  to	  be	  associated	  with	  clinical	  disease	  (Figs.1,2	  and	  3),	  including	  three	  species	  of	  pathogenic	  chewing	  lice,	  M.pallidulus,	  M.cornutus	  and	  G.dissimilis,	  not	  previously	  reported	  in	  Ethiopia.	  •  StaFsFcally	  signiﬁcant	  diﬀerences	  were	  found	  between	  infestaFon	  prevalence	  at	  the	  3	  study	  sites,	  with	  a	  greater	  diversity	  of	  ectoparasites	  infesFng	  birds	  in	  Horro	  than	  in	  Jarso	  and	  Godino.	  Scaly	  leg	  mites	  (C.mutans)	  and	  chewing	  lice	  species	  (Fig.4	  A-­‐G,L)	  represented	  the	  most	  commonly	  idenFﬁed	  ectoparasites	  in	  both	  Horro	  and	  Jarso,	  with	  some	  species	  speciﬁc	  to	  each	  region	  (Fig.5).	  The	  sFck-­‐Fght	  ﬂea	  (E.gallinae),	  was	  only	  found	  in	  Godino,	  where	  it	  was	  the	  dominant	  species	  infesFng	  birds	  (Fig.6).	  	  •  There	  was	  an	  overall	  41%	  prevalence	  of	  scaly	  leg	  mite	  infestaFon,	  with	  no	  staFsFcally	  signiﬁcant	  diﬀerence	  in	  prevalence	  between	  the	  study	  regions.	  	  	  •  Low	  numbers	  of	  Fck,	  Red	  Mite	  and	  true	  bug	  samples	  were	  collected.	  Poultry-­‐speciﬁc	  Fck	  species,	  previously	  reported	  in	  Ethiopia,	  were	  not	  found.	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  	  Conclusions	   •  There	  is	  a	  widespread	  and	  diverse	  range	  of	  pathogenic	  ectoparasite	  species	  infesFng	  backyard	  ﬂocks	  in	  these	  rural	  communiFes.	  However,	  most	  adult	  birds	  appeared	  healthy	  despite	  high	  infestaFon	  prevalence	  and	  ectoparasite	  burdens.	  •  The	  discovery	  of	  novel	  species	  of	  lice	  not	  previously	  reported	  in	  Ethiopia	  shows	  that	  ectoparasite	  epidemiology	  in	  rural	  seengs	  is	  not	  fully	  understood	  and	  calls	  for	  further	  research	  in	  this	  ﬁeld.	  	  	  	  •  Clear	  diﬀerences	  in	  species	  diversity	  between	  regions	  suggest	  there	  may	  be	  local	  risk	  factors	  associated	  with	  infestaFon,	  including	  management,	  environment	  or	  bird-­‐speciﬁc	  factors.	  Future	  invesFgaFons	  should	  include	  not	  only	  young	  stock,	  which	  in	  the	  literature	  and	  by	  farmer	  percepFon,	  represent	  the	  highest	  risk	  group	  for	  ectoparasiFc	  disease,	  but	  also	  pathogenic	  ectoparasites	  that	  undergo	  much	  of	  their	  life	  cycle	  away	  from	  the	  host,	  such	  as	  sof	  Fcks	  (Argas	  species)	  and	  blood	  feeding	  dermanyssid	  mites.	  	  •  A	  greater	  understanding	  of	  ectoparasite	  species	  infesFng	  ﬂocks	  can	  be	  used	  to	  tailor	  guidelines	  for	  farmers	  and	  animal	  health	  professionals	  on	  local	  ectoparasite	  control.	  The	  provision	  of	  pracFcal	  and	  culturally	  sensiFve	  control	  measures,	  as	  part	  of	  poultry	  health	  management	  at	  village	  level,	  is	  currently	  lacking.	  Improved	  housing	  and	  management	  of	  young	  birds	  could	  oﬀer	  eﬀecFve	  means	  to	  minimize	  and	  prevent	  ectoparasite	  infestaFon.	  Fig.3.	  List	  of	  ectoparasite	  species	  iden3ﬁed	  in	  the	  study.	  Colour	  denotes	  species	  groups:	  orange	  –	  chewing	  lice,	  pink	  –	  mites,	  green	  –	  3cks,	  blue	  –	  ﬂeas	  and	  brown	  –	  bugs.	  Fig.4.	  Microscope	  photographs	  (x100	  magniﬁca3on)	  of	  ectoparasite	  species	  isolated	  from	  birds	  in	  Horro,	  Jarso	  and	  Godino.	  	  	  Fig.5.	  Ectoparasite	  species	  found	  in	  Horro	  and	  Jarso	  over	  the	  four	  sampling	  periods	  of	  the	  study.	  Values	  represent	  the	  propor3on	  of	  a	  given	  species	  within	  the	  overall	  number	  of	  samples	  collected	  Fig.6.	  Ectoparasites	  found	  in	  Godino	  village	  during	  the	  one	  day	  sampling	  in	  November	  2012.	  Values	  represent	  a	  propor3on	  of	  a	  given	  species	  within	  the	  overall	  number	  of	  samples	  collected.	  	  Fig	  1.	  Specimens	  and	  clinical	  signs	  of	  two	  pathogenic	  ectoparasites	  found	  in	  village	  poultry.	  A	  –	  C.mutans,	  the	  scaly	  leg	  mite	  (x400	  mag.),	  B	  –	  normal	  feet	  	  in	  an	  unaﬀected	  bird,	  C	  –	  Scaly	  Leg	  (exuda3ve	  hyperkeratosis)	  due	  to	  severe	  C.mutans	  infesta3on,	  D	  –	  M.cornutus,	  the	  body	  louse	  (x100	  mag.),	  E-­‐	  lice	  infesta3on	  (pediculosis)	  around	  the	  vent	  of	  a	  hen,	  F	  –	  feather	  loss,	  inﬂamma3on	  and	  crusted	  lesions	  typical	  of	  pediculosis.	  	  !!"#$%#&! 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A new look at ectoparasites affecting indigenous village poultry in Ethiopia

https://cgspace.cgiar.org/bitstream/10568/64993/1/newLook.pdf

A new look at ectoparasites affecting indigenous village poultry in Ethiopia

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