. / REPUBLIQUE DU SENEGAL $--’ *: ., ...
.
/ REPUBLIQUE DU SENEGAL
$--’
*:
.,
.
i ,
- - - - - -
MINISTERE DU DEVELOPPEMENT RURAL
ET DE L’HYDRAULIQUE
- - - - - -
INSTITUT SENEGALAIS DE RECHERCHES
A G R I C O L E S ( I . S . R . A . )
DEPARTEMENT DE RECHERCHES SUR LES
PRODUCTIONS ET LA SANTE ANIMALES
LABORATOIRE NATIONAL DE L’ELEVAGE
ET DE RECHERCHES VETERINAIRES
DAKAR-HANN
TICKS AND TICK-BORNE DISEASES IN SENEGAL :
PRESENT SITUATION
---oo---
A. GUEYE, Mb. MBENGUE, A. DIOUF
R é f . no 072IPARASITO.
Novembre 1990
t
*.
TICKS AND TICK-BORNE DISEASES IN SENEGAL :
PRESENT SITUATION
--oo--
A. GUEYE, Mb. MBENGUE, A. DIOUF
There is now a particular interest in ticks and tick borne
diseases of Iivestock in Africa. Until recently, their impact as a patholo-
gical constraint was not well investigated in some parts of the continent.
The climatic changes in the past ten years have modified several epide-
miological parameters. Consequently some species of ticks became more
important in some
areas and decreased in others regions. At the same
time, diseases transmitted, previously silent, suddenly spread in herds
(GUEYE & al., 1984).
The research carried out,for few years on cattle ticks in
Senegal, have precised their distribution and populations dynamic as well
as the areas infected by vector borne protozoon diseases (GUEYE & al,
1986, 1987, 1989a, 1989b).
1, MAIN ECOLOGICAL ZONES
There are siy main ecological zones in Senegal. They are
defined by the annual rainfall’ level and the caracteristic type of vege-
tation (mapl, table 1).
The presence of tse tse fly and animal trypanosomiasis is a
serious constraint for the development of several domestic ruminants and
cattle industry in general.
The Sahel is the aerea of zebu Cobra, of Touabir and Peulh
sheep breeds and of Sahel goat.
The trypanotolerant animals (Ndama cattle, Djallonke breeds
of sheep and goat) live in Soudanian and North-Guinean zones.
In the Niayes zone the Diakore is predominant ; it is a cross
breed from zebu and Ndama.
. . . / . . .
21
Table I -
Ecdogical zomes in Senegal
Zone
Rainfall (mm)
Vegetation
Coastal Niayes
400 -
600
Mix of grass savanna, oil
palm and depression with
clay soils
Sahel zone
300 -
500
Grass savanna
Soudano-Sahel ian
500 -
800
Grass savanna - some trees
Northern Sudan
800 - 1000
T r e e - Savanna
Southern Sudan
1000 - 1200
Savanna woodland
Northern Cuinea
1200 - 1500
Wood land
31
II. DISTRIBIOTl,ON OF CATTE TICKS
The following species of ticks belonging to the genus Amblyom-
ma, Boophilus, Hyalomma and Rhipicephalus have been identified on cattle,
sheep and goat :
- Genus Amblyomma
: A. variegatum (Fabricius 1794)
- Genus Boophilus
: B. decoloratus (Koch 1844)
B. geigyi Aeschlimann et More1 1965
B. annulatus (Say 1821)
- Cenus Hyalomma
: H. truncatum (Koch 1844)
H. marginatum rufipes Koch 1844
H. impeltatutn (Schultz et Schlottke)
H. impressum ( Koch 1844)
H. nitidum (Schulze, 1919)
- Genus Rhipicephalus
Rh. evertsi evertsi (Neumann 1897)
Rh. sulcatus (Neumann 1908)
Rh. senegalensis (Koch 1844)
Rh. muhsamae More1 et Vassiliades 1965
Rh. guilhoni
More1 et Vassiliades 1962
Rh. lunulatus Neumann 1907
The geographical distribution of these ticks as well as the
level of their populationshave changed significantly during the last ten
years (GUEYE & al, 1987, 1989c). This evolution of the distribution of the
different species are shown on maps 2, 3 and 4 which have data on the
per iod before the 1972 - 1986 draught and on the recent years.
The changes in the distribution of the different species have
had a considerable epidemiological impact on disease prevalence.
Diseuses transmïtkd
The main animal diseases transmitted by ticks in Senegal are
the following : bovine anaplasmosis, cowdriosis, bovine erlichiosis, bovine
babesiosis by Babesia bigemina.
. . . / . . .
Table II -
TiiWme Riiettsiall dliseases of cattk
Disease
Geographical
Vector (s)
Epidemiology
(cause)
Distribution
Anaplasmosis
All ecological zones
Epidemic in Sahel
(A. marginale)
Amblyomma
Enz-stable in other
Varieaatum
zones
Heart water dis,
Coasted N iayes
Variable - Dependin
IC. ruminantuml
II
Sudano-Sahel
on zone and on the
Northern-Guinea
use of the cattle
Sudan zones
Ehrlichiosis
Coasted N iayes
Epidemic in Niayes
(E.bovis)
Sudano-Sahel
Stable in other
Northern-Guinea
zones
Sudan zones
51
.
Table 111 -
Tick-borne Protozual disemes af cattle
Disease
Geographical
Vector (s)
Epidemiology
(cause)
Distribution
Babesiosis
Boophilus sp
Niayes
Enzootically
(B. bigemina)
Sudan zone
stable in all zones
Northern Guinea
Theileriosis
Amblyomma
niayes
Enzootically
(T.mutansI
Variegatum
Sudan Sahel
stable in all zones
Sudan and Northern
Guinea zone
Non pathogen ic
Amblyomma
N iayes
Enzootically
(T.veIifera)
Variegatum
Sudan and Northern stable in all zones
Guinea zone
I
I
The infections by Theileria mufans a n d Theileria Vdifera are
mild or non pathogenic.
These different diseases may have various enzootic caracteris-
tics according to the ecological zone, the animal species, and the season.
Further investigation is required in order to collect more data on their
epidemiology. Tables 2 and 3 give informations on the evolution of these
diseases.
CONCLUSION
Ticks distribution may be subject to considerable changes due
to ecolog ical factors. Consequently animal health may be seriously affected
because cattle may loose the immunity previously induced by repeated in-
fections. This one moves from a stable enzootic state to an unstable enzootic
state which is often difficult to control. However, further indepth investiga-
tions are required to identify the parameters influencing these enzootic
diseases.
t
,
’
SUMMARY
The authors present a record of ticks species which infest
the livestock. The distribution of these ticks before the draught of 1972 -
1986 and thereafter mentioned as well.
All tick borne diseases of cattle in this country are reported
too, and their enzootic characteristic in the different ecological areas dis-
cribed.
BIBLIOGRAPHY
GUEYE (A), LEFORBAN (Y) - Note sur des épizooties d’anaplasmose chez des
zébus indigènes au Sénégal.
Rev. Elev. Méd. vét. Pays trop., 1984, 37 (4) : 433-436.
-
GUEYE (A), MBENGUJE (RwL>), DIOUF (A), SEYE (U) - Tiques et hémoparasito-
ses du bétail au Sénégal.
I/- La région des Niayes.
Rev. Elev. Méd. vét. Pays trop., 1986, 39 (3-4) : 381-393.
-
GUEYE (A), MBENGIWE (Mb), DIOUF (A) - Tiques et hémoparasitoses du bétail
au Sénégal.
I I /- La zone sahélienne.
Rev. Elev. Méd. vét. Pays trop., 1987, 40 (2) : 119-125.
-
GUEYE (A), MBElNlGUlE (Mb), DIOUF (A) - Tiques et hémoparasitoses du bétail
au Sénégal.
I I I I- La zone nord-soudanienne.
Rev. Elev. Méd. vét. Pays trop., 1989a, 42 (3) : 411-420.
-
GUIEYE (A), MBENGUE (Mb), DIOUF (A) - Tiques et hémoparasitoses du bétail
au Sénéga 1.
I I I /- La zone
sud-soudanienne
Rev. Elev. Méd. vét. Pays trop., 1989b, 42 (4) : 517-528.
-
GUEYE CA), CAMICAS (J-L) - Distribution des tiques du bétail.
In : Atlas de l’élevage et des potentialités pastorales sahéliennes - synthèses
cartographiques - SENEGAL / CTA / IEMVT, 1989c p : 20.
/ REPUBLIQUE DU SENEGAL
$--’
*:
.,
.
i ,
- - - - - -
MINISTERE DU DEVELOPPEMENT RURAL
ET DE L’HYDRAULIQUE
- - - - - -
INSTITUT SENEGALAIS DE RECHERCHES
A G R I C O L E S ( I . S . R . A . )
DEPARTEMENT DE RECHERCHES SUR LES
PRODUCTIONS ET LA SANTE ANIMALES
LABORATOIRE NATIONAL DE L’ELEVAGE
ET DE RECHERCHES VETERINAIRES
DAKAR-HANN
TICKS AND TICK-BORNE DISEASES IN SENEGAL :
PRESENT SITUATION
---oo---
A. GUEYE, Mb. MBENGUE, A. DIOUF
R é f . no 072IPARASITO.
Novembre 1990
t
*.
TICKS AND TICK-BORNE DISEASES IN SENEGAL :
PRESENT SITUATION
--oo--
A. GUEYE, Mb. MBENGUE, A. DIOUF
There is now a particular interest in ticks and tick borne
diseases of Iivestock in Africa. Until recently, their impact as a patholo-
gical constraint was not well investigated in some parts of the continent.
The climatic changes in the past ten years have modified several epide-
miological parameters. Consequently some species of ticks became more
important in some
areas and decreased in others regions. At the same
time, diseases transmitted, previously silent, suddenly spread in herds
(GUEYE & al., 1984).
The research carried out,for few years on cattle ticks in
Senegal, have precised their distribution and populations dynamic as well
as the areas infected by vector borne protozoon diseases (GUEYE & al,
1986, 1987, 1989a, 1989b).
1, MAIN ECOLOGICAL ZONES
There are siy main ecological zones in Senegal. They are
defined by the annual rainfall’ level and the caracteristic type of vege-
tation (mapl, table 1).
The presence of tse tse fly and animal trypanosomiasis is a
serious constraint for the development of several domestic ruminants and
cattle industry in general.
The Sahel is the aerea of zebu Cobra, of Touabir and Peulh
sheep breeds and of Sahel goat.
The trypanotolerant animals (Ndama cattle, Djallonke breeds
of sheep and goat) live in Soudanian and North-Guinean zones.
In the Niayes zone the Diakore is predominant ; it is a cross
breed from zebu and Ndama.
. . . / . . .
21
Table I -
Ecdogical zomes in Senegal
Zone
Rainfall (mm)
Vegetation
Coastal Niayes
400 -
600
Mix of grass savanna, oil
palm and depression with
clay soils
Sahel zone
300 -
500
Grass savanna
Soudano-Sahel ian
500 -
800
Grass savanna - some trees
Northern Sudan
800 - 1000
T r e e - Savanna
Southern Sudan
1000 - 1200
Savanna woodland
Northern Cuinea
1200 - 1500
Wood land
31
II. DISTRIBIOTl,ON OF CATTE TICKS
The following species of ticks belonging to the genus Amblyom-
ma, Boophilus, Hyalomma and Rhipicephalus have been identified on cattle,
sheep and goat :
- Genus Amblyomma
: A. variegatum (Fabricius 1794)
- Genus Boophilus
: B. decoloratus (Koch 1844)
B. geigyi Aeschlimann et More1 1965
B. annulatus (Say 1821)
- Cenus Hyalomma
: H. truncatum (Koch 1844)
H. marginatum rufipes Koch 1844
H. impeltatutn (Schultz et Schlottke)
H. impressum ( Koch 1844)
H. nitidum (Schulze, 1919)
- Genus Rhipicephalus
Rh. evertsi evertsi (Neumann 1897)
Rh. sulcatus (Neumann 1908)
Rh. senegalensis (Koch 1844)
Rh. muhsamae More1 et Vassiliades 1965
Rh. guilhoni
More1 et Vassiliades 1962
Rh. lunulatus Neumann 1907
The geographical distribution of these ticks as well as the
level of their populationshave changed significantly during the last ten
years (GUEYE & al, 1987, 1989c). This evolution of the distribution of the
different species are shown on maps 2, 3 and 4 which have data on the
per iod before the 1972 - 1986 draught and on the recent years.
The changes in the distribution of the different species have
had a considerable epidemiological impact on disease prevalence.
Diseuses transmïtkd
The main animal diseases transmitted by ticks in Senegal are
the following : bovine anaplasmosis, cowdriosis, bovine erlichiosis, bovine
babesiosis by Babesia bigemina.
. . . / . . .
Table II -
TiiWme Riiettsiall dliseases of cattk
Disease
Geographical
Vector (s)
Epidemiology
(cause)
Distribution
Anaplasmosis
All ecological zones
Epidemic in Sahel
(A. marginale)
Amblyomma
Enz-stable in other
Varieaatum
zones
Heart water dis,
Coasted N iayes
Variable - Dependin
IC. ruminantuml
II
Sudano-Sahel
on zone and on the
Northern-Guinea
use of the cattle
Sudan zones
Ehrlichiosis
Coasted N iayes
Epidemic in Niayes
(E.bovis)
Sudano-Sahel
Stable in other
Northern-Guinea
zones
Sudan zones
51
.
Table 111 -
Tick-borne Protozual disemes af cattle
Disease
Geographical
Vector (s)
Epidemiology
(cause)
Distribution
Babesiosis
Boophilus sp
Niayes
Enzootically
(B. bigemina)
Sudan zone
stable in all zones
Northern Guinea
Theileriosis
Amblyomma
niayes
Enzootically
(T.mutansI
Variegatum
Sudan Sahel
stable in all zones
Sudan and Northern
Guinea zone
Non pathogen ic
Amblyomma
N iayes
Enzootically
(T.veIifera)
Variegatum
Sudan and Northern stable in all zones
Guinea zone
I
I
The infections by Theileria mufans a n d Theileria Vdifera are
mild or non pathogenic.
These different diseases may have various enzootic caracteris-
tics according to the ecological zone, the animal species, and the season.
Further investigation is required in order to collect more data on their
epidemiology. Tables 2 and 3 give informations on the evolution of these
diseases.
CONCLUSION
Ticks distribution may be subject to considerable changes due
to ecolog ical factors. Consequently animal health may be seriously affected
because cattle may loose the immunity previously induced by repeated in-
fections. This one moves from a stable enzootic state to an unstable enzootic
state which is often difficult to control. However, further indepth investiga-
tions are required to identify the parameters influencing these enzootic
diseases.
t
,
’
SUMMARY
The authors present a record of ticks species which infest
the livestock. The distribution of these ticks before the draught of 1972 -
1986 and thereafter mentioned as well.
All tick borne diseases of cattle in this country are reported
too, and their enzootic characteristic in the different ecological areas dis-
cribed.
BIBLIOGRAPHY
GUEYE (A), LEFORBAN (Y) - Note sur des épizooties d’anaplasmose chez des
zébus indigènes au Sénégal.
Rev. Elev. Méd. vét. Pays trop., 1984, 37 (4) : 433-436.
-
GUEYE (A), MBENGUJE (RwL>), DIOUF (A), SEYE (U) - Tiques et hémoparasito-
ses du bétail au Sénégal.
I/- La région des Niayes.
Rev. Elev. Méd. vét. Pays trop., 1986, 39 (3-4) : 381-393.
-
GUEYE (A), MBENGIWE (Mb), DIOUF (A) - Tiques et hémoparasitoses du bétail
au Sénégal.
I I /- La zone sahélienne.
Rev. Elev. Méd. vét. Pays trop., 1987, 40 (2) : 119-125.
-
GUEYE (A), MBElNlGUlE (Mb), DIOUF (A) - Tiques et hémoparasitoses du bétail
au Sénégal.
I I I I- La zone nord-soudanienne.
Rev. Elev. Méd. vét. Pays trop., 1989a, 42 (3) : 411-420.
-
GUIEYE (A), MBENGUE (Mb), DIOUF (A) - Tiques et hémoparasitoses du bétail
au Sénéga 1.
I I I /- La zone
sud-soudanienne
Rev. Elev. Méd. vét. Pays trop., 1989b, 42 (4) : 517-528.
-
GUEYE CA), CAMICAS (J-L) - Distribution des tiques du bétail.
In : Atlas de l’élevage et des potentialités pastorales sahéliennes - synthèses
cartographiques - SENEGAL / CTA / IEMVT, 1989c p : 20.