i Tsetse control and development of related areas ...
i
Tsetse control and development of related areas in Senegal
A DIAITE
ISRA LNERV BP 2057 Dakar Hann Senegal
Introduction.
The Niayes region in Senegal is a residu of guinean forest and because of this, it has a quite different
ecological feature in a sahelian zone. This area used to be infested by Ghsirza palpulis gambietais
and local transmition of a number of species of Trypanosomes has regularly been reported.
It is generally accepted that development of agriculture is drastically impeded in large areas of fertile
land in Africa by these infections thus contributing in a large part for the non food secure status of
sub saharan Africa. In Senegal very fertile peri urban lands were likely to be lost if nothing was
quickly done to solve this problem. Fortunately, because of its awareness of the importance of urban
agriculture in feeding people, the Government of Senegal initiated with the kind help of United
Nations’ FAO Tsetse control operations in the region.
Tsetse control campaigns in the Niayes region (Senegal).
The first control campaign was launched in the early seventies and consisted only in ground spraying
of insecticide (Dieldrin). The spraying lasted for three years fi-om March to Mai each year (Tour&
1971; 1974, 1980). At that time, the lack of appropriate information on particular biotopes that
existed such as mango trees farms and live euphorbia fentes conducted to the non treatment of these
new types of habitats. As a result, tsetse flies were still present in the Niayes until 1980 when a new
campaign was again launched using this time, in addition to the ground spraying, insecticide
impregneted biconical traps and screens (5% Deltametrine).
The combination of these two methods in addition to the drought that subsequently oceured resulted
in the vit-tua1 eradication of G/ossina pdpalis gambiensis from this area (Diaité et Vassiliades 1984).
Subsequently, despite several attempts to trap tsetse no evidence of the presence of glossina flics was
clearly established until 1992 when a male of Glossina pafpdis gambiensis was caught in the same
area where a case of human trypanosomiasis was reported; there was however no fùrther
consolidation of this interesting data.
The “Parc zoologique et forestier de Hann”, which is an isolated entity, is itself still infested and very
recent surveys (September 1997) have confirmed the presence of Glossina paipdis gambiensis
(Diaite et Diouf, 1997). Problems encountered by a horse show jumping club situated in the vicinity
of the parc were found to have been caused by 1: vivax.
Investments and agricultural production in the area
lnvestment
Following the cleaning of the six hundred hectares infested out of 36.500 hectares of the region,
Sign&ant investments were made in the agropastoral sector by either projects such Soca or the
“ferme de Niacourab” or by individuals holding good savings and willing to go back to farm work ,
Respectively these macro and micro entrepreneurships created, in addition, jobs for unemployed
: Young people in that rural area.
REF N” 002/PATHO/ANIM Fevrier 1998.
Production
Varieties of vegetables are being produced including Oignons, patatoes, cabbages fresh tomatoes,
string beans, and SO on, specially during the cool season (from December to april). But according to
the “Bureau pour le Developpement de la Production Agricole BDPA” the production of vegetables
needs to be intensified and may be multiplied by three to meet the local demand.
Fruits are also being produced such as manges and oranges. This production is shared between the
local and foreign markets specially in Europe thus enabling trees farms owners to earn cash for
further investments
In the animal agriculture subsector, big effeorts have been made to import high performing european
dairy or meat breeds (Montbeliard, Jersayais, Hollstein Charolais) . Some of these attempts are very
successml as, in one farm, a daily production of 1.500 liters of milk has been recently reported. This
milk is entirely used locally for consumption fresh or alter transformation by the industry. An
important increase in the production is still needed to meet the demand.
Curent Problems of the area.
Unfortunately the situation of trypanosomiasis and flies (either tsetse or other biting flies) is not quite
clear and urgently needs to be up dated. Importantly, cases of trypanosomiasis are regularly
reported in local animais herds around these more modem type of farts. SO far diagnosis using
parasitology methods such as stained blood smears and the bufI!y coat technique has indicated that
the cases derived from infections by 1: Y~VQX. However the epidemiology of T. vivax needs to be
better understood because, if it is documented that strict mechanical transmission results in the
inability of tsetse flies to cyclically transmit such strains, it is not known wether it also may result in
the adaptation to new hosts such as rodents in which case the epidemiology may be different. Recent
works have also reported that in laboratory conditions, T. hcei could be mechanically transmitted
to animal hosts even more efftciently than T. ~&LX (Mihok et cri 1995) by different species of
stomoxes.
If confirmed in the field, this observation may represent a new dimension in the
epidemiology of animal as well as human trypanosomiasis as it is reported that stomoxes cari
occasionally feed on humans.
What is currently needed.
The situation in the Niayes appeals for the old data to be urgently up dated meaning that
investigations should be undertaken to:
* establish wether or not tsetse flies are present
* have a precise idea of non tsetse biting flies present and their seasonal variation in population
density
* precisely establish which species of trypanosomes are present using three methods of diagnosis
namely stained blood smears bufi coat technique and the Elisa for the detection of antibodies and
eventually antigens.
References
Diaite, A. et Diouf, A., (1997). Prospections entomologiques dans le parc zoologique et
forestier de Hann, suggestions pour l’éradication de Glossirza ptxlpalis gambiensis Rapport LNERV
Diaite, A. et Vassiliades G., (1984). Note sur la situation actuelle des glossines dans la
région des Niayes Ref No 109fParasito; Decembre 1984.
S. Mihok, 0. Maramba, E. Munyoki, J. Kagoiya. (1995). Mechanical transmission ot
Trypanosoma spp. By African Stomoxyinae (Diptera: Muscidae). Trou. Med. Parasitol. 46 103-
105
Tour-é, S.M., (1971).
Campagne de lutte contre Glossina palpalis gambiensis,
Vanderplanck, 1949 dans la région des Niayes du Sénégal {Mars-mai 1970): Communication
presentée à la réunion du conseil internation conjoint OUA/FAO/OMS de recherche sur la
trypanosomose Lapas 7-11 Septembre 1971.
Tour-é, S.M. (1974). Bilan de trois années de lutte contre les glossines dans la region des
Niayes du Sénégal. Coiloaue sur les movens de lutte contre les trwanosomes et leurs vecteurs,
Paris, 12-15 mars 1974- Actes du colloaue, RR 355-356; Edité Dar 1’I.E.M.V.T.
Tour& S.M. (1980). Rapport sur l’exécution du projet de lutte contre les glossines dans les
Niayes et la petite côte du Sénégal: Ram~ort Lab. Nat. Elev. Rech. Vet. Juillet 1980, 13 Dages
Dakar.
Tsetse control and development of related areas in Senegal
A DIAITE
ISRA LNERV BP 2057 Dakar Hann Senegal
Introduction.
The Niayes region in Senegal is a residu of guinean forest and because of this, it has a quite different
ecological feature in a sahelian zone. This area used to be infested by Ghsirza palpulis gambietais
and local transmition of a number of species of Trypanosomes has regularly been reported.
It is generally accepted that development of agriculture is drastically impeded in large areas of fertile
land in Africa by these infections thus contributing in a large part for the non food secure status of
sub saharan Africa. In Senegal very fertile peri urban lands were likely to be lost if nothing was
quickly done to solve this problem. Fortunately, because of its awareness of the importance of urban
agriculture in feeding people, the Government of Senegal initiated with the kind help of United
Nations’ FAO Tsetse control operations in the region.
Tsetse control campaigns in the Niayes region (Senegal).
The first control campaign was launched in the early seventies and consisted only in ground spraying
of insecticide (Dieldrin). The spraying lasted for three years fi-om March to Mai each year (Tour&
1971; 1974, 1980). At that time, the lack of appropriate information on particular biotopes that
existed such as mango trees farms and live euphorbia fentes conducted to the non treatment of these
new types of habitats. As a result, tsetse flies were still present in the Niayes until 1980 when a new
campaign was again launched using this time, in addition to the ground spraying, insecticide
impregneted biconical traps and screens (5% Deltametrine).
The combination of these two methods in addition to the drought that subsequently oceured resulted
in the vit-tua1 eradication of G/ossina pdpalis gambiensis from this area (Diaité et Vassiliades 1984).
Subsequently, despite several attempts to trap tsetse no evidence of the presence of glossina flics was
clearly established until 1992 when a male of Glossina pafpdis gambiensis was caught in the same
area where a case of human trypanosomiasis was reported; there was however no fùrther
consolidation of this interesting data.
The “Parc zoologique et forestier de Hann”, which is an isolated entity, is itself still infested and very
recent surveys (September 1997) have confirmed the presence of Glossina paipdis gambiensis
(Diaite et Diouf, 1997). Problems encountered by a horse show jumping club situated in the vicinity
of the parc were found to have been caused by 1: vivax.
Investments and agricultural production in the area
lnvestment
Following the cleaning of the six hundred hectares infested out of 36.500 hectares of the region,
Sign&ant investments were made in the agropastoral sector by either projects such Soca or the
“ferme de Niacourab” or by individuals holding good savings and willing to go back to farm work ,
Respectively these macro and micro entrepreneurships created, in addition, jobs for unemployed
: Young people in that rural area.
REF N” 002/PATHO/ANIM Fevrier 1998.
Production
Varieties of vegetables are being produced including Oignons, patatoes, cabbages fresh tomatoes,
string beans, and SO on, specially during the cool season (from December to april). But according to
the “Bureau pour le Developpement de la Production Agricole BDPA” the production of vegetables
needs to be intensified and may be multiplied by three to meet the local demand.
Fruits are also being produced such as manges and oranges. This production is shared between the
local and foreign markets specially in Europe thus enabling trees farms owners to earn cash for
further investments
In the animal agriculture subsector, big effeorts have been made to import high performing european
dairy or meat breeds (Montbeliard, Jersayais, Hollstein Charolais) . Some of these attempts are very
successml as, in one farm, a daily production of 1.500 liters of milk has been recently reported. This
milk is entirely used locally for consumption fresh or alter transformation by the industry. An
important increase in the production is still needed to meet the demand.
Curent Problems of the area.
Unfortunately the situation of trypanosomiasis and flies (either tsetse or other biting flies) is not quite
clear and urgently needs to be up dated. Importantly, cases of trypanosomiasis are regularly
reported in local animais herds around these more modem type of farts. SO far diagnosis using
parasitology methods such as stained blood smears and the bufI!y coat technique has indicated that
the cases derived from infections by 1: Y~VQX. However the epidemiology of T. vivax needs to be
better understood because, if it is documented that strict mechanical transmission results in the
inability of tsetse flies to cyclically transmit such strains, it is not known wether it also may result in
the adaptation to new hosts such as rodents in which case the epidemiology may be different. Recent
works have also reported that in laboratory conditions, T. hcei could be mechanically transmitted
to animal hosts even more efftciently than T. ~&LX (Mihok et cri 1995) by different species of
stomoxes.
If confirmed in the field, this observation may represent a new dimension in the
epidemiology of animal as well as human trypanosomiasis as it is reported that stomoxes cari
occasionally feed on humans.
What is currently needed.
The situation in the Niayes appeals for the old data to be urgently up dated meaning that
investigations should be undertaken to:
* establish wether or not tsetse flies are present
* have a precise idea of non tsetse biting flies present and their seasonal variation in population
density
* precisely establish which species of trypanosomes are present using three methods of diagnosis
namely stained blood smears bufi coat technique and the Elisa for the detection of antibodies and
eventually antigens.
References
Diaite, A. et Diouf, A., (1997). Prospections entomologiques dans le parc zoologique et
forestier de Hann, suggestions pour l’éradication de Glossirza ptxlpalis gambiensis Rapport LNERV
Diaite, A. et Vassiliades G., (1984). Note sur la situation actuelle des glossines dans la
région des Niayes Ref No 109fParasito; Decembre 1984.
S. Mihok, 0. Maramba, E. Munyoki, J. Kagoiya. (1995). Mechanical transmission ot
Trypanosoma spp. By African Stomoxyinae (Diptera: Muscidae). Trou. Med. Parasitol. 46 103-
105
Tour-é, S.M., (1971).
Campagne de lutte contre Glossina palpalis gambiensis,
Vanderplanck, 1949 dans la région des Niayes du Sénégal {Mars-mai 1970): Communication
presentée à la réunion du conseil internation conjoint OUA/FAO/OMS de recherche sur la
trypanosomose Lapas 7-11 Septembre 1971.
Tour-é, S.M. (1974). Bilan de trois années de lutte contre les glossines dans la region des
Niayes du Sénégal. Coiloaue sur les movens de lutte contre les trwanosomes et leurs vecteurs,
Paris, 12-15 mars 1974- Actes du colloaue, RR 355-356; Edité Dar 1’I.E.M.V.T.
Tour& S.M. (1980). Rapport sur l’exécution du projet de lutte contre les glossines dans les
Niayes et la petite côte du Sénégal: Ram~ort Lab. Nat. Elev. Rech. Vet. Juillet 1980, 13 Dages
Dakar.