2. Tsetse Repellent Technology
Novel tsetse repellent technology
for enhanced livestock
productivity and food security in
Africa
R. K. Saini
3. African Animal Trypanosomiasis (AAT)
Amongst the 42 poorest countries in the
world, 32 are African and
host tsetse - vectors of
trypanosomes
Spread over 7 million km2
Threatening 60 million cows
230 million sheep
40 million goats with
trypanosomosis
Leading to death of 3 million cattle every year
Loss of 500 000 tonnes of meat
and 1 million tonnes of milk.
Reduction to 10% animal draught power
and to 50% livestock production
Costs $ 40 million annually on drugs
4.5 billion US$ a year for the
African economy
4. Vectors of Human Sleeping Sickness
• 70 million people are at risk of getting
human sleeping sickness ( HAT)
• 10,000 more people infected yearly
• 95% of infected persons are not treated
• palpalis group of tsetse in West Africa
• Savannah species (morsitans group) in
Eastern and Southern Africa
G. f. fuscipes
Sleeping sickness patients
(Angola) pic. courtesy WHO
5. Host Seeking Behaviour
resulted in 2 major discoveries:
- Development of the NGU series of traps
(NG2B, NG2G) which are cheap and easy to
make
- Identification of odour attractants to enhance
visual appeal of the traps – Buffalo and cow
urine shown to be potent attractant for
G. pallidipes 4-cresol and 3-n-propyl phenol
identified as attractive compounds
6. Repellents for tsetse control
Why Repellents?
Pastoralists need mobile technology suited to their lifestyle
7. Tsetse Repellent work at icipe
Identification of Repellents
Synthetic
sources
Natural blends of
un-preferred animals
(waterbuck, zebra)
8. Tsetse - synthetic repellent (SR)
• A synthetic Repellent (SR) 2methoxy-4- methylphenol
(patent No: KE00185) identified by molecular
optimisation studies, wind tunnel and field assays
• Prototype dispenser with a constant release
rate that individual cow wears designed
• Initial field tests with SR showed a reduction in
disease incidence among cattle from 40% in Masai
Mara to 70% in Coastal areas of Kenya
• Drug use significantly reduced
Challenges
• Loss and leakage of dispensers (85%)
• Mixing of herds
9. Tsetse – identification of repellents from un-preferred hosts
• Waterbuck are present in tsetse habitats but not fed
upon
• Refractoriness is mediated by repellents
• 15 EAD active compounds were found in the waterbuck
odour
• Through series of field experiments 5 - component
blend was identified (icipe patent application)
• WRB reduces fly catches by 80% and
feeding efficiency >95%
Cows in waterbuck clothing
Gas chromatogram of body odors from waterbuck
10. Dispensing of Repellents
Repellency attained with new
dispensers model is comparable
with icipe prototype dispensers
Release rates:
SR: 9.00 + 0.5mg hr-1
WRB: 10.5 + 0.5mg hr-1
11. Validation trials in Shimba Hills
Objective: Integration of repellents with other tsetse control tactics –
evaluation of ‘push-pull’
Large scale repellent
technology validation
trials in ‘push’ mode or
in ‘push-pull’ mode were
undertaken at Shimba
Hills, Kenya Coast
12. Map of trial sites in Kwale District
Shimba Hills
Game Reserve
• 600km2
• 260 farmers
• 1528 animals
13. Effect of repellents on disease levels
Disease incidence in herds protected with WRB
b
c
d
a
15. Mean monthly body weight in cattle with WRB
Weight of cattle protected with WRB treatments was significantly more than those in control or in areas with
traps (pull) No difference between traps and control. Weight gain translates into more money
a a
b
b
16. Farmers assessment of repellent collars
Treatments % of HH aware of
collars
technology
Rating for
effective and
very effective
Push pull WRB 100 100
Push pull SR 100 100
Push WRB 100 96.6
Push SR 97.8 91.1
Pull 80.0 100
Control 75.6 94.1
NPF 81.6 100
• 97% farmers report that the technology is
very effective in protecting their cattle
17. Impact on grazing
Livestock farmers are reporting:
• 95% can graze their animals anywhere including
in tsetse infested areas. Animals are now more
settled when grazing or ploughing
• Farmers have stopped lighting fires to smoke
away the flies in the evenings
• 45% farmers without collars prefer to graze their
animals with protected animals
18. Impact on ploughing
• Protected animals plough 75% more land
• Average area ploughed increased by 3.2
acres per household with protected animals
• Number of farmers hiring oxen for ploughing
land reduced by 62%
• Food Security enhanced & livelihoods
improved
19. Impact on milk production
• Number of households reporting
lactating animals in the herd has
increased by 67% (103 to 172)
• The number of animals lactating
is 2x more in protected animals
compared to control
• The average milk production per
animal is 42.2% higher in the
protected animals compared to
the control
• cows are native
20. Potential for Adoption
• 99.5% of the respondents in all the
treatments, control and non
participating farmers are willing to
buy the repellent collars
• On average, farmers willing to pay
Kshs. 212/= (US $ 2.5) for collars
• Farmers wish the repellent dispenser
would last 4.8 months on average
• 67% farmers willing to change breed
of animals if collars are available
21. Dispensers - problems
% dispensers working in cattle herds with WRB treatments
About 75% dispensers are working at any given time
22. Cost of dispenser and repellent compounds per month
Dispensers: $1.50
Repellent compounds: $2.75
Belt: $0.08
Total costs: $4.33
(lab. Costs)
Cost of drugs (chemotherapy)
2 treatments per month : $ 2.35
(mass produced)
Costs of technology
23. Way Forward
Tabanid fly Stomoxys calcitrans
camel trypanosomaisis (surra)
• Roll out novel tsetse repellent technology in African
countries
• Ensure manufacturing scale-up of the technology
through public-private- partnerships (non-metallic,
robust, low cost dispensers through p-p-p)
• Integrated use of the repellent technology with
other tsetse and disease control tactics to eliminate
the constraint of tsetse and trypanosomiasis
(T&T) in African countries
• Evaluate potential to control vectors of human
sleeping sickness.
• Evaluate repellents to protect safari vans and
tourists from tsetse attack in parks
• Develop repellent collars for camels and their
integration with other vector control tactics
24. Acknowledgements
Mathews Bett PhD student (Moi University)
Spala Ohaga PhD student (Jomo Kenyatta
University)
Hippolyte Affognon (PDF)icipe
Norber Mbahin (PDF)
John Andoke
Peter Musa
David Mbuvi Mbesi
John Otieno Ngiela
Tiberius Marete
Phillip Kolei
Lemorora Nkoyokoi
Caroline Muya
Abel Orone KARI-TRC
Gabriel Karanja KARI-TRC
Abdalla Mwachongwa Vet. Services
KIRDI
Thanks to EU
for funding the
research