Aedes (Diptera: Culicidae)
vectors of arboviruses in
Mayotte: distribution area and
breeding sites
by Leïla BAGNY PhD student
Directed by S. QUILICI (CIRAD) and D. FONTENILLE (IRD)
Introduction
• Epidemics of Chikungunya in 2005-2006
with 38% of populations affected
(Cire Mayotte)
Culicidae fauna
• 35 species of Culicidae recorded :
Anopheles, Culex, Eretmapodites, Mansonia, Orthopodomyia, Ficalbia, Uranotaenia and Aedes (Brunhes 1978)
• Stegomyia species:
Ae. vittatus, Ae.simpsoni complex, Ae. aegypti (Brunhes 1978)
• 2001: first record of Ae. albopictus
on the island
(Girod 2004)Introduction
Ae. albopictus Ae. aegypti Ae. simpsoni
Aedes albopictus in the world
• Invasive since 30 years
• Species mentionned as rural in its native area also in some invaded areas (like Brazil,
Florida, Puerto Rico…)
Ae. aegypti
Introduction
Native Introduced Intercepted
Objectives
• Update of Aedes (Stegomyia)
distribution, 7 years after the first
record of Ae. albopictus in Mayotte
• Is there an impact of the introduction
of Ae. albopictus on resident species?
• What are the effects of the
introduction of this species on public
health?
Field survey
Mat & Meth
Chiconi Mtsapéré Bandrélé Labattoir Dzoumogné Mtsamoudou
• 2 seasons
• 6 locations
• 3 habitats
– 10 houses in urban and
suburban areas
– 1 ha in rural areas
• Larval
identification
• Only breeding sites with Aedes spp.
Labattoir
0% 20% 40% 60% 80% 100% Leaf a xilla e Bamboo stum ps Tree hole Roc k ho les Dead l eave s Coc onut s hells Bottle s Tin c ans Small was tes CansBarrels Pots Bucke ts Tire s Earthe nwar e jar s Othe rs Total
Ae. albopictus Ae. aegypti Ae. albopictus - Ae. aegypti Ae. lilii
Breeding sites surveyed
• Ae. aegypti more in natural breeding sites
• Ae. albopictus and Ae. aegypti, often share the same breeding site
• Ae. albopictus more in artificial breeding sites
Results
Larvae Ae. albopictus >>> Larvae Ae. aegypti Pupae Ae. albopictus > Pupae Ae. aegypti
Pupae Ae. albopictus < Pupae Ae.
aegypti
Average productivity of breeding sites
Conclusion L ea f a xi lla ( 9; 8) B am boo s tum ps ( 9; 7) S na il s he lls ( 1; 1) T re e hol es ( 13; 4) R oc k ho le s ( 6; 2) D ea d l ea ve s on gr oun d ( 21; 9) C oc onu t s he lls ( 31; 22) B roke n bo ttl es ( 9; 14) T in c ans ( 12; 15) S m al l pl as tic w as te s( 18; 17) C ans ( 19; 19) B ar re ls ( 26; 59) P ot s ( 38; 47) B uc ke ts ( 23; 42) U se d t ir es ( 4; 10) E ar the nw ar e j ar s ( 1; 5) O the rs ( 18; 18) 0 20 40 60 80 100 120 140 L ea f a xi lla ( 1; 1) B am boo s tum ps ( 0; 2) S na il s he lls ( 0; 0) T re e hol es ( 1; 1) R oc k ho le s ( 1; 0) D ea d l ea ve s on gr oun d ( 12; 1) C oc onu t s he lls ( 8; 8) B roke n bo ttl es ( 1; 4) T in c ans ( 2; 4) S m al l pl as tic w as te s ( 6; 10) C ans ( 6; 4) B ar re ls ( 10; 32) P ot s ( 20; 14) B uc ke ts ( 4; 21) U se d t ir es ( 0; 1) E ar the nw ar e j ar s ( 0; 4) O the rs ( 4; 6) 0 2 4 6 8 10 Storage containers LARVAE PUPAE Natural sites Results Ae. albopictus Ae. aegypti
Estimated relative frequency of species in
rural (R), suburban (S) and urban (U) habitats
Location: Bandrélé more in rural areas more in suburban areas more in urban areas 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 R R R S S S U U
Ae. aegypti Ae. aegypti + Ae. albopictus Ae.albopictus 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 Rainy season R U S R S S U
Ae. aegypti Ae. aegypti + Ae. albopictus Ae.albopictus Dry season Chiconi Mtsapéré Bandrélé Labattoir Dzoumogné Mtsamoudou Bandrélé
Aedes spp. distribution in Mayotte
• Ae. albopictus :
• Rapid spread in Mayotte • Artificial breeding sites • Occurrence in urban areas
Conclusion Poor implication in arboviruses emergence in Mayotte
• Ae. lilii :
• Uncommon • Very rural• Natural breeding sites
• Ae. aegypti :
• Rural
Effect on resident species?
• Displacement of Ae. aegypti to rural
habitats by Ae. albopictus is
on-going in Mayotte
• Probably due to competitive interactions between these 2 species (Williamson 1996;
Juliano 2004)
• Further studies are required to identify mechanisms involved in the eventual competition
• It may have modify arboviruses
transmission in Mayotte like in other
countries (Mitchell 1995; Lounibos 2002)
• Probably the major vector implicated in
the Chikungunya epidemics in
2005-2006 because of its dominance in
inhabitated areas and its good transmission competence for this virus (Vazeille 2007)
• As it preferentially colonizes storage containers a mechanic control can be
suggested to reduce the populations of this vector
Effect on public health?
Conclusion
