@article{PAR00021210,
  title = {{D}istribution of insecticide resistance and mechanisms involved in the arbovirus vector {A}edes aegypti in {L}aos and implication for vector control},
  author = {{M}arcombe, {S}. and {F}ustec, {B}{\'e}n{\'e}dicte and {C}attel, {J}. and {C}honephetsarath, {S}. and {T}hammavong, {P}. and {P}hommavanh, {N}. and {D}avid, {J}. {P}. and {C}orbel, {V}incent and {S}utherland, {I}. {W}. and {H}ertz, {J}. {C}. and {B}rey, {P}. {T}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground {T}he yellow fever mosquito {A}edes aegypti is the major vector of dengue, yellow fever, {Z}ika, and {C}hikungunya viruses. {W}orldwide vector control is largely based on insecticide treatments but, unfortunately, vector control programs are facing operational challenges due to mosquitoes becoming resistant to commonly used insecticides. {I}n {S}outheast {A}sia, resistance of {A}e. aegypti to chemical insecticides has been documented in several countries but no data regarding insecticide resistance has been reported in {L}aos. {T}o fill this gap, we assessed the insecticide resistance of 11 {A}e. aegypti populations to larvicides and adulticides used in public health operations in the country. {W}e also investigated the underlying molecular mechanisms associated with resistance, including target site mutations and detoxification enzymes putatively involved in metabolic resistance. {M}ethods and results {B}ioassays on adults and larvae collected in five provinces revealed various levels of resistance to organophosphates (malathion and temephos), organochlorine ({DDT}) and pyrethroids (permethrin and deltamethrin). {S}ynergist bioassays showed a significant increased susceptibility of mosquitoes to insecticides after exposure to detoxification enzyme inhibitors. {B}iochemical assays confirmed these results by showing significant elevated activities of cytochrome {P}450 monooxygenases ({P}450), glutathione {S}-transferases ({GST}) and carboxylesterases ({CCE}) in adults. {T}wo kdr mutations, {V}1016{G} and {F}1534{C}, were detected by q{PCR} at low and high frequency, respectively, in all populations tested. {A} significant negative association between the two kdr mutations was detected. {N}o significant association between kdr mutations frequency (for both 1534{C} and 1016{G}) and survival rate to {DDT} or permethrin ({P} > 0.05) was detected. {G}ene {C}opy {N}umber {V}ariations ({CNV}) were detected for particular detoxification enzymes. {A}t the population level, the presence of {CNV} affecting the carboxylesterase {CCEAE}3{A} and the two cytochrome {P}450 {CYP}6{BB}2 and {CYP}6{P}12 were significantly correlated to insecticide resistance. {C}onclusions {T}hese results suggest that both kdr mutations and metabolic resistance mechanisms are present in {L}aos but their impact on phenotypic resistance may differ in proportion at the population or individual level. {M}olecular analyses suggest that {CNV} affecting {CCEAE}3{A} previously associated with temephos resistance is also associated with malathion resistance while {CNV} affecting {CYP}6{BB}2 and {CYP}6{P}12 are associated with pyrethroid and possibly {DDT} resistance. {T}he presence of high levels of insecticide resistance in the main arbovirus vector in {L}aos is worrying and may have important implications for dengue vector control in the country.},
  keywords = {{LAOS}},
  booktitle = {},
  journal = {{PL}o{S} {N}eglected {T}ropical {D}iseases},
  volume = {13},
  numero = {12},
  pages = {e0007852 [22 p.]},
  ISSN = {1935-2735},
  year = {2019},
  DOI = {10.1371/journal.pntd.0007852},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00021210},
}