@article{fdi:010083325,
  title = {{O}nchocerca volvulus transmission in the {M}bam valley of {C}ameroon following 16 years of annual community-directed treatment with ivermectin, and the description of a new cytotype of {S}imulium squamosum},
  author = {{H}endy, {A}. and {K}rit, {M}. and {P}farr, {K}. and {L}aemmer, {C}. and {D}e {W}itte, {J}. and {N}wane, {P}. and {K}amgno, {J}. and {N}ana-{D}jeunga, {H}. {C}. and {B}oussinesq, {M}ichel and {D}ujardin, {J}. {C}. and {P}ost, {R}. and {C}olebunders, {R}. and {O}'{N}eill, {S}. and {E}nyong, {P}. and {N}jamnshi, {A}. {K}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {T}he onchocerciasis focus surrounding the lower {M}bam and {S}anaga rivers, where {O}nchocerca volvulus is transmitted by {S}imulium damnosum s.l. ({D}iptera: {S}imuliidae), was historically the largest in the southern regions of {C}ameroon. {A}nnual community- directed treatment with ivermectin ({CDTI}) has been taking place since 2000, but recent studies have shown that new infections are occurring in children. {W}e aimed to investigate blackfly biting and {O}. volvulus transmission rates along the lower {M}bam river 16 years after the formal onset of annual {CDTI}. {M}ethods: {B}lack flies were collected for three consecutive days each month between {J}uly 2016 and {J}une 2017 at two riverside villages and two inland sites situated 4.9 km and 7.9 km from the riverside. {S}pecimens collected at each site were dissected on one of the three collection days each month to estimate parity rates and {O}. volvulus infection rates, while the remaining samples were preserved for pool screening. {R}esults: {I}n total, 93,573 {S}. damnosum s.l. black flies were recorded biting humans and 9281 were dissected. {A}nnual biting rates of up to 606,370 were estimated at the riverside, decreasing to 20,540 at 7.9 km, while, based on dissections, annual transmission potentials of up to 4488 were estimated at the riverside, decreasing to 102 and 0 at 4.9 km and 7.9 km, respectively. {H}owever, pool screening showed evidence of infection in black flies at the furthest distance from the river. {R}esults of both methods demonstrated the percentage of infective flies to be relatively low (0.100.36%), but above the {WHO} threshold for interruption of transmission. {I}n addition, a small number of larvae collected during the dry season revealed the presence of {S}imulium squamosum {E}. {T}his is the first time {S}. squamosum {E} has been found east of {L}ake {V}olta in {G}hana, but our material was chromosomally distinctive, and we call it {S}. squamosum {E}2. {C}onclusions: {R}elatively low {O}. volvulus infection rates appear to be offset by extremely high densities of biting black flies which are sustaining transmission along the banks of the lower {M}bam river.},
  keywords = {{O}nchocerciasis ; {E}limination ; {I}vermectin ; {O}nchocerca volvulus ; {S}imulium damnosum ; {S}imulium squamosum ; {M}bam ; {C}ameroon ; {CAMEROUN} ; {MBAM}},
  booktitle = {},
  journal = {{P}arasites and {V}ectors},
  volume = {14},
  numero = {1},
  pages = {563 [14 p.]},
  ISSN = {1756-3305},
  year = {2021},
  DOI = {10.1186/s13071-021-05072-y},
  URL = {https://www.documentation.ird.fr/hor/fdi:010083325},
}