@article{fdi:010088240,
  title = {{E}valuating post-treatment {L}oa loa microfilarial densities to classify serious adverse events caused by ivermectin : a retrospective analysis},
  author = {{B}oull{\'e}, {C}. and {C}hesnais, {C}{\'e}dric and {K}amgno, {J}. and {G}ardon, {J}acques and {C}hippaux, {J}ean-{P}hilippe and {R}anque, {S}. and {G}arcia, {A}ndr{\'e} and {P}ion, {S}{\'e}bastien and {B}oussinesq, {M}ichel},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground : {T}he elimination of onchocerciasis requires increasing ivermectin treatment coverage in communities hypoendemic for onchocerciasis. {I}n areas where loiasis is co-endemic, this approach is complicated by the risk of serious adverse events following treatment with ivermectin in individuals with a high {L}oa loa microfilarial density ({MFD}). {W}e aimed to evaluate the extent to which the pre-treatment {MFD} can be inferred from post-treatment {MFD}s. {M}ethods : {F}or this retrospective analysis, we used data from seven clinical or community trials (six were used for the main analysis and one for the secondary analysis) conducted in {C}ameroon, in which {MFD}s were measured both before and after (within 14 days) receiving a single dose of ivermectin (150-200 ?g/kg bodyweight). {T}he primary objective was to establish the receiver operating characteristic curves and the corresponding area under the curve statistics of {MFD} measured after treatment to classify pre-treatment {MFD} ({MFDD}0) according to common risk thresholds of serious adverse events. {W}e assessed the performance of post-treatment {MFD} to accurately classify {MFDD}0 according to commonly used thresholds using bootstrap procedures.{F}indings : 281 individuals with {MFD} measurements available before and 3-10 days after ivermectin treatment were enrolled. {O}ur results show that an {MFD} of more than 3500 {L} loa microfilariae per m{L} of blood (mf per m{L}) 3 or 4 days after treatment indicates a 68·6% chance (positive predictive value) of an {MFDD}0 of more than 20?000 mf per m{L}. {A}n {MFD} of more than 3500 mf per m{L} at day 5-10 corresponds to a 72·2% chance of having an {MFDD}0 of more than 20?000 mf per m{L}. {C}onversely, an {MFD} of less than 2500 microfilariae per m{L} at day 3-4 or day 5-10 corresponds to a probability of 92·3% or 92·8% (negative predictive value) of having {MFDD}0 of less than 20?000 mf per m{L}. {A}n {MFD} less than 1500 mf per m{L} on days 3-4 after treatment was associated with a 78·3% probability of having an {MFDD}0 less than 8000 mf per m{L}; this probability increased to 89·6% on days 5-10 after treatment. {I}nterpretation : {T}he {MFD} threshold of 1000 mf per m{L} within 1 month of treatment, which is commonly used to attribute the occurrence of a serious adverse event to ivermectin, should be revised. {I}n this study, we present tables that can help to assess this attributability as part of mass or individual treatments.},
  keywords = {},
  booktitle = {},
  journal = {{L}ancet {M}icrobe},
  volume = {4},
  numero = {2},
  pages = {e93--e101 [9 ]},
  ISSN = {2666-5247},
  year = {2023},
  DOI = {10.1016/s2666-5247(22)00331},
  URL = {https://www.documentation.ird.fr/hor/fdi:010088240},
}