@article{fdi:010082275,
  title = {{U}nusual localization of blood-borne {L}oa loa microfilariae in the skin depends on microfilarial density in the blood : implications for onchocerciasis diagnosis in coendemic areas},
  author = {{N}iamsi-{E}malio, {Y}. and {N}ana-{D}jeunga, {H}. {C}. and {C}hesnais, {C}{\'e}dric and {P}ion, {S}{\'e}bastien and {T}chatchueng-{M}bougua, {J}. {B}. and {B}oussinesq, {M}ichel and {B}asanez, {M}. {G}. and {K}amgno, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground. {T}he diagnostic gold standard for onchocerciasis relies on identification and enumeration of (skin-dwelling) {O}nchocerca volvulus microfilariae (mf) using the skin snip technique ({SST}). {I}n a recent study, blood-borne {L}oa loa mf were found by {SST} in individuals heavily infected with {L}. loa, and microscopically misidentified as {O}. volvulus due to their superficially similar morphology. {T}his study investigates the relationship between {L}. loa microfilarial density ({L}oa {MFD}) and the probability of testing {SST} positive. {M}ethods. {A} total of 1053 participants from the (onchocerciasis and loiasis coendemic) {E}ast {R}egion in {C}ameroon were tested for (1) {L}oa {MFD} in blood samples, (2) {O}. volvulus presence by {SST}, and (3) {I}mmunoglobulin ({I}g) {G}4 antibody positivity to {O}v16 by rapid diagnostic test ({RDT}). {A} {C}lassification and {R}egression {T}ree ({CART}) model was used to perform a supervised classification of {SST} status and identify a {L}oa {MFD} threshold above which it is highly likely to find {L}. loa mf in skin snips. {R}esults. {O}f 1011 {O}v16-negative individuals, 28 (2.8%) tested {SST} positive and 150 (14.8%) were {L}. loa positive. {T}he range of {L}oa {MFD} was 0-85 200 mf/m{L}. {T}he {CART} model subdivided the sample into 2 {L}oa {MFD} classes with a discrimination threshold of 4080 (95% {CI}, 2180-12 240) mf/m{L}. {T}he probability of being {SST} positive exceeded 27% when {L}oa {MFD} was >4080 mf/m{L}. {C}onclusions. {T}he probability of finding {L}. loa mf by {SST} increases significantly with {L}oa {MFD}. {S}kin-snip polymerase chain reaction would be useful when monitoring onchocerciasis prevalence by {SST} in onchocerciasis-loiasis coendemic areas.},
  keywords = {{O}nchocerca volvulus ; {L}oa loa ; diagnosis ; classification and regression ; tree model ; skin snip technique ; {CAMEROUN}},
  booktitle = {},
  journal = {{C}linical {I}nfectious {D}iseases},
  volume = {72},
  numero = {3},
  pages = {{S}158--{S}164},
  ISSN = {1058-4838},
  year = {2021},
  DOI = {10.1093/cid/ciab255},
  URL = {https://www.documentation.ird.fr/hor/fdi:010082275},
}