@article{fdi:010092064,
  title = {{V}ariability of {L}oa loa microfilarial counts in successive blood smears and its potential implication in drug-related serious adverse events},
  author = {{L}epage, {T}. {M}. and {C}ampillo, {J}{\'e}r{\'e}my and {L}ouya, {F}. and {B}ikita, {P}. and {M}issamou, {F}. and {H}emilembolo, {M}. {C}. and {P}ion, {S}{\'e}bastien and {B}oussinesq, {M}ichel and {C}hesnais, {C}{\'e}dric},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground {T}he standard method to diagnose {L}oa loa infection and quantify microfilarial density ({MFD}) is the microscopic examination of calibrated thick blood smears ({TBS}s). {I}n 1950, it was noticed that successive {L}. loa {MFD} samples from a single capillary puncture could exhibit up to 20% variation. {A}lthough loiasis treatment allocation is based on {MFD} to prevent serious adverse events ({SAE}s), data on this variability are scarce. {T}here are also no guidelines supporting the collection and analysis of one or two {TBS}s. {M}ethods {W}e assessed the variability of two successive {L}. loa {MFD} samples ({MFD}1 and {MFD}2), collected from 255 patients. {W}e analyzed the influence of sex, age, weight, heart rate, arterial pressure, body temperature, and sampling time on {MFD} variability, as well the impact of {MFD} variability on {MFD} thresholds relevant to loiasis treatment protocols. {R}esults {T}he {MFD}2 was found to have increased in 63% (1145/1826) of {TBS} pairs and to have decreased in 37% (681/1826) of {TBS} pairs. {T}he {MFD}2 were on average 28% higher than the {MFD}1. {T}hese variations drove a total of 333 (17.4%) changes in {MFD} classes according to loiasis treatment protocol, including 210 (11.3%) class increases. {TBS}s generated from blood samples from subjects with lower {MFD} (1-1000 mf/ml) or lower mean arterial pressure ({MAP}; 55-80 mm{H}g), or from blood samples collected at an earlier hour time-point (10:00-10:59 a.m.) were more subject to {MFD}2 variability in a multivariate analysis. {T}he {MFD} relative change was not constant over time for a given person. {C}onclusions {W}e observed a trend towards an increase in {MFD}2 with an important variability between samples that may impact loiasis treatment allocation. {W}e suggest that systematically sampling at least two successive {TBS}s might allow better {MFD} assessments to prevent post-treatment {SAE}s. {F}urther studies are needed to verify this variability in larger samples as well as confirm the potential explanatory variables identified.},
  keywords = {{L}oiasis ; {D}iagnosis ; {V}ariability ; {M}icrofilaremia},
  booktitle = {},
  journal = {{P}arasites and {V}ectors},
  volume = {17},
  numero = {1},
  pages = {457 [15 p.]},
  ISSN = {1756-3305},
  year = {2024},
  DOI = {10.1186/s13071-024-06494-0},
  URL = {https://www.documentation.ird.fr/hor/fdi:010092064},
}