%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Campillo, Jérémy
%A Louya, F.
%A Bikita, P.
%A Missamou, F.
%A Pion, Sébastien
%A Boussinesq, Michel
%A Chesnais, Cédric
%T Factors associated with the periodicity of Loa loa microfilaremia in the Republic of the Congo
%D 2022
%L fdi:010086486
%G ENG
%J Parasites and Vectors
%@ 1756-3305
%K Loa loa ; Microfilaremia ; Periodicity ; Temperature ; Republic of the Congo
%K CONGO
%M ISI:000885078200002
%N 1
%P 417 [7 ]
%R 10.1186/s13071-022-05541-y
%U https://www.documentation.ird.fr/hor/fdi:010086486
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2022-12/010086486.pdf
%V 15
%W Horizon (IRD)
%X Background: Loa loa microfilariae circulate in the peripheral blood of human hosts following a diurnal periodicity, with maximal microfilaremia levels generally observed between 10:00 am and 3:00 pm. Few studies have assessed factors potentially associated with this periodicity. Methods: Microfilaremia data were collected repeatedly between 9:00 am and 8:00 pm from 13 individuals in the Republic of the Congo. Using local polynomial regression (LOESS), we determined the best models representing the dynamics of microfilaremia over this period. In a second step, using cosinor models, we evaluated the influence of sex, age, and body temperature on the periodicity of L. loa microfilaremia in blood. Results: All subjects reached their maximum microfilaremia between 10:00 am and 4:00 pm. Individual microfilaremia showed different patterns between individuals, and some clearly showed multiple peaks within a day. LOESS provided a good fit to the observed data. Without adjustment, the maximum microfilarial density was reached around 11:00 am. Adjustment revealed three distinct modes of microfilaremia, occurring around 10:00 am, 1:00 pm, and 4:00 pm. Cosinor models also provided good fit to our data. After adjustment on body temperature, the L. loa microfilaremia fluctuation amplitude decreased significantly from 1684.8 to 310.6 microfilariae(mf)/ml and the predicted peak was estimated at 12:02 pm. Conclusions: We characterized the periodicity of L. loa microfilaremia mathematically with two different approaches: cosinor models and LOESS regression. Both models suggest that body temperature plays a role in the variation in microfilaremia within a day. Further studies are needed to identify individual co-factors affecting microfilaremia.
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