Estimation of uncertainty in Loa loa microfilarial load by microscopy

For determine the uncertainty of reading and measurement, as well as the Pari intervals of microfilarial load or microfilaremia (mf) per millimeter of Loa loa performed by microscopy. It is important to consider the uncertainty in the measurement or reading of the Loa Loa microfilarial load for the administration of ivermectin. We review existing methods for calculating the uncertainty in the measurement of a particular quantity, with emphasis on the one proposed in GUM. The data used here come from research conducted by CRFilMT in Ebolowa and Mbalmayo in 2007 and 2010, respectively, and in the Okola health district in Cameroon in 2015. The data consist of several measurements or readings of Loa loa load on each sampled individual. The application of the GUM method to our data was done using a 2-level hierarchical model. We estimated the uncertainty and sources of variation in the measurements and readings of Loa loa microfilarial load, and provided 95% intervals for the true values (8,000 mf/mL and 30,000 mf/mL), of this load for each individual. For reading, the reading uncertainty is 3.84 with a Pari interval of [6, 723.15, 11, 264] of the 8,000 mf/mL microfilar charge and 7.45 with a Pari interval of [26, 819.55, 35, 152.09] of the 30,000 mf/mL microfilar charge. For the measurement, the reading uncertainty is 20.93 with a Pari interval of [7, 647.32, 8, 216.26] of the 8,000 mf/mL microfilar charge and 40.53 with a Pari interval of [26, 819.55, 35, 152.09] of the 30,000 mf/mL microfilar charge.