TY - JOUR
T1 - A more appropriate white blood cell count for estimating malaria parasite density in Plasmodium vivax patients in northeastern Myanmar
AU - Liu, Huaie
AU - Feng, Guohua
AU - Zeng, Weilin
AU - Li, Xiaomei
AU - Bai, Yao
AU - Deng, Shuang
AU - Ruan, Yonghua
AU - Morris, James
AU - Li, Siman
AU - Yang, Zhaoqing
AU - Cui, Liwang
N1 - Funding Information:
We thank the staff at the clinics and patients for participation in this study. This work was supported by National Natural Science Foundation of China ( #U1202226 and # 31260508 ), Special Research Funds from the Ministry of Education of China ( #20125317110001 ), a talent introduction project of Yunnan province ( #2013HA026 ), and National Institutes of Health, USA ( U19AI089672 ). H.L. is a recipient of the Academic Newcomer Scholarship from Yunnan province.
Publisher Copyright:
© 2016 .
PY - 2016/4/1
Y1 - 2016/4/1
N2 - The conventional method of estimating parasite densities employ an assumption of 8000 white blood cells (WBCs)/μl. However, due to leucopenia in malaria patients, this number appears to overestimate parasite densities. In this study, we assessed the accuracy of parasite density estimated using this assumed WBC count in eastern Myanmar, where Plasmodium vivax has become increasingly prevalent. From 256 patients with uncomplicated P. vivax malaria, we estimated parasite density and counted WBCs by using an automated blood cell counter. It was found that WBC counts were not significantly different between patients of different gender, axillary temperature, and body mass index levels, whereas they were significantly different between age groups of patients and the time points of measurement. The median parasite densities calculated with the actual WBC counts (1903/μl) and the assumed WBC count of 8000/μl (2570/μl) were significantly different. We demonstrated that using the assumed WBC count of 8000 cells/μl to estimate parasite densities of P. vivax malaria patients in this area would lead to an overestimation. For P. vivax patients aged five years and older, an assumed WBC count of 5500/μl best estimated parasite densities. This study provides more realistic assumed WBC counts for estimating parasite densities in P. vivax patients from low-endemicity areas of Southeast Asia.
AB - The conventional method of estimating parasite densities employ an assumption of 8000 white blood cells (WBCs)/μl. However, due to leucopenia in malaria patients, this number appears to overestimate parasite densities. In this study, we assessed the accuracy of parasite density estimated using this assumed WBC count in eastern Myanmar, where Plasmodium vivax has become increasingly prevalent. From 256 patients with uncomplicated P. vivax malaria, we estimated parasite density and counted WBCs by using an automated blood cell counter. It was found that WBC counts were not significantly different between patients of different gender, axillary temperature, and body mass index levels, whereas they were significantly different between age groups of patients and the time points of measurement. The median parasite densities calculated with the actual WBC counts (1903/μl) and the assumed WBC count of 8000/μl (2570/μl) were significantly different. We demonstrated that using the assumed WBC count of 8000 cells/μl to estimate parasite densities of P. vivax malaria patients in this area would lead to an overestimation. For P. vivax patients aged five years and older, an assumed WBC count of 5500/μl best estimated parasite densities. This study provides more realistic assumed WBC counts for estimating parasite densities in P. vivax patients from low-endemicity areas of Southeast Asia.
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U2 - 10.1016/j.actatropica.2016.01.018
DO - 10.1016/j.actatropica.2016.01.018
M3 - Article
C2 - 26802490
AN - SCOPUS:84961316429
VL - 156
SP - 152
EP - 156
JO - Acta Tropica
JF - Acta Tropica
SN - 0001-706X
ER -