All Title Author
Keywords Abstract

Haemoglobin and haematocrit: the threefold conversion is also non valid for assessing anaemia in Plasmodium vivax malaria-endemic settings

DOI: 10.1186/1475-2875-6-166

Full-Text   Cite this paper   Add to My Lib


Carneiro et al [1] recently reported that the standard threefold conversion from haematocrit to haemoglobin underestimates the prevalence of anaemia and low levels of haemoglobin in children under five years of age in malaria endemic settings.In agreement with Carneiro et al findings, demonstrating that the usual threefold conversion represents a significant bias when haemoglobin (Hb) is estimated based on haematocrit (Hct) values in children with malaria, the present report describes the experience in a vivax malaria-endemic zone in northeastern Venezuela. It has been a widely accepted assumption that this conversion could be used as an alternative measurement to haemoglobin in malaria studies [2]. This is particularly important in African settings where Plasmodium falciparum malaria is endemic, but the corresponding haemoglobin levels cannot be derived with an acceptable accuracy using the value three as a conversion factor [2]. As a consequence, the relationship between haematocrit and haemoglobin needs to be specifically evaluated according to each particular region or epidemiological setting. In order to illustrate this important issue, the experience in a malaria-endemic zone in northeastern Venezuela (state of Sucre) is described [3,4], showing a similar bias between haematocrit and haemoglobin in patients with Plasmodium vivax infection.Data from one study that have measured haemoglobin and haematocrit was used to assess the reliability of the standard threefold conversion factor. Finger-prick blood samples were collected for determination of anaemia status from 120 patients with malaria aged 4–89 years-old from a prospective survey carried out between 2000 and 2002 in Carupano, Sucre, Venezuela [5]. In this study, haemoglobin concentration was assessed by haemophotometry and haematocrit was assessed by centrifugation using standard procedures for microhaematocrit tubes and centrifuge (i.e. 10 minutes at a fixed speed of 11,000 rpm).As described by Carneiro


comments powered by Disqus