Population screening for glucose-6-phosphate dehydrogenase deficiencies in Isabel Province, Solomon Islands, using a modified enzyme assay on filter paper dried bloodspots

Melissa Kuwahata,Losi Landry,Mei-Fong Ho,Albino Bobogare,Andrew Vallely,Anita Pelecanos,James Mccarthy,Hugo Bugora,Rushika Wijesinghe

doi:10.1186/1475-2875-9-223

Melissa Kuwahata, Losi Landry + Show 7 more

Open Access

https://doi.org/10.1186/1475-2875-9-223

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Abstract

BackgroundGlucose-6-phosphate dehydrogenase deficiency poses a significant impediment to primaquine use for the elimination of liver stage infection with Plasmodium vivax and for gametocyte clearance, because of the risk of life-threatening haemolytic anaemia that can occur in G6PD deficient patients. Although a range of methods for screening G6PD deficiency have been described, almost all require skilled personnel, expensive laboratory equipment, freshly collected blood, and are time consuming; factors that render them unsuitable for mass-screening purposes.MethodsA published WST8/1-methoxy PMS method was adapted to assay G6PD activity in a 96-well format using dried blood spots, and used it to undertake population screening within a malaria survey undertaken in Isabel Province, Solomon Islands. The assay results were compared to a biochemical test and a recently marketed rapid diagnostic test.ResultsComparative testing with biochemical and rapid diagnostic test indicated that results obtained by filter paper assay were accurate providing that blood spots were assayed within 5 days when stored at ambient temperature and 10 days when stored at 4 degrees. Screening of 8541 people from 41 villages in Isabel Province, Solomon Islands revealed the prevalence of G6PD deficiency as defined by enzyme activity < 30% of normal control was 20.3% and a prevalence of severe deficiency that would predispose to primaquine-induced hemolysis (WHO Class I-II) of 6.9%.ConclusionsThe assay enabled simple and quick semi-quantitative population screening in a malaria-endemic region. The study indicated a high prevalence of G6PD deficiency in Isabel Province and highlights the critical need to consider G6PD deficiency in the context of P. vivax malaria elimination strategies in Solomon Islands, particularly in light of the potential role of primaquine mass drug administration.

Highlights

Glucose-6-phosphate dehydrogenase deficiency poses a significant impediment to primaquine use for the elimination of liver stage infection with Plasmodium vivax and for gametocyte clearance, because of the risk of life-threatening haemolytic anaemia that can occur in Glucose-6-phosphaste dehydrogenase (G6PD) deficient patients
The present study reports the evaluation of this method for in-field mass-screening of G6PD to determine the prevalence of G6PD deficiency in Isabel Province, Solomon Island
Evaluation of bloodspot and assay mix storage Bloodspots stored at 4°C, 25°C and 37°C were assayed on Day 1, 5, 10 and 14 to determine its effect on enzyme degradation and the resulting reduced G6PD activity

Summary

Introduction

Glucose-6-phosphate dehydrogenase deficiency poses a significant impediment to primaquine use for the elimination of liver stage infection with Plasmodium vivax and for gametocyte clearance, because of the risk of life-threatening haemolytic anaemia that can occur in G6PD deficient patients. With the exception of rare sporadic WHO class I individuals, most G6PD deficient individuals are asymptomatic [1,2]. Specific triggers such as ingestion of certain foods (e.g. fava beans), exposure to oxidative drugs, and infection can cause haemolytic anaemia, and in severe cases haemolysis sufficiently severe to require blood transfusion. Such adverse events are generally confined to individuals with G6PD activity < 10% of normal (WHO Class II)

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