PREVALENCE OF GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY AMONG VIVAX MALARIA PATIENTS AT THE HOSPITAL FOR TROPICAL DISEASES, THAILAND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency and Plasmodium vivax malaria infections are not uncommon in Thailand. Primaquine is prescribed to prevent malaria relapse in patients with P. vivax malaria but may cause hemolysis in patients with G6PD deficiency. The aim of this study was to determine the prevalence of G6PD deficiency among P. vivax malaria patients treated at the Hospital for Tropical Diseases, Bangkok, Thailand during 2005-2014. A population prevalence of G6PD deficiency > 10% warrants screening all P. vivax malaria patients for G6PD deficiency prior to prescribing primaquine but a prevalence < 10% may not warrant screening. The results of this study can inform the Ministry of Public Health, Thailand to enable them to make an informed decision when updating the Thai National Treatment Guidelines for P. vivax malaria. The study hospital is a referral hospital for malaria treatment in Bangkok. The medical records of all 309 adult patients with P. vivax malaria mono-infection treated at the Hospital for Tropical Diseases, Bangkok, Thailand during 2005-2014 were retrospectively reviewed. Malaria was diagnosed by light microscopy. G6PD status was diagnosed by fluorescent spot test. Descriptive data are presented as means and medians. Continuous data with abnormal distribution are presented as medians and interquartile ranges (IQR). Binary outcome data are presented as proportions with 95% confident intervals (95%CI). The prevalence of G6PD deficiency was calculated using period prevalence as the proportion of the study population with an abnormal G6PD screening test during the study period. The chi-square test and odds ratio were used to compare the distribution of categorical variables among the different groups. Of the 309 study subjects, 288 (93.2%) were males. The median (IQR) age of the study subjects was 24 (20-31) years. Sixty-seven point three percent of subjects were Myanmar citizens. Eeleven point five percent of male subjects and 4.8% of female subjects had a positive screening test for G6PD deficiency (p = 0.48). Further study using molecular method to detect G6PD deficiency is suggested to better determine the better prevalence of G6PD deficiency in female subjects. Since the prevalence of G6PD deficiency in this study was high (more than 10%) particularly in male patients, the G6PD test should be conducted in all P. vivax malaria patients, rather than optional screening test, and should be recommended in the near future Thai National Treatment Guidelines for P. vivax malaria in order to avoid hemolysis risk of daily primaquine treatment in the G6PD deficient patients.