Low and heterogeneous prevalence of glucose-6-phosphate dehydrogenase deficiency in different settings in Ethiopia using phenotyping and genotyping approaches.

BACKGROUND: 8-Aminoquinolines such as primaquine clear mature Plasmodium falciparum gametocytes that are responsible for transmission from human to mosquitoes and bring radical cure in Plasmodium vivax by clearing dormant liver stages. Deployment of primaquine is thus of relevance for malaria elimination efforts but challenged by the widespread prevalence of glucose-6-phosphate dehydrogenase deficiency (G6PDd) in endemic countries since primaquine in G6PDd individuals may lead to acute haemolysis. In this study, the prevalence of G6PDd was investigated in different settings in Ethiopia using phenotyping and genotyping approaches. METHODS: Community and school based cross-sectional surveys were conducted from October to December 2016 in four administrative regions (Gambela, Benishangul Gumuz, Oromia, and Amhara) in Ethiopia. Finger prick blood samples were collected for G6PD enzyme activity using the CareStart™ G6PD screening test and genotyping of 36 selected single nucleotide polymorphisms (SNPs) located in the G6PD gene and its flanking regions. RESULTS: Overall, the prevalence of phenotypic G6PDd was 1.4% (22/1609). For the first time in the Ethiopian population, the African variant (A-) was detected in 3.5% (7/199) of the limited set of genotyped samples, which were all phenotypically normal. Interestingly, all of these individuals had a variation at the rs2515904 locus. Strong geographical variation was observed for both phenotypic and genotypic G6PDd; three-quarters of the phenotypically G6PDd individuals were detected in Gambela. CONCLUSION: A very low prevalence of G6PDd was detected in the present study populations. The presence of the A- variant alongside other G6PD mutants and the patchy distribution of G6PDd indicate that larger studies specifically designed to unravel the distribution of G6PDd at small geographical scale may be needed to tailor malaria elimination efforts in Ethiopia to the local context.

The Unmet Need: Low Performance of Laboratory Professionals in Malaria Microscopy, Oromia Regional State, Ethiopia.

Ethiopia aims to diagnose and treat all clinical malaria within 24 hours of fever onset in its stride to eliminate the disease by 2030. Microscopy remains to be the mainstay for diagnosis at the health center and hospital level. Continuous evaluation and performance upgrading of malaria microscopists is one of the cornerstones in this effort. We assessed the performance of malaria microscopists compared with reference readers in diagnosing, identifying the species, and quantifying parasitemia. A total of 174 microscopists were enrolled from health facilities located in 86 districts in Oromia region (Ethiopia) from January 2017 to June 2018. Panel slides with known Plasmodium species, diagnostic blood stage, and parasite density were prepared by the reference readers. Sociodemographics, education, in-service training, and routine practice of participants were captured. Sensitivity, specificity, percent agreement, and kappa score were calculated. An overall low performance was observed that could threaten the malaria diagnostic service. Of all the slides distributed (1,218), only 17.0% of the positive and 30.0% of the negative slides were correctly identified and 22.4% were correctly quantified. Compared with the reference readers, participants had lower competence in diagnosing (74.3% agreement and kappa 0.45) and identifying the species (71.2% agreement and kappa 0.40). Two-fifths of the participants were graded as "in training" with respect to identifying the species (41.0%) and the diagnostic stages (40.0%). An in-service training/retraining and supportive supervision are needed to raise and maintain the competence of microscopists in settings with a recent decline in malaria transmission and aiming for ultimate elimination of the disease.