Implementation of a modified drive-through sampling strategy for SARS-CoV-2-the Nigerian experience.

INTRODUCTION: effective and safe means of sample collection is a crucial component of testing for Covid-19. Uptake of testing is key to containing and controlling the spread of the virus. Scientists have been working on various strategies that will increase the uptake of testing for COVID-19. One such method involves the use of the drive-through sampling strategy. METHODS: data was collected by both qualitative and quantitative methods. An eligibility form was filled online. While in-depth interviews were conducted for the qualitative aspect of the study. RESULTS: 2,600 visits were recorded at the website, 2300 (88.46%) participants successfully registered for the test. 57.4% were found eligible of which 78.0% presented for the test. This Consisted of 78.0% drive-through and 22.0% walk-in. The average time for transiting through the drive-through site was 19.2 ± 4.6minutes while that of the walk-in was 28 ± 9.2min. This difference was statistically significant (p<0.001). In the qualitative component, respondents opined that maximum safety measures were deployed to protect both participants and health workers. Most said that the turnaround time for the sampling process was short. CONCLUSION: the sampling strategy although largely successful, is largely dependent on Internet penetrability, thus this sampling modality will be best utilized as an adjunct to established models of sample collection.

A barcode of multilocus nuclear DNA identifies genetic relatedness in pre- and post-Artemether/Lumefantrine treated Plasmodium falciparum in Nigeria.

BACKGROUND: The decline in the efficacy of artemisinin-based combination treatment (ACT) in some endemic regions threatens the progress towards global elimination of malaria. Molecular surveillance of drug resistance in malaria-endemic regions is vital to detect the emergence and spread of mutant strains. METHODS: We observed 89 malaria patients for the efficacy of artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum infections in Lagos, Nigeria and determined the prevalence of drug resistant strains in the population. Parasite clearance rates were determined by microscopy and the highly sensitive var gene acidic terminal sequence (varATS) polymerase chain reaction for 65 patients with samples on days 0, 1, 3, 7, 14, 21 and 28 after commencement of treatment. The genomic finger print of parasite DNA from pre- and post-treatment samples were determined using 24 nuclear single nucleotide polymorphisms (SNP) barcode for P. falciparum. Drug resistance associated alleles in chloroquine resistance transporter gene (crt-76), multidrug resistance genes (mdr1-86 and mdr1-184), dihydropteroate synthase (dhps-540), dihydrofolate reductase (dhfr-108) and kelch domain (K-13580) were genotyped by high resolution melt analysis of polymerase chain reaction (PCR) fragments. RESULTS: By varATS qPCR, 12 (18.5%) of the participants had detectable parasite DNA in their blood three days after treatment, while eight (12.3%) individuals presented with genotypable day 28 parasitaemia. Complexity of infection (CoI) was 1.30 on day 0 and 1.34 on day 28, the mean expected heterozygosity (HE) values across all barcodes were 0.50 ± 0.05 and 0.56 ± 0.05 on days 0 and 28 respectively. Barcode (π) pairwise comparisons showed high genetic relatedness of day 0 and day 28 parasite isolates in three (37.5%) of the eight individuals who presented with re-appearing infections. Crt-76 mutant allele was present in 38 (58.5%) isolates. The mdr1-86 mutant allele was found in 56 (86.2%) isolates. No mutation in the K-13580 was observed. CONCLUSIONS: Persistence of DNA-detectable parasitaemia in more than 18% of cases after treatment and indications of genetic relatedness between pre- and post-treatment infections warrants further investigation of a larger population for signs of reduced ACT efficacy in Nigeria.