Background:Interventions are currently being used against‘infectious diseases of poverty’,which remain highly debilitating and deadly in most endemic countries,especially malaria,schistosomiasis,echinococcosis and African sleeping sickness.However,major limitations of current‘traditional’methods for diagnosis are neither simple nor convenient for population surveillance,and showed low sensitivity and specificity.Access to novel technologies for the development of adequate and reliable tools are expressly needed.A collaborative project between African Network for Drugs and Diagnostics Innovation and partner institutions in Africa and China aims to screen suitable serological biomarkers for diagnostic pipelines against these‘diseases of the poor’.Methods:Parasite-specific exposed versus unexposed individuals were screened and sera or urine/stools were collected through case-control studies in China and African countries.Target genes/open reading frames were selected,then will be cloned and cell-free expressed,quantified and immuno-detected.Target antigens/epitopes will be probed and screened with sera from exposed or unexposed individuals using a high-throughput antigen screening platform as the study progresses.The specificity and sensitivity of highly immunoreactive biomarkers will be evaluated as well,using enzyme-linked immunosorbent assays or dipsticks.Discussion:This roadmap explicitly unfolds the integrated operating procedures with focus on malaria and schistosomiasis,for the identification of suitable biomarkers that will aid the prioritization of diagnostics for population use.However,there is need to further validate any new diagnostic through comparison with standard methods in field deployable tests for each region.Our expectations for the future are to seek regulatory approval and promote the use of diagnostics in endemic areas.
Background:China has made progress in malaria control and aims to eliminate malaria nationwide,but implementing effective interventions along the border regions remain a huge task.The Plasmodium falciparum cases imported from Southeast Asia has frequently reported especially in the China-Myanmar border(CMB)area.Though,information is scant on P.falciparum genetic variability in this area.Methods:This study reported P.falciparum isolates genome sequence of six clinical isolates in the CMB area.Furthermore,we estimated the nucleotide diversity,Watterson’s estimator and Tajima’s D value for the whole genome mutation rate in slide window.Results:Our data were aligned onto 96.05-98.61%of the reference 3D7 genome in high fold coverages.Principal component analysis result showed that P.falciparum clustered generally according to their geographic origin.A total of 91 genes were identified as positive selection with Ka/Ks ratio significantly higher than 1,and most of them were multigene families encoding variant surface antigens(VSAs)such as var,rif and stevor.The enrichment of the positive selection on VSA genes implied that the environment complexity subjected CMB’s P.falciparum to more pressure for survival.Conclusions:Our research suggests that greater genetic diversity in CMB area and the positive selection signals in VSA genes,which allow P.falciparum to fit the host immune system well and aggravate the difficulty of treatment.Meanwhile,results obtained from this study will provide the fundamental basis for P.falciparum population genomic research in CMB area.
Hai-Mo ShenShen-Bo ChenYan-Bing CuiBin XuKokouvi KassegneEniola Michael AbeYue WangJun-Hu Chen
