RESUMO
Human immunodeficiency virus type 1 (HIV-1) sequences that pre-date the recognition of AIDS are critical to defining the time of origin and the timescale of virus evolution. A viral sequence from 1959 (ZR59) is the oldest known HIV-1 infection. Other historically documented sequences, important calibration points to convert evolutionary distance into time, are lacking, however; ZR59 is the only one sampled before 1976. Here we report the amplification and characterization of viral sequences from a Bouin's-fixed paraffin-embedded lymph node biopsy specimen obtained in 1960 from an adult female in Léopoldville, Belgian Congo (now Kinshasa, Democratic Republic of the Congo (DRC)), and we use them to conduct the first comparative evolutionary genetic study of early pre-AIDS epidemic HIV-1 group M viruses. Phylogenetic analyses position this viral sequence (DRC60) closest to the ancestral node of subtype A (excluding A2). Relaxed molecular clock analyses incorporating DRC60 and ZR59 date the most recent common ancestor of the M group to near the beginning of the twentieth century. The sizeable genetic distance between DRC60 and ZR59 directly demonstrates that diversification of HIV-1 in west-central Africa occurred long before the recognized AIDS pandemic. The recovery of viral gene sequences from decades-old paraffin-embedded tissues opens the door to a detailed palaeovirological investigation of the evolutionary history of HIV-1 that is not accessible by other methods.
Assuntos
Evolução Molecular , Variação Genética/genética , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/isolamento & purificação , Adulto , Canadá , República Democrática do Congo/epidemiologia , Feminino , Infecções por HIV/patologia , HIV-1/classificação , História do Século XX , Humanos , Masculino , Microtomia , Dados de Sequência Molecular , Inclusão em Parafina , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
Quality patient care requires correct and timely evidence-based diagnoses. Pathology and laboratory medicine training varies significantly across the continent, but is inadequate to serve the needs of the population. This article summarizes the current state of pathology workforce and training in sub-Saharan Africa; discusses challenges to recruitment and retention; and outlines the necessary elements for training and sustaining a robust workforce in pathology and laboratory medicine. The authors provide several case studies of institutions around the continent that include expansion of existing programs, a de novo program, South-South collaborations, and skill building for the existing workforce.