Leishmaniasis is a serious infectious disease caused by Leishmania parasites, predominantly affecting tropical and subtropical regions. These parasites replicate within macrophages, manipulating the host immune response and facilitating infection progression. This study examined the expression profiles of long non-coding RNAs (lncRNAs), potential cis-target genes, and hub genes at different time points in human macrophages infected with Leishmania major. RNA-Seq analysis identified 39,828 lncRNAs, with 2,903 showing differential expression at one or more time points. As the infection progressed (4, 24, 48, and 72 hours), the number of up- and down-regulated lncRNAs gradually decreased. Six lncRNAs (lnc-UNC5D-8, lnc-TENM3-1, DIRC3-1, lnc-MTRNR2L12-10, lnc-FAM43A-6, and AKAP2-1) were consistently differentially expressed across all time points, potentially playing key roles in regulating the host immune response. Time-specific hub genes were also identified, regulating critical processes such as keratinization, epigenetic modifications, and immune responses. In particular, these genes were pivotal during the later stages of infection in maintaining tissue integrity and regulating immune responses. Early immune responses were dominated by immunoglobulin receptor activity and adaptive immune system activation. These findings highlight the critical roles of lncRNAs and hub genes in macrophage responses to Leishmania infection, offering potential targets for future therapeutic strategies.

Infectious diseases impose a significant burden on global health systems due to high morbidity and mortality rates. According to the World Health Organization, millions die from infectious diseases annually, often due to delays in accurate diagnosis. Traditional diagnostic methods in clinical microbiology, primarily culture-based techniques, are time-consuming and may fail with hard-to-culture pathogens. Molecular biology advancements, notably the Polymerase Chain Reaction (PCR), have revolutionized infectious disease diagnostics by allowing rapid and sensitive detection of pathogens' genetic material. PCR has become the gold standard for many infections, particularly highlighted during the COVID-19 pandemic. Following PCR, Next-Generation Sequencing (NGS) has emerged, enabling comprehensive genomic analysis of pathogens, thus facilitating the detection of new strains and antibiotic resistance tracking. Innovative approaches like CRISPR technology are also enhancing diagnostic precision by identifying specific DNA/RNA sequences. However, the implementation of these methods faces challenges, particularly in low- and middle-income countries due to infrastructural and financial constraints. This review will explore the role of molecular diagnostic methods in infectious disease diagnosis, comparing their advantages and limitations, with a focus on PCR and NGS technologies and their future potential.