The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). We observed a significant association (P<1.00×10⁻¹⁰) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10×10⁻⁵) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae.

Background: Estimating prevalence of Chlamydia trachomatis (CT) worldwide is necessary in designing control programs and allocating health resources. We performed a meta-analysis to calculate the prevalence of CT in the general population. Methods: The Pubmed and Embase databases were searched for eligible population-based studies from its inception through June 5, 2019. Q test and I² statistic were used to calculate the heterogeneity between studies. Random effects models were used to pool the prevalence of CT. Meta regression was performed to explore the possible sources of heterogeneity. Publication bias was evaluated using a funnel plot and “trim and fill” method. Results: Twenty nine studies that reported prevalence of CT infection from 24 countries were identified, including a total population of 89,886 persons. The pooled prevalence of CT among the general population was 2.9% (95% CI, 2.4–3.5%), and females had a higher CT prevalence (3.1, 95% CI, 2.5–3.8%) than males (2.6, 95% CI, 2.0–3.2%) (χ² = 10.38, P < 0.01). Prevalence of CT was highest in region of America (4.5, 95% CI, 3.1–5.9%), especially in Latin America (6.7, 95% CI, 5.0–8.4%), followed by females in region of Africa (3.8, 95% CI, 0.7–6.9%), while South-East Asia had a lowest CT prevalence 0.8% (95% CI, 0.3–1.3%). Conclusions: This study provided the updated prevalence of CT among general population worldwide. General population from Latin America, especially females, and women in Africa should be given priority by WHO when design and delivery CT control programs.