ABSTRACT
BACKGROUND: Immigrants represented 21.8% of cases in a Spanish cohort of hospitalised patients with COVID-19, a proportion exceeding the percentage of immigrants in that area's total population. Among the ethnic-related genetic risk factors for COVID-19, human leukocyte antigen (HLA) genotypes in diverse populations might bias the response to SARS-CoV-2 infection and/or progression. Similarly, genetic differences in natural killer-activating and inhibitory receptors could play a role in the immune system's response to the viral infection. METHODS: We characterised HLA alleles and KIR genes in 52 Ecuadorian patients hospitalised for moderate and severe COVID-19 and 87 Ecuadorian controls from the general population living in the same area. RESULTS: There was a significantly increased frequency of the HLA-B*39 antigen and the activating KIR2DS4 receptor in the presence of its HLA-C*04 ligand in the COVID-19 group when compared with the control group. In contrast, there was a significant reduction in the frequency of carriers of KIR2DL1 and of the KIR3DL1/Bw4 receptor/ligand combination among COVID-19 group. On the other hand, HLA-A*24:02 and HLA-DRB1*09:01 alleles showed significantly lower frequencies specifically in the severe COVID-19 group. CONCLUSION: HLA-B*39 alleles might be genetic risk factors for developing COVID-19 in Ecuadorian individuals. In the presence of its ligand C*04, the natural killer-activating receptor KIR2DS4 might also increase the risk of developing COVID-19, while, in the presence of HLA-Bw4 alleles, the inhibitory receptor KIR3DL1 might play a protective role. Patients with COVID-19 who carry HLA-A*24:02 and HLA-DRB1*09:01 alleles might be protected against more severe forms of COVID-19.
Subject(s)
COVID-19 , Receptors, KIR , Humans , HLA-DRB1 Chains/genetics , Ligands , Protective Factors , Ecuador/epidemiology , Receptors, KIR/genetics , COVID-19/genetics , SARS-CoV-2 , HLA Antigens/genetics , Histocompatibility Antigens Class I/genetics , HLA-B Antigens/genetics , Genotype , HLA-A Antigens/geneticsABSTRACT
Increasing numbers of travellers returning from Cuba with dengue virus infection were reported to the GeoSentinel Network from June to September 2022, reflecting an ongoing local outbreak. This report demonstrates the importance of travellers as sentinels of arboviral outbreaks and highlights the need for early identification of travel-related dengue.