Genome-wide association analysis allows the identification of potential candidate genes involved in the development of severe coronavirus disease 2019 (COVID-19). Hence, it seems that genetics matters here, as well. Nevertheless, the virus's nature, including its RNA structure, determines the rate of mutations leading to new viral strains with all epidemiological and clinical consequences. Given these observations, we herein comment on the current hypotheses about the possible role of the genes in association with COVID-19 severity. We discuss some of the major candidate genes that have been identified as potential genetic factors associated with the COVID-19 severity and infection susceptibility: HLA, ABO, ACE2, TLR7, ApoE, TYK2, OAS, DPP9, IFNAR2, CCR2 , etc. Further study of genes and genetic variants will be of great benefit for the prevention and assessment of the individual risk and disease severity in different populations. These scientific data will serve as a basis for the development of clinically applicable diagnostic and prognostic tests for patients at high risk of COVID-19.

No abstract

The prevalence of hepatitis E virus (HEV) in the Bulgarian population remains underestimated. The aim of the present study was to evaluate age and gender trends in HEV prevalence in the heterogeneous Bulgarian population. Stored serum samples from blood donors and different patient sub-populations—kidney recipients (KR), patients with Guillain–Barre syndrome (GBS), Lyme disease (LD), patients with liver involvement and a clinical diagnosis other than viral hepatitis A and E (non-AE), hemodialysis (HD) and HIV-positive patients (HIV)—were retrospectively investigated for markers of past and recent/ongoing HEV infection. The estimated overall seroprevalence of past infection was 10.6%, ranging from 5.9% to 24.5% for the sub-populations evaluated, while the seroprevalence of recent/ongoing HEV infection was 7.5%, ranging from 2.1% to 20.4%. The analysis of the individual sub-populations showed a different prevalence with respect to sex. In regard to age, the cohort effect was preserved, as a multimodal pattern was observed only for the GBS sub-population. Molecular analysis revealed HEV 3f and 3e. The type of the population is one of the main factors on which the anti-HEV prevalence depends, highlighting the need for the development of guidelines related to the detection and diagnosis of HEV infection with regard to specific patient populations.

West Nile fever (WNF) is a vector-borne infection caused by a Flavivirus-West Nile virus (WNV). WNV is transmitted by mosquitoes, and birds are the major natural reservoir. A recent increase in the number of the WNF cases has been reported in Europe, the Balkans, and Bulgaria. We herein present the clinical course, laboratory and imaging findings of three patients – a female and two male patients, who were diagnosed with WNF. They were investigated in an epidemiological study, and by using clinical observation, laboratory and microbiological methods, serological tests for specific anti-WNV antibodies detection, molecular biology techniques (polymerase chain reaction, PCR), computed tomography (CT) and magnetic resonance imaging (MRI). The patients presented with fever, headache, drowsiness, and dizziness and anti-WNV antibodies were detected in their serum samples. WNV-RNA was found in a blood sample from the female patient. Both anti-WNV IgM and Herpes simplex virus-1 DNA were detected in a cerebrospinal fluid sample from one of the men. The three patients recovered from the disease after a long convalescent period. WNF has no specific signs, laboratory and imaging findings and could be a life-threatening condition, leading to serious complications. Therefore, WNF should be taken into consideration during the summer when the vector of the infection is active. 

No abstract