Comparative analysis of asymptomatic infection prevalence in Beta, Delta, and Omicron surges of COVID-19

Abstract Background The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had a devastating impact on the global population, with an estimated 650 million people infected and more than 6.6 million lives lost. Asymptomatic individuals have been shown to play a significant role in the transmission of the virus. Therefore, this study aims to investigate and compare the prevalence of asymptomatic individuals across three waves associated with the Beta, Delta, and Omicron variants of the virus. Methods This retrospective study was conducted between December 2020 and March 2022. The study population consisted of passengers on international flights who were referred to the Gerash Clinical and Molecular Diagnosis Laboratory. Real-time PCR was employed for the diagnosis of SARS-CoV-2. Results Out of a total of 8592 foreign travelers referred to our laboratory, 139 (1.16 %) tested positive for SARS-CoV-2 infection and were asymptomatic. During the Beta surge, 35 (1.49 %) out of 2335 passengers tested positive for SARS-CoV-2. In the Delta surge, 31 (0.6 %) out of 5127 passengers tested positive. However, during the Omicron surge, a significantly higher number of passengers, specifically 73 (6.46 %) out of 1130, had a positive result for the SARS-CoV-2 test. Conclusion Considering the significant role of asymptomatic transmission in the spread of COVID-19, it is imperative to reconsider health policies when dealing with future surges of the Omicron subvariants. Additionally, we strongly recommend that the World Health Organization prioritize the development and distribution of second-generation vaccines that target not only disease but also infection prevention.

Molecular characterization of Torque teno virus and SEN virus co-infection with HIV in patients from Southern Iran

Introduction Torque teno virus (TTV) and SEN virus are circular single-stranded DNA viruses that cause blood-borne infections. The SEN virus (SEN-V) was originally detected in the serum of an injection drug user infected with human immunodeficiency virus (HIV). Recently TTV was discovered as a potential causative agent of non-A-E hepatitis. The aim of this study was to investigate the prevalence of the SEN-V-D/H and TTV in HIV patients and healthy blood donors in Iran. Methods One hundred and fifty HIV patients with a mean age of 50.46 ± 18.46 years and 150 healthy blood donors with a mean age of 48.16 ± 13.73 years were included in this study. TTV and SEN-V were detected by the PCR and were quantitatively assayed by competitive PCR (nested and semi-nested PCR). Restriction fragment length polymorphisms (RFLPs) were used to determine the heterogeneity of TTV. Results TTV and SEN-V were detected 96 (64%) and 84 (56%) of 150 HIV patients respectively. These rates were 34% (n=51) and 37.33% (n=56) in healthy blood donors (significant, p<0.05). PCR detected SEN-V/TTV DNA from 32 of the healthy blood donors (21.33%), while 65 (43.33%) of HIV patients were positive for SEN-V/TTV DNA. Of 150 HIV patients, 32.66% and 23.33% were positive for SEN-V-H and SEN-V-D, respectively and 18.66% (n=28) were co-infected with SEN-V-D/H. Conclusions The prevalence of SEN-VD/H and TTV is higher in HIV patients than in healthy blood donors in Southern Iran. Our results suggest that TTV and SEN-V might play a role in the development of liver disease in patients with immunodeficiency diseases. .

Association of MMP 9-1562 C/T Single Nucleotide Polymorphism with the Susceptibility to Lung Cancer Disease in South Iranian Population.

Aims: The aim of this study was to investigate the association of MMP9 -1562 C /T single nucleotide polymorphism with lung cancer in south Iranian population. Matrix metalloproteinases (MMPs) are a family of highly conserved metal-dependent proteolytic enzymes that are able to degrade ECM components and regulate various cell behaviors. Among several candidate genes, MMP9 is one of the most important genes known to play a key role in relation to lung cancer initiation and progression. A common - 1562(C/T) single nucleotide polymorphism in the promoter region of MMP9 was reported to have an association with lung cancer disease. Study Design: A case - control study was carried out using 90 lung cancer patients and 100 healthy controls. Place and Duration of Study: Cellular and Molecular Gerash Research Center, Shiraz University of Medical sciences, shiraz, Iran, between 2010-2012. Methodology: The association of MMP9 promoter single nucleotide polymorphism and lung cancer was examined in a PCR-RFLP method. Our results suggest an association between MMP9 single nucleotide polymorphism and lung cancer initiation and progression. Conclusion: According to our results, the frequency of T allele in patient group (OR=4.6111, 95% CI, 1.9005 to 11.1879) and TT genotype in smoker group (OR=1.7726, 95% CI, 0.7947 to 3.9538) is higher compared to other groups.

Molecular detection of TT virus and SEN virus infections in hemodialysed patients and blood donors in south of Iran.

Background: SEN virus (SEN-V) and TT virus (TTV) have been classified in the circoviridae family. Both are single-stranded, non-enveloped DNA viruses of about 3800 nucleotides. Patients on maintenance hemodialysis (HD) have a high risk of blood-borne viral infections. SEN-V and TTV has been reported from a number of HD units from various countries throughout the world. Materials and Methods: A total of 377 blood samples obtained from 150 healthy donors and 227 HD patients were collected at the HD center. SEN-V and TTV DNA was determined by polymerase chain reaction (PCR) in all samples. Results: TTV was detected in 109 (48.01%) of 227 hemodialysed patients and 14 (9.33%) of 150 voluntary blood donors (significant, P < 0.05). The PCR results for SEN-V-D/H DNA showed that 65 (28.63%) were positive for SEN-V-D and 33 (14.53%) were positive for SEN-V-H. 9.69% of 227 patients were positive for SEN-V-D/H co-infection. In the control group, SEN-V-D was detected in 14 (9.33%) and SEN-V-H was detected in 15 (10%) of the 150 (100%) blood donors. Conclusion: These findings show that the prevalence of SEN-V-D/H and TTV is higher than healthy blood donors. Also, these results indicate that the prevalence of SEN-V and TTV infections in our region is similar with that in other countries.