SARS-CoV-2 infections before, during, and after the Omicron wave: a 2-year Indian community cohort study.

Background: We measured the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and re-infections in an adult community-based cohort in southern India. Methods: We conducted a 2-year follow-up on 1229 participants enrolled between May and October 2021. Participants provided vaccination histories, weekly saliva samples, and blood samples at 0, 6, 12, and 24 months. Salivary reverse transcription polymerase chain reaction (RT-PCR) and Meso-Scale Discovery panels were used for SARS-CoV-2 detection and anti-spike, anti-nucleocapsid immunoglobulin G quantification. Whole genome sequencing was performed on a subset of positive samples. SARS-CoV-2 infection incidence was measured across Pre-Omicron (May-December 2021), Omicron-I (December 2021-June 2022), and Omicron-II (July 2022-October 2023) periods. Findings: In total, 1166 (95%) participants with 83% seropositivity at baseline completed the follow-up, providing 2205 person-years of observation. Utilizing both RT-PCR and serology we identified 1306 infections and yielded an incidence rate of 591.3 per 1000 person-years (95% confidence interval, 559.6-624.3), which peaked during Omicron-I at 1418.1 per 1000 person-years (95% confidence interval, 1307.4-1535.6). During Omicron-I and II, neither prior infection nor vaccination conferred protection against infection. Overall, 74% of infections were asymptomatic. Interpretation: Integrated RT-PCR and serology revealed significant SARS-CoV-2 infection frequency, highlighting the prevalence of asymptomatic cases among previously infected or vaccinated individuals. This underscores the effectiveness of combining surveillance strategies when monitoring pandemic trends and confirms the role of non-invasive sampling in ensuring participant compliance, reflecting national transmission patterns. Funding: The study was funded by the Bill and Melinda Gates Foundation.

Factor XIII polymorphism and risk of aneurysmal subarachnoid haemorrhage in a south Indian population.

BACKGROUND: The rupture of a brain aneurysm causes bleeding in the subarachnoid space and is known as aneurysmal subarachnoid haemorrhage (aSAH). In our study, we evaluated the association of factor XIII polymorphism and the risk of Aneurysmal subarachnoid haemorrhage (aSAH) in South Indian population. METHODS: The study was performed in 200 subjects with aSAH and 205 healthy control subjects. Genotyping of rs5985(c.103G > T (p.Val35Leu)) and rs5982(c.1694C > T (p.Pro564Leu)) polymorphism was performed by Taqman® allelic discrimination assay. RESULTS: In our study, Val/Leu genotype frequency was higher in control subjects (18%) compared to aSAH patients (9%).The Val/Leu genotype was associated with lower risk of aSAH (OR = 0.48, 95%CI = 0.26-0.88, p = 0.02). When compared with Val allele, Leu allele was significantly associated with lower risk of aSAH (OR = 0.55, 95%CI = 0.32-0.95, p = 0.03). In subtyping, we found a significant association of Leu/Leu genotype with the Basilar top aneurysm (OR = 3.59, 95%CI = 1.11-11.64, p = 0.03). In c.1694C > T (p.Pro565Leu) variant, Pro/Pro Vs Pro/Leu genotype (OR = 2.06, 95%CI = 1.10-3.85, p = 0.02) was significantly associated with higher risk of aSAH. The 564Leu allelic frequency in aSAH patients (36%) was higher when compared with that in healthy controls (30%) in our study. When allele frequency (Pro Vs Leu) was compared, 564Leu allele was found to be significantly associated with higher aSAH risk (OR = 1.36, 95%CI = 1.01-1.83, p = 0.04). (OR = 1.36, 95%CI = 1.01-1.83, p = 0.04). Regarding rs5985 and rs5982, significant association was found in the log-additive model (OR = 0.57, 95%CI = 0.33-0.97, p = 0.034; OR = 1.32, 95%CI = 1.00-1.72, p = 0.043). CONCLUSION: These results suggest that 34Leu allele was a protective factor for lower risk of aSAH whereas 564Leu allele was associated with higher risk of aSAH in South Indian population.

Apolipoprotein E polymorphism and the risk of aneurysmal subarachnoid hemorrhage in a South Indian population.

BACKGROUND: The rupture of a brain aneurysm causes bleeding in the subarachnoid space. This is known as aneurysmal subarachnoid hemorrhage (aSAH). We evaluated the association of apolipoprotein E (APOE) polymorphism and the risk of aSAH in a South Indian population. METHODS: The study was performed on 200 subjects with aSAH and 253 healthy control subjects. Blood samples (5 ml) were used to isolate DNA and genotyping was performed for rs7412 and rs429358 using a Taqman allelic discrimination assay. Statistical software R.3.0.11 was used to statistically analyze the data and a p value < 0.05 was considered as statistically significant. RESULTS: We found a significant association with the risk of aSAH in ε3/ ε4 genetic model (OR = 1.91, 95% CI = 1.16-3.14, p = 0.01). However, in the other genetic models and allele frequency, there was no significant association with the risk of aSAH. In subtyping, we found a significant association of ε2 allele frequency with posterior communicating artery (PCOM) aneurysm (OR = 3.59, 95% CI = 1.11-11.64, p = 0.03). CONCLUSION: Our results suggest that APOE polymorphism has an influence on the risk of aSAH in this South Indian population, specifically in the PCOM subtype.

Overexpression and lack of copy number variation in the BMI-1 gene in human glioma.

Malignant gliomas are neoplasms of the brain that are associated with a poor prognosis. The B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) gene is one of the major cancer stem cell factors responsible for treatment failure in glioma. In the present study, the DNA-RNA-protein alterations in the BMI-1 gene were assessed in 50 glioma samples. Copy number variations in the BMI-1 gene were analyzed using SYBR® Green quantitative polymerase chain reaction. Gene expression analysis was performed using a Taqman assay and protein quantitation was performed using western blotting. A comparative Ct analysis showed the absence of copy number variations in all glioma samples. BMI-1 mRNA expression was found to be overexpressed in 36 out of 50 samples (72.0%), and 37 out of 50 samples showed overexpression (74.0%) of BMI-1 protein; this was statistically significant when compared with non-glioma tissues. It was observed that the protein and RNA expression in glioma were concordant. In this study on the BMI-1 gene, transcription and translation in glioma were observed and BMI-1 overexpression was found to be a common phenomenon.