Viral load, clinical disease severity and cellular immune responses in primary varicella zoster virus infection in Sri Lanka

Background In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied. Methodology We used IFNγ ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection. Principal Findings Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p<0.001) and were significantly higher in those over 25 years of age (P<0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNγ ELISpot responses of patients (P<0.001, r = −0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation. Conclusions Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses

Dengue type 1 viruses circulating in humans are highly infectious and poorly neutralized by human antibodies

The four dengue virus (DENV) serotypes are mosquito-borne flaviviruses of humans. The interactions between DENVs and the human host that lead to asymptomatic, mild, or severe disease are poorly understood, in part, because laboratory models are poor surrogates for human DENV disease. Virologists are interested in how the properties of DENVs replicating in people compare with virions propagated on laboratory cell lines, which are widely used for research and vaccine development. Using clinical samples from a DENV type 1 epidemic in Sri Lanka and new ultrasensitive assays, we compared the properties of DENVs in human plasma and after one passage on laboratory cell lines. DENVs in plasma were 50- to 700-fold more infectious than cell culture-grown viruses. DENVs produced by laboratory cell lines were structurally immature and hypersensitive to neutralization by human antibodies compared with DENVs circulating in people. Human plasma and cell culture-derived virions had identical genome sequences, indicating that these phenotypic differences were due to the mature state of plasma virions. Several dengue vaccines are under development. Recent studies indicate that vaccine-induced antibodies that neutralized DENVs in cell culture assays were not sufficient for protecting people from DENV infections. Our results about structural differences between DENVs produced in humans versus cell lines may be key to understanding vaccine failure and developing better models for vaccine evaluation

Hybrid conferences in the new normal: reality in a resource restricted context

No abstract availabl

Viral Load, Clinical Disease Severity and Cellular Immune Responses in Primary Varicella Zoster Virus Infection in Sri Lanka

BACKGROUND: In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied. METHODOLOGY: We used IFNgamma ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection. PRINCIPAL FINDINGS: Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p&lt;0.001) and were significantly higher in those over 25 years of age (P&lt;0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNgamma ELISpot responses of patients (P&lt;0.001, r = -0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation. CONCLUSIONS: Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses

A living WHO guideline on drugs for covid-19

CITATION: Agarwal, A. et al. 2022. A living WHO guideline on drugs for covid-19. British Medical Journal, 370. doi:10.1136/bmj.m3379The original publication is available at https://jcp.bmj.com/This living guideline by Arnav Agarwal and colleagues (BMJ 2020;370:m3379, doi:10.1136/bmj.m3379) was last updated on 22 April 2022, but the infographic contained two dosing errors: the dose of ritonavir with renal failure should have read 100 mg, not 50 mg; and the suggested regimen for remdesivir should have been 3 days, not 5-10 days. The infographic has now been corrected.Publishers versio

A preliminary study on efficacy of rupatadine for the treatment of acute dengue infection

Currently there are no specific treatments available for acute dengue infection. We considered that rupatadine, a platelet-activating factor receptor inhibitor, might modulate dengue-associated vascular leak. The effects of rupatadine were assessed in vitro, and in a dengue model, which showed that rupatadine significantly reduced endothelial permeability by dengue sera in vitro, and significantly inhibited the increased haematocrit in dengue-infected mice with dose-dependency. We conducted a randomised, placebo-controlled trial in 183 adult patients in Sri Lanka with acute dengue, which showed that rupatadine up to 40 mg daily appeared safe and well-tolerated with similar proportions of adverse events with rupatadine and placebo. Although the primary end-point of a significant reduction in fluid leakage (development of pleural effusions or ascites) was not met, post-hoc analyses revealed small but significant differences in several parameters on individual illness days - higher platelet counts and lower aspartate-aminotransferase levels on day 7 in the rupatadine group compared to the placebo group, and smaller effusions on day 8 in the subgroup of patients with pleural effusions. However, due to the small sample size and range of recruitment time, the potential beneficial effects of rupatadine require further evaluation in large studies focused on recruitment during the early febrile phase.</p

Hyperparathyroidism Jaw Tumor Syndrome Presenting as Recurrent Femur Fractures in a Young Woman; a Rare Presentation of a Rare Disease

Background. Primary hyperparathyroidism usually occurs secondary to parathyroid adenoma, multiglandular hyperplasia, or parathyroid carcinoma. The patients usually present with incidentally discovered high calcium level and systemic or skeletal manifestations. In young patients with primary hyperparathyroidism, familial syndromes including multiple endocrine neoplasia types 1, 2, and 4 and hyperparathyroidism jaw tumor syndrome should be considered. Case Description. We present a case of a 22-year-old Sri Lankan woman who presented with femur fractures in a background of childhood nephroblastoma and maxillary fibro-osseous tumor. The patient had biochemical parameters suggestive of primary hyperparathyroidism with a parathyroid mass. The histology following excision of the mass revealed a parathyroid adenoma. Based on the associated clinical manifestations, hyperparathyroidism jaw tumor syndrome was suspected, and genetic studies reported a positive CDC73 mutation with a whole-gene deletion of exon 1–17. Conclusion. Hyperparathyroidism jaw tumor syndrome is an important diagnosis to consider in a young patient presenting with classic clinical features due to the risk of malignancy, familial involvement, and need to monitor for progressive systemic manifestations. As this is a rare disease, it can often be missed due to low degree of suspicion and the ability of the jaw tumor to mimic a metastatic deposit

A preliminary study on efficacy of rupatadine for the treatment of acute dengue infection

Currently there are no specific treatments available for acute dengue infection. We considered that rupatadine, a platelet-activating factor receptor inhibitor, might modulate dengue-associated vascular leak. The effects of rupatadine were assessed in vitro, and in a dengue model, which showed that rupatadine significantly reduced endothelial permeability by dengue sera in vitro, and significantly inhibited the increased haematocrit in dengue-infected mice with dose-dependency. We conducted a randomised, placebo-controlled trial in 183 adult patients in Sri Lanka with acute dengue, which showed that rupatadine up to 40 mg daily appeared safe and well-tolerated with similar proportions of adverse events with rupatadine and placebo. Although the primary end-point of a significant reduction in fluid leakage (development of pleural effusions or ascites) was not met, post-hoc analyses revealed small but significant differences in several parameters on individual illness days - higher platelet counts and lower aspartate-aminotransferase levels on day 7 in the rupatadine group compared to the placebo group, and smaller effusions on day 8 in the subgroup of patients with pleural effusions. However, due to the small sample size and range of recruitment time, the potential beneficial effects of rupatadine require further evaluation in large studies focused on recruitment during the early febrile phase.</p