Dengue virus serotype did not contribute to clinical severity or mortality in Taiwan's largest dengue outbreak in 2015.

BACKGROUND: Dengue virus serotype 2 (DENV-2) was the major serotype in the 2015 dengue outbreak in Taiwan, while DENV-1 and DENV-3 were dominant between 2005 and 2014. We aimed to investigate whether DENV-2 contributed to disease severity and mortality in the outbreak in Kaohsiung city, Taiwan. METHODS: We collected serum samples from dengue patients to detect the presence of DENV and determine the serotypes by using quantitative reverse transcription-polymerase chain reaction. Our cohorts comprised 105 DENV-1-infected cases and 1,550 DENV-2-infected cases. Demographic data, DENV serotype, and comorbidities were covariates for univariate and multivariate analyses to explore the association with severity and mortality. RESULTS: The results suggested that DENV-1 persisted and circulated, while DENV-2 was dominant during the dengue outbreak that occurred between September and December 2015. However, DENV-2 did not directly contribute to either severity or mortality. Aged patients and patients with diabetes mellitus (DM) or moderate to severe chronic kidney disease (CKD) had a higher risk of developing severe dengue. The mortality of dengue patients was related to a higher Charlson comorbidity index score and severe dengue. Among DENV-2-infected patients and older patients, preexisting anti-dengue IgG, DM, and moderate to severe CKD were associated with severe dengue. Moreover, female sex and severe dengue were associated with a significantly higher risk of death. CONCLUSIONS: Our findings highlight the importance of timely serological testing in elderly patients to identify potential secondary infections and focus on the meticulous management of elderly patients with DM or moderate to severe CKD to reduce dengue-related death.

COVID-19 outcomes in patients with rheumatoid arthritis with biologic or targeted synthetic DMARDs.

OBJECTIVES: We aimed to investigate the role of rheumatoid arthritis (RA) with biologic or targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARD) exposure in COVID-19 outcomes. METHODS: Our study retrieved data from the US Collaborative Network in TriNetX between 1 January 2018 and 31 December 2022. We investigated b/tsDMARD use for RA: interleukin 6 inhibitor (IL-6i), Janus-associated kinase inhibitors (JAKi) or tumour necrosis factor-alpha inhibitors (TNFi, reference group). The outcomes of COVID-19 were the incidence of infection and adverse outcomes (hospitalisation, critical care services, mechanical ventilation and mortality). The HR and 95% CI of the outcomes were calculated between propensity score-matched (PSM) patients with different b/tsDMARDs. RESULTS: After PSM, 2676 JAKi vs 2676 TNFi users and 967 IL-6i vs 967 TNFi users were identified. As for COVID-19 incidence, JAKi users did not reach statistical significance (HR: 1.058, 95% CI: 0.895 to 1.250) than TNFi users. RA with JAKi users had a significant risk for hospitalisation (HR: 1.194, 95% CI: 1.003 to 1.423), mortality (HR: 1.440, 95% CI: 1.049 to 1.976) and composite adverse outcomes (HR: 1.242, 95% CI: 1.051 to 1.468) compared with TNFi users. Mortality risk tended to be significantly higher in the JAKi group without COVID-19 vaccination (HR: 1.511, 95% CI: 1.077 to 2.121). IL-6i users compared with TNFi users did not have the above findings. CONCLUSIONS: RA with JAKi users had a significant risk for hospitalisation, mortality or composite adverse outcomes, especially higher mortality among those without COVID-19 vaccination. COVID-19 vaccination should be encouraged in these target cohorts. When using JAKi for patients with RA, clinicians should be vigilant about these adverse outcomes to prevent their occurrence or detect them early for early intervention.

The identification and phylogenetic analysis of SARS-CoV-2 delta variants in Taiwan.

In Taiwan, coronavirus disease 2019 (COVID-19) involving the delta variant occurred after that involving the alpha variant in 2021. In this study, we aimed to analyze the Delta variant. A total of 318 patients in Taiwan infected with delta variants were identified. The case fatality rate (CFR) of patients infected with delta variants was 0.94% in Taiwan compared with that of those infected with alpha variants (5.95%). The possible reasons for the low CFR might be hybrid immunity due to infection and rapid promotion of the COVID-19 vaccination program during the alpha variant outbreak. We identified three 21J delta variants. Two long gene deletions were detected in these severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) isolates: ORF7aΔ91 in KMUH-8 and SpikeΔ30 in KMUH-9. Protein structure prediction indicates that ORF7aΔ91 results in malfunction of NS7a as an interferon antagonist and that SpikeΔ30 results in a truncated spike protein (N679-A688del), resulting in a lower infection rate compared with the delta variant without these deletions. The impact of these two deletions on SARS-CoV-2-associated pathogenesis deserves further investigation. Delta variants still exist in many regions in the omicron era, and the backbone of the delta variant genome possibly spread worldwide in the form of delta-omicron hybrids (deltacron; e.g., XBC.1 and XAY.2), which casts a potential threat to public health. Our study further highlighted the importance of more understanding of the delta variants.