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Journal of Clinical Virology Plus ; : 100133, 2022.
Article in English | ScienceDirect | ID: covidwho-2165517


Although real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) remains as a golden standard for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, it can not be easily expanded to large-scaled screening during outbreaks, and the positive results do not necessarily correlate with infectious status of the identified subjects. In this study, the performance of Vstrip® RV2 COVID-19 Antigen Rapid Test (RAT) and its correlation with virus infectivity was examined by virus culture using 163 sequential respiratory specimens collected from 26 SARS-CoV-2 infected patients. When the presence of cytopathic effects (CPE) in cell culture was used as a reference method for virus infectivity, the sensitivity, specificity and accuracy of Vstrip® RV2 COVID-19 Antigen Rapid Test was 96.43%, 89.63%, and 90.8%, respectively. The highest Ct value was 27.7 for RdRp gene and 25.79 for E gene within CPE-positive samples, and the highest Ct value was 31.9 for RdRp gene and 29.1 for E gene within RAT positive samples. When the Ct values of specimens were below 25, the CPE and RAT results had high degree of consistency. We concluded that the RAT could be a great alternative method for determining the infectious potential of individuals with high viral load.

Journal of the Formosan Medical Association ; 2022.
Article in English | ScienceDirect | ID: covidwho-2131481


Background Patients recovering from COVID-19 may need vaccination against SARS-CoV-2 because acquired immunity from primary infection may wane, given the emergence of new SARS-CoV-2 variants. Understanding the trends of anti-spike IgG and neutralizing antibody titers in patients recovering from COVID-19 may inform the decision made on the appropriate interval between recovery and vaccination. Methods Participants aged 20 years or older and diagnosed with COVID-19 between January and December, 2020 were enrolled. Serum specimens were collected every three months from 10 days to 12 months after the onset of symptom for determinations of anti-spike IgG and neutralizing antibody titers against SARS-CoV-2 Wuhan strain with D614G mutation, alpha, gamma and delta variants. Results Of 19 participants, we found a decreasing trend of geometric mean titers of anti-spike IgG from 560.9 to 217 and 92 BAU/mL after a 4-month and a 7-month follow-up, respectively. The anti-spike IgG titers declined more quickly in the ten participants with severe or critical disease than the nine participants with only mild to moderate disease between one month and seven months after SARS-CoV-2 infection (-8.49 vs - 2.34-fold, p<0.001). The neutralizing activity of the convalescent serum specimens collected from participants recovering from wild-type SARS-CoV-2 infection against different variants was lower, especially against the delta variants (p<0.01 for each variant with Wuhan strain as reference). Conclusion Acquired immunity from primary infection with SARS-CoV-2 waned within 4-7 months in COVID-19 patients, and neutralizing cross-activities against different SARS-CoV-2 variants were lower compared with those against wild-type strain.

Emerg Microbes Infect ; 11(1): 1664-1671, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1978179


To reach the WHO target of hepatitis C virus (HCV) elimination by 2025, Taiwan started to implement free-of-charge direct-acting antiviral (DAA) treatment programme in 2017. Evaluating the progress of HCV microelimination among people living with HIV (PLWH) is a critical step to identify the barriers to HCV elimination. PLWH seeking care at a major hospital designated for HIV care in Taiwan between January 2011 and December 2021 were retrospectively included. For PLWH with HCV-seropositive or HCV seroconversion during the study period, serial HCV RNA testing was performed using archived samples to confirm the presence of HCV viremia and estimate the prevalence and incidence of HCV viremia. Overall, 4199 PLWH contributed to a total of 27,258.75 person-years of follow-up (PYFU). With the reimbursement of DAAs and improvement of access to treatments, the prevalence of HCV viremia has declined from its peak of 6.21% (95% CI, 5.39-7.12%) in 2018 to 2.09% (95% CI, 1.60-2.77%) in 2021 (decline by 66.4% [95% CI, 55.4-74.7%]); the incidence has declined from 25.94 per 1000 PYFU (95% CI, 20.44-32.47) in 2019 to 12.15% per 1000 PYFU (95% CI, 8.14-17.44) (decline by 53.2% [95% CI, 27.3-70.6%]). However, the proportion of HCV reinfections continued to increase and accounted for 82.8% of incident HCV infections in 2021. We observed significant declines of HCV viremia among PLWH with the expansion of the DAA treatment programme in Taiwan. Further improvement of the access to DAA retreatments is warranted to achieve the goal of HCV microelimination.

HIV Infections , Hepatitis C, Chronic , Hepatitis C , Antiviral Agents/therapeutic use , HIV Infections/drug therapy , HIV Infections/epidemiology , Hepacivirus/genetics , Hepatitis C/drug therapy , Hepatitis C/epidemiology , Hepatitis C, Chronic/drug therapy , Humans , Retrospective Studies , Taiwan/epidemiology , Viremia/drug therapy , Viremia/epidemiology