RESUMO
The first case of severe acute respiratory syndrome 2 (SARS CoV2) was imported to Pakistan in February 2020 since then 10,258 deaths have been witnessed. The virus has been mutating and local transmission cases from different countries vary due to host dependent viral adaptation. Many distinct clusters of variant SARS CoV2 have been defined globally. In this study, the epidemiology of SARS CoV2 was studied and locally transmitted SARS CoV2 isolates from Karachi were sequenced to compared and identify any possible variants.The real time PCR was performed on nasopharyngeal specimen to confirm SARSCoV2 with Orf 1ab and E gene as targets. The viral sequencing was performed through oxford nanopore technology MinION platform. Isolates from first and second wave of COVID-19 outbreak in Karachi were compared. The overall positivity rate for PCR was 26.24% with highest number of positive cases in June. Approximately, 37.45% PCR positive subjects aged between 19-40 years. All the isolates belonged to GH clade and shared missense mutation D614G in spike protein linked to increased transmission rate worldwide. Another spike protein mutation A222V coexisted with D614G in the virus from second wave of COVID-19. Based on the present findings it is suggested that the locally transmitted virus from Karachi vary from those reported from other parts of Pakistan. Slight variability was also observed between viruses from first and second wave. Variability in any potential vaccine target may result in failed trials therefore information on any local viral variants is always useful for effective vaccine design and/or selection. Authors summaryDespite precautionary measures the COVID-19 pandemic is causing deaths all over the world. The continuous mutations in viral genome is making it difficult to design vaccines. Variability in genome is host dependent and data sharing has revealed that variant for different geographical locations may harbor different mutations. Keeping this in mind the current study was focused on the epidemiology of SARS CoV2 in symptomatic and asymptomatic COVID -19 suspected cases with impact of age and gender. The locally transmitted SARS CoV2 isolates from Karachi were sequenced to compared and identify any possible variants. The sequenced viral genome varied from the already submitted sequences from Pakistan thereby confirming that slightly different viruses were causing infections during different time periods in Karachi. All belonged to GH clade with D614G, P323L and Q57H mutations. The virus from second wave had A222V mutation making it more different. This information can be useful in selecting or designing a vaccine.
RESUMO
The clinical and epidemiological use of SARS-CoV-2 antibody assays is under debate with urgent need to validate and verify the performance of SARS-CoV-2 serologic assays. We aim to assess the clinical and analytical performance of three commercial serological assays of SARS-CoV-2, comparing three anti-SARS-CoV-2-IgG ELISA and identifying the seroconversion and seroprevalence in our population. A cross sectional study conducted from April 2020 to July 2020 at National Institute of Blood disease and Bone Marrow Transplantation Karachi, Pakistan with sample size of 404, enrolled consecutively. Participants were categorized into four groups namely convalescent plasmadonors (CPDs n=239), health care professionals (HCPs n=44), healthy blood donors (HBDs n=70) and from community (n=51). We evaluated the performance of Elecsys anti-SARS-CoV-2 electrochemiluminescence (ECLIA) assay on Cobas-e411 by Roche, three qualitative anti-SARS-CoV-2-IgG enzyme linked imunosorbant assay (ELISA) by (Generic assays, Euroimmun & Omega diagnostics), one quantitative ELISA assay by AESKU Diagnostics and two immune chromatography(ICT) kits namely InstaTest by CORTEZ and TEST IT by TURKLAB. From total 404 subjects, 322 (83.5%) were males. Mean age was 36.79{+/-}11.95 years. Among 239 in CPDs group, 202(84.5%) showed positive antibodies by ECLIA. The qualitative anti-SARS-CoV-2 IgG ELISA was positive in 174 (72.8%) and quantitative IgG in 180(75.3%) with mean titer of 56.7 {+/-}39.7 U/ml. Sensitivity and specificity of ECLIA were 97.44& 99%, ELISA by Generic assays were 67.85% and 89.9%; Euroimmun had 90.38% and 94.9%; Omega Diagnostics 96.4% and 95% and the AESKULISA 93.75% and 100% respectively. Seroconversion was found to be 53.8% and 77.77% within 7 -8 days and 12 to 14 days post onset of symptoms respectively. ICT had more specificity but less sensitivity. Seroprevalence was found to be 84.5%, 40.9% and 21.4% in CPDs, HCPs and HBDs respectively. The Roche ECLIA, qualitative ELISA by Omega Diagnostics & Euroimmun showed higher sensitivity as well as higher specificity. Quantitative ELISA has higher specificity and relatively high sensitivity. Significant numbers of COVID patients do not have detectable antibodies by all assays.
RESUMO
Background. Idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder in which the immune system destroys native platelets. In this condition an autoantibody is generated against a platelet antigen. ITP affects women more often than men and is more common in children than adults. Objective. To assess the effect of Helicobacter pylori eradication therapy (HPET) on platelet count in Helicobacter pylori associated chronic immune thrombocytopenic purpura (chronic ITP) in adult. Materials and Methods. It is an interventional prospective study conducted at Liaquat University of Medical and Health Sciences, Jamshoro, from 2014 to 2015. A set of 85 patients diagnosed with chronic ITP were included in the study via convenient sampling. Patients with platelets count < 100 × 109/L for >3 months were selected. They were posed to first-line investigations which comprised complete blood count (CBC) and peripheral blood smear examination followed by second-line tests including bone marrow examination and Helicobacter pylori stool specific antigen (HpSA-EIA). Standard H. pylori eradication therapy was offered and the patients were assessed at regular intervals for 6 months. Results. Of the 85 study patients, 32 (37.6%) were male and 53 (62.3%) were female. Mean ages of H. pylori positive and negative subjects were 43.89 ± 7.06 and 44.75 ± 7.91 years, respectively. Bone marrow examination confirmed the diagnosis and excluded other related BM disorders. H. pylori stool antigen (HpSA) was detected in 34 (40%) patients and hence regarded as H. pylori positive; the rest were negative. Treatment with eradication therapy significantly improved the mean platelet counts from 48.56 ± 21.7 × 109/l to 94.2 ± 26.8 × 109/l. Conclusion. We concluded that the anti-H. pylori eradication therapy improves blood platelet counts in chronic immune thrombocytopenia.
