ABSTRACT
Background & objectives: The COVID-19 disease profile in Indian patients has been found to be different from the Western world. Changes in lymphocyte compartment have been correlated with disease course, illness severity and clinical outcome. This study was aimed to assess the peripheral lymphocyte phenotype and subset distribution in patients with COVID-19 disease from India with differential clinical manifestations. Methods: Percentages of peripheral lymphocyte subsets were measured by flow cytometry in hospitalized asymptomatic (n=53), mild symptomatic (n=36), moderate and severe (n=30) patients with SARS-CoV-2 infection, recovered individuals (n=40) and uninfected controls (n=56) from Pune, Maharashtra, India. Results: Percentages of CD4+Th cells were significantly high in asymptomatic, mild symptomatic, moderate and severe patients and recovered individuals compared to controls. Percentages of Th memory (CD3+CD4+CD45RO+), Tc memory (CD3+CD8+CD45RO+) and B memory (CD19+CD27+) cells were significantly higher in the recovered group compared to both asymptomatic, mild symptomatic patient and uninfected control groups. NK cell (CD56+CD3-) percentages were comparable among moderate +severe patient and uninfected control groups. Interpretation & conclusions: The observed lower CD4+Th cells in moderate+severe group requiring oxygen support compared to asymptomatic+mild symptomatic group not requiring oxygen support could be indicative of poor prognosis. Higher Th memory, Tc memory and B memory cells in the recovered group compared to mild symptomatic patient groups might be markers of recovery from mild infection; however, it remains to be established if the persistence of any of these cells could be considered as a correlate of protection.
ABSTRACT
Background & objectives: Polio, measles, rubella, influenza and rotavirus surveillance programmes are of great public health importance globally. Virus isolation using cell culture is an integral part of such programmes. Possibility of unintended isolation of SARS-CoV-2 from clinical specimens processed in biosafety level-2 (BSL-2) laboratories during the above-mentioned surveillance programmes, cannot be ruled out. The present study was conducted to assess the susceptibility of different cell lines to SARS- CoV-2 used in these programmes. Methods: Replication of SARS-CoV-2 was studied in RD and L20B, Vero/hSLAM, MA-104 and Madin–Darby Canine Kidney (MDCK) cell lines, used for the isolation of polio, measles, rubella, rotavirus and influenza viruses, respectively. SARS-CoV-2 at 0.01 multiplicity of infection was inoculated and the viral growth was assessed by observation of cytopathic effects followed by real-time reverse transcription–polymerase chain reaction (qRT-PCR). Vero CCL-81 cell line was used as a positive control. Results: SARS-CoV-2 replicated in Vero/hSLAM, and MA-104 cells, whereas it did not replicate in L20B, RD and MDCK cells. Vero/hSLAM, and Vero CCL-81 showed rounding, degeneration and detachment of cells; MA-104 cells also showed syncytia formation. In qRT-PCR, Vero/hSLAM and MA-104 showed 106 and Vero CCL-81 showed 107 viral RNA copies per ?l. The 50 per cent tissue culture infectious dose titres of Vero/hSLAM, MA-104 and Vero CCL-81 were 105.54, 105.29 and 106.45/ml, respectively. Interpretation & conclusions: Replication of SARS-CoV-2 in Vero/hSLAM and MA-104 underscores the possibility of its unintended isolation during surveillance procedures aiming to isolate measles, rubella and rotavirus. This could result in accidental exposure to high titres of SARS-CoV-2, which can result in laboratory acquired infections and community risk, highlighting the need for revisiting biosafety measures in public health laboratories
ABSTRACT
Background & objectives: An outbreak of influenza was investigated between June 24 and July 30, 2009 in a residential school at Panchgani, Maharashtra, India. The objectives were to determine the aetiology, study the clinical features in the affected individuals and, important epidemiological and environmental factors. The nature of public health response and effectiveness of the control measures were also evaluated. Methods: Real time reverse transcriptase polymerase chain reaction was performed on throat swabs collected from 82 suspected cases to determine the influenza types (A or B) and sub-types [pandemic (H1N1) 2009, as well as seasonal influenza H1N1, H3N2]. Haemagglutination inhibition assay was performed on serum samples collected from entire school population (N = 415) to detect antibodies for pandemic (H1N1) 2009, seasonal H1N1, H3N2 and influenza B/Yamagata and B/Victoria lineages. Antibody titres ≥ 10 for pandemic (H1N1) 2009 and ≥ 20 for seasonal influenza A and B were considered as positive for these viruses. Results: Clinical attack rate for influenza-like illness was 71.1 per cent (295/415). The attack rate for pandemic (H1N1) 2009 cases was 42.4 per cent (176/415). Throat swabs were collected from 82 cases, of which pandemic (H1N1) 2009 virus was detected in 15 (18.3%), influenza type A in (6) 7.4 per cent and influenza type B only in one case. A serosurvey carried out showed haemagglutination inhibition antibodies to pandemic (H1N1) 2009 in 52 per cent (216) subjects in the school and 9 per cent (22) in the community. Interpretation & conclusion: Our findings confirmed an outbreak of pandemic (H1N1) 2009 due to local transmission among students in a residential school at Panchgani, Maharashtra, India.