ABSTRACT
Respiratory viral infections are important cause of morbidity and mortality in early life. The relative influence of host and viral factors possibly contribute to the disease pathogenesis. Predisposing conditions like prematurity, Low birth weight and congenital heart diseases etc. have been incriminated in the disease progression. The development of cough, wheezing, and tachypnea, usually peaking on days 4 to 5, go parallel with host cytokine responses and viral load. Various host cytokines, chemokines and molecules involved in the immune response against RSV infection might be responsible for the outcome of the disease process. Nasopharyngeal aspirates (NPAs) from children (n = 349) between 2013-2017 were subjected for IL-17A, IFN-gamma, TNF-alpha, IL-10, IL-6 levels by CBA and MMP-9 and TIMP-1 levels by ELISA. The viral load in RSV positive samples and cytokine levels were correlated with the WHO criteria for acute lower respiratory tract illness (ALRTI). RSV viral load, Pro-inflammatory cytokine (TNF-alpha) levels in severe ALRTI patients were significantly higher than the ALRTI patients [p<0.001]. Whereas Th17 cytokine (IL-17) was found to be significantly higher (p<0.05) in ALRTI patients than severe patients. MMP-9 is secreted in higher levels in severe ALRTI patients (n = 77) in comparison to Acute LRTI patients (n = 35) with an increase of thirty seven fold (p<0.001). Thus, the study highlights the role of TNF -alpha, IL-17 and Th2 cytokine biasness in the pathogenesis of RSV disease with the possible contribution of higher MMP-9/TIMP-1 ratio as a bad prognostic marker towards disease severity. To study the gene expression of autophagy and mTOR signalling pathways in RSV infected children with ALRTI. Nasopharyngeal aspirate (NPA) samples (n = 145) from children suffering from ALRTI were subjected for detection of RSV (Oct 2019 to March 2020). Semi-quantitative gene expression analysis for 5 representative genes each of mTOR signalling and autophagy pathway were performed in respiratory tract epithelial cells using 25 RSV positive cases and 10 healthy controls subjects. Autophagy gene expression analysis revealed significant upregulation in NPC1 and ATG3 autophagy genes. mTOR, AKT1 and TSC1 genes of mTOR pathway were significantly down-regulated in RSV positive patients except RICTOR gene which was significantly upregulated. Thus, survival of RSV within autophagosome might have been facilitated by upregulation of autophagy and downregulation of mTOR signalling genes. To assess the impact of SARS-CoV2 pandemic on RSV, samples were collected from children with ALRTIs admitted to emergency, PICU and indoor admissions during pre-pandemic period (October 2019 to February 2020;n = 166) and during COVID-19 Pandemic (July 2021 to July 2022;n = 189, SARS-CoV2 negative). These NP swabs were analyzed for pdm InfA H1N1, InfA H3N2, Inf B, RSV, hMPV, hBoV, hRV, PIV-2 and PIV-3 by PCR. Higher proportion of children with ALRTIs have had virus/es isolated during pre-pandemic period than during pandemic period (p<0.001). During pre-pandemic period, significantly higher proportion of children had RSV positivity (p<0.001);and significantly lower positivity for hRV (p<0.05), hMPV (p<0.05), and hBoV (p <= 0.005). The occurrence of COVID-19 pandemic has significantly impacted the frequency and pattern of detection of RSV among hospitalized children with LRTIs. RSV Fusion protein plays a critical role in the entry of the virus into the host cell by initiating the fusion of host and viral membranes. It happens to be a target of neutralizing antibodies paving the way as a vaccine candidate. Hence effort was made to introduce point mutation in hRSV fusion protein which can confer stability in its prefusion form. In-silico a stable structure of RSV fusion protein was generated making it a potential vaccine candidate. The timely diagnosis of RSV infection in this population is important for initiating therapy and instituting appropriate infection prevention measures. Serological testing is not widely used for the diagnosis of RSV. C ll Cultures including shell vial culture were used for RSV diagnosis. However, culture approaches lack sensitivity, often quite significantly, compared to nucleic acid amplification assays for the diagnosis of RSV infections. Molecular multiplex assays now offer increased sensitivity for a more accurate diagnosis. However issues with the use of these types of commercial panel assays include the requirement for substantial training, quality systems, and infrastructure to maintain and run these assays and many a times identification of viruses where the true pathogenic potential of those multiple viruses are debatable. Studies are available with laboratory- developed nucleic acid amplification test systems for the detection of RSVA and RSVB in clinical specimens either by PCRbased technologies or RT-LAMP. Gene targets of laboratory-developed molecular assays point towards M gene and the N gene in RSVA and -B with the benefits of flexibility to modify assays when targets are under evolutionary pressure to change, as well as a perceived initial low cost to carry out testing.
ABSTRACT
Environmental surfaces are potential source of SARS-CoV2 transmission. The study assessed the efficacy of hospital disinfection policy and contamination of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) RNA in COVID management Hospital. Inanimate surfaces from both patient areas (n = 70) and non-patient areas (n = 39) were sampled through surface swabbing and subjected to Reverse transcriptase PCR. Out of the 70 samples collected from the COVID hospital, SARS-CoV2 RNA positivity of 17.5% (7/40) and 6.7% (2/30) was seen in high risk and moderate risk area respectively. Samples from Non COVID related patient area such as CD ward and administrative block were assessed and the SARS CoV-2 RNA positivity was 0% and 10% respectively. Among the total 8 environmental surface samples positive for SARS-CoV2 RNA detected from the area surrounding the SARS-CoV2 infected patients, maximum positivity of 31.8% (7/22) was found among the environmental samples collected around the patients with < 20 Ct value in nasopharyngeal swab samples followed by 3.3% positivity (1/30) around patients with Ct value ranging from 20 to 25 whereas no SARS-CoV2 RNA (0/5) was detected around the patient with > 25 Ct value. Nearly 50% (2/4) of the surface samples came positive from the resident PPE and mobile of the treating doctors which largely elaborates the need for stringent doffing measurement and hand hygiene policy post doffing. The study emphasizes the necessity of frequent and aggressive disinfection policy to prevent nosocomial infection in such high risk areas within close vicinity of the patients.
ABSTRACT
Acute respiratory infections due to viral or bacterial etiology can cause 60 deaths per one lakh population. Viral etiology is more common as compared to bacterial, but lack of definite diagnosis leads to increased usage of empirical antibiotics. During the first wave of the COVID-19 pandemic, there was a need to identify co-infections especially in severe acute respiratory illness (SARI) patients to identify it as one of the cofactors for increased severity of illness and to identify the causative agents in COVID-19 negative individuals. The SARS CoV-2 real time PCR was carried out using ICMR approved kits and the other respiratory viruses were detected using the multiplex commercially available real time kit. A total of 186 patients presenting with either SARI (89.8%) or influenza like illness (10.2%) were included in the study. Out of these, 43 (23.1%) were positive for SARS CoV-2 RNA and 2 (4.6%) patients with SARI showed concomitant infection with either human rhinovirus or human respiratory syncytial virus . Out of 143 patients negative for SARS CoV-2, 35 (24.5%) were positive for one or more microbial infections and 28 (19.6%) infected with other respiratory viral infection most common being human rhinovirus. The results suggest that viral coinfections are significantly higher among COVID-19 negative individuals (24.5% vs 4.6%) presenting with respiratory illness as compared to COVID-19 positive individuals possibly due to viral interference and competitive advantage of SARS-CoV-2 in modulating the host immunity. Further detailed research is required for the understanding of mechanisms of viral co-infection.
ABSTRACT
An ongoing pandemic Coronavirus disease (COVID-19), caused by a newly emerged Coronavirus, SARS-CoV-2 has affected millions of people globally. One of the most crucial structural proteins of SARS-CoV-2 is the Spike glycoprotein (S-glycoprotein), for which the first de novo modelling was envisaged by our group in early 2020, and was superimposed to its predecessor SARS-CoV S-glycoprotein, to determine structural divergence, glycosylation and antigenic variation between SARS-CoV-2 and SARS-CoV. S-glycoprotein is involved in binding with the cellular receptor, membrane fusion, internalization via angiotensin-converting enzyme 2 (ACE2) receptor, and tissue tropism. Upon internalization into the target host cells, the viral genome encodes two precursor polypeptides which get processed into 16 mature nonstructural proteins that play a crucial role in replication and transcription of SARS-CoV-2. Currently S-glycoprotein is one of the most vital targets for vaccine and therapeutics development for COVID-19.
ABSTRACT
In December 2019, suddenly 54 cases of viral pneumonia emerged in Wuhan, China, caused by some unknown microorganism. The virus responsible for these pneumonia infections was identified as novel coronavirus of the family Coronaviridae. The novel coronavirus was renamed as COVID-19 by WHO. Infection from the virus has since increased exponentially and has spread all over the world in more than 196 countries. The WHO has declared a Public Health Emergency of International Concern due to the outbreak of COVID-19. The virus is highly infectious and can cause human-to-human transmission. Every 24 h, cases of COVID-19 increase severalfolds. The WHO is monitoring the SARS-CoV-2 spread very closely via a global surveillance system. The current situation demands the enforcement of strict laws which would help in inhibiting the further spread of COVID-19. Social distancing, international travel restrictions to affected countries, and hygiene are three important ways to nullify SARS-CoV-2.Government and private organizations need to come forward and work together during this pandemic. Public awareness, social distancing, and sterilization must be maintained to neutralize the viral infection, especially in major hot spots.