Th2-predominant immune response underlies the pathogenesis of Dengue.

BACKGROUND: Dengue is a rapidly emerging pandemic-prone disease, whose manifestations range from asymptomatic infection to life-threatening complications like Dengue Hemorrhagic Fever and Dengue Shock Syndrome. This study investigates and compares the immune response in clinically defined cohorts of Dengue with and without warning signs, with the aim of identifying immunological correlates of clinical disease and potential markers of disease severity. METHODS: Blood samples, collected from study participants fulfilling the WHO definition of Dengue with and without warning signs and healthy volunteers, were analyzed using flow cell-based fluorometric methods for cytokines and chemokines. Gene expression analysis, using RT-PCR, was conducted on T helper cell subset-specific transcription factors and cytokines. Demographic details, virological markers, serotype distribution, and hematological parameters were also investigated in all the subjects. RESULTS: The 35 participants recruited in the study, included 11 healthy volunteers and 12 patients each fulfilling the WHO criteria of Dengue with and without warning signs. While the demographic characteristics and serotype distribution was similar in Dengue with and without warning signs cohorts of the disease, platelet counts and Aspartate Aminotransferase (AST) levels changed significantly between Dengue with and without warning signs patients. Plasma cytokine analysis showed up-regulation of IL-4, IL-10, IP-10, and MCP-1 in Dengue patients compared to healthy volunteers. Disease severity was associated with elevated levels of IL-10, IP-10, IL-4, MCP-1, and MIP-1α. IL-8 and MIP-1α were significantly up-regulated in Dengue with warning sign compared to Dengue without warning signs cases. Transcription factor analysis indicated increased expression of RORα, FoxP3, and GATA3 in Dengue patients. mRNA expression of TGFß and IL-4 was also elevated in Dengue patients. A positive correlation between mRNA expression of IL-4 and plasma IL-4 was observed. CONCLUSION: The study reveals a Th2-predominant immune response in all Dengue patients, regardless of disease severity, with overexpression of IL-8 and MIP-1α being observed in patients with warning signs.

A Pilot Seroprevalence Study Suggests Silent Zika virus Transmission in Bhopal Region of Central India.

BACKGROUND: Several sporadic cases and outbreaks of Zika virus disease have been reported from different states of India. OBJECTIVES: This paper explored the possibility of any ongoing transmission of Zika virus (ZIKV) in the Bhopal region of Central India, where the last outbreak of this disease was reported in 2018. MATERIALS AND METHODS: We screened a group of 75 febrile patients who had already tested negative for the locally endemic causes of fever like dengue, chikungunya, enteric fever, malaria, and scrub typhus and two groups of asymptomatic healthy individuals represented by blood donors (n = 75) and antenatal mothers (n = 75). We tested blood samples of febrile patients for ZIKV RNA using real-time polymerase chain reaction (PCR), and for the healthy individuals, we determined anti-zika immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay. RESULTS: ZIKV RNA was not detected in any of the 75 samples tested by real-time PCR assay. Among the voluntary blood donors and antenatal mothers, a total of 10 (15.38%) and 5 (6.66%) individuals were found to be seropositive for anti-ZIKV IgG antibodies, respectively. The seropositive group was found to have higher age 33.06 (±10.83) years as compared to seronegative individuals 26.60 (±5.12) years (P = 0.037). CONCLUSION: This study, which is the first survey of seroprevalence of anti-Zika antibodies from India, reports an overall seropositivity rate of 10% for anti-Zika antibodies among the healthy population, suggesting an ongoing, low level, silent transmission of ZIKV in the local community.

Intestinal viral infections of nSARS-CoV2 in the Indian community: Risk of virus spread in India.

In December 2019, novel severe acute respiratory syndrome coronavirus 2 (nSARS-CoV-2) virus outbreaks emerged from Wuhan, China, and spread all over the world, including India. Molecular diagnosis of Coronavirus Disease 2019 (COVID) 19 for densely and highly populated countries like India is time-consuming. A few reports have described the successful diagnosis of nSARS-CoV-2 virus from sewage and wastewater samples contaminated with fecal matter, suggesting the diagnosis of COVID 19 from the same to raise an alarm about the community transmission of virus for implementation of evacuation and lockdown strategies. So far, the association between the detection of virus and its concentration in stool samples with severity of the disease and the presence or absence of gastrointestinal symptoms have been rarely reported. We led the search utilizing multiple databases, specifically PubMed (Medline), EMBASE, and Google Scholar. We conducted a literature survey on gastrointestinal infection and the spread of this virus through fecal-oral transmission. Reports suggested that the existence and persistence of nSARS-CoV-2 in anal/rectal swabs and stool specimens for a longer period of time than in nasopharyngeal swabs provides a strong tenable outcome of gastrointestinal contamination and dissemination of this infection via potential fecal-oral transmission. This review may be helpful to conduct further studies to address the enteric involvement and excretion of nSARS-CoV-2 RNA in feces and control the community spread in both COVID-19 patients ahead of the onset of symptoms and in asymptomatic individuals through wastewater and sewage surveillance as an early indication of infection. The existence of the viral genome and active viral particle actively participate in genomic variations. Hence, we comprehended the enteric spread of different viruses amongst communities with special reference to nSARS-CoV-2.

Interleukin-17-A multifaceted cytokine in viral infections.

Viral infections are a major threat to the human population due to the lack of selective therapeutic measures. The morbidity and mortality reported worldwide are very alarming against viral pathogens. The proinflammatory environment is required for viral inhibition by initiating the host immune response. The host immune response fights these pathogens by secreting different cytokines. Interleukin-17 (IL-17) a proinflammatory cytokine mainly produced by T helper type 17 cells, plays a vital role in the regulation of host immune response against various pathogens, including viruses. However, dysregulated production of IL-17 induces chronic inflammation, autoimmune disorders, and may lead to cancer. Recent studies suggest that IL-17 is not only involved in the antiviral immune response but also promotes virus-mediated illnesses. In this review, we discuss the protective and pathogenic role of IL-17 against various viral infections. A detailed understanding of IL-17 during viral infections could contribute to improve therapeutic measures and enable the development of an efficient and safe IL-17 based immunotherapy.

Antibacterial properties and in vivo efficacy of a novel nitrofuran, IITR06144, against MDR pathogens.

OBJECTIVES: The emergence of MDR Gram-negative pathogens and increasing prevalence of chronic infections presents an unmet need for the discovery of novel antibacterial agents. The aim of this study was to evaluate the biological properties of a small molecule, IITR06144, identified in a phenotypic screen against the Gram-negative model organism Escherichia coli. METHODS: A small-molecule library of 10956 compounds was screened for growth inhibition against E. coli ATCC 25922 at concentration 50 µM. MICs of lead compounds were determined by the broth microdilution method. Time-kill kinetics, anti-persister activity, spontaneous frequency of resistance, biofilm inhibition and disruption were assessed by standard protocols. Resistant mutants were generated by serial passaging followed by WGS. In vitro toxicity studies were carried out via the MTT assay. In vivo toxicity and efficacy in a mouse model were also evaluated. RESULTS: IITR06144 was identified as the most promising candidate amongst 29 other potential antibacterial leads, exhibiting the lowest MIC, 0.5 mg/L. IITR06144 belongs to the nitrofuran class and exhibited broad-spectrum bactericidal activity against most MDR bacteria, including the 'priority pathogen', carbapenem-resistant Acinetobacter baumannii. IITR06144 retained its potency against nitrofurantoin-resistant clinical isolates. It displayed anti-persister, anti-biofilm activity and lack of spontaneous resistance development. IITR06144 demonstrated a large therapeutic index with no associated in vitro and in vivo toxicity. CONCLUSIONS: In the light of excellent in vitro properties displayed by IITR06144 coupled with its considerable in vivo efficacy, further evaluation of IITR06144 as a therapeutic lead against antibiotic-resistant infections is warranted.

Pooled testing for COVID-19 diagnosis by real-time RT-PCR: A multi-site comparative evaluation of 5- & 10-sample pooling.

BACKGROUND & OBJECTIVES: Public health and diagnostic laboratories are facing huge sample loads for COVID-19 diagnosis by real-time reverse transcription-polymerase chain reaction (RT-PCR). High sensitivity of optimized real-time RT-PCR assays makes pooled testing a potentially efficient strategy for resource utilization when positivity rates for particular regions or groups of individuals are low. We report here a comparative analysis of pooled testing for 5- and 10-sample pools by real-time RT-PCR across 10 COVID-19 testing laboratories in India. METHODS: Ten virus research and diagnostic laboratories (VRDLs) testing for COVID-19 by real-time RT-PCR participated in this evaluation. At each laboratory, 100 nasopharyngeal swab samples including 10 positive samples were used to create 5- and 10-sample pools with one positive sample in each pool. RNA extraction and real-time RT-PCR for SARS-CoV-2-specific E gene target were performed for individual positive samples as well as pooled samples. Concordance between individual sample testing and testing in the 5- or 10-sample pools was calculated, and the variation across sites and by sample cycle threshold (Ct) values was analyzed. RESULTS: A total of 110 each of 5- and 10-sample pools were evaluated. Concordance between the 5-sample pool and individual sample testing was 100 per cent in the Ct value ≤30 cycles and 95.5 per cent for Ctvalues ≤33 cycles. Overall concordance between the 5-sample pooled and individual sample testing was 88 per cent while that between 10-sample pool and individual sample testing was 66 per cent. Although the concordance rates for both the 5- and 10-sample pooled testing varied across laboratories, yet for samples with Ct values ≤33 cycles, the concordance was ≥90 per cent across all laboratories for the 5-sample pools. INTERPRETATION & CONCLUSIONS: Results from this multi-site assessment suggest that pooling five samples for SARS-CoV-2 detection by real-time RT-PCR may be an acceptable strategy without much loss of sensitivity even for low viral loads, while with 10-sample pools, there may be considerably higher numbers of false negatives. However, testing laboratories should perform validations with the specific RNA extraction and RT-PCR kits in use at their centres before initiating pooled testing.

MicroRNA hsa-miR-324-5p Suppresses H5N1 Virus Replication by Targeting the Viral PB1 and Host CUEDC2.

MicroRNAs (miRNAs) are small noncoding RNAs that are crucial posttranscriptional regulators for host mRNAs. Recent studies indicate that miRNAs may modulate host response during RNA virus infection. However, the role of miRNAs in immune response against H5N1 infection is not clearly understood. In this study, we showed that expression of cellular miRNA miR-324-5p was downregulated in A549 cells in response to infection with RNA viruses H5N1, A/PR8/H1N1, and Newcastle disease virus (NDV) and transfection with poly(I·C). We found that miR-324-5p inhibited H5N1 replication by targeting the PB1 viral RNA of H5N1 in host cells. In addition, transcriptome analysis revealed that miR-324-5p enhanced the expression of type I interferon, type III interferon, and interferon-inducible genes (ISGs) by targeting CUEDC2, the negative regulator of the JAK1-STAT3 pathway. Together, these findings highlight that the miR-324-5p plays a crucial role in host defense against H5N1 by targeting viral PB1 and host CUEDC2 to inhibit H5N1 replication.IMPORTANCE Highly pathogenic influenza A virus (HPAIV) continues to pose a pandemic threat globally. From 2003 to 2017, H5N1 HPAIV caused 453 human deaths, giving it a high mortality rate (52.74%). This work shows that miR-324-5p suppresses H5N1 HPAIV replication by directly targeting the viral genome (thereby inhibiting viral gene expression) and cellular CUEDC2 gene, the negative regulator of the interferon pathway (thereby enhancing antiviral genes). Our study enhances the knowledge of the role of microRNAs in the cellular response to viral infection. Also, the study provides help in understanding how the host cells utilize small RNAs in controlling the viral burden.

Geographical distribution of primary & secondary dengue cases in India - 2017: A cross-sectional multicentric study.

Background & objectives: Dengue virus infection is endemic in India with all the four serotypes of dengue virus in circulation. This study was aimed to determine the geographic distribution of the primary and secondary dengue cases in India. Methods: A multicentre cross-sectional study was conducted at Department of Health Research / Indian Council of Medical Research (DHR)/(ICMR) viral research and diagnostic laboratories (VRDLs) and selected ICMR institutes located in India. Only laboratory-confirmed dengue cases with date of onset of illness less than or equal to seven days were included between September and October 2017. Dengue NS1 antigen ELISA and anti-dengue IgM capture ELISA were used to diagnose dengue cases while anti-dengue IgG capture ELISA was used for identifying the secondary dengue cases. Results: Of the 1372 dengue cases, 897 (65%) were classified as primary dengue and 475 (35%) as secondary dengue cases. However, the proportion varied widely geographically, with Theni, Tamil Nadu; Tirupati, Andhra Pradesh and Udupi-Manipal, Karnataka reporting more than 65 per cent secondary dengue cases while Srinagar, Jammu and Kashmir reporting as low as 10 per cent of the same. The median age of primary dengue cases was 25 yr [interquartile range (IQR 17-35] while that of secondary dengue cases was 23 yr (IQR 13.5-34). Secondary dengue was around 50 per cent among the children belonging to the age group 6-10 yr while it ranged between 20-43 per cent among other age groups. Interpretation & conclusions: Our findings showed a wide geographical variation in the distribution of primary and secondary dengue cases in India. It would prove beneficial to include primary and secondary dengue differentiation protocol in the national dengue surveillance programme.

Noncanonical SMC protein in Mycobacterium smegmatis restricts maintenance of Mycobacterium fortuitum plasmids.

Research on tuberculosis and leprosy was revolutionized by the development of a plasmid transformation system in the fast-growing surrogate, Mycobacterium smegmatis. This transformation system was made possible by the successful isolation of a M. smegmatis mutant strain mc(2)155, whose efficient plasmid transformation (ept) phenotype supported the replication of Mycobacterium fortuitum pAL5000 plasmids. In this report, we identified the EptC gene, the loss of which confers the ept phenotype. EptC shares significant amino acid sequence homology and domain structure with the MukB protein of Escherichia coli, a structural maintenance of chromosomes (SMC) protein. Surprisingly, M. smegmatis has three paralogs of SMC proteins: EptC and MSMEG_0370 both share homology with Gram-negative bacterial MukB; and MSMEG_2423 shares homology with Gram-positive bacterial SMCs, including the single SMC protein predicted for Mycobacterium tuberculosis and Mycobacterium leprae. Purified EptC was shown to bind ssDNA and stabilize negative supercoils in plasmid DNA. Moreover, an EptC-mCherry fusion protein was constructed and shown to bind to DNA in live mycobacteria, and to prevent segregation of plasmid DNA to daughter cells. To our knowledge, this is the first report of impaired plasmid maintenance caused by a SMC homolog, which has been canonically known to assist the segregation of genetic materials.

Application of lipoarabinomannan antigen in tuberculosis diagnostics: current evidence.

Tests based on the detection of mycobacterial lipoarabinomannan (LAM) antigen in urine have emerged as potential point-of-care tests for tuberculosis (TB). We aimed to assimilate the current evidence regarding the diagnostic performance of LAM assays and to ascertain their clinical indication in settings with high and low prevalence of HIV-TB co-infection. Owing to suboptimal sensitivity, the urinary LAM assays are unsuitable as general screening tests for TB. However, unlike traditional diagnostic methods, they demonstrate improved sensitivity in HIV-TB co-infection which further increases with low CD4 counts. Accordingly, these assays are indicated as rule-in tests for TB in patients with advanced HIV-induced immunosuppression, and facilitate the early initiation of antituberculous treatment in them. They also offer incremental sensitivity and specificity when used as adjunct tests to smear microscopy and chest radiography in HIV-TB co-infection. They obviate the biohazards associated with sputum samples and provide an alternative diagnostic tool in sputum-scarce patients. Notwithstanding these advantages, the specificity of these assays is variable, which is mostly attributable to misclassification bias and cross-reactivity with non-tuberculous mycobacteria or other commensal flora. Furthermore, the inability to detect low titres of antigen in HIV-uninfected patients makes these assays unsuitable for use in settings with a low HIV prevalence. Future research targeted towards inclusion of specific monoclonal antibodies and more sensitive immunoassay platforms might help to improve the diagnostic performance of these assays and extend their applicability to the general population of patients with TB.

Detectable Viremia at Presentation Is a Predictor of Disease Severity in Chikungunya.

Background Chikungunya is a mosquito-borne re-emerging disease that has caused a significant number of outbreaks recently in diverse geographic settings across the globe. It leads to severe debilitating illness in a significant proportion of persons who are infected. Measures to limit the impact produced by recurrent outbreaks of the disease are limited and there is an urgent clinical need for early identification of those predisposed to develop severe disease. A comprehensive understanding regarding the proportion of individuals predisposed to developing severe disease is lacking as its correlation with detectable viremia is hinted at by some studies. In this context, we hypothesized that detectable viremia reflected in the diagnostic RT-PCR assay could be significantly associated with the development of severe disease in Chikungunya among those diagnosed on the basis of seroconversion. Our study aims to confirm the same in relation to disease severity among the suspected patients of Chikungunya in the setting of a tertiary care center. Methods In a prospective observational study at a tertiary care center, a total number of 1021 Chikungunya suspects presenting within seven days of illness were screened with Chikungunya Virus IgM ELISA from 2021 to 2023. Those having positive IgM results were further tested with RT-PCR in a blinded manner. According to the information entered into the predesigned form and the hospital follow-up/discharge data, the cases where symptoms like fever and joint pain persisted beyond two weeks were classified as severe versus those resolving within two weeks as mild. The patients in each group were compared for their clinical symptoms and association with the disease severity with detectable viremia (RT-PCR positivity). Results We identified a total of 178 (17.4%) lab-confirmed Chikungunya IgM-positive cases amongst the recruited patients. Here a total of 31 (18.9%) cases could be classified as severe and 133 (74.7%) as mild illness, the remaining 14 patients were excluded from analysis due to insufficient clinical data. Severe illness was significantly higher in elderly individuals belonging to more than 60 years (p = 0.01). Viremia was detected in 16 (9%), those with detectable viremia had higher odds (OR = 4.1) of manifesting as severe disease. Among the severe cases, the proportion of cases with RT-PCR positivity (8, 25.8%) at presentation was significantly higher (P = 0.01) versus those who presented with mild disease (7, 5.5%). Conclusion Our study reveals a correlation between detectable viremia in Chikungunya virus (CHIKV) patients and an increased risk of manifesting into a severe disease, where severe cases exhibited a significantly higher proportion of viremia, indicated by RT-PCR positivity. This study hints at the presence of viremia, joint symptoms, and elderly age as potentially useful clinical predictors of disease outcomes, these may serve as indicators for closer monitoring among individuals seeking medical attention due to Chikungunya infection. However, we need to validate these findings in future longitudinal studies incorporating multiple, time-bound follow-up data on clinical outcomes, viral titers, and its long-term complications.

Rubella immunity among pregnant women and the burden of congenital rubella syndrome (CRS) in India, 2022.

BACKGROUND: India aims to eliminate rubella and congenital rubella syndrome (CRS) by 2023. We conducted serosurveys among pregnant women to monitor the trend of rubella immunity and estimate the CRS burden in India following a nationwide measles and rubella vaccination campaign. METHODS: We surveyed pregnant women at 13 sentinel sites across India from Aug to Oct 2022 to estimate seroprevalence of rubella IgG antibodies. Using age-specific seroprevalence data from serosurveys conducted during 2017/2019 (prior to and during the vaccination campaign) and 2022 surveys (after the vaccination campaign), we developed force of infection (FOI) models and estimated incidence and burden of CRS. RESULTS: In 2022, rubella seroprevalence was 85.2% (95% CI: 84.0, 86.2). Among 10 sites which participated in both rounds of serosurveys, the seroprevalence was not different between the two periods (pooled prevalence during 2017/2019: 83.5%, 95% CI: 82.1, 84.8; prevalence during 2022: 85.1%, 95% CI: 83.8, 86.3). The estimated annual incidence of CRS during 2017/2019 in India was 218.3 (95% CI: 209.7, 226.5) per 100, 000 livebirths, resulting in 47,120 (95% CI: 45,260, 48,875) cases of CRS every year. After measles-rubella (MR) vaccination campaign, the estimated incidence of CRS declined to 5.3 (95% CI: 0, 21.2) per 100,000 livebirths, resulting in 1141 (95% CI: 0, 4,569) cases of CRS during the post MR-vaccination campaign period. CONCLUSION: The incidence of CRS in India has substantially decreased following the nationwide MR vaccination campaign. About 15% of women in childbearing age in India lack immunity to rubella and hence susceptible to rubella infection. Since there are no routine rubella vaccination opportunities for this age group under the national immunization program, it is imperative to maintain high rates of rubella vaccination among children to prevent rubella virus exposure among women of childbearing age susceptible for rubella.

Antibiotic associated diarrhea due to Clostridioides difficile in a tertiary care teaching hospital, central India.

Background and Objectives: The misuse of antibiotics in recent years has led to an increase in antibiotic associated diarrheas (AAD). Out of several implicated pathogens, Clostridioides difficile is responsible for causing 15-25% of all cases of AAD. However, it has remained under diagnosed for a long time. The current study is planned to explore prevalence of C. difficile amongst AAD patients and to study clinical presentation and associated risk factors. Materials and Methods: Hospital based cross sectional study conducted in patients above 2 years of age. Diagnosis of C. difficile was done by two modalities i.e. glutamate dehydrogenase test followed by toxin detection using enzyme immunoassay and stool culture followed by toxin gene detection. Results: Twelve of 65 patients (18.4%) were positive for C. difficile. Maximum cases were found in younger age group. Abdominal pain and fever were most common complaints. 12 (18.4%) out of 65 study subjects were found to be positive by ELISA. 2/65 (3%) patients were positive for culture with presence of only tcdB gene. Ceftriaxone was the most commonly used antibiotic (25%). Conclusion: C. difficile is significant pathogen implicated in AAD with a prevalence rate of 18.4%. GDH antigen detection followed by Toxin A/B ELISA for C. difficile yielded better detection rate as compared to stool culture.

Molecular Identification of Non-tuberculous Mycobacteria in Suspected Tuberculosis Cases in Central India.

Introduction Mycobacterium tuberculosis complex (MTBC), the primary cause of tuberculosis (TB), must be accurately identified to implement effective patient management and control strategies. Non-tuberculous mycobacteria (NTM) in suspected TB cases can result in erroneous diagnoses and needless treatment. Objective The study aimed to identify NTM in patients suspected of TB at a tertiary care hospital in central India using molecular methods. Methods This prospective study enrolled 400 suspected pulmonary and extra-pulmonary TB patients. Patients between the age of two to 90 years, of either gender, new and previously treated cases, Culture positive, patients with immune-compromised status, patients not responding to ATT, HIV positive and negative, and willing to give consent were included in the study. Liquid culture via the Mycobacterial growth indicator tube (MGIT) system was used to culture mycobacteria from clinical samples. The SD Bioline Ag MPT64 Test (Standard Diagnostics, South Korea) and in-house multiplex-PCR (mPCR) were used to differentiate between Mycobacterium tuberculosis complex and NTM species for the molecular identification of NTM GenoType® Mycobacterium Common Mycobacteria (CM) assay kit (HAIN Life Science, Nehren, Germany) was used following the manufacturer's protocol. Results Only 59/400 (14.7%) of the samples produced a positive result in MGIT culture, indicating the presence of mycobacteria, and 85.25% of the remaining 341 samples were negative for mycobacterial growth. Further investigation of these 59 cultures with mPCR and SD Bioline Ag MPT64 test showed that 12 (20.33%) cultures were determined to be NTM, while the remaining 47 (79.67%) were identified as MTBC. Genotype characterization with GenoType® mycobacterium CM assay kit revealed that five of the 12 NTM isolates (41.67%) showed patterns that were consistent with Mycobacterium (M.) fortuitum, three (25%) showed patterns that were consistent with M. abscessus, and four (33.33%) showed patterns that were consistent with M. tuberculosis. Conclusion These results emphasize the value of molecular methods for precisely identifying mycobacterial species, particularly in suspected TB cases. The high prevalence of NTM in positive cultures emphasizes the significance of differentiating between MTBC and NTM to prevent misdiagnosis and ensure proper care. Understanding the epidemiology and clinical significance of these organisms in central India is made possible by the identification of particular NTM species.

Role of real-time polymerase chain reaction in diagnosing Hepatitis E, the commonest cause of acute hepatitis in adult patients seeking institutional care.

Background: This cross-sectional study was performed with the aim of determining the prevalence of hepatitis E virus (HEV) infection among acute hepatitis patients attending a tertiary care teaching hospital in a developing country and to determine the relative performance of prevalent diagnostic assays in establishing its diagnosis. Materials and Methods: A total of 46 adult patients were included in this study, all of whom presented with jaundice of <4 weeks' duration and elevation of AST and ALT above 500 U/L. The prevalence of HEV among patients with acute hepatitis was calculated on the basis of the proportion of recruited patients reacting positively in serum anti-HEV immunoglobulin M (IgM) and real-time polymerase chain reaction (RT-PCR) assays. Results: Among the recruited patients, 11 (23.91%) and 15 (32.6%) patients were positive for anti-HEV IgM and RT-PCR, respectively. The two tests demonstrated poor inter-test agreement, thereby implying the necessity of performing both tests for reliable diagnosis of acute HEV virus infection. We also observed a significant difference in the duration of illness between RT-PCR positive and negative patients (P = 0.008). The mean (±SD) duration of illness in the two groups was 8.6 (±3.50) and 11.66 (± 5.15) days, respectively. Combining the results of IgM ELISA and RT-PCR, we observed that 23 out of 46 patients (50%) had evidence of acute HEV virus infection among our patients. Conclusion: Our study suggests that HEV is the commonest cause of acute hepatitis in adult patients attending a tertiary care teaching hospital and that the diagnostic algorithm for its confirmation should include both IgM ELISA and RT-PCR assays.

Role of Streptococcus pneumoniae extracellular glycosidases in immune evasion.

Streptococcus pneumoniae (pneumococcus) typically colonizes the human upper airway asymptomatically but upon reaching other sites of the host body can cause an array of diseases such as pneumonia, bacteremia, otitis media, and meningitis. Be it colonization or progression to disease state, pneumococcus faces multiple challenges posed by host immunity ranging from complement mediated killing to inflammation driven recruitment of bactericidal cells for the containment of the pathogen. Pneumococcus has evolved several mechanisms to evade the host inflicted immune attack. The major pneumococcal virulence factor, the polysaccharide capsule helps protect the bacteria from complement mediated opsonophagocytic killing. Another important group of pneumococcal proteins which help bacteria to establish and thrive in the host environment is surface associated glycosidases. These enzymes can hydrolyze host glycans on glycoproteins, glycolipids, and glycosaminoglycans and consequently help bacteria acquire carbohydrates for growth. Many of these glycosidases directly or indirectly facilitate bacterial adherence and are known to modulate the function of host defense/immune proteins likely by removing glycans and thereby affecting their stability and/or function. Furthermore, these enzymes are known to contribute the formation of biofilms, the bacterial communities inherently resilient to antimicrobials and host immune attack. In this review, we summarize the role of these enzymes in host immune evasion.

Pan-India influenza-like illness (ILI) and Severe acute respiratory infection (SARI) surveillance: epidemiological, clinical and genomic analysis.

Background: Over time, COVID-19 testing has significantly declined across the world. However, it is critical to monitor the virus through surveillance. In late 2020, WHO released interim guidance advising the use of the existing Global Influenza Surveillance and Response System (GISRS) for the integrated surveillance of influenza and SARS-CoV-2. Methods: In July 2021, we initiated a pan-India integrated surveillance for influenza and SARS-CoV-2 through the geographically representative network of Virus Research and Diagnostic Laboratories (VRDLs) across 26 hospital and laboratory sites and 70 community sites. A total of 34,260 cases of influenza-like illness (ILI) and Severe acute respiratory infection (SARI) were enrolled from 4 July 2021 to 31 October 2022. Findings: Influenza A(H3) and B/Victoria dominated during 2021 monsoon season while A(H1N1)pdm09 dominated during 2022 monsoon season. The SARS-CoV-2 "variants of concern" (VoC) Delta and Omicron predominated in 2021 and 2022, respectively. Increased proportion of SARI was seen in extremes of age: 90% cases in < 1 year; 68% in 1 to 5 years and 61% in ≥ 8 years age group. Approximately 40.7% of enrolled cases only partially fulfilled WHO ILI and SARI case definitions. Influenza- and SARS-CoV-2-infected comorbid patients had higher risks of hospitalization, ICU admission, and oxygen requirement. Interpretation: The results depicted the varying strains and transmission dynamics of influenza and SARS-CoV-2 viruses over time, thus emphasizing the need to continue and expand surveillance across countries for improved decision making. The study also describes important information related to clinical outcomes of ILI and SARI patients and highlights the need to review existing WHO ILI and SARI case definitions.

Congenital rubella syndrome surveillance in India, 2016-21: Analysis of five years surveillance data.

Background: In India, facility-based surveillance for congenital rubella syndrome (CRS) was initiated in 2016 to estimate the burden and monitor the progress made in rubella control. We analyzed the surveillance data for 2016-2021 from 14 sentinel sites to describe the epidemiology of CRS. Method: We analyzed the surveillance data to describe the distribution of suspected and laboratory confirmed CRS patients by time, place and person characteristics. We compared clinical signs of laboratory confirmed CRS and discarded case-patients to find independent predictors of CRS using logistic regression analysis and developed a risk prediction model. Results: During 2016-21, surveillance sites enrolled 3940 suspected CRS case-patients (Age 3.5 months, SD: 3.5). About one-fifth (n = 813, 20.6%) were enrolled during newborn examination. Of the suspected CRS patients, 493 (12.5%) had laboratory evidence of rubella infection. The proportion of laboratory confirmed CRS cases declined from 26% in 2017 to 8.7% in 2021. Laboratory confirmed patients had higher odds of having hearing impairment (Odds ratio [OR] = 9.5, 95% confidence interval [CI]: 5.6-16.2), cataract (OR = 7.8, 95% CI: 5.4-11.2), pigmentary retinopathy (OR = 6.7, 95 CI: 3.3-13.6), structural heart defect with hearing impairment (OR = 3.8, 95% CI: 1.2-12.2) and glaucoma (OR = 3.1, 95% CI: 1.2-8.1). Nomogram, along with a web version, was developed. Conclusions: Rubella continues to be a significant public health issue in India. The declining trend of test positivity among suspected CRS case-patients needs to be monitored through continued surveillance in these sentinel sites.