INTRODUCTION:Hepatitis B vaccination is a key strategy for preventing occupationally acquired hepatitis B virus infection among healthcare workers. However, variability in vaccination coverage, awareness, and post-vaccination serological monitoring persists across different professional groups in healthcare settings. This study assessed hepatitis B vaccination status, awareness, and seroprotection among healthcare and support staff in a tertiary care center in Central India. METHODS:A prospective cross-sectional observational study was conducted from January to June 2025 among healthcare workers and support staff at a tertiary care teaching hospital. Sociodemographic details, vaccination history, occupational exposure, and awareness were collected using a structured questionnaire. Serum anti-hepatitis B surface antibody levels were measured using an enzyme-linked immunosorbent assay. Seroprotection was defined as anti-HBs ≥ 10 mIU/mL. Associations were assessed using chi-square tests, and multivariate logistic regression was performed to identify predictors of seroprotection. RESULTS:A total of 676 participants were enrolled, including 429 (63.5%) healthcare workers and 247 (36.5%) support staff. Overall, 328 (48.5%) participants were fully vaccinated, 26 (3.8%) were partially vaccinated, and 322 (47.6%) were unvaccinated. The overall seroprotection rate was 359 (53.1%). Healthcare workers demonstrated higher vaccination coverage and seroprotection compared with support staff. Among fully vaccinated participants, 288 (87.8%) achieved seroprotection, while 40 (12.2%) were non-responders. Natural immunity was observed in a subset of unvaccinated participants. Vaccination status was the strongest independent predictor of seroprotection, and increasing age was associated with lower antibody response among fully vaccinated individuals. Self-reported vaccination awareness showed a significant association with verified seroprotection. CONCLUSION:Hepatitis B vaccination coverage and seroprotection varied across professional groups, with comparatively lower levels among support staff. Strengthening inclusive occupational health strategies, improving vaccination documentation, and promoting post-vaccination antibody assessment may further enhance workforce protection in tertiary care settings.

Objectives: The objective of the study is to evaluate the diagnostic performance of commercially available hepatitis A virus (HAV) immunoglobulin M (IgM) index tests, specifically enzyme-linked immunosorbent assays (ELISA) and rapid immunochromatographic tests (ICTs), against a chemiluminescence immunoassay (CLIA) serological reference standard. Materials and Methods: The diagnostic performance of four commercially available HAV IgM ELISA kits (Dia.Pro, MBS New S.R.L., Wantai, and Biogenix) and three rapid ICT kits (Biogenix, Biotrol, and Insight) was evaluated using a CLIA as the reference comparator. An initial assessment was conducted using 48 well-characterized external quality assurance serum samples, followed by evaluation of 250 residual clinical serum samples. Statistical analysis: Statistical analysis was performed using MedCalc Statistical Software. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated with 95% confidence intervals. Inter-assay agreement with the reference comparator was assessed using Cohen’s kappa (κ) coefficient. A p <0.05 was considered statistically significant. Results: Among the ELISA kits, Dia.Pro and Wantai demonstrated optimal performance with 100% sensitivity and specificity and perfect agreement with the reference comparator. MBS New S.R.L. and Biogenix ELISA kits showed lower sensitivities of 92.0 and 84.8%, respectively, despite high specificity. Among rapid ICT kits, only the Insight assay showed complete concordance with the reference method, whereas Biogenix and Biotrol ICT kits demonstrated reduced sensitivity. Conclusions: Significant inter-assay variability exists among commercially available HAV IgM immunoassays. Independent evaluation and careful selection of diagnostic platforms are essential to ensure reliable laboratory diagnosis of acute HAV infection.

The emergence of COVID-19 underscored the urgent need for fast and reliable diagnostic methods for SARS-CoV-2 detection. The Xpert® Xpress SARS-CoV-2 assay, a rapid RT-PCR-based platform, was introduced as a potential solution for timely diagnosis. This study assessed its diagnostic performance among hospitalized patients during the first wave of the pandemic in India. A total of 1190 patients admitted with suspected COVID-19 and presenting acute hypoxic respiratory symptoms were included in this cross-sectional analysis. Nasopharyngeal swabs were processed using the Xpert® assay. Additionally, a randomly selected subgroup of 100 samples was retested using the TaqPath™ COVID-19 Combo Kit to evaluate concordance. Statistical analysis involved the use of GraphPad Prism and MedCalc, employing Fisher’s exact test and ROC curve analysis to assess test performance. The study cohort had a mean age of 41.3 years, with males comprising 58.5%. Notably, individuals aged 45 years and above showed the highest infection rates. The Xpert® assay demonstrated perfect sensitivity and negative predictive value (NPV), accurately identifying positive cases while effectively ruling out negatives. These findings suggest that the Xpert® Xpress assay is a valuable rapid diagnostic tool for SARS-CoV-2, exhibiting high diagnostic precision. Further prospective studies with expanded cohorts are recommended to validate its broader clinical utility.

Background: Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections pose a significant global public health burden. However, a substantial proportion of individuals remain undiagnosed, forming a hidden reservoir that perpetuates onward transmission. This study aimed to assess the prevalence of undiagnosed HBV and HCV infections within a population presenting for diagnoses unrelated to viral hepatitis. Methods: A cross-sectional study was conducted at a tertiary care hospital in central India. Clinical specimens from patients undergoing diagnostic workup for suspected illnesses other than HBV or HCV were analyzed for HBV and HCV serological markers. Results: Among 1,630 specimens, a concerning prevalence of undiagnosed HBV and HCV infections was identified: 3.1% for HBV and 0.5% for HCV. Notably, a significant proportion of individuals testing positive were unaware of their infection status. Conclusion: This study unveils a concerning reservoir of undiagnosed chronic viral hepatitis within a population not routinely screened for HBV/HCV. These findings highlight the critical need for expanding HBV and HCV screening strategies beyond traditionally high-risk populations or patients with specific clinical presentations.

Background Central India is hyperendemic for dengue and chikungunya virus infections, with yearly outbreaks being recorded. As these infections are clinically overlapping, co-infection of these viruses poses a diagnostic challenge. Therefore, it is imperative to identify them using serological or molecular tests. In this study, seroprevalence of dengue and chikungunya mono-infection as well as co-infections was estimated in suspected patients presented at our tertiary care center. Also, we compared the biochemical and other lab parameters of all the dengue and chikungunya mono-infected and co-infected IPD (Inpatient Department) patients. Methods A total of 3350 dengue and chikungunya suspected samples were recruited in this study. Sero-diagnosis of dengue was done using IgM MAC and NS-1 antigen enzyme-linked immunosorbent assay (ELISA), and chikungunya by IgM MAC ELISA. Further, we compared the demographic characteristics, temporal variations, clinical features, and biochemical parameters in patients with dengue and chikungunya mono-infection vs. co-infection. Results Seropositivity for dengue (DENV) and chikungunya (CHIKV) mono-infections was observed to be 23.86% (n=800) and 13.30% (n=444), respectively, while seropositivity for dengue and chikungunya co-infections was observed to be 6.55% (n=220). Leucopenia was significantly higher among the co-infected patients as compared to DENV and CHIKV mono-infected cases. Hypokalemia was significantly higher among the DENV patients and co-infected patients as compared to the CHIKV patients. Urea and creatinine levels were significantly elevated among the CHIKV patients as compared to DENV and co-infected patients. Conclusions Leucopenia and hypokalemia were found to be significantly high among the co-infected patients. Clinically suspected samples should be tested for both viruses, especially in the monsoon and post-monsoon seasons, as high sero-prevalence has been observed. Simultaneous diagnosis of these infections is required to diagnose dual infections and thus triage patients for monitoring and initiating supportive treatment to prevent fatal complications.

BACKGROUND OBJECTIVES:Co-infection of dengue virus and acute hepatitis A virus in paediatric population is a major health concern in endemic countries. This cross-sectional retrospective study was conducted to evaluate the prevalence of hepatitis A virus among the clinically dengue suspected paediatric cases presented at our tertiary care centre during the two-year period (2022-2023). METHODS:A total of 747 dengue suspected paediatric clinical specimens were included in this study. Serological diagnosis of DENV and HAV was done using Dengue IgM capture ELISA kit and anti-HAV IgM ELISA kits. RESULTS:Out of the 747 dengue suspected paediatric patients, 245 (32.8%) were seropositive for either DENV, HAV, or both viruses and among these 135 (18.07%) were positive for DENV, 110 (14.72%) were positive for HAV, 22 (2.94%) were co-infected with both DENV2 and HAV. Further, among DENV seronegative cases, 88 (11.78%) clinical samples were found to be HAV positive. Among all the age groups, the highest prevalence of DENV and HAV was observed in 6-10 years. The monsoon season observed the highest number of seropositive cases compared to winter season and summer seasons. Fever was found to be the most prevalent clinical symptom followed by nausea/vomiting and stomach discomfort. INTERPRETATION CONCLUSION:This study underlines the significance of differential diagnosis for the detection of concurrently transmitted viral diseases during the common seasons in the endemic areas. Diagnostic challenges like misdiagnosis events can be solved by advising differential diagnosis especially in paediatric cases.

Central India faced major dengue outbreaks in 2019 and 2021. In the present study, we aimed to identify the dengue virus serotypes and genotypes circulating in Central India during the COVID pre-pandemic year (2019) and ongoing-pandemic year (2021). For this purpose, the suspected cases were first tested by serological assays. Sero-positive samples were then subjected to molecular diagnosis by RT-PCR and semi-nested PCR. The serotypes obtained were confirmed by nucleotide sequencing. A phylogenetic analysis of serotypes was performed to identify the circulating genotypes. All four DENV serotypes were detected during 2019 and 2021, with the predominance of DENV2. Cases with multiple DENV serotype infections were also identified, involving DENV-2 in all the coinfections. Genotyping revealed that DENV-1 (Genotype V, American/African), DENV-2 (Genotype IV, Cosmopolitan), DENV-3 (Genotype III, Cosmopolitan), and DENV-4 (Genotype I) were involved during both outbreaks. DENV-2 detected in 2019 and 2021 has diverged from the previous strains detected in Central India (2016 and 2018), which may account for the higher transmission of DENV-2 during these outbreaks. The detection of heterologous DENV serotypes with high transmission efficiency calls for continuous viral monitoring and surveillance, which will contribute to a better understanding of changing viral dynamics and transmission patterns.

PurposeThe present study was conducted retrospectively to assess the frequency of acute viral hepatitis among the clinically suspected dengue cases presented at our tertiary care centre during 2021.MethodsTo determine the presence of acute viral hepatitis; Hepatitis A virus (HAV) and Hepatitis E virus (HEV) infections, 104 specimens were selected from the dengue-suspected clinical specimens received during 2021 on the basis of acute viral hepatitis symptoms. Following this, serological diagnosis was performed on those samples using anti-HAV IgM and anti-HEV IgM ELISA kits.ResultsBased on sero-positivity for IgM antibodies, 3 (5.3%) dengue virus (DENV) seropositive samples were positive for both HAV and HEV, while among DENV seronegative cases, 11 (22.91%) samples were positive for HEV and 1 (2.08%) sample was positive for HAV, pointing towards misdiagnosis due to overlapping symptoms. Additionally, co-infection of HAV & HEV in 1 sample was also observed in this study.ConclusionsThis study revealed the presence of acute hepatitis infections among the dengue cases during monsoon and post-monsoon season. Overlapping of the clinical manifestations of these diseases can create misdiagnosis incidences raising risk for underreporting of the true cases of acute viral hepatitis infection. Dengue-suspected patients with selected symptoms during the monsoon and post-monsoon season should additionally be screened for acute hepatitis infections, as suggested in this study.

Introduction Dengue fever is hyperendemic in several Southeast and South Asian countries, including India, with all four serotypes (DENV 1–4) circulating at different periods and in different locations. Sustainable and improved virological and entomological surveillance is the only tool to prevent dengue and other vector-borne diseases. Objectives The present study has been carried out to detect and characterize the circulating dengue virus (DENV) in field-collected Aedes mosquitoes in Bhopal, Central India. Methods Aedes mosquitoes were collected from 29 localities within Bhopal city during October 2020 to September 2022. DENV infection was assessed in the individual head and thorax regions of Aedes mosquitoes using reverse transcriptase PCR. Positive samples were sequenced, and the circulating serotypes and genotypes were determined using phylogenetic analysis. Results DENV RNA was detected in 7 Aedes aegypti and 1 Aedes albopictus , with infection rates of 0.59 and 0.14%, respectively. Phylogenetic analysis revealed all the isolates belonged to DENV serotype 2 and distinctly clustered with the non-Indian lineage (cosmopolitan genotype 4a), which was not recorded from the study area earlier. The time to most common recent ancestor (TMRCA) of these sequences was 7.4 years old, with the highest posterior density (HPD) of 3.5–12.2 years, indicating that this new lineage emerged during the year 2014. This is the first report on the DENV incrimination in both Ae. aegypti and Ae. albopictus mosquitoes collected from Bhopal, Central India. Conclusion The observed emergence of the non-Indian lineage of DENV-2 in Bhopal, which again is a first report from the area, coincides with the gradual increase in DENV cases in Bhopal since 2014. This study emphasizes the importance of DENV surveillance and risk assessment in this strategically important part of the country to decipher its outbreak and severe disease-causing potential.

Dengue is one of the most critical diseases, caused by Dengue virus (DENV) serotypes (DENV-1 to DENV-4). Study aims to detect DENV in natural A. aegypti from endemic regions of Uttar Pradesh. From 2010- 2013, mosquitoes collected from Uttar Pradesh tested for Dengue virus serotypes by capsid-premembrane gene-based PCR analyzed for genotypes sequencing of the C-prM junction of DENV genome. A total of 4731, 53.54% (n=2671) A. aegypti and 46 % (n=2060) A. albopictus mosquitoes were collected. Of 226 mosquito pools, 10 pools of A. aegypti and 14 pools of A. albopictus were positive for DENV by PCR. All 24 isolates identified as DENV-I; Genotype (G)-III (n=8), G-V (n=1); DENV-2; G-IV (n=4); DENV-3; G-III (n=11). The overall minimum infection rate was much higher in A. albopictus mosquitoes and presence of MIR in male mosquitoes is an indicating natural vertical transmission and important observation in geographical area indicating natural vertical transmission.

Purpose: The present study was conducted to determine an optimum cut-off IgM/IgG ratio for differentiating between primary and secondary Dengue. The calculated cut-off was used to estimate the relative prevalence of primary and secondary Dengue in central India during the 2021 outbreak.Methods: To differentiate between primary and secondary Dengue, optimum cut-off IgM/IgG ratio was determined using ROC curve analysis and Area under the curve (AUC) was calculated. For this 84 IgM positive samples were selected during the study period and Dengue IgM and IgG testing was performed.Results: Based on sero-positivity for IgG antibodies, we observed a prevalence of 77.4% for secondary Dengue during this outbreak. IgM/IgG ratio of 1.59 delivered a sensitivity of 100% and specificity of 90.8%. Comparison of clinical characteristics revealed significant differences in rigors (p = 0.04) and haemorrhagic manifestations (p = 0.01) between the two types of infection.Conclusions: This study revealed an overwhelming predominance of secondary Dengue during the reported outbreak, which hints at increasing endemicity in this region and raises the risk of severe clinical manifestations. An optimal IgM/IgG cut-off ratio, tailored according to the endemicity of this geographical region, is therefore suggested in this study.

Vector-borne diseases, such as dengue, chikungunya, zika, yellow fever etc pose significant burden among the infectious diseases globally, especially in tropical and sub-tropical regions. Globalization, deforestation, urbanization, climate change, uncontrolled population growth, inadequate waste management and poor vector-management infrastructure have all contributed to the expansion of vector habitats and subsequent increase in vector-borne diseases throughout the world. Conventional vector control methods, such as use of insecticides, have significant negative environmental repercussions in addition to developing resistance in vectors. Till date, a very few vaccines or antiviral therapies have been approved for the treatment of vector borne diseases. In this review, we have discussed emerging molecular approaches like CRISPR (clustered regularly interspaced short palindromic repeats)/Cas-9, sterile insect technique (SIT), release of insects carrying a dominant lethal (RIDL), Wolbachia (virus transmission blocking) and RNA interference (RNAi) to combat vector and vector-borne viruses. Due to the extensive advancements in RNAi research, a special focus has been given on its types, biogenesis, mechanism of action, delivery and experimental studies evaluating their application as anti-mosquito and anti-viral agent. These technologies appear to be highly promising in terms of contributing to vector control and antiviral drug development, and hence can be used to reduce global vector and vector-borne disease burden.

"Concerns and public health challenges for arboviral and other respiratory infections amidst SARS-CoV-2 pandemic." Pathogens and Global Health, 114(8), pp. 405–406 Author contributionsA.A. conceived and drafted the manuscript, constructed the figure, D.C. and P.K.D. reviewed the manuscript and provided suggestions.Disclosure statementNo potential conflict of interest was reported by the authors.

Summary Zika virus (ZIKV) outbreaks and their adverse clinical consequences have raised concerns throughout the world. ZIKV was little known during the initial outbreaks in Yap islands and French Polynesia, but it came to attention after the series of Brazil outbreaks in which severe complications like microcephaly in newborn babies was detected. During 2018, outbreaks of ZIKV occurred in two states of India which, being a tropical country, has congenial climatic conditions, abundance of highly competent mosquito vectors such as Aedes aegypti and Aedes albopictus , and an immunologically naïve population. In this review, we will briefly discuss the history, epidemiology, evolution, transmission (vector‐borne and non‐vector borne), pathogenesis, clinical signs and unusual presentations, laboratory diagnosis, treatment, prevention and control of ZIKV. Finally, we suggest priorities for urgent research required to address unanswered questions about Zika infections and help bring this virus under control.

Central India witnessed Chikungunya virus (CHIKV) outbreaks in 2016 and 2017. The present report is a hospital based cross-sectional study on the serological and molecular epidemiology of the outbreak. Mutational and phylogenetic analysis was conducted to ascertain the genetic relatedness of the central Indian strains with other Indian and global strains. Chikungunya infection was confirmed in the clinically suspected patients by the detection of anti-CHIKV IgM antibody by ELISA and viral RNA by RT-PCR. A representative set of the RT-PCR positive samples were sequenced for E1 gene and analyzed to identify the emerging mutations and establish their phylogenetic relationship, particularly with other contemporary strains. Phylogenetic analysis revealed the present strains to be of East Central South African (ECSA) genotype. Emergence of a variant strain was observed in the year 2016, which became the predominant strain in this region in 2017. The strains showed significant identity with recent New Delhi strains of 2015 and 2016 and Bangladesh strains of 2017. The epidemic mutation A226V which emerged in 2006 outbreaks of India and Indian Ocean Islands was found to be absent in the current strains. Among the important mutations viz. K211E, M269 V, D284E, I317V & V322A observed in the recent strains. I317V is a novel mutation which has emerged very recently as it was found only in central Indian (2016, 2017), New Delhi strains (2015, 2016) and Bangladesh strains (2017). This study has identified a unique mutation E1:I317V in the Central Indian strains, which is present only in recent New Delhi and Bangladesh strains till date. This study highlights the need for continuous molecular surveillance of circulating CHIKV strains in order to facilitate the prompt identification of novel strains of this virus and enable the elucidation of their clinical correlates.

In view of paucity of information on serotype distribution of Dengue virus (DENV) in Central India, we undertook a cross-sectional study to identify clinical and virological characteristics of DENV serotypes that circulated in this region during the 2016 outbreak. Suspected cases were screened by ELISA for NS1 antigen and anti-DENV IgM antibodies. Serologically confirmed cases were subjected to RT-PCR based detection and serotyping. The RT-PCR results were confirmed by nucleotide sequencing. Genome-wide association was undertaken with DENV sequences from ViPR database and the immune evasion potential of infecting serotypes was ascertained by computing antigenic variability in B cell and Cytotoxic T cell (CTL) epitopes of all DENV proteins. The immunological basis of more prolonged viremia in DENV2-infected patients was also addressed through sequencing of NS2a gene and comparing the CTL activity in NS2a sequences identified among patients with ≤5 days and >5 days of illness. Among 166 serologically confirmed Dengue patients, 75 were positive for DENV RNA. Serotyping revealed predominance of DENV-1 and DENV-2, followed by DENV-3. Co-infection with multiple serotypes was observed in 15.5% of cases. In ~40% cases, DENV RNA was detectable beyond 5 days, among whom majority were DENV-2 infected (p = .044). Highest prevalence of antigenic variability was observed in B cell and CTL epitopes of DENV-2. The potential association between prolonged viremia and higher ability for immune evasion in DENV-2 patients was further corroborated with the observation of poorer HLA-I binding affinity in CTL epitopes observed in NS2a sequences retrieved from patients with >5 days of illness, compared to those with ≤5 days. This is the first report from central India revealing circulation of all DENV serotypes and high prevalence of co-infection with multiple serotypes. We also observed prolonged viremia upon DENV-2 infection, which could be potentially associated with its superior immune evasion potential.

Dengue is a pandemic-prone viral disease which is endemic in more than 100 countries and which puts half of the world's population at risk. While the disease presents as subclinical infection or mild fever in the majority of cases, approximately a quarter of the infected individuals experience severe forms of disease like dengue hemorrhagic fever/dengue shock syndrome that cause significant rates of mortality and morbidity. The pathogenesis of this differential outcome of infection is determined by a complex interplay of factors associated with the virus, vector, and host; much of which is not completely understood. In this review, we present an update on the various host genetic polymorphisms that have been reported to influence the susceptibility to dengue. For the convenience of discussion, we have categorized the genetic factors according to the different arms of the immune system with which the corresponding immune determinants are associated.

The pathogenesis of dengue hemorrhagic fever (DHF), following dengue virus (DENV) infection, is a complex and poorly understood phenomenon. In view of the clinical need of identifying patients with higher likelihood of developing this severe outcome, we undertook a comparative genome-wide association analysis of epitope variants from sequences available in the ViPR database that have been reported to be differentially related to dengue fever and DHF. Having enumerated the incriminated epitope variants, we determined the corresponding HLA alleles in the context of which DENV infection could potentially precipitate DHF. Our analysis considered the development of DHF in three different perspectives: (a) as a consequence of primary DENV infection, (b) following secondary DENV infection with a heterologous serotype, (c) as a result of DENV infection following infection with related flaviviruses like Zika virus, Japanese Encephalitis virus, West Nile virus, etc. Subject to experimental validation, these viral and host markers would be valuable in triaging DENV-infected patients for closer supervision owing to the relatively higher risk of poor prognostic outcome and also for the judicious allocation of scarce institutional resources during large outbreaks.

Arboviruses are transmitted between arthropod vectors and vertebrate host. Arboviral infection in mosquitoes is initiated when a mosquito feeds on a viremic host. Following ingestion of a viremic blood meal by mosquitoes, virus enters midgut along with the blood, infects and replicates in midgut epithelial cells, and then escapes to the hemocoel, from where it disseminates to various secondary organs including salivary glands. Subsequently, when mosquito bites another host, a new transmission cycle is initiated. The midgut and salivary glands act as anatomical barriers to virus infection and escape. These complex interactions between the virus and vector dictate the vector competence. Thus, vector competence reflects the success in overcoming different barriers within the vector. Along with these, other intrinsic factors like midgut microbiota and immune responses, extrinsic factors like temperature and humidity, and genetic factors like vector genotype and viral genotype have been discussed in this review. Recent advancement on novel molecular tools to study vector competence is also included. Different modes of arboviral transmission like horizontal, vertical, and venereal and how these play role in sustenance and emergence of arboviruses in nature are also discussed. These factors can be exploited to reduce the susceptibility of vectors for the viruses, so as to control arboviral diseases to certain extent.

Chikungunya virus is now recognised as a resurging arbovirus of global public health significance, with their circulation in both new and old world. It is horizontally transmitted among vertebrates by Aedes mosquitoes. So far, the existence of vertical transmission of Chikungunya virus in Aedes vector is riddled with conflicting reports. In this study, presence of Chikungunya virus was detected in adult Aedes aegypti mosquitoes that emerged from field-collected larvae from Gwalior, northern India during 2010. This was further confirmed through nucleotide sequencing that revealed the presence of novel east central south African (ECSA) genotype of Chikungunya virus. This provides molecular evidence for vertical transmission of Chikungunya virus in mosquitoes in nature, which may have important consequences for viral survival during inter-epidemic period and adverse climatic conditions.