Journal of Global Infectious Diseases最新文献

Introduction: Prolonged COVID-19 pandemic accelerates the emergence and transmissibility of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants through the accumulation of adaptive mutations. Particularly, adaptive mutations in spike (S) protein of SARS-CoV-2 leads to increased viral infectivity, severe morbidity and mortality, and immune evasion. This study focuses on the phylodynamic distribution of SARS-CoV-2 variants during the year 2021 in India besides analyzing the functional significance of mutations in S-protein of SARS-CoV-2 variants.

Methods: Whole genome of SARS-CoV-2 sequences (n = 87957) from the various parts of India over the period of January to December 2021 was retrieved from Global Initiative on Sharing All Influenza Data. All the S-protein sequences were subjected to clade analysis, variant calling, protein stability, immune escape potential, structural divergence, Furin cleavage efficiency, and phylogenetic analysis using various in silico tools.

Results: Delta variant belonging to 21A, 21I, and 21J clades was found to be predominant throughout the year 2021 though many variants were also present. A total of 4639 amino acid mutations were found in S-protein. D614G was the most predominant mutation in the S-protein followed by P681R, L452R, T19R, T478K, and D950N. The highest number of mutations was found in the N-terminal domain of S-protein. Mutations in the crucial sites of S-protein impacting pathogenicity, immunogenicity, and fusogenicity were identified. Intralineage diversity analysis showed that certain variants of SARS-CoV-2 possess high diversification.

Conclusions: The study has disclosed the distribution of various variants including the Delta, the predominant variant, in India throughout the year 2021. The study has identified mutations in S-protein of each SARS-CoV-2 variant that can significantly impact the virulence, immune evasion, increased transmissibility, high morbidity, and mortality. In addition, it is found that mutations acquired during each viral replication cycle introduce new sub-lineages as studied by intralineage diversity analysis.

Introduction: Establishing the etiological cause of acute encephalitis syndrome (AES) is challenging due to the distinct distribution of various etiological agents. This study aims to determine the etiological profiles of both viruses and bacteria and their associated clinico-epidemiological features among the AES suspected cases in Tamil Nadu, India.

Methods: Samples of 5136 suspected AES cases from January 2016 to December 2020 (5 years) were subjected to the detection of etiological agents for AES through serological and molecular diagnosis methods. Further, the clinical profile, age- and gender-wise susceptibility of cases, co-infection with other AES etiological agents, and seasonality pattern with respect to various etiological agents were examined.

Results: AES positivity was established in 1480 cases (28.82%) among the 5136 suspected cases and the positivity for male and female groups were 57.77% and 42.23%, respectively. The pediatric group was found to be more susceptible than others. Among the etiological agents tested, the Japanese encephalitis virus (JEV) was the predominant followed by Cytomegalovirus, Herpes Simplex virus, Epstein-Barr virus, Varicella Zoster virus, and others. Co-infection with other AES etiological agents was observed in 3.5% of AES-positive cases. Seasonality was observed only for vector-borne diseases such as JEV, dengue virus, and West Nile virus infections in this study.

Conclusion: AES was found to be a significant burden for Tamil Nadu with a diverse etiological spectrum including both sporadic and outbreak forms. Overlapping clinical manifestations of AES agents necessitate the development of region-specific diagnostic algorithm with distinct etiological profiles for early detection and effective case management.

Introduction: Patients on central lines are often having multiple morbidities, and invasive devices provide a niche for biofilm formation, which makes central line-associated bloodstream infections (CLABSIs), a serious concern in health-care settings, as the infections difficult to treat. In this study, we evaluated the common bacteria causing CLABSI, and various patient and pathogen factors affecting the clinical outcome.

Methods: In the prospective observational study, patients diagnosed with CLABSI were recruited. Extensive clinical, microbiological, and other laboratory workup was done, and observations were recorded. Congo red agar method, tube test, and microtiter plate assay were used for eliciting the biofilm-forming attributes of the bacterial pathogens.

Results: Klebsiella pneumoniae was responsible for 48% of CLABSI, followed by Coagulase-negative Staphylococci (16%) and Staphylococcus aureus and Acinetobacter baumannii (12% each). Fifty-six percent of the isolates produced biofilms. The median (interquartile range) duration of hospital stay till death or discharge was 30 (20, 43) days. The all-cause mortality was 44%. Patients having a deranged liver function on the day of diagnosis (P value for total bilirubin 0.001 and for aspartate transaminase 0.02), and those infected with multidrug-resistant organisms (P value = 0.04) had significantly poor prognosis. The difference in the demographic, clinical, laboratory profile, and outcome of patients infected with biofilm producers and nonproducers was not found to be statistically significant.

Conclusion: The study throws light on various host and pathogen factors determining the cause and outcome of CLABSI patients. To the best of our knowledge, this is the first study trying to decipher the role of biofilm formation in the virulence of pathogens and the prognosis of CLABSI.

Introduction: Melioidosis is an under-recognized but important infection with high mortality and morbidity. It is endemic along the coastal regions of the Southern part of India. The present study focuses on the varied clinical manifestations, associated risk factors, and outcomes in patients from the Southeastern part of India.

Methods: Seventy patients from January 2018 to June 2021 from a Tertiary Care Hospital were included and prospectively followed up from 6 months to 3 years. Cox regression was performed to test for the association of various clinical and demographic factors with overall survival.

Results: Diabetes and occupational exposure to soil and water (78.6%) followed by alcoholism (61.4%) were the most common risk factors for melioidosis. The most frequent presentation was sepsis (47.1%), followed by skin and soft tissue infection (32.9%) and pneumonia (25.7%). Mortality was 50%. Patients with sepsis had a 3.5-fold higher risk of mortality (adjusted hazard ratio = 3.50; P = 0.01) while other risk factors were not significantly associated with mortality.

Conclusion: Lifestyle-dependent risk factors (diabetes, occupational exposure, and alcoholism) were most common among patients with melioidosis. Hospitalization among patients with sepsis is associated with high mortality despite the initiation of specific therapy.

Introduction: Significant surge of mucormycosis was reported in the Indian Subcontinent during the second wave of the COVID-19 pandemic. COVID-associated mucormycosis (CAM) was defined as the development of features of mucormycosis with prior or current history of COVID-19 infection. Rapid angioinvasion is an important characteristic of mucormycosis. Authors intended to find out the prevalence of retinal arterial occlusion and its association with vascular embolic occlusion elsewhere in the body among CAM patients in this study.

Methods: This was an observational study. All consecutive-confirmed cases of mucormycosis (n = 89) and age-/gender-/risk factor-matched controls (n = 324) admitted in the designated COVID center were included in the study. All cases and controls underwent comprehensive ophthalmological, otorhinological, and neurological examinations. All necessary investigations to support the clinical diagnosis were done. Qualitative data were analyzed using the Chi-square test. Quantitative data for comparison of means between the cases and controls were done using unpaired t-test.

Results: Twenty-one (23.59%) patients manifested the defined outcome of central retinal artery occlusion (CRAO). Among age-matched control, with similar diabetic status, none had developed the final outcome as defined (P < 0.05). About 90.47% of subjects with CRAO presented with no perception of light vision. Thirteen subjects (61.9%) with the final outcome developed clinical manifestations of stroke during the course of their illness with radiological evidence of watershed infarction (P = 0.001). Orbital debridement was performed in 9 (42.85%) subjects while orbital exenteration was done in 8 (38.09%) subjects.

Conclusions: CRAO in CAM patients was found to have aggressive nature turning the eye blind in a very short period of time. CRAO can serve as a harbinger for subsequent development of more debilitating and life-threatening conditions such as stroke among CAM patients.