Prevalence of SARS CoV-2 infection among Health Care Workers of a hybrid tertiary COVID 19 hospital in Kerala

Back ground and objectivesThis study was undertaken to estimate the prevalence of SARS-CoV-2 infection among Health care workers [HCWs] of a hybrid COVID treatment hospital in Kerala. MethodsThe study was conducted during 3rd week of January 2021. Among 3550 HCWs, 979 subjects were selected by stratified random sampling and grouped into high risk and low risk category based on job setting. Demographic details and clinical information regarding previous history of COVID 19 were collected at the time of SARS-CoV-2 IgG testing. ResultsFrom 979 subjects, the data with respect to 940 health care workers were analysed. SARS-CoV-2 IgG was detected in 19.1% of HCWs. Seroprevalence among high risk group was 20.3% and that in low risk group was 7.4% [p=0.005]. In high-risk group, seropositivity was noted in 30.54 % of nurses, 19% hospital attenders, 18.9% resident doctors and 6.4% consultant doctors. In those with past history of SARS-CoV-2 infection, seropositivity was 75.4%. In those who were COVID positive during July2020, 33.3% were still IgG reactive. Interpretation and conclusionThe study reported 19.1% SARS CoV-2 IgG reactivity among health care workers in our hospital. Seropositivity was significantly higher in high risk group compared to low risk group. Antibody decay kinetics in our study is comparable to that in published literature. Infection control challenges in hybrid hospitals account for higher seropositivity in this study compared to overall seroprevalence among HCWs in Kerala.

A Multi-Classifier System for Automatic Mitosis Detection in Breast Histopathology Images Using Deep Belief Networks.

Mitotic count is an important diagnostic factor in breast cancer grading and prognosis. Detection of mitosis in breast histopathology images is very challenging mainly due to diffused intensities along object boundary and shape variation in different stages of mitosis. This paper demonstrates an accurate technique for detecting the mitotic cells in Hematoxyline and Eosin stained images by step by step refinement of segmentation and classification stages. Krill Herd Algorithm-based localized active contour model precisely segments cell nuclei from background stroma. A deep belief network based multi-classifier system classifies the labeled cells into mitotic and nonmitotic groups. The proposed method has been evaluated on MITOS data set provided for MITOS-ATYPIA contest 2014 and also on clinical images obtained from Regional Cancer Centre (RCC), Thiruvananthapuram, which is a pioneer institute specifically for cancer diagnosis and research in India. The algorithm provides improved performance compared with other state-of-the-art techniques with average F-score of 84.29% for the MITOS data set and 75% for the clinical data set from RCC.

Detection of mitotic nuclei in breast histopathology images using localized ACM and Random Kitchen Sink based classifier.

The exact measure of mitotic nuclei is a crucial parameter in breast cancer grading and prognosis. This can be achieved by improving the mitotic detection accuracy by careful design of segmentation and classification techniques. In this paper, segmentation of nuclei from breast histopathology images are carried out by Localized Active Contour Model (LACM) utilizing bio-inspired optimization techniques in the detection stage, in order to handle diffused intensities present along object boundaries. Further, the application of a new optimal machine learning algorithm capable of classifying strong non-linear data such as Random Kitchen Sink (RKS), shows improved classification performance. The proposed method has been tested on Mitosis detection in breast cancer histological images (MITOS) dataset provided for MITOS-ATYPIA CONTEST 2014. The proposed framework achieved 95% recall, 98% precision and 96% F-score.

2-D Fused Image Reconstruction approach for Microwave Tomography: a theoretical assessment using FDTD Model.

This paper describes an efficient two-dimensional fused image reconstruction approach for Microwave Tomography (MWT). Finite Difference Time Domain (FDTD) models were created for a viable MWT experimental system having the transceivers modelled using thin wire approximation with resistive voltage sources. Born Iterative and Distorted Born Iterative methods have been employed for image reconstruction with the extremity imaging being done using a differential imaging technique. The forward solver in the imaging algorithm employs the FDTD method of solving the time domain Maxwell's equations with the regularisation parameter computed using a stochastic approach. The algorithm is tested with 10% noise inclusion and successful image reconstruction has been shown implying its robustness.

Allele frequencies of 20 Y-chromosomal short tandem repeat loci in a tribal population of Deccan Plateau, India.

POPULATION: Eighty male individuals from a nomadic tribal population belonging to Dravidian and Indo-Caucasian ethnicities from Deccan Plateau, Andhra Pradesh, India, were analyzed in the present study.

Allele frequency distribution based on 17 STR markers in three major Dravidian linguistic populations of Andhra Pradesh, India.

Allele frequencies for 15 tetranucleotides and 2 pentanucleotides repeat loci were determined in 317 unrelated, healthy individuals of Andhra Pradesh, India, belonging to three pre-dominant endogamous populations namely, Kappu Naidu, Kamma Chaudhary and Kapu Reddy. Adherence to the expectations of the Hardy-Weinberg equilibrium (HWE) was confirmed for all loci with few exceptions, which were not significant after applying Bonferroni's correction. Statistical parameters of forensic interest; observed heterozygosity, probability of homozygosity, probability of extact test, power of discrimination, match probability, polymorphism information content, power of exclusion and mean paternity index were determined for all loci. The present study reveals that Penta E and D2S1338 are the most informative loci in all the studied populations. The combined power of discrimination was greater than 0.976, whereas the cumulative power of exclusion gave an expected value of 0.9999 for all the tested microsatellite loci. No difference was observed in the discriminatory power of 15 loci in studied populations on comparison with other populations of India. Population differentiation tests revealed significant differences between the studied and neighboring populations at several loci. Analyzed parameters indicate the utility and efficacy of the studied 17 STR systems as a powerful tool in forensic human identification, paternity testing and human population genetic studies.

Genetic structure of Indian populations based on fifteen autosomal microsatellite loci.

BACKGROUND: Indian populations endowed with unparalleled genetic complexity have received a great deal of attention from scientists world over. However, the fundamental question over their ancestry, whether they are all genetically similar or do exhibit differences attributable to ethnicity, language, geography or socio-cultural affiliation is still unresolved. In order to decipher their underlying genetic structure, we undertook a study on 3522 individuals belonging to 54 endogamous Indian populations representing all major ethnic, linguistic and geographic groups and assessed the genetic variation using autosomal microsatellite markers. RESULTS: The distribution of the most frequent allele was uniform across populations, revealing an underlying genetic similarity. Patterns of allele distribution suggestive of ethnic or geographic propinquity were discernible only in a few of the populations and was not applicable to the entire dataset while a number of the populations exhibited distinct identities evident from the occurrence of unique alleles in them. Genetic substructuring was detected among populations originating from northeastern and southern India reflective of their migrational histories and genetic isolation respectively. CONCLUSION: Our analyses based on autosomal microsatellite markers detected no evidence of general clustering of population groups based on ethnic, linguistic, geographic or socio-cultural affiliations. The existence of substructuring in populations from northeastern and southern India has notable implications for population genetic studies and forensic databases where broad grouping of populations based on such affiliations are frequently employed.

Genotypic polymorphisms at seventeen autosomal short tandem repeat loci in four tribal populations of Andhra Pradesh, India.

Four tribal populations of Andhra Pradesh, South India (1), Chenchu (n=100), Lambadi (n=107), Naikpod Gond (n=104) and Yerukula (n=101) were analyzed for DNA polymorphisms at 15 tetranucleotide and 2 pentanucleotide short tandem repeat (STR) loci in the present study.