Antibody Response after Homologous and Heterologous Prime-Boost COVID-19 Vaccination in a Bangladeshi Residential University Cohort.

COVID-19 vaccination strategies, including heterologous prime-boost regimens and additional booster doses, aim to optimize immune responses. However, seroepidemiological studies on immune responses to different COVID-19 vaccine types and schedules remain limited. This study investigated antibody levels following homologous and heterologous prime-and-boost COVID-19 vaccination in Bangladesh. In a cohort of 606 participants who received first/second/booster doses of vaccines (AstraZeneca, Moderna, Pfizer-BioNTech, and Sinopharm), anti-spike IgG and anti-nucleocapsid IgG levels were measured. Antibody titer variations with respect to age, gender, intervals between doses, and prior infection status were analyzed. mRNA vaccines elicited the highest antibody levels after homologous and heterologous boosting. The AstraZeneca booster resulted in a sharp titer decline rate of ~0.04 units per day. Second or booster vaccine doses significantly increased antibody levels, especially in males (p < 0.05). Older age correlated with higher titers, likely reflecting previous infection, which was further confirmed by the elevation of anti-nucleocapsid IgG levels. About 95.5% of non-Sinopharm recipients were anti-nucleocapsid IgG positive, suggesting prior exposure exceeding self-reported infections (12.5%). mRNA and heterologous COVID-19 boosting enhances humoral immunity over homologous prime-boost vector/inactivated vaccination. However, waning immunity merits further investigation across vaccine platforms.

Coding-Complete Genome Sequences and Mutation Profiles of Nine SARS-CoV-2 Strains Detected from COVID-19 Patients in Bangladesh.

Here, we report the coding-complete genome sequences of nine clinical severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and their mutations. The samples were collected from nine Bangladeshi coronavirus disease 2019 (COVID-19) patients. We have identified the E484K escape mutation and the S359T mutation within the spike protein coding region of the sequenced genomes.

Molecular and Epidemiologic Analysis of Diarrheal Pathogens in Children With Acute Gastroenteritis in Bangladesh During 2014-2019.

BACKGROUND: Diarrheal disease is one of the leading causes of childhood morbidity and mortality in the 21st century in developing countries. Mainly infants and young children develop diarrheal diseases. This study aims to determine the incidence of diarrheal pathogens in children in Bangladesh. METHODS: During 2014 to 2019, 387 fecal specimens were collected from children with diarrhea in Bangladesh. Bacterial pathogens were detected by conventional bacteriologic, biochemical and molecular sequence analysis methods. DNA virus and RNA virus (diarrheal viruses) were detected using polymerase chain reaction and reverse transcriptase polymerase chain reaction, respectively and confirmed by molecular sequence analysis. RESULTS: Bacterial infections were detected in 39.27% (152 of 387) of the stool samples. Escherichia coli was the most prevalent (17.3%) followed by Vibrio cholerae (13.5%), Salmonella spp. (4.9%) and Shigella spp. (3.6%). From 387 fecal specimens tested, 42.4% (164 of 387) were positive for viral infections. Rotavirus was the most prevalent (26.3%), followed by adenovirus (5.7%), norovirus (5.4%) and human bocavirus (4.9%). Dual infection between rotavirus and E. coli accounted for the largest portion of coinfection (48%). Diarrhea (77%) and abdominal pain (65%) were most common followed by vomiting (63%), fever (43%) and dehydration (39%). E. coli and V. cholerae were most resistant against ciprofloxacin (62.7%) and tetracycline (88.5%). qnrA and sul4 resistance genes were isolated from these pathogens. CONCLUSIONS: Data from this study underline the high incidence of diarrheal pathogens and presence of antibiotics resistance genes in a pediatric population in Bangladesh.

Parathyroid Frozen Section Interpretation via Desktop Telepathology Systems: A Validation Study.

BACKGROUND: Telepathology can potentially be utilized as an alternative to having on-site pathology services for rural and regional hospitals. The goal of the study was to validate two small-footprint desktop telepathology systems for remote parathyroid frozen sections. SUBJECTS AND METHODS: Three pathologists retrospectively diagnosed 76 parathyroidectomy frozen sections of 52 patients from three pathology services in Australia using the "live-view mode" of MikroScan D2 and Aperio LV1 and in-house direct microscopy. The final paraffin section diagnosis served as the "gold standard" for accuracy evaluation. Concordance rates of the telepathology systems with direct microscopy, inter-pathologist and intra-pathologist agreement, and the time taken to report each slide were analyzed. RESULTS: Both telepathology systems showed high diagnostic accuracy (>99%) and high concordance (>99%) with direct microscopy. High inter-pathologist agreement for telepathology systems was demonstrated by overall kappa values of 0.92 for Aperio LV1 and 0.85 for MikroScan D2. High kappa values (from 0.85 to 1) for intra-pathologist agreement within the three systems were also observed. The time taken per slide by Aperio LV1 and MicroScan D2 within three pathologists was about 3.0 times (P < 0.001, 95% confidence interval [CI]: 2.8-3.2) and 7.7 times (P < 0.001, 95% CI: 7.1-8.3) as long as direct microscopy, respectively, while MikroScan D2 took about 2.6 times as long as Aperio LV1 (P < 0.001, 95% CI: 2.4-2.7). All pathologists evaluated Aperio LV1 as being more user-friendly. CONCLUSIONS: Telepathology diagnosis of parathyroidectomy frozen sections through small-footprint desktop systems is accurate, reliable, and comparable with in-house direct microscopy. Telepathology systems take longer than direct microscopy; however, the time taken is within clinically acceptable limits. Aperio LV1 takes shorter time than MikroScan D2 and is more user-friendly.