The severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) omicron sub-variants in Bangladesh cause mild COVID-19 and associate with similar antibody responses irrespective of natural infection or vaccination history.

Objective: Genomic surveillance and seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) in Bangladesh is paramount for COVID-19 pandemic preparedness yet lagging the high-income countries due to limited resources. Methods: SARS-CoV-2 variants, COVID-19 symptoms, and serology were prospectively evaluated in a cross-sectional study of Bangladeshi adults testing RT-PCR positive in 2021 and 2022. Results: SARS CoV-2 Omicron variants of asymptomatic or mild COVID-19 in 2022 replaced Delta variant infections requiring hospitalization and oxygen support. The omicron XBB became predominant in July 2022 and associated with cough, headache or body ache and loss of smell; 47 of 68 (69 %), 30 of 68 (44 %) and 27 of 68 (40 %) respectively at higher frequency than BA.1/BA.2; 16 of 88 (18 %), 13 of 88 (15 %) and 0 of 88 (0 %) p < 0.01, p < 0.01 and p < 0.0001. Linear regression analysis reveals no associations between the number of previous infections and the number of symptoms, r = -0.084, p = 0.68. The anti-nucleoprotein (N)-protein IgG post COVID-19 and anti-Spike (S) protein IgG post-COVID-19 vaccination were similar between BA.2, BA.4/BA.5 and XBB and significantly lower than the levels in delta variant infections (p < 0.001). Conclusions: Omicron XBB subvariants emerged in Bangladesh two months prior to previous reports and include unique patterns of S-protein mutations not assigned in PANGO lineage. The SARS CoV-2 omicron break-through infections persist in the presence of sustained antibody responses and vaccinations, underscoring the importance of molecular surveillance in low-income countries.

Clinical Presentation of COVID-19 and Antibody Responses in Bangladeshi Patients Infected with the Delta or Omicron Variants of SARS-CoV-2.

The clinical presentation of COVID-19 and the specific antibody responses associated with SARS-CoV-2 variants have not been investigated during the emergence of Omicron variants in Bangladesh. The Delta and Omicron variants were identified by post-PCR melting curve analysis of the spike (S) protein receptor binding domain amplicons. Anti-S-protein immunoglobulin-G anti-nucleocapsid (N)-protein immunoglobulin-G and immunoglobulin-A levels were measured by ELISA. The Delta variant was found in 40 out of 40 (100%) SARS-CoV-2 RT-PCR positive COVID-19 patients between 13 September and 23 October 2021 and Omicron variants in 90 out of 90 (100%) RT-PCR positive COVID-19 patients between 9 January and 10 February 2022. The Delta variant associated with hospitalization (74%, 80%, and 40%) and oxygen support (60%, 57%, and 40%) in the no vaccine, dose-1, and dose-2 vaccinated cases, respectively, whereas the Omicron COVID-19 required neither hospitalization nor oxygen support (0%, p < 0.0001). Fever, cough, and breathlessness were found at a significantly higher frequency among the Delta than Omicron variants (p < 0.001). The viral RNA levels of the Delta variant were higher than that of the Omicron variants (Ct median 19.9 versus 23.85; p < 0.02). Anti-spike protein immunoglobulin-G and anti-N-protein immunoglobulin-G within 1 week post onset of Delta variant COVID-19 symptoms indicate prior SARS-CoV-2 infection. The Delta variant and Omicron BA.1 and BA.2 breakthrough infections in the Dhaka region, at 240 days post onset of COVID-19 symptoms, negatively correlated with the time interval between the second vaccine dose and serum sampling. The findings of lower anti-spike protein immunoglobulin-G reactivity after booster vaccination than after the second vaccine dose suggest that the booster vaccine is not necessarily beneficial in young Bangladeshi adults having a history of repeated SARS-CoV-2 infections.

SARS-CoV-2 infection reduces human nasopharyngeal commensal microbiome with inclusion of pathobionts.

The microbiota of the nasopharyngeal tract (NT) play a role in host immunity against respiratory infectious diseases. However, scant information is available on interactions of SARS-CoV-2 with the nasopharyngeal microbiome. This study characterizes the effects of SARS-CoV-2 infection on human nasopharyngeal microbiomes and their relevant metabolic functions. Twenty-two (n = 22) nasopharyngeal swab samples (including COVID-19 patients = 8, recovered humans = 7, and healthy people = 7) were collected, and underwent to RNAseq-based metagenomic investigation. Our RNAseq data mapped to 2281 bacterial species (including 1477, 919 and 676 in healthy, COVID-19 and recovered metagenomes, respectively) indicating a distinct microbiome dysbiosis. The COVID-19 and recovered samples included 67% and 77% opportunistic bacterial species, respectively compared to healthy controls. Notably, 79% commensal bacterial species found in healthy controls were not detected in COVID-19 and recovered people. Similar dysbiosis was also found in viral and archaeal fraction of the nasopharyngeal microbiomes. We also detected several altered metabolic pathways and functional genes in the progression and pathophysiology of COVID-19. The nasopharyngeal microbiome dysbiosis and their genomic features determined by our RNAseq analyses shed light on early interactions of SARS-CoV-2 with the nasopharyngeal resident microbiota that might be helpful for developing microbiome-based diagnostics and therapeutics for this novel pandemic disease.

Molecular and Serological Characterization of the SARS-CoV-2 Delta Variant in Bangladesh in 2021.

Novel SARS-CoV-2 variants are emerging at an alarming rate. The delta variant and other variants of concern (VoC) carry spike (S)-protein mutations, which have the potential to evade protective immunity, to trigger break-through infections after COVID-19 vaccination, and to propagate future waves of COVID-19 pandemic. To identify SARS CoV-2 variants in Bangladesh, patients who are RT-PCR-positive for COVID-19 infections in Dhaka were screened by a RT-PCR melting curve analysis for spike protein mutations. To assess the anti-SARS CoV-2 antibody responses, the levels of the anti-S -proteins IgA and IgG and the anti-N-protein IgG were measured by ELISA. Of a total of 36 RT-PCR positive samples (75%), 27 were identified as delta variants, with one carrying an additional Q677H mutation and two with single nucleotide substitutions at position 23029 (compared to Wuhan-Hu-1 reference NC 045512) in the genome sequence. Three (8.3%) were identified as beta variants, two (5.5%) were identified as alpha variants, three (8.3%) were identified as having a B.1.1.318 lineage, and one sample was identified as an eta variant (B.1.525) carrying an additional V687L mutation. The trend of higher viral load (lower Cp values) among delta variants than in the alpha and beta variants was of borderline statistical significance (p = 0.045). Prospective studies with larger Bangladeshi cohorts are warranted to confirm the emergence of S-protein mutations and their association with antibody response in natural infection and potential breakthrough in vaccinated subjects.

HIV-1 molecular epidemiology in Bangladesh: A systematic review.

BACKGROUND AND AIMS: It is postulated that molecular methods along with mathematical modeling can provide critical inference regarding epidemiological parameters, transmission dynamics, spatiotemporal characteristics, and intervention efficacy. Hence, studying molecular epidemiology of human immunodeficiency virus (HIV)-1 infection, especially in resource-limited settings and with a large diaspora of the migrant population such as that of Bangladesh, is of paramount importance. The purpose of this systematic review was to concisely present and discuss the findings from previous studies conducted in Bangladesh regarding HIV-1 subtype prevalence. METHODS: Articles were retrieved from six publicly available databases regarding HIV-1 molecular epidemiology using keywords HIV, HIV-1, subtype(s), Bangladesh, and any combination of aforementioned keywords using Boolean operators. A total of 14 articles were downloaded and screened for suitability. Finally, five studies, containing pooled sequences from 317 individuals, were included in this systematic review. RESULTS: Results revealed a preponderance of subtype C among HIV-1 infected population (51.10%), followed by circulating recombinant form (CRF)_07BC (15.46%), CRF_01AE (5.68%), A1 (4.73%), CRF_02AG (3.47%), G (3.15%), CRF_62BC (2.84%), B (2.21%), and other subtypes and recombinant forms in small percentages. Subtype C was largely predominant in intravenous drug users as well as female sex workers, whereas the migrant population exhibited a diverse subtype including rare recombinant forms, largely due to their travel in the Middle East and other South East Asian countries. CONCLUSION: With the number of HIV-1 infections increasing among the general population and a steady increase in the migrant population, molecular epidemiological data are required to curb the progression of the HIV-1 epidemic in Bangladesh.

Antibiotic Prescribing Patterns at COVID-19 Dedicated Wards in Bangladesh: Findings from a Single Center Study.

BACKGROUND: As evidence is mounting regarding irrational and often unnecessary use of antibiotics during the COVID-19 pandemic a cross-sectional Point Prevalence Survey (PPS) (in accordance with WHO guideline) was conducted across COVID-19 dedicated wards in Dhaka Medical College and Hospital (DMCH). METHODOLOGY: Antibiotic usage data were collected from 193 patients at different COVID-19 dedicated wards at DMCH on 11 June 2020. Comparisons in antibiotic usage were made between different groups using Pearson chi-square and Fisher's exact test. RESULT: Findings reveal all surveyed patients (100%) were receiving at least one antibiotic with 133 patients (68.91%) receiving multiple antibiotics. Overall, patients presenting with the severe disease received more antibiotics. Third-generation cephalosporins (i.e. ceftriaxone) (53.8%), meropenem (40.9%), moxifloxacin (29.5%), and doxycycline (25.4%) were the four most prescribed antibiotics among surveyed patients. Diabetes mellitus (DM) was independently associated with multiple antibiotic prescribing. Abnormal C-reactive protein (CRP) and serum d-dimer were linked with higher odds of multiple antibiotic prescribing among study patients. CONCLUSION: Prevalence of multiple antibiotic prescriptions was high among severely ill patients and those with abnormal CRP and d-dimer levels. Data regarding the quality of antibiotic prescribing were lacking.

Detection of Anti-Nucleocapsid Antibody in COVID-19 Patients in Bangladesh Is not Correlated with Previous Dengue Infection.

BACKGROUND: The assessment of antibody responses to severe acute respiratory syndrome coronavirus-2 is potentially confounded by exposures to flaviviruses. The aims of the present research were to determine whether anti-dengue antibodies affect the viral load and the detection of anti-coronavirus nucleocapsid (N)-protein antibodies in coronavirus infectious disease 2019 (COVID-19) in Bangladesh. METHODS: Viral RNA was evaluated in swab specimens from 115 COVID-19 patients by real-time reverse transcription polymerase chain reaction (rT-PCR). The anti-N-protein antibodies, anti-dengue virus E-protein antibodies and the dengue non-structural protein-1 were determined in serum from 115 COVID-19 patients, 30 acute dengue fever pre-COVID-19 pandemic and nine normal controls by ELISA. RESULTS: The concentrations of viral RNA in the nasopharyngeal; Ct median (95% CI); 22 (21.9-23.3) was significantly higher than viral RNA concentrations in oropharyngeal swabs; and 29 (27-30.5) p < 0.0001. Viral RNA concentrations were not correlated with-dengue IgG levels. The anti-nucleocapsid antibodies were IgA 27% positive and IgG 35% positive at days 1 to 8 post-onset of COVID-19 symptoms versus IgA 0% and IgG 0% in dengue patients, p < 0.0001. The levels of anti- nucleocapsid IgA or IgG versus the levels of anti-dengue IgM or IgG revealed no significant correlations. CONCLUSIONS: Viral RNA and anti-nucleocapsid antibodies were detected in COVID-19 patients from dengue-endemic regions of Bangladesh, independently of the dengue IgG levels.

Decreasing transmission and initiation of countrywide vaccination: Key challenges for future management of COVID-19 pandemic in Bangladesh.

With a fragile healthcare system, Bangladesh, much like other countries in South East Asia, struggled during the early days of COVID-19 pandemic. In following months several encouraging initiatives were undertaken including nationwide lockdown, maintaining social distancing and setting up COVID-19 dedicated laboratories and hospitals. Despite fear of an escalation in COVID-19 transmission during the winter months like their European counterparts, fortunately infection rates subsided and Bangladesh came out largely unharmed. But the next phase of COVID-19 pandemic management that includes viral transmission suppression and conduction of nationwide immunization program require several urgent steps from government of Bangladesh (GoB) and relevant stakeholders. This qualitative research piece discussed about issues including an urgent need to enhance critical care facilities around the country, especially in peripheral districts; ramping up COVID-19 testing at existing laboratories in view of diagnosing each case, and ensuring vaccines for the vulnerable populations in the country. Furthermore, the researchers shed light on other issues including a need to reinforce a struggling healthcare workforce, encouraging people to take vaccine, proper maintenance of social distancing regulations, routine epidemiological surveillance, management of environment and biomedical waste and undertaking a holistic approach to combat the pandemic and its environmental and financial consequences.

Challenges in the establishment of a biosafety testing laboratory for COVID-19 in Bangladesh.

At the beginning of the coronavirus disease 2019 (COVID-19) pandemic in Bangladesh, there was a scarcity of ideal biocontainment facilities to detect the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a risk group of 3 organisms. Molecular detection of SARS-CoV-2 must be performed in a BSL-2 laboratory with BSL-3-equivalent infection prevention and control practices. Establishing these facilities within a short timeframe proved to be an enormous challenge, including locating a remote space distant from the university campus to establish a laboratory, motivating the laboratory staff to work with a novel pathogen without any prior experience, allocation of funds for essential equipment and accessories, and arrangement of a safe waste management system for environmental hazard reduction. This report also highlights several limitations, such as the facility's architectural design that did not follow the biosafety guidelines, lack of continuous flow of funds, and an inadequate number of laboratory personnel. This article describes various efforts taken to overcome the challenges during the establishment of this facility that may be adopted to create similar facilities in other regions of the country. Establishing a BSL-2 laboratory with BSL-3-equivalent infection prevention and control practices will aid in the early detection of a large number of cases, thereby isolating persons with COVID-19, limiting the transmission of SARS-CoV-2, and promoting a robust public health response to contain the pandemic.

Coding-Complete Genome Sequences of Three SARS-CoV-2 Strains from Bangladesh.

We report the sequencing of three severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from Bangladesh. We have identified a unique mutation (NSP2_V480I) in one of the sequenced genomes (isolate hCoV-19/Bangladesh/BCSIR-NILMRC-006/2020) compared to the sequences available in the Global Initiative on Sharing All Influenza Data (GISAID) database. The data from this analysis will contribute to advancing our understanding of the epidemiology of SARS-CoV-2 in Bangladesh as well as worldwide at the molecular level and will identify potential new targets for interventions.