Uzzaman, M. S. | Search bioRxiv

bioRxiv2020

The genetic variants analysis of circulating SARS-CoV-2 in Bangladesh.

Genomic mutation of the virus may impact the viral adaptation to the local environment, their transmission, disease manifestation, and the effectiveness of existing treatment and vaccination. The objectives of this study were to characterize genomic variations, non-synonymous amino acid substitutions, especially in target proteins, mutation events per samples, mutation rate, and overall scenario of coronaviruses across the country. To investigate the genetic diversity, a total of 184 genomes of virus strains sampled from different divisions of Bangladesh with sampling dates between the 10th of May 2020 and the 27th of June 2020 were analyzed. To date, a total of 634 mutations located along the entire genome resulting in non-synonymous 274 amino acid substitutions in 22 different proteins were detected with nucleotide mutation rate estimated to be 23.715 substitutions per year. The highest non-synonymous amino acid substitutions were observed at 48 different positions of the papain-like protease (nsp3). Although no mutations were found in nsp7, nsp9, nsp10, and nsp11, yet orf1ab accounts for 56% of total mutations. Among the structural proteins, the highest non-synonymous amino acid substitution (at 36 positions) observed in spike proteins, in which 9 unique locations were detected relative to the global strains, including 516E>Q in the boundary of the ACE2 binding region. The most dominated variant G614 (95%) based in spike protein is circulating across the country with co-evolving other variants including L323 (94%) in RNA dependent RNA polymerase (RdRp), K203 (82%) and R204 (82%) in nucleocapsid, and F120 (78%) in NSP2. These variants are mostly seen as linked mutations and are part of a haplotype observed in Europe. Data suggest effective containment of clade G strains (4.8%) with sub-clusters GR 82.4%, and GH clade 6.4%. HighlightsO_LIWe have sequenced 137 and analyzed 184 whole-genomes sequences of SARS-CoV-2 strains from different divisions of Bangladesh. C_LIO_LIA total of 634 mutation sites across the SARS-CoV-2 genome and 274 non-synonymous amino acid substitutions were detected. C_LIO_LIThe mutation rate of SARS-CoV-2 estimated to be 23.715 nucleotide substitutions per year. C_LIO_LINine unique variants were detected based on non-anonymous amino acid substitutions in spike protein relative to the global SARS-CoV-2 strains. C_LI

genomics↗

bioRxiv2019

Hepatitis E as a cause of adult hospitalization in Bangladesh: Results from an acute jaundice surveillance study in six tertiary hospitals, 2014-2017

In the absence of reliable data on the burden of hepatitis E virus (HEV) in high endemic countries, we established a hospital-based acute jaundice surveillance program in six tertiary hospitals in Bangladesh to estimate the burden of HEV infection among hospitalized acute jaundice patients aged [≥]14 years, identify seasonal and geographic patterns in the prevalence of hepatitis E, and examine factors associated with death.\n\nWe collected blood specimens from enrolled acute jaundice patients, defined as new onset of either yellow eyes or skin during the past three months of hospital admission, and tested for immunoglobulin M (IgM) antibodies against HEV, HBV and HAV. The enrolled patients were followed up three months after hospital discharge to assess their survival status; pregnant women were followed up three months after their delivery to assess pregnancy outcomes.\n\nFrom December2014 to September2017, 1925 patients with acute jaundice were enrolled; 661 (34%) had acute hepatitis E, 48 (8%) had hepatitis A, and 293 (15%) had acute hepatitis B infection. Case fatality among hepatitis E patients was 5% (28/589). Most of the hepatitis E cases were males (74%; 486/661), but case fatality was higher among females--12% (8/68) among pregnant and 8% (7/91) among non-pregnant women. Half of the patients who died with acute hepatitis E had co-infection with HAV or HBV. Of the 62 HEV infected mothers who were alive until the delivery, 9 (15%) had miscarriage/stillbirth, and of those children who were born alive, 19% (10/53) died, all within one week of birth.\n\nThis study confirms that hepatitis E is the leading cause of acute jaundice, leads to hospitalizations in all regions in Bangladesh, occurs throughout the year, and is associated with considerable morbidity and mortality. Effective control measures should be taken to reduce the risk of HEV infections including improvements in water quality, sanitation and hygiene practices and the introduction of HEV vaccine to high-risk groups.\n\nAuthor summaryIn the absence of reliable surveillance data on the burden of hepatitis E in endemic countries, we conducted a hospital-based acute jaundice surveillance study over a two and a half year period in six tertiary hospitals in Bangladesh. The study confirms that HEV infections occur throughout the year, and is a major (34%) cause of acute jaundice in tertiary hospitals in Bangladesh. Three-quarters of the acute hepatitis E cases were male, and HEV infection was higher among patients residing in urban areas than patients in rural areas (41% vs 32%). The overall case fatality rate of acute HEV infections in hospitals was 5%, but was higher among pregnant women (12%). Hepatitis E patients who died were more likely to have co-infection with HAV or HBV than the HEV infected patients who did not die. Fifteen percent of HEV infected mothers had miscarriage/stillbirth. Of the children who were born alive, 19% died, all within one week of birth. Considering the high burden of hepatitis E among hospitalized acute jaundice patients, Bangladesh could take control measures to reduce this risk including improvements in water quality, sanitation and hygiene practices and the introduction of hepatitis E vaccine in high-risk areas.

scientific communication and education↗