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Abstract Background Rotavirus genotyping is performed by using reverse transcription PCR with type-specific-primers. Because the high rotavirus mutation rate generates an extensive genomic variation, different G-type-specific primer sets are applied in different geographical locations. In Bangladesh, a significant proportion (36.9%) of the rotavirus strains isolated in 2002 could not be G-typed using the routinely used primer set. To investigate the reason why the strains were untypeable, nucleotide sequencing of the VP7 genes was performed. Results Four nucleotide substitutions at the G1 primer-binding site of the VP7 gene of Bangladeshi G1 rotaviruses rendered a major proportion of circulating strains untypeable using the routine primer set. Using an alternative primer set, we could identify G1 rotaviruses as the most prevalent genotype (44.8%), followed by G9 (21.7%), G2 (15.0%) and G4 (13.8%). Conclusion Because of the natural variation in the rotaviral gene sequences, close monitoring of rotavirus genotyping methods is important.

Introduction: RNF213 mutations have been reported mostly in moyamoya disease (MMD) with varying frequencies across different ethnicities. However, its prevalence in non-MMD adult-onset ischemic stroke is still not well explored., Aims and Objectives: This present study thus aims to screen the most common RNF213 variant (Arg4810Lys, among East Asians) in the Eastern Indian non-MMD ischemic stroke patients and correlate it with long-term progression and prognosis of the patients. The subjects were analyzed for this variant using PCR-RFLP and confirmed using Sanger sequencing method., Result and Conclusion: We have identified Arg4810Lys variant among eleven young-onset familial ischemic stroke patients in heterozygous manner. A positive correlation of the variant with positive family history (P = 0.001), earlier age at onset (P = 0.002), and history of recurrent stroke (P = 0.015) was observed. However, the carriers showed better cognitive performances in memory (P = 0.042) and executive function (P = 0.004). Therefore, we can conclude that Arg4810Lys/RNF213 - a pathogenic variant for young-onset familial ischemic stroke with higher incidence of recurrent events unlike in MMD cases, have no additional impact on cognition among Eastern Indians., (© 2023. Fondazione Società Italiana di Neurologia.)

Post-stroke cognitive impairment (PSCI) is a clinical outcome in around 30% of post-stroke survivors. BDNF is a major gene in this regard. It is regulated by circadian rhythm. The circadian genes are correlated with stroke timings at molecular level. However, studies suggesting the role of these on susceptibility to PSCI are limited. We aim here to determine: (a) genetic risk variants in circadian clock genes, BDNF and (b) dysregulation in expression level of CLOCK, BMAL1, and BDNF that may be associated with PSCI. BDNF (rs6265G/A, rs56164415C/T), CLOCK (rs1801260T/C, rs4580704G/C), and CRY2 (rs2292912C/G) genes variants were genotyped among 119 post-stroke survivors and 292 controls from Eastern part of India. In addition, we analyzed their gene expression in Peripheral blood Mononuclear cells (PBMC) from 15 PSCI cases and 12 controls. The mRNA data for BDNF was further validated by its plasma level through ELISA (n = 38). Among the studied variants, only rs4580704/CLOCK showed an overall association with PSCI (P = 0.001) and lower Bengali Mini-Mental State Examination (BMSE) score. Its 'C' allele showed a correlation with attention deficiency. The language and memory impairments showed association with rs6265/BDNF, while the 'CC' genotype of rs2292912/CRY2 negatively influenced language and executive function. A significant decrease in gene expression for CLOCK and BDNF in PBMC (influenced by specific genotypes) of PSCI patients was observed than controls. Unlike Pro-BDNF, plasma-level mBDNF was also lower in them. Our results suggest the genetic variants in CLOCK, CRY2, and BDNF as risk factors for PSCI among eastern Indians. At the same time, a lowering expression of CLOCK and BDNF genes in PSCI patients than controls describes their transcriptional dysregulation as underlying mechanism for post-stroke cognitive decline., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Active Nipah virus encephalitis surveillance identified an encephalitis cluster and sporadic cases in Faridpur, Bangladesh, in January 2010. We identified 16 case-patients; 14 of these patients died. For 1 case-patient, the only known exposure was hugging a deceased patient with a probable case, while another case-patient's exposure involved preparing the same corpse for burial by removing oral secretions and anogenital excreta with a cloth and bare hands. Among 7 persons with confirmed sporadic cases, 6 died, including a physician who had physically examined encephalitis patients without gloves or a mask. Nipah virus-infected patients were more likely than community-based controls to report drinking raw date palm sap and to have had physical contact with an encephalitis patient (29% vs. 4%, matched odds ratio undefined). Efforts to prevent transmission should focus on reducing caregivers' exposure to infected patients' bodily secretions during care and traditional burial practices.

Objective: To estimate influenza-associated mortality in Bangladesh in 2009., Methods: In four hospitals in Bangladesh, respiratory samples were collected twice a month throughout 2009 from inpatients aged < 5 years with severe pneumonia and from older inpatients with severe acute respiratory infection. The samples were tested for influenza virus ribonucleic acid (RNA) using polymerase chain reaction. The deaths in 2009 in five randomly selected unions (the smallest administrative units in Bangladesh) in each hospital's catchment area were then investigated using formal records and informal group discussions. The deaths of those who had reportedly died within 14 days of suddenly developing fever with cough and/or a sore throat were assumed to be influenza-associated. The rate of such deaths in 2009 in each of the catchment areas was then estimated from the number of apparently influenza-associated deaths in the sampled unions, the proportion of the sampled inpatients in the local hospital who tested positive for influenza virus RNA, and the estimated number of residents of the sampled unions., Findings: Of the 2500 people known to have died in 2009 in all 20 study unions, 346 (14%) reportedly had fever with cough and/or sore throat within 14 days of their deaths. The estimated mean annual influenza-associated mortality in these unions was 11 per 100,000 population: 1.5, 4.0 and 125 deaths per 100,000 among those aged < 5, 5-59 and > 59 years, respectively., Conclusion: The highest burden of influenza-associated mortality in Bangladesh in 2009 was among the elderly.

Objective: To determine how much influenza contributes to severe acute respiratory illness (SARI), a leading cause of death in children, among people of all ages in Bangladesh., Methods: Physicians obtained nasal and throat swabs to test for influenza virus from patients who were hospitalized within 7 days of the onset of severe acute respiratory infection (SARI) or who consulted as outpatients for influenza-like illness (ILI). A community health care utilization survey was conducted to determine the proportion of hospital catchment area residents who sought care at study hospitals and calculate the incidence of influenza using this denominator., Findings: The estimated incidence of SARI associated with influenza in children < 5 years old was 6.7 (95% confidence interval, CI: 0-18.3); 4.4 (95% CI: 0-13.4) and 6.5 per 1000 person-years (95% CI: 0-8.3/1000) during the 2008, 2009 and 2010 influenza seasons, respectively. The incidence of SARI in people aged ≥ 5 years was 1.1 (95% CI: 0.4-2.0) and 1.3 (95% CI: 0.5-2.2) per 10,000 person-years during 2009 and 2010, respectively. The incidence of medically attended, laboratory-confirmed seasonal influenza in outpatients with ILI was 10 (95% CI: 8-14), 6.6 (95% CI: 5-9) and 17 per 100 person-years (95% CI: 13-22) during the 2008, 2009 and 2010 influenza seasons, respectively., Conclusion: Influenza-like illness is a frequent cause of consultation in the outpatient setting in Bangladesh. Children aged less than  5 years are hospitalized for influenza in greater proportions than children in other age groups.

Objective: In March 2007, we investigated a cluster of Nipah encephalitis to identify risk factors for Nipah infection in Bangladesh., Methods: We defined confirmed Nipah cases by the presence of IgM and IgG antibodies against Nipah virus in serum. Case-patients, who resided in the same village during the outbreak period but died before serum could be collected, were classified as probable cases., Results: We identified three confirmed and five probable Nipah cases. There was a single index case. Five of the secondary cases came in close physical contact to the index case when she was ill. Case-patients were more likely to have physical contact with the index case (71% cases versus 0% controls, p = <0.001). The index case, on her third day of illness, and all the subsequent cases attended the same religious gathering. For three probable cases including the index case, we could not identify any known risk factors for Nipah infection such as physical contact with Nipah case-patients, consumption of raw date palm juice, or contact with sick animals or fruit bats., Conclusion: Though person-to-person transmission remains an important mode of transmission for Nipah infection, we could not confirm the source of infection for three of the probable Nipah case-patients. Continued surveillance and outbreak investigations will help better understand the transmission of Nipah virus and develop preventive strategies.

Background: Rotavirus vaccine has proved effective for prevention of severe rotavirus gastroenteritis in infants in developed countries, but no efficacy studies have been done in developing countries in Asia. We assessed the clinical efficacy of live oral pentavalent rotavirus vaccine for prevention of severe rotavirus gastroenteritis in infants in Bangladesh and Vietnam., Methods: In this multicentre, double-blind, placebo-controlled trial, undertaken in rural Matlab, Bangladesh, and urban and periurban Nha Trang, Vietnam, infants aged 4-12 weeks without symptoms of gastrointestinal disorders were randomly assigned (1:1) to receive three oral doses of pentavalent rotavirus vaccine 2 mL or placebo at around 6 weeks, 10 weeks, and 14 weeks of age, in conjunction with routine infant vaccines including oral poliovirus vaccine. Randomisation was done by computer-generated randomisation sequence in blocks of six. Episodes of gastroenteritis in infants who presented to study medical facilities were reported by clinical staff and from parent recollection. The primary endpoint was severe rotavirus gastroenteritis (Vesikari score >or=11) arising 14 days or more after the third dose of placebo or vaccine to end of study (March 31, 2009; around 21 months of age). Analysis was per protocol; infants who received scheduled doses of vaccine or placebo without intervening laboratory-confirmed naturally occurring rotavirus disease earlier than 14 days after the third dose and had complete clinical and laboratory results were included in the analysis. This study is registered with ClinicalTrials.gov, number NCT00362648., Findings: 2036 infants were randomly assigned to receive pentavalent rotavirus vaccine (n=1018) or placebo (n=1018). 991 infants assigned to pentavalent rotavirus vaccine and 978 assigned to placebo were included in the per-protocol analysis. Median follow up from 14 days after the third dose of placebo or vaccine until final disposition was 498 days (IQR 480-575). 38 cases of severe rotavirus gastroenteritis (Vesikari score >or=11) were reported during more than 1197 person-years of follow up in the vaccine group, compared with 71 cases in more than 1156 person years in the placebo group, resulting in a vaccine efficacy of 48.3% (95% CI 22.3-66.1) against severe disease (p=0.0005 for efficacy >0%) during nearly 2 years of follow-up. 25 (2.5%) of 1017 infants assigned to receive vaccine and 20 (2.0%) of 1018 assigned to receive placebo had a serious adverse event within 14 days of any dose. The most frequent serious adverse event was pneumonia (vaccine 12 [1.2%]; placebo 15 [1.5%])., Interpretation: In infants in developing countries in Asia, pentavalent rotavirus vaccine is safe and efficacious against severe rotavirus gastroenteritis, and our results support expanded WHO recommendations to promote its global use., Funding: PATH (GAVI Alliance grant) and Merck., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Approximately 20,000 stool specimens from patients with diarrhea visiting 1 urban and 1 rural hospital in Bangladesh during January 2001-May 2006 were tested for group A rotavirus antigen, and 4,712 (24.0%) were positive. G and P genotyping was performed on a subset of 10% of the positive samples (n = 471). During the 2001-2005 rotavirus seasons, G1P[8] (36.4%) and G9P[8] (27.7%) were the dominant strains, but G2[4] and G12P[6] were present in 15.4% and 3.1% of the rotavirus-positive patients, respectively. During the 2005-06 rotavirus season, G2P[4] (43.2%) appeared as the most prevalent strain, and G12P[6] became a more prevalent strain (11.1%) during this season. Because recently licensed rotavirus vaccines include only the P[8] specificity, it is unknown how the vaccines will perform in settings where non-P[8] types are prevalent.

The incidence of aetiology-specific diarrhoea and the pathogenicity of infectious agents in a birth cohort (n=252) in rural Bangladesh were determined. Stool specimens or rectal swabs were collected from diarrhoeal cases over two years and routinely on a monthly basis. Stool samples from children with diarrhoea were compared with stool samples from children without diarrhoea to calculate rates of isolation and pathogenicity of agents. In total, 1750 stool specimens from diarrhoea patients and 5679 stool specimens from children without diarrhoea were tested. An infectious agent was identified in 58% of the stool specimens from diarrhoea patients and 21.6% of the stool specimens from children without diarrhoea. The most commonly-isolated pathogens from all specimens were enterotoxigenic Escherichia coli (ETEC), enteroadherent E. coli, Shigella, Campylobacter jejuni, Giardia, and rotavirus. ETEC (ST and LT-ST toxin), enterotoxigenic Bacteroides fragilis, Shigella, and rotavirus were associated more with disease than with asymptomatic infections. Aetiology-specific infections were associated with acute episodes. The isolated enteropathogens were essentially the same as those found in other tropical rural settings. Enterotoxigenic B. fragilis was also identified as a pathogen. Ongoing vaccine efforts focusing on Shigella, rotavirus, and ETEC would be useful.

Dengue and dengue hemorrhagic fever re-emerged in Bangladesh in 2000 and 2001 and nearly all viruses isolated were dengue type 3. Phylogenetic analyses of the envelope genes of examples of these viruses indicated that they were most closely related to recently emerged dengue type 3 viruses from neighboring Thailand and Myanmar but distinct from those from India and Sri Lanka. Since this strain of dengue virus type 3 had not been associated with unusual patterns of disease in Thailand or Myanmar, it suggested that the outbreak in Bangladesh was due to local factors after the introduction of viruses from countries to the east rather than to the evolution of an unusually virulent strain of virus in Bangladesh.

Limited information is available on the etiology of acute lower respiratory infection (ALRI) particularly pneumonia in the rural community of developing countries since most etiological studies are carried out in the hospital settings. This study examined the etiology of pneumonia among young children in a rural community of Bangladesh. A cohort of 252 newborns was followed till 24 months of age during 1993-1996. Community health workers (CHWs) identified cases of ALRI during household surveillance and recommended hospitalization. On admission, nasopharyngeal aspirates (NPA) and blood were collected for bacterial and viral identification, and chest x-rays were done. Multiple regression analysis identified factors associated with a viral etiology. Physicians diagnosed 67 pneumonia; 45% of NPA were positive for viral agents of pneumonia, and respiratory syncytial virus (RSV) was predominant (81%); 6 of 48 blood cultures were positive. X-ray was done for 58 cases; 52% had pneumonic consolidation. Of the RSV cases, 33% were found in children without pneumonic consolidation. Children living in a one-room house were 3 times more likely to develop viral pneumonia (odds ratio (OR) = 3.67, CI 1.05-12.83) than children living in a larger house. Counseling on avoiding crowding where a newborn is accommodated might reduce pneumonia incidence.

A novel rotavirus strain (Dhaka6) isolated from a 21-year-old Bangladeshi male patient was characterized by sequence analysis of its VP7 and VP4 gene segments. Phylogenetic analysis of the VP7 gene of the Dhaka6 strain revealed a common evolutionary lineage with porcine G11 rotavirus strains. This isolate is the first reported G11 rotavirus strain infecting a human host. Comparison of the VP4 gene sequences with all currently recognized 24 different P genotypes revealed only low nucleotide (54 to 71%) and amino acid (52 to 76%) sequence identities. This lack of high sequence similarity in the VP4 gene indicates that the Dhaka6 isolate represents a new group A rotavirus P genotype, to which we propose assignment of the designation P[25].

Background: Rotavirus genotyping is performed by using reverse transcription PCR with type-specific-primers. Because the high rotavirus mutation rate generates an extensive genomic variation, different G-type-specific primer sets are applied in different geographical locations. In Bangladesh, a significant proportion (36.9%) of the rotavirus strains isolated in 2002 could not be G-typed using the routinely used primer set. To investigate the reason why the strains were untypeable, nucleotide sequencing of the VP7 genes was performed., Results: Four nucleotide substitutions at the G1 primer-binding site of the VP7 gene of Bangladeshi G1 rotaviruses rendered a major proportion of circulating strains untypeable using the routine primer set. Using an alternative primer set, we could identify G1 rotaviruses as the most prevalent genotype (44.8%), followed by G9 (21.7%), G2 (15.0%) and G4 (13.8%)., Conclusion: Because of the natural variation in the rotaviral gene sequences, close monitoring of rotavirus genotyping methods is important.

We developed a novel method that uses sodium dodecyl sulfate-EDTA-treated chromatography paper strips to collect unconcentrated fresh stool samples. After the paper strips were stored for 4 months at room temperature, rotavirus RNA could be successfully amplified by using reverse transcriptase PCR. The use of filter paper strips as a specimen support allows (self-)collection of stool samples by untrained persons. Diarrheal stool samples from remote areas can be stored and transported to a central diagnostic laboratory without the need for freezers or special shipping conditions. This convenient and inexpensive rotavirus sample collection system can be of use in epidemiological surveillance studies and vaccine trials.

Rotavirus-specific subclass antibody responses and cytokines, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-8 (IL-8), and IL-10, were measured in children 7-24 months of age with rotavirus diarrhoea (n = 29); the responses were compared with children with watery diarrhoea from whom no enteric pathogens were isolated (controls; n = 11). All children had diarrhoea for < 5 days and were enrolled from the Dhaka Hospital of the Centre for Health and Population Research. Samples of blood and stools were collected on the day of enrollment and 18-21 days after the onset of diarrhoea. Children showing a > or = 4-fold rise in antibody titre between the acute and convalescent stages were considered to have a response. The numbers of children with rotavirus-specific IgA and IgA1 responses in stool were similar in the two groups of children. In the plasma, more children with rotavirus diarrhoea had rotavirus-specific IgA, IgA1, IgG, IgG1, and IgG3 responses than did control children (P = 0.049, 0.007, 0.001, 0.002, and 0.012, respectively). IgA2 was not detectable. Among cytokines measured in supernatants from peripheral blood mononuclear cells (PBMCs) cultured for 6 and 24 hr, IFN-gamma was the only cytokine that was higher in children with rotavirus diarrhoea compared with controls (P = 0.013). Severity of illness did not correlate with nutritional status or antibody titres, but severity did correlate with TNF-alpha during the acute stage of illness. IFN-gamma correlated positively with IgG1 titres. These findings suggest a role for IFN-gamma in the pathogenesis of rotavirus infection, but this needs confirmation by other studies. The immune responses described are relevant to future vaccine trials, as immune responses in vaccinees should mimic those in natural infection.

Background: Rotavirus is the most common cause of severe gastroenteritis among children worldwide., Objectives: To compare the safety, immunogenicity and shedding patterns of rhesus rotavirus (RRV)-tetravalent vaccine vs. placebo among infants in rural Bangladesh., Methods: A double blinded, placebo-controlled trial was conducted in which infants (n = 120) were randomly assigned to receive three doses of either vaccine or placebo administered at approximately 6, 10 and 14 weeks of age together with routine immunizations. Data on possible adverse effects of vaccinations were collected daily for 7 days after each dose. Stool samples were collected after each dose, and serum samples were obtained before the first and after the third vaccination., Results: Fever (> or = 38 degrees C), as measured by study assistants, was noted more frequently among vaccinees (15%) than among placebo recipients (2%) during the 7 days after vaccination but was not reported more frequently by parents of vaccinees vs. placebo recipients. Overall 87% of vaccinees had an antibody response (measured by IgA or anti-RRV-neutralizing antibodies) after vaccination compared with 32% of placebo recipients. Rates of seroconversion were higher among subjects with lower levels of prevaccination antibodies and those who shed rotavirus after vaccination. Vaccine strain viruses were detected in stools from placebo vaccine recipients who had evidence of IgA seroconversion., Conclusions: In this population RRV-tetravalent vaccine was comparably immunogenic and safe as in trials conducted in developed countries, where this vaccine has been proved effective in preventing severe rotavirus diarrhea. These data support continued evaluation of rotavirus vaccines in developing countries.

We characterized 1,534 rotavirus (RV) strains collected in Bangladesh from 1992 to 1997 to assess temporal changes in G type and to study the most common G and P types using reverse transcription-PCR, oligonucleotide probe hybridization, and monoclonal antibody-based enzyme immunoassay. Results from this study combined with our previous findings from 1987 to 1991 (F. Bingnan et al., J. Clin. Microbiol. 29:862-868, 1991, and L. E. Unicomb et al., Arch. Virol. 132:201-208, 1993) (n = 2,515 fecal specimens) demonstrated that the distribution of the four major G types varied from year to year, types G1 to G4 constituted 51% of all strains tested (n = 1,364), and type G4 was the most prevalent type (22%), followed by type G2 (17%). Of 351 strains tested for both G and P types, three globally common types, type P[8], G1, type P[4], G2, and type P[8], G4, comprised 45% (n = 159) of the strains, although eight other strains were circulating during the study period. Mixed G and/or P types were found in 23% (n = 79) of the samples tested. Type G9 RVs that were genotype P[6] and P[8] with both long and short electrophoretic patterns emerged in 1995. The finding of five different genotypes among G9 strains, of which three were frequently detected, suggests that they may have an unusual propensity for reassortment that exceeds that found among the common G types. We also detected antigenic changes in serotypes G2 and G4 over time, as indicated by the loss of reactivity with standard typing monoclonal antibodies. Our data suggest that a vaccine must provide protection against type G9 RVs as well as against the four major G types because G9 strains constituted 16% (n = 56) of the typeable RV strains and have predominated since 1996.

Eight infants followed longitudinally were found to have enteric adenovirus (EAdv) infections: in 5 infants with diarrhea and in 3 with no accompanying diarrhea. Sequential stool samples prior to EAdv infections were tested for adenovirus antigen, anti-adenoviral IgA and neutralizing antibodies to serotypes 40, 41 and 2 in order to ascertain whether protection from symptoms was due to prior infection. No difference was found in the number of adenoviral infections among infants prior to their EAdv infections with or without accompanying diarrhea. However, in 3 of the 5 infants in whom EAdv infection was accompanied by diarrhea and 2 of 3 control infants, previous EAdv infections had occurred as detected by serotype-specific antibody rises.