Nipah virus infection outbreak with nosocomial and corpse-to-human transmission, Bangladesh.

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.

Influenza-associated mortality in 2009 in four sentinel sites in Bangladesh.

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.

Incidence of influenza-like illness and severe acute respiratory infection during three influenza seasons in Bangladesh, 2008-2010.

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.

Resumen OBJETIVO: Determinar en qué medida contribuye la gripe a la enfermedad respiratoria aguda grave (ERAG), una de las principales causas de muerte infantil, en personas de todas las edades en Bangladesh. MÉTODOS: Los médicos tomaron muestras de exudado nasal y faríngeo para realizar la prueba del virus de la gripe en pacientes que estuvieron hospitalizados en los 7 días posteriores al inicio de la infección respiratoria agua grave (IRAG) o que acudieron a consulta como pacientes ambulatorios por síndrome gripal (SG). Se llevó a cabo un estudio sobre el uso de la asistencia sanitaria comunitaria para determinar la proporción de residentes del área de cobertura del hospital que solicitaron asistencia médica en hospitales pertenecientes al estudio y se calculó la incidencia de la gripe con este denominador. RESULTADOS: La incidencia estimada de la IRAG asociada con la gripe en niños menores de 5 años fue del 6,7 (95% de intervalo de confianza, IC: 0-18,3); 4,4 (95% IC: 0-13,4) y 6,5 por 1000 años-persona (95% IC: 0-8,3/1000) durante las temporadas de gripe de 2008, 2009 y 2010, respectivamente. La incidencia de la IRAG en las personas con una edad igual o superior a 5 años fue del 1,1 (95% IC: 0,4- 2,0) y 1,3 (95% IC: 0,5-2,2) por 10 000 años-persona durante 2009 y 2010, respectivamente. La incidencia de la gripe de temporada tratada médicamente y confirmada en laboratorio en pacientes ambulatorios con SG fue de 10 (95% IC: 8-14); 6,6 (95% IC: 5-9) y 17 por 100 años-persona (95% IC: 13-22/1000) durante las temporadas de gripe de 2008, 2009 y 2010, respectivamente. CONCLUSIÓN: El síndrome gripal es una causa frecuente de consulta en los centros ambulatorios en Bangladesh. La proporción de niños menores de 5 años hospitalizados por gripe es mayor que la de niños en otros grupos de edad.

Résumé OBJECTIF: Déterminer l'impact de la grippe sur le syndrome respiratoire aigu sévère (SRAS), une cause majeure de la mortalité chez les enfants, chez les personnes de tous les âges au Bangladesh. MÉTHODES: Les médecins ont obtenu des écouvillons de prélèvement de nez et de gorge afin de tester le virus de la grippe chez des patients qui avaient été hospitalisés dans les 7 jours suivants l'apparition de l'infection respiratoire aiguë sévère (SRAS) ou qui avaient eu une consultation déambulatoire pour un syndrome de type grippal (STG). Une enquête sur l'utilisation des soins de santé communautaires a été effectuée afin de définir la proportion des riverains de la circonscription hospitalière, qui avaient reçu des soins dans les hôpitaux universitaires, et afin de calculer l'incidence de la grippe à l'aide de ce dénominateur. RÉSULTATS: L'estimation de l'incidence du SRAS associé à la grippe chez les enfants de moins de 5 ans était de 6,7 (intervalle de confiance de 95%, IC: 0-18.3); de 4,4 (IC de 95%: 0-13.4) et de 6,5 pour 1 000 personnes-années (IC de 95%: 0-8.3/1000) lors des saisons de la grippe de 2008, 2009 et 2010, respectivement. L'incidence du SRAS chez les personnes âgées de plus de 5 ans était de 1,1 (IC de 95%: 0.4-2.0) et 1,3 (IC de 95%: 0.5-2.2) pour 10 000 personnes-années en 2009 et 2010, respectivement. L'incidence de la grippe saisonnière traitée médicalement et confirmée en laboratoire chez les patients en consultation ambulatoire souffrant du STG était de 10 (IC de 95%: 8-14), 6,6 (IC de 95%: 5-9) et de 17 pour 100 personnes-années (IC de 95%: 13-22) lors des saisons de la grippe de 2008, 2009 et 2010, respectivement. CONCLUSION: Le syndrome de type grippal est une cause fréquente de consultation dans la configuration de la consultation ambulatoire au Bangladesh. Les enfants de moins de 5 ans sont hospitalisés pour la grippe dans des proportions supérieures aux enfants des autres groupes d'âge.

Efficacy of pentavalent rotavirus vaccine against severe rotavirus gastroenteritis in infants in developing countries in Asia: a randomised, double-blind, placebo-controlled trial.

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.

Origin of dengue type 3 viruses associated with the dengue outbreak in Dhaka, Bangladesh, in 2000 and 2001.

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.

Aetiology of diarrhoea in a birth cohort of children aged 0-2 year(s) in rural Mirzapur, Bangladesh.

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.

Typing of human rotaviruses: nucleotide mismatches between the VP7 gene and primer are associated with genotyping failure.

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.

Cluster of Nipah virus infection, Kushtia District, Bangladesh, 2007.

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.

Prevalence of G2P[4] and G12P[6] rotavirus, Bangladesh.

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.

Viral etiology of pneumonia in a cohort of newborns till 24 months of age in Rural Mirzapur, 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.

Characterization of a novel P[25],G11 human group a rotavirus.

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].

Chromatography paper strip method for collection, transportation, and storage of rotavirus RNA in stool samples.

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 and cytokine responses in Bangladeshi children with rotavirus diarrhoea.

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.