Showing papers by "International Centre for Diarrhoeal Disease Research, Bangladesh published in 2005"
TL;DR: The pathogenesis of ETEC-induced diarrhea is similar to that of cholera and includes the production of enterotoxins and colonization factors, and clinical symptoms can range from mild diarrhea to a severe choline-like syndrome.
Abstract: ETEC is an underrecognized but extremely important cause of diarrhea in the developing world where there is inadequate clean water and poor sanitation. It is the most frequent bacterial cause of diarrhea in children and adults living in these areas and also the most common cause of traveler's diarrhea. ETEC diarrhea is most frequently seen in children, suggesting that a protective immune response occurs with age. The pathogenesis of ETEC-induced diarrhea is similar to that of cholera and includes the production of enterotoxins and colonization factors. The clinical symptoms of ETEC infection can range from mild diarrhea to a severe cholera-like syndrome. The effective treatment of ETEC diarrhea by rehydration is similar to treatment for cholera, but antibiotics are not used routinely for treatment except in traveler's diarrhea. The frequency and characterization of ETEC on a worldwide scale are inadequate because of the difficulty in recognizing the organisms; no simple diagnostic tests are presently available. Protection strategies, as for other enteric infections, include improvements in hygiene and development of effective vaccines. Increases in antimicrobial resistance will dictate the drugs used for the treatment of traveler's diarrhea. Efforts need to be made to improve our understanding of the worldwide importance of ETEC.
898Â citations
TL;DR: The data support the conclusion that cholERA phages can influence cholera seasonality and may also play a role in emergence of new V. cholerae pandemic serogroups or clones.
Abstract: The relationship among (i) the local incidence of cholera, (ii) the prevalence in the aquatic environment of Vibrio cholerae, and (iii) bacterial viruses that attack potentially virulent O1 and O139 serogroup strains of this organism (cholera phages) was studied in Dhaka, Bangladesh. Over nearly a 3-year period, we found that significantly more environmental water samples contained either a phage or a phage-susceptible V. cholerae strain than both (P < 0.00001). The number of cholera patients varied seasonally during this period and frequently coincided with the presence of pathogenic V. cholerae strains in water samples that otherwise lacked detectable cholera phages. Interepidemic periods were characterized by water samples containing cholera phages but no viable bacteria. Our data support the conclusion that cholera phages can influence cholera seasonality and may also play a role in emergence of new V. cholerae pandemic serogroups or clones.
325Â citations
TL;DR: Development, implementation, and monitoring of national action plans for neonatal survival is a priority and the running costs of the selected packages at 90% coverage in the 75 countries with the highest mortality rates are estimated to be US4.1 billion dollars a year.
323Â citations
TL;DR: The results of environmental sampling and analysis of the environmental and clinical data have revealed significant correlations of water temperature, water depth, rainfall, conductivity, and copepod counts with the occurrence of cholera toxin-producing bacteria (presumably V. cholerae).
Abstract: The occurrence of outbreaks of cholera in Africa in 1970 and in Latin America in 1991, mainly in coastal communities, and the appearance of the new serotype Vibrio cholerae O139 in India and subsequently in Bangladesh have stimulated efforts to understand environmental factors influencing the growth and geographic distribution of epidemic Vibrio cholerae serotypes. Because of the severity of recent epidemics, cholera is now being considered by some infectious disease investigators as a "reemerging" disease, prompting new work on the ecology of vibrios. Epidemiological and ecological surveillance for cholera has been under way in four rural, geographically separated locations in Bangladesh for the past 4 years, during which both clinical and environmental samples were collected at biweekly intervals. The clinical epidemiology portion of the research has been published (Sack et al., J. Infect. Dis. 187:96-101, 2003). The results of environmental sampling and analysis of the environmental and clinical data have revealed significant correlations of water temperature, water depth, rainfall, conductivity, and copepod counts with the occurrence of cholera toxin-producing bacteria (presumably V. cholerae). The lag periods between increases or decreases in units of factors, such as temperature and salinity, and occurrence of cholera correlate with biological parameters, e.g., plankton population blooms. The new information on the ecology of V. cholerae is proving useful in developing environmental models for the prediction of cholera epidemics.
321Â citations
TL;DR: In addition to providing direct protection to vaccine recipients, killed oral cholera vaccines confer significant herd protection to neighbouring non-vaccinated individuals.
303Â citations
TL;DR: Factors associated with domestic violence in urban and rural Bangladesh revealed that in both residential areas, dowry or other demands in marriage and a history of abuse of the husband's mother by his father increased the risk of violence.
Abstract: Using data from a population-based survey of 2,702 women of reproductive age and from 28 in-depth interviews of abused women conducted during 2000-01, this study explores factors associated with domestic violence in urban and rural Bangladesh. Multilevel analysis revealed that in both residential areas, dowry or other demands in marriage and a history of abuse of the husband's mother by his father increased the risk of violence. Better spousal communication and husband's education beyond the tenth grade decreased the risk of violence. In the urban area, women's being younger than their husband and participating in savings and credit groups increased the risk of abuse, whereas husband's education beyond the sixth grade had a protective effect. In the rural area, women's earning an income increased the risk. These factors are important to consider when designing interventions.
263Â citations
TL;DR: The rBS-WC vaccine was highly effective against clinically significant cholera in an urban sub-Saharan African population with a high prevalence of HIV infection.
Abstract: Background New-generation, orally administered cholera vaccines offer the promise of improved control of cholera in sub-Saharan Africa. However, the high prevalence of human immunodeficiency virus (HIV) infection in many cholera-affected African populations has raised doubts about the level of protection possible with vaccination. We evaluated a mass immunization program with recombinant cholera-toxin B subunit, killed whole-cell (rBS-WC) oral cholera vaccine in Beira, Mozambique, a city where the seroprevalence of HIV is 20 to 30 percent. Methods From December 2003 to January 2004, we undertook mass immunization of nonpregnant persons at least two years of age, using a two-dose regimen of rBS-WC vaccine in Esturro, Beira (population 21,818). We then assessed vaccine protection in a case–control study during an outbreak of El Tor Ogawa cholera in Beira between January and May 2004. To estimate the level of vaccine protection, antecedent rates of vaccination were compared between persons with culture-confi...
244Â citations
TL;DR: A regression model showed that children in a Dhaka urban slum with a bacteremic typhoid fever incidence of 3.9 episodes/1,000 person-years were clinically ill, which suggests a role for preschool immunization.
Abstract: We confirmed a bacteremic typhoid fever incidence of 3.9 episodes/1,000 person-years during fever surveillance in a Dhaka urban slum. The relative risk for preschool children compared with older persons was 8.9. Our regression model showed that these children were clinically ill, which suggests a role for preschool immunization.
243Â citations
TL;DR: The genetic characterization of a new strain of NV isolated during outbreaks in Bangladesh in 2004 is described, which confirms that NV was the etiologic agent responsible for these outbreaks.
Abstract: Until 2004, identification of Nipah virus (NV)-like outbreaks in Bangladesh was based on serology. We describe the genetic characterization of a new strain of NV isolated during outbreaks in Bangladesh (NV-B) in 2004, which confirms that NV was the etiologic agent responsible for these outbreaks.
230Â citations
TL;DR: Host-mediated phage amplification during the cholera epidemic likely contributed to increased environmental phage abundance, decreased load of environmental V. cholerae and, hence, the collapse of the epidemic.
Abstract: Phage predation of Vibrio cholerae has recently been reported to be a factor that influences seasonal epidemics of cholera in Bangladesh To understand more about this phenomenon, we studied the dynamics of the V cholerae-phage interaction during a recent epidemic in Dhaka Because the outbreak strain causing this epidemic was resistant to multiple antibiotics, including streptomycin, we used a selective medium containing streptomycin to monitor accurately the abundance of this strain in the environment The changing prevalence in the environment of the epidemic V cholerae O1 strain and a particular lytic cholera phage (JSF4) to which it was sensitive was measured every 48-72 h for 17 weeks We also monitored the incidence of phage excretion in stools of 387 cholera patients during the epidemic The peak of the epidemic was preceded by high V cholerae prevalence in the environment and was followed by high JSF4 phage levels as the epidemic ended The buildup to the phage peak in the environment coincided with increasing excretion of the same phage in the stools of cholera patients These results suggest that patients toward the end of the epidemic ingested both JSF4 phage and the outbreak V cholerae strain Host-mediated phage amplification during the cholera epidemic likely contributed to increased environmental phage abundance, decreased load of environmental V cholerae and, hence, the collapse of the epidemic Thus, in vivo phage amplification in patients and subsequent phage predation in the environment may explain the self-limiting nature of seasonal cholera epidemics in Bangladesh
216Â citations
TL;DR: It is made the novel observation that persons with blood group O were less likely than those with other blood groups to become infected with V. cholerae O1 and O139 as well as the risk of developing severe symptoms once infected.
Abstract: Individuals with blood group O are more susceptible than other individuals to severe cholera, although the mechanism underlying this association is unknown. To assess the respective roles of both intrinsic host factors and adaptive immune responses that might influence susceptibility to infection with Vibrio cholerae, we prospectively followed a cohort of household contacts of patients with cholera in Bangladesh. In this study, we made the novel observation that persons with blood group O were less likely than those with other blood groups to become infected with V. cholerae O1 (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.53 to 0.85; P = 0.008). Consistent with prior studies, however, household contacts with blood group O were more likely to develop severe illness if infected with V. cholerae O1 (OR, 2.3; 95% CI, 0.98 to 5.59; P = 0.05). While blood group O protected significantly against infection with V. cholerae O1, there was no evidence of protection against V. cholerae O139. A multivariate analysis demonstrated that the association between blood group O and protection from infection with V. cholerae O1 was independent of age, gender, and baseline anti-cholera toxin and vibriocidal antibody titers. Based on this epidemiologic evidence, we propose a hypothesis for understanding the association between blood group O and the risk of infection with V. cholerae O1 and O139 as well as the risk of developing severe symptoms once infected.
TL;DR: Strong clustering is confirmed and it is suggested that insecticide-treated nets could be effective in preventing kala-azar.
Abstract: Since 1990, South Asia has experienced a resurgence of kala-azar (visceral leishmaniasis). To determine risk factors for kala-azar, we performed cross-sectional surveys over a 3-year period in a Bangladeshi community. By history, active case detection, and serologic screening, 155 of 2,356 residents had kala-azar with onset from 2000 to 2003. Risk was highest for persons 3–45 years of age, and no significant difference by sex was seen. In age-adjusted multivariable models, 3 factors were identified: proximity to a previous kala-azar patient (odds ratio [OR] 25.4, 95% confidence interval [CI] 15–44 within household; OR 3.2 95% CI 1.7–6.1 within 50 m), bed net use in summer (OR 0.7, 95% CI 0.53–0.93), and cattle per 1,000 m2 (OR 0.8, 95% CI 0.70–0.94]). No difference was seen by income, education, or occupation; land ownership or other assets; housing materials and condition; or keeping goats or chickens inside bedrooms. Our data confirm strong clustering and suggest that insecticide-treated nets could be effective in preventing kala-azar.
TL;DR: Although fatalism and cultural acceptance of high mortality have been cited as reasons for high levels of neonatal mortality, Sylheti families seek to protect newborns in several ways, which have implications for the design of interventions for neonatal care.
TL;DR: All three methods for the detection of E. histolytica were highly specific, with real-time PCR being the most sensitive.
Abstract: We developed a real-time-PCR assay utilizing a molecular-beacon probe for the detection of Entamoeba histolytica and compared its sensitivity to stool antigen detection and traditional PCR. A total of 205 stool and liver abscess pus specimens from patients and controls were used for this purpose, 101 (49%) of which were positive by the TechLab E. histolytica-specific antigen detection test, while the other 104 (51%) stool and liver abscess pus specimens were negative by the antigen detection test. DNA was extracted from the stool and liver abscess pus specimens by the QIAGEN method and the small-subunit rRNA gene of E. histolytica and then amplified by traditional and real-time PCR. Out of these 205 stool and liver abscess pus specimens, 124 were positive by the real-time-PCR assay and 90 were positive by the traditional-PCR test. Compared to the real-time-PCR assay, the antigen detection test was 79% sensitive and 96% specific. When the traditional-PCR test results were compared to the real-time-PCR assay, the sensitivity of traditional PCR was 72% and the specificity was 99%. In conclusion, all three methods for the detection of E. histolytica were highly specific, with real-time PCR being the most sensitive.
TL;DR: It can be concluded from the findings of the study that intensive nutrition education significantly improves the status of moderately-malnourished children with or without supplementary feeding.
Abstract: This prospective randomized trial was carried out to test the efficacy of a specific intervention for reducing the extent of their malnutrition and to change behaviour of mothers relating to child-feeding practices, care-giving, and health-seeking practices under the Bangladesh Integrated Nutrition Project (BINP). The study was conducted in rural Bangladesh among 282 moderately-malnourished (weight-for-age between 61% and 75% of median of the National Center for Health Statistics standard) children aged 6-24 months. Mothers of the first intervention group received intensive nutrition education (INE group) twice a week for three months. The second intervention group received the same nutrition education, and their children received additional supplementary feeding (INE+SF group). The comparison group received nutrition education from the community nutrition promoters twice a month according to the standard routine service of BINP. The children were observed for a further six months. After three months of interventions, a significantly higher proportion of children in the INE and INE+SF groups improved (37% and 47% respectively) from moderate to mild or normal nutrition compared to the comparison group (18%) (p<0.001). At the end of six months of observation, the nutritional status of children in the intervention groups improved further from moderate to mild or normal nutrition compared to the comparison group (59% and 86% vs 30%, p<0.0001). As the intensive nutrition education and supplementation given were highly effective, more children improved from moderate malnutrition to mild or normal nutritional status despite a higher incidence of morbidity. The frequency of child feeding and homebased complementary feeding improved significantly (p<0.001) in both the intervention groups after three months of interventions and six months of observation. Body-weight gain was positively associated with age, length-for-age, weight-for-length, frequency of feeding of khichuri, egg, and potato (p<0.05). Ability of mothers to identify malnutrition improved from 15% to 99% in the INE group and from 15% to 100% in the INE+SF group, but reduced from 24% to 21% in the comparison group. Use of separate feed pots, frequency of feeding, and cooking of additional complementary feeds improved significantly in the INE and INE+SF groups compared to the comparison group after three months of interventions and six months of observation. It can be concluded from the findings of the study that intensive nutrition education significantly improves the status of moderately-malnourished children with or without supplementary feeding.
TL;DR: Enterotoxigenic Escherichia coli (ETEC) was almost as prevalent as Vibrio cholerae O1 in diarrheal stools in Dhaka in July 2004, and 78% of strains had colonization factors.
Abstract: Flooding in Dhaka in July 2004 caused epidemics of diarrhea. Enterotoxigenic Escherichia coli (ETEC) was almost as prevalent as Vibrio cholerae O1 in diarrheal stools. ETEC that produced heat-stable enterotoxin alone was most prevalent, and 78% of strains had colonization factors. Like V. cholerae O1, ETEC can cause epidemic diarrhea.
TL;DR: It is concluded that although greater intakes of complementary foods were associated with higher total energy intake, micronutrient intake remained low due to the low micRONutrient density of the complementary foods consumed and the partial displacement of breast milk.
Abstract: We assessed the adequacy of nutrient intakes of 135 rural Bangladeshi breast-fed infants 6-12 mo of age and examined nutritional trade-offs due to possible displacement of breast milk by complementary foods. Observers completed 12-h daytime measurements of breast milk and complementary food intakes; data for the previous 12 h were obtained from maternal recall, yielding estimates of total 24-h intakes. On average, infants were mildly wasted (mean +/- SD weight-for-length Z-score = -0.92 +/- 0.88) and moderately stunted (length-for-age Z-score = -1.49 +/- 0.96). Total energy intakes at 6-8 and 9-12 mo were 88 and 86% of absolute energy requirements (kJ/d), 106 and 105% of requirements per kg body weight, and 97 and 94% of requirements per kg median weight-for-length, respectively. Breast milk contributed 78% of energy intake at 6-8 mo and 75% at 9-12 mo. Mean meal frequency and energy density of complementary foods were generally consistent with recommendations, but only small amounts of food were offered. Nevertheless, only 72% of the food energy offered was consumed. Total energy intake was positively correlated with meal frequency, quantity consumed per meal, and energy intake from breast milk, but not with energy density of complementary foods. Energy intake from complementary foods was inversely related to energy intake from breast milk. The diets fell short of recommended intakes for numerous vitamins and minerals. We conclude that although greater intakes of complementary foods were associated with higher total energy intake, micronutrient intake remained low due to the low micronutrient density of the complementary foods consumed and the partial displacement of breast milk.
TL;DR: The authors collected acute-phase serum samples from febrile patients at 2 major hospitals in Dhaka, Bangladesh, during an outbreak of dengue fever in 2001 and found that the case-fatality rate among leptospirosis patients (5%) was higher than among d Dengue fever patients (1.2%).
Abstract: We collected acute-phase serum samples from febrile patients at 2 major hospitals in Dhaka, Bangladesh, during an outbreak of dengue fever in 2001. A total of 18% of dengue-negative patients tested positive for leptospirosis. The case-fatality rate among leptospirosis patients (5%) was higher than among dengue fever patients (1.2%).
TL;DR: Comparison of the VP4 gene sequences with all currently recognized 24 different P genotypes revealed only low nucleotide and amino acid sequence identities, which indicates that the Dhaka6 isolate represents a new group A rotavirus P genotype, to which the proposed assignment of the designation P is proposed.
Abstract: 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].
Universidade Federal de Pelotas1, Ifakara Health Institute2, University of London3, National University of San Marcos4, Federal University of Ceará5, International Centre for Diarrhoeal Disease Research, Bangladesh6, Makerere University7, World Health Organization8, University of Brescia9, Royal Tropical Institute10, Cornell University11
TL;DR: The experience acquired in measuring and accounting for contextual factors in the Multi-Country Evaluation of the IMCI (Integrated Management of Childhood Illness) strategy in five countries is described and two case studies show how appropriate consideration of contextual factors may help explain apparently conflicting evaluation results.
Abstract: Appropriate consideration of contextual factors is essential for ensuring internal and external validity of randomized and non-randomized evaluations. Contextual factors may confound the association between delivery of the intervention and its potential health impact. They may also modify the effect of the intervention or programme, thus affecting the generalizability of results. This is particularly true for large-scale health programmes, for which impact may vary substantially from one context to another. Understanding the nature and role of contextual factors may improve the validity of study results, as well as help predict programme impact across sites. This paper describes the experience acquired in measuring and accounting for contextual factors in the Multi-Country Evaluation of the IMCI (Integrated Management of Childhood Illness) strategy in five countries: Bangladesh, Brazil, Peru, Uganda and Tanzania. Two main types of contextual factors were identified. Implementation-related factors include the characteristics of the health systems where IMCI was implemented, such as utilization rates, basic skills of health workers, and availability of drugs, supervision and referral. Impact-related factors include baseline levels and patterns of child mortality and nutritional status, which affect the scope for programme impact. We describe the strategies used in the IMCI evaluation in order to obtain data on relevant contextual factors and to incorporate them in the analyses. Two case studies - from Tanzania and Peru - show how appropriate consideration of contextual factors may help explain apparently conflicting evaluation results.
TL;DR: This is the first report of the isolation of pandemic strains of V. parahaemolyticus in sub-Saharan Africa and clearly indicates that the pandemic has spread into the African continent.
Abstract: Forty-two episodes of Vibrio parahaemolyticus infections were detected in Beira, Mozambique, from January to May 2004. The majority of the isolates (81%) belonged to the pandemic serovars (O3:K6 and O4:K68) of V. parahaemolyticus. The pandemic serovars were positive by group-specific PCR (GS-PCR) and a PCR specific for open reading frame ORF8 (ORF8-PCR), which are molecular markers of the pandemic clone, and were positive for tdh but negative for trh. The remaining 19% of the strains also possessed the tdh gene but were GS-PCR and ORF8-PCR negative and did not belong to the pandemic serovars. Patients with V. parahaemolyticus infection were older (mean age, 27 years) than patients infected by other diarrheal agents (mean age, 21 years). Ten percent of diarrhea patients from whom no V. parahaemolyticus was cultured were severely dehydrated, but none of the V. parahaemolyticus cases were severely dehydrated. This is the first report of the isolation of pandemic strains of V. parahaemolyticus in sub-Saharan Africa and clearly indicates that the pandemic of V. parahaemolyticus has spread into the African continent.
TL;DR: The pattern of gene expression indicates that the human upper intestine may be a uniquely suitable environment for the transfer of genetic elements that are important in the evolution of pathogenic strains of V. cholerae in the human host and have implications for cholera control and the design of improved vaccines.
Abstract: Understanding gene expression by bacteria during the actual course of human infection may provide important insights into microbial pathogenesis. In this study, we evaluated the transcriptional profile of Vibrio cholerae, the causative agent of cholera, in clinical specimens from cholera patients. We collected samples of human stool and vomitus that were positive by dark-field microscopy for abundant vibrios and used a microarray to compare gene expression in organisms recovered directly from specimens collected during the early and late stages of human infection. Our results reveal that V. cholerae gene expression within the human host environment differs from patterns defined in in vitro models of pathogenesis. tcpA, the major subunit of the essential V. cholerae colonization factor, was significantly more highly expressed in early than in late stages of infection; however, the genes encoding cholera toxin were not highly expressed in either phase of human infection. Furthermore, expression of the virulence regulators toxRS and tcpPH was uncoupled. Interestingly, the pattern of gene expression indicates that the human upper intestine may be a uniquely suitable environment for the transfer of genetic elements that are important in the evolution of pathogenic strains of V. cholerae. These findings provide a more detailed assessment of the transcriptome of V. cholerae in the human host than previous studies of organisms in stool alone and have implications for cholera control and the design of improved vaccines.
TL;DR: An urgent need for interventions to improve the quality of care provided for sick children in first-level facilities in Bangladesh is demonstrated, and the findings suggest that the IMCI strategy offers a promising set of interventions to address the child health service problems in Bangladesh.
Abstract: OBJECTIVE: The multi-country evaluation of Integrated Management of Childhood Illness (IMCI) effectiveness, cost and impact (MCE) is a global evaluation to determine the impact of IMCI on health outcomes and its cost-effectiveness. MCE studies are under way in Bangladesh, Brazil, Peru, Uganda and the United Republic of Tanzania. The objective of this analysis from the Bangladesh MCE study was to describe the quality of care delivered to sick children under 5 years old in first-level government health facilities, to inform government planning of child health programmes. METHODS: Generic MCE Health Facility Survey tools were adapted, translated and pre-tested. Medical doctors trained in IMCI and these tools conducted the survey in all 19 health facilities in the study areas. The data were collected using observations, exit interviews, inventories and interviews with facility providers. FINDINGS: Few of the sick children seeking care at these facilities were fully assessed or correctly treated, and almost none of their caregivers were advised on how to continue the care of the child at home. Over one-third of the sick children whose care was observed were managed by lower-level workers who were significantly more likely than higher-level workers to classify the sick child correctly and to provide correct information on home care to the caregiver. CONCLUSION: These results demonstrate an urgent need for interventions to improve the quality of care provided for sick children in first-level facilities in Bangladesh, and suggest that including lower-level workers as targets for IMCI case-management training may be beneficial. The findings suggest that the IMCI strategy offers a promising set of interventions to address the child health service problems in Bangladesh.
TL;DR: Although the first introduction of G9 isolates in the Belgian population was recorded in 1997, G9 strains were able to establish themselves quickly as the predominant genotype, indicating the urgent consideration of the G9 moiety in rotavirus vaccines.
TL;DR: A single-reaction multiplex real-time PCR assay distinguishes assemblage A Giardia infections from assemblages B infections directly on fecal samples and may aid epidemiologic investigation.
Abstract: Two major genotypic assemblages of Giardia lamblia infect humans; the epidemiologic significance of this phenomenon is poorly understood. We developed a single-vessel multiplex real-time PCR (qPCR) assay that genotypes Giardia infections into assemblages A and/or B directly from fecal samples. The assay utilized Scorpion probes that combined genotype-specific primers and probes for the 18S rRNA gene into the same molecule. The protocol was capable of detecting as few as 20 trophozoites per PCR on fecal DNA isolated using a commercial method or 1.25 trophozoites per PCR on fecal DNA isolated using a G. lamblia-specific oligonucleotide capture technique. The assay was specific for fecal specimens, with no amplification of the discordant genotype with the opposite Scorpion probe. When 97 clinical specimens from Bangladesh were used, the multiplex PCR assay detected 95% (21 of 22) of Giardia microscopy-positive specimens and 18% (13 of 74) of microscopy-negative specimens. Microscopy-negative and qPCR-positive specimens had higher average cycle threshold values than microscopy-positive and qPCR-positive specimens, suggesting that they represented true low-burden infections. Most (32 of 35) infections were assemblage B infections. This single-reaction multiplex qPCR assay distinguishes assemblage A Giardia infections from assemblage B infections directly on fecal samples and may aid epidemiologic investigation.
TL;DR: It is demonstrated that passage of V. cholerae through the infant mouse intestine leads to an equivalent degree of hyperinfectivity as passage through the human host.
Abstract: It has previously been shown that passage of Vibrio cholerae through the human intestine imparts a transient hyperinfectious phenotype that may contribute to the epidemic spread of cholera. The mechanism underlying this human-passaged hyperinfectivity is incompletely understood, in part due to inherent difficulties in recovering and studying organisms that are freshly passed in human stool. Here, we demonstrate that passage of V. cholerae through the infant mouse intestine leads to an equivalent degree of hyperinfectivity as passage through the human host. We have used this infant mouse model of host-passaged hyperinfectivity to characterize the timing and the anatomic location of the competitive advantage of mouse-passaged V. cholerae as well as the contribution of three type IV pili to the phenotype.
TL;DR: The safety and immunogenicity of this Peru-15 vaccine candidate indicates the usefulness of future studies in Bangladesh, where cholera is endemic, and a lower immunological response against cholERA toxin B subunit was detected.
Abstract: BACKGROUND: A live oral Vibrio cholerae O1 El Tor vaccine candidate, Peru-15, was studied for safety, immunogenicity, and excretion in phase 1 (inpatient) and phase 2 (outpatient) studies of Bangladeshi adults.METHODs. The study was conducted among adults, by use of a double-blind, randomized, placebo-controlled design. A single dose of Peru-15 (approximately 2 x 108 cfu) or placebo (buffer only) was given in standard bicarbonate and ascorbic acid buffer.RESULTS. Study treatment did not elicit any major adverse events in the volunteers, during either the inpatient or the outpatient phases, and there were no reports of diarrhea. V. cholerae was isolated from the stool of only 1 volunteer and was found to be genetically identical to the vaccine strain. Vibriocidal antibody responses were seen in 30 (75%) of 40 vaccine recipients and in 3 (10%) of 30 placebo recipients. Peripheral blood immunoglobulin (Ig) A and IgM antibody-secreting cell responses to lipopolysaccharide were seen in the majority of vaccine recipients (response rate, 78%--88%). Seroconversion for lipopolysaccharide-specific IgA antibodies was seen in 88% of vaccine recipients. The response in vaccine recipients was significantly higher than that in placebo recipients, in all of the immunological assays (P=.036 to <.001). A lower immunological response against cholera toxin B subunit was detected.CONCLUSIONS. The safety and immunogenicity of this Peru-15 vaccine candidate indicates the usefulness of future studies in Bangladesh, where cholera is endemic.
TL;DR: Phylogenetic analysis suggested that all human group C rotaviruses, including the strains isolated in the authors' study, clustered in a monophyletic branch, which was distantly related to the branch comprised of animal group CRotavirus.
Abstract: Group C rotaviruses were detected by reverse transcription-PCR in 14 (2.3%) of 611 group A rotavirus-negative stool specimens from the patients admitted to the International Centre for Diarrhoeal Disease Research, Bangladesh hospital, Dhaka, Bangladesh, during July to December 2003. The low rate of detection suggested that infection with group C rotaviruses was an uncommon cause of hospitalization due to gastroenteritis. In addition, coinfections with pathogenic enteric bacteria were frequently observed in group C rotavirus-infected patients. Nucleotide sequence comparison of the VP4, VP6, and VP7 genes revealed that the Bangladeshi group C rotaviruses were most similar to Nigerian group C rotavirus strains. Phylogenetic analysis suggested that all human group C rotaviruses, including the strains isolated in our study, clustered in a monophyletic branch, which was distantly related to the branch comprised of animal group C rotaviruses.
TL;DR: The study examines the relationship between pregnancy spacing and seven measures of maternal morbidity in Matlab, Bangladesh to find out if there is a positive relationship between spacing and morbidity.
TL;DR: The prevalence of STIs/RTIs among SWs in brothels in Bangladesh is high and an intervention strategy addressing both symptomatic and asymptomatic infections and periodic screening of SWs for RTIs/STIs is essential for successful HIV and STIs prevention programs.
Abstract: Objective and Goal:The goal of this study was to study the prevalence of sexually transmitted infections (STIs)/reproductive tract infections (RTIs) among brothel-based sex workers (SWs) in Bangladesh.Study:A cross-sectional study was conducted among SWs in 4 randomly selected brothels. A sociodemog