Showing papers by "International Centre for Diarrhoeal Disease Research, Bangladesh published in 2006"
TL;DR: A broad perspective on maternal health is taken and links to a range of global survival initiatives, particularly neonatal health, HIV, and malaria, and to reproductive health.
549 citations
TL;DR: Teams of providers are the efficient option, creating the possibility of scaling up as much as 10 times more quickly than would be the case with deployment of solo health workers in home deliveries with dedicated or multipurpose workers.
522 citations
TL;DR: The Nipah virus was likely transmitted from fruit bats to humans by drinking fresh date palm sap, according to the TOC summary line, which indicates that drinking freshdate palm sap may be a source of infection for humans.
Abstract: We investigated an outbreak of encephalitis in Tangail District, Bangladesh. We defined case-patients as persons from the outbreak area in whom fever developed with new onset of seizures or altered mental status from December 15, 2004, through January 31, 2005. Twelve persons met the definition; 11 (92%) died. Serum specimens were available from 3; 2 had immunoglobulin M antibodies against Nipah virus by capture enzyme immunoassay. We enrolled 11 case-patients and 33 neighborhood controls in a case-control study. The only exposure significantly associated with illness was drinking raw date palm sap (64% among case-patients vs. 18% among controls, odds ratio [OR] 7.9, p = 0.01). Fruit bats (Pteropus giganteus) are a nuisance to date palm sap collectors because the bats drink from the clay pots used to collect the sap at night. This investigation suggests that Nipah virus was transmitted from P. giganteus to persons through drinking fresh date palm sap.
391 citations
TL;DR: In this paper, a norm-based explanation for the fertility transition in rural Bangladesh is provided, where norms are organized at the level of the religious group and interactions rarely cross religious boundaries.
306 citations
TL;DR: The results of this study support a model of cholera transmission in which in vivo-formed biofilms contribute to enhanced infectivity and environmental persistence of pathogenic V. cholerae.
Abstract: The factors that enhance the waterborne spread of bacterial epidemics and sustain the epidemic strain in nature are unclear. Although the epidemic diarrheal disease cholera is known to be transmitted by water contaminated with pathogenic Vibrio cholerae, routine isolation of pathogenic strains from aquatic environments is challenging. Here, we show that conditionally viable environmental cells (CVEC) of pathogenic V. cholerae that resist cultivation by conventional techniques exist in surface water as aggregates (biofilms) of partially dormant cells. Such CVEC can be recovered as fully virulent bacteria by inoculating the water into rabbit intestines. Furthermore, when V. cholerae shed in stools of cholera patients are inoculated in environmental water samples in the laboratory, the cells exhibit characteristics similar to CVEC, suggesting that CVEC are the infectious form of V. cholerae in water and that CVEC in nature may have been derived from human cholera stools. We also observed that stools from cholera patients contain a heterogenous mixture of biofilm-like aggregates and free-swimming planktonic cells of V. cholerae. Estimation of the relative infectivity of these different forms of V. cholerae cells suggested that the enhanced infectivity of V. cholerae shed in human stools is largely due to the presence of clumps of cells that disperse in vivo, providing a high dose of the pathogen. The results of this study support a model of cholera transmission in which in vivo-formed biofilms contribute to enhanced infectivity and environmental persistence of pathogenic V. cholerae.
299 citations
TL;DR: Oral butyrate treatment in shigellosis may be of clinical value because of induction of the endogenous cathelicidin CAP-18 in the colonic epithelium, stimulation of the release of the active peptide CAP- 18, and promoting elimination of Shigella.
Abstract: Shigella is a major cause of morbidity, mortality, and growth retardation for children in developing countries. Emergence of antibiotic resistance among Shigellae demands the development of effective medicines. Previous studies found that the endogenous antimicrobial peptide LL-37 is down-regulated in the rectal epithelium of patients during shigellosis and that butyrate up-regulates the expression of LL-37 in colonic epithelial cells in vitro and decreases severity of inflammation in experimental shigellosis. In this study, Shigella-infected dysenteric rabbits were treated with butyrate (0.14 mmol/kg of body weight) twice daily for 3 days, and the expression levels of the rabbit homologue to LL-37, CAP-18, were monitored in the colon. Butyrate treatment resulted in (i) reduced clinical illness, severity of inflammation in the colon, and bacterial load in the stool, (ii) significant up-regulation of CAP-18 in the surface epithelium, and (iii) disappearance of CAP-18-positive cells in lamina propria. The active CAP-18 peptide was released in stool from its proform by butyrate treatment. In healthy controls, CAP-18 expression was localized predominantly to the epithelial surface of the colon. In infected rabbits, CAP-18 expression was localized to immune and inflammatory cells in the colon, whereas the ulcerated epithelium was devoid of CAP-18 expression. The combination of CAP-18 and butyrate was more efficient in killing Shigella in vitro than CAP-18 alone. Our findings indicate that oral butyrate treatment in shigellosis may be of clinical value because of induction of the endogenous cathelicidin CAP-18 in the colonic epithelium, stimulation of the release of the active peptide CAP-18, and promoting elimination of Shigella.
275 citations
TL;DR: All of the El Tor strains of V. cholerae O1 isolated since 2001 produced CT of the classical biotype, while those isolated before 2001 producedCT of theEl Tor biotype.
Abstract: We determined the types of cholera toxin (CT) produced by a collection of 185 Vibrio cholerae O1 strains isolated in Bangladesh over the past 45 years. All of the El Tor strains of V. cholerae O1 isolated since 2001 produced CT of the classical biotype, while those isolated before 2001 produced CT of the El Tor biotype.
236 citations
TL;DR: The findings show that although providing appropriate services is absolutely necessary, it is also important to foster the use of such services and to help women overcome the barriers for accessing these services.
210 citations
TL;DR: Findings confirm that a rotavirus strain with an entirely lapine genome complement was able to infect and cause severe disease in a human child.
Abstract: The Belgian rotavirus strain B4106, isolated from a child with gastroenteritis, was previously found to have VP7 (G3), VP4 (P[14]), and NSP4 (A genotype) genes closely related to those of lapine rotaviruses, suggesting a possible lapine origin or natural reassortment of strain B4106 To investigate the origin of this unusual strain, the gene sequences encoding VP1, VP2, VP3, VP6, NSP1, NSP2, NSP3, and NSP5/6 were also determined To allow comparison to a lapine strain, the 11 double-stranded RNA segments of a European G3P[14] rabbit rotavirus strain 30/96 were also determined The complete genome similarity between strains B4106 and 30/96 was 934% at the nucleotide level and 969% at the amino acid level All 11 genome segments of strain B4106 were closely related to those of lapine rotaviruses and clustered with the lapine strains in phylogenetic analyses In addition, sequence analyses of the NSP5 gene of strain B4106 revealed that the altered electrophoretic mobility of NSP5, resulting in a super-short pattern, was due to a gene rearrangement (head-to-tail partial duplication, combined with two short insertions and a deletion) Altogether, these findings confirm that a rotavirus strain with an entirely lapine genome complement was able to infect and cause severe disease in a human child
207 citations
TL;DR: It is concluded that amebiasis was a substantial burden on the overall health of the cohort children and was associated with a stool anti-CRD IgA response.
Abstract: The contribution of amebiasis to the burden of diarrheal disease in children and the degree to which immunity is acquired from natural infection were assessed in a 4-year prospective observational study of 289 preschool children in an urban slum in Dhaka, Bangladesh. Entamoeba histolytica infection was detected at least once in 80%, and repeat infection in 53%, of the children who completed 4 years of observation. Annually there were 0.09 episodes/child of E. histolytica-associated diarrhea and 0.03 episodes/child of E. histolytica-associated dysentery. Fecal immunoglobulin A (IgA) anti-parasite Gal/GalNAc lectin carbohydrate recognition domain (anti-CRD) was detected in 91% (183/202) of the children at least once and was associated with a lower incidence of infection and disease. We concluded that amebiasis was a substantial burden on the overall health of the cohort children. Protection from amebiasis was associated with a stool anti-CRD IgA response. The challenge of producing an effective vaccine will be to improve upon naturally acquired immunity, which does not provide absolute protection from reinfection.
191 citations
TL;DR: In this article, the authors examined demographic, microbiologic, and clinical data from patients presenting during 1988, 1998, and 2004 flood-associated diarrheal epidemics at a diarrhea treatment hospital in Bangladesh.
Abstract: We examined demographic, microbiologic, and clinical data from patients presenting during 1988, 1998, and 2004 flood-associated diarrheal epidemics at a diarrhea treatment hospital in Dhaka, Bangladesh. Compared with non-flood periods, individuals presenting during flood-associated epidemics were older, more severely dehydrated, and of lower socioeconomic status. During flood-associated epidemics, Vibrio cholerae was the most commonly identified cause of diarrhea, and the only diarrheal pathogen whose incidence proportionally increased in each epidemic compared with seasonally matched periods. Rotavirus was the second most frequently identified flood-associated pathogen, although the proportion of cases caused by rotavirus infection decreased during floods compared with matched periods. Other causes of diarrhea did not proportionally change, although more patients per day presented with enterotoxigenic Escherichia coli, Shigella, and Salmonella species-associated diarrhea during floods compared with matched periods. Our findings suggest that cholera is the predominant cause of flood-associated diarrheal epidemics in Dhaka, but that other organisms spread by the fecal-oral route also contribute.
TL;DR: The different patterns of mortality identified may be a result of recent changes in the availability and effectiveness of health interventions against childhood cluster diseases.
Abstract: OBJECTIVE: To provide internationally comparable data on the frequencies of different causes of death. METHODS: We analysed verbal autopsies obtained during 1999 -2002 from 12 demographic surveillance sites in sub-Saharan Africa and Bangladesh to find cause-specific and age-specific mortality rates. The cause-of-death codes used by the sites were harmonized to conform to the ICD-10 system, and summarized with the classification system of the Global Burden of Disease 2000 (Version 2). FINDINGS: Causes of death in the African sites differ strongly from those in Bangladesh, where there is some evidence of a health transition from communicable to noncommunicable diseases, and little malaria. HIV dominates in causes of mortality in the South African sites, which contrast with those in highly malaria endemic sites elsewhere in sub-Saharan Africa (even in neighbouring Mozambique). The contributions of measles and diarrhoeal diseases to mortality in sub-Saharan Africa are lower than has been previously suggested, while malaria is of relatively greater importance. CONCLUSION: The different patterns of mortality we identified may be a result of recent changes in the availability and effectiveness of health interventions against childhood cluster diseases.
TL;DR: Assessment of prevalence of arsenic exposure through drinking water and skin lesions in Bangladesh showed sex, age, and socioeconomic differentials in both exposure andSkin lesions clearly showed the urgency of effective arsenic mitigation activities.
Abstract: Study objective: To assess prevalence of arsenic exposure through drinking water and skin lesions, and their variation by geographical area, age, sex, and socioeconomic conditions. Design, setting, and participants: Skin lesion cases were identified by screening the entire population above 4 years of age (n = 166 934) living in Matlab, a rural area in Bangladesh, during January 2002 and August 2003. The process of case identification involved initial skin examinations in the field, followed by verification by physicians in a clinic, and final confirmation by two independent experts reviewing photographs. The tubewell water arsenic concentrations (n = 13 286) were analysed by atomic absorption spectrometry. Drinking water history since 1970 was obtained for each person. Exposure information was constructed using drinking water histories and data on water arsenic concentrations. Main results: The arsenic concentrations ranged from Conclusions: The result showed sex, age, and socioeconomic differentials in both exposure and skin lesions. Findings clearly showed the urgency of effective arsenic mitigation activities.
TL;DR: In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic periods, and the biofilm community is concluded to be an additional reservoir of cholera bacteria in the aquatic environment between seasonal epidemics of choline in Bangladesh.
Abstract: Toxigenic Vibrio cholerae, rarely isolated from the aquatic environment between cholera epidemics, can be detected in what is now understood to be a dormant stage, i.e., viable but nonculturable when standard bacteriological methods are used. In the research reported here, biofilms have proved to be a source of culturable V. cholerae, even in nonepidemic periods. Biweekly environmental surveillance for V. cholerae was carried out in Mathbaria, an area of cholera endemicity adjacent to the Bay of Bengal, with the focus on V. cholerae O1 and O139 Bengal. A total of 297 samples of water, phytoplankton, and zooplankton were collected between March and December 2004, yielding eight V. cholerae O1 and four O139 Bengal isolates. A combination of culture methods, multiplex-PCR, and direct fluorescent antibody (DFA) counting revealed the Mathbaria aquatic environment to be a reservoir for V. cholerae O1 and O139 Bengal. DFA results showed significant clumping of the bacteria during the interepidemic period for cholera, and the fluorescent micrographs revealed large numbers of V. cholerae O1 in thin films of exopolysaccharides (biofilm). A similar clumping of V. cholerae O1 was also observed in samples collected from Matlab, Bangladesh, where cholera also is endemic. Thus, the results of the study provided in situ evidence for V. cholerae O1 and O139 in the aquatic environment, predominantly as viable but nonculturable cells and culturable cells in biofilm consortia. The biofilm community is concluded to be an additional reservoir of cholera bacteria in the aquatic environment between seasonal epidemics of cholera in Bangladesh.
TL;DR: Single-dose azithromycin was effective in the treatment of severe cholera in adults and the lack of efficacy of ciprofloxacin may result from its diminished activity against V. cholerae O1 strains currently circulating in Bangladesh.
Abstract: Background Single-dose azithromycin is effective in the treatment of severe cholera in children, but its effectiveness in adults has not been evaluated. Methods We conducted a double-blind, randomized trial comparing the equivalence of azithromycin and ciprofloxacin (each given in a single 1-g dose of two 500-mg tablets) among 195 men with severe cholera caused by Vibrio cholerae O1 or O139. Patients were hospitalized for five days. A stool culture was performed daily. Primary outcome measures were clinical success (the cessation of watery stools within 48 hours after drug administration) and bacteriologic success (the inability to isolate V. cholerae after 48 hours). Results Therapy was clinically successful in 71 of 97 patients receiving azithromycin (73 percent) and in 26 of 98 patients receiving ciprofloxacin (27 percent) (P<0.001) and bacteriologically successful in 76 of 97 patients receiving azithromycin (78 percent) and in 10 of 98 patients receiving ciprofloxacin (10 percent) (P<0.001). Patients ...
TL;DR: The coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae O1, O139, and non-O1/non-O139 and are autochthonous to the aquatic environment.
Abstract: Since Vibrio cholerae O139 first appeared in 1992, both O1 El Tor and O139 have been recognized as the epidemic serogroups, although their geographic distribution, endemicity, and reservoir are not fully understood. To address this lack of information, a study of the epidemiology and ecology of V. cholerae O1 and O139 was carried out in two coastal areas, Bakerganj and Mathbaria, Bangladesh, where cholera occurs seasonally. The results of a biweekly clinical study (January 2004 to May 2005), employing culture methods, and of an ecological study (monthly in Bakerganj and biweekly in Mathbaria from March 2004 to May 2005), employing direct and enrichment culture, colony blot hybridization, and direct fluorescent-antibody methods, showed that cholera is endemic in both Bakerganj and Mathbaria and that V. cholerae O1, O139, and non-O1/non-O139 are autochthonous to the aquatic environment. Although V. cholerae O1 and O139 were isolated from both areas, most noteworthy was the isolation of V. cholerae O139 in March, July, and September 2004 in Mathbaria, where seasonal cholera was clinically linked only to V. cholerae O1. In Mathbaria, V. cholerae O139 emerged as the sole cause of a significant outbreak of cholera in March 2005. V. cholerae O1 reemerged clinically in April 2005 and established dominance over V. cholerae O139, continuing to cause cholera in Mathbaria. In conclusion, the epidemic potential and coastal aquatic reservoir for V. cholerae O139 have been demonstrated. Based on the results of this study, the coastal ecosystem of the Bay of Bengal is concluded to be a significant reservoir for the epidemic serogroups of V. cholerae.
TL;DR: Genomic comparison of these two African G8 strains revealed that 10 out of their 11 gene segments, except for VP4, were nearly identical, suggesting that this rare G8P[8] rotavirus strain originated recently from a reassortment between a common G8p[6] strain and a strain with a P[8) specificity.
Abstract: Several G8P[6] and G8P[8] rotavirus strains were isolated from hospitalized patients in the Democratic Republic of Congo in 2003. To investigate their overall genomic relatedness and to determine to which genogroup they belonged, the complete genomes of strains DRC88 (G8P[8]) and DRC86 (G8P[6]) were determined. Genomic comparison of these two African G8 strains revealed that 10 out of their 11 gene segments, except for VP4, were nearly identical (>98.9% identical at the nucleotide level), suggesting that this rare G8P[8] rotavirus strain originated recently from a reassortment between a common G8P[6] strain and a strain with a P[8] specificity. A very close evolutionary relationship between 9 out of the 11 gene segments of DRC88 and DRC86 and rotavirus strains belonging to the DS-1-like (G2P[4]) "genogroup" was found, and several possible reassortment events preceding the occurrence of G8P[8] and G8P[6] human rotaviruses were hypothesized. Since the genes of G2P[4] rotavirus strains are very well adapted to infect humans, the acquirement of a new VP7 (G8) gene, and especially the replacement of P[6] (believed to be of animal origin) by P[8] (most common in human rotaviruses), might make DRC88-like rotaviruses very well equipped to become a predominant human rotavirus strain and an important pathogen on the African continent and the rest of the world. These findings have important implications for rotavirus vaccine development and highlight that typing of new rotavirus strains by merely sequencing their VP7 and VP4 genes provides us with only the tip of the iceberg regarding rotavirus diversity.
TL;DR: Before developing countries reinforce home-based births with a skilled attendant, research is needed to compare the feasibility, cost, effectiveness, acceptability, and implications for health-care equity in both approaches.
TL;DR: It is concluded that supplementation of fish-oil during the last trimester of pregnancy does not have any added benefit over supplementation of soy-oil on the development or behaviour of infants in this population.
Abstract: Supplementation of docosahexaenoic acid (DHA) in infancy improves neuro-developmental outcomes, but there is limited information about the impact of supplementing pregnant mothers with DHA on the development of their infants. In a follow-up of a randomized, double-blind controlled trial with 400 pregnant mothers, the effects of supplementation of fish-oil or soy-oil (4 g/day) during the last trimester of pregnancy on psychomotor development and behaviour of infants at 10 months of age (n=249) were assessed. The quality of psychosocial stimulation at home (HOME) and nutritional status of the subjects were also measured. There were no significant differences in the fish-oil group and soy-oil group in any of the developmental (mean +/-SD mental development index: 102.5 +/- 8.0 vs. 101.5 +/- 7.8, psychomotor development index: 101.7 +/- 10.0 vs. 100.5 +/- 10.1) or behavioural outcomes. It may, therefore, be concluded that supplementation of fish-oil during the last trimester of pregnancy does not have any added benefit over supplementation of soy-oil on the development or behaviour of infants in this population.
TL;DR: In order to reduce world hunger by half in the coming decade, it is important to recognise that a substantial proportion of the elderly population, particularly in low-income countries, is undernourished.
Abstract: Objective: In stating the Millennium Development Goals, the United Nations aims to halve malnutrition around the world by 2015. Nutritional status of the elderly population in low-income countrie ...
TL;DR: Enteric protozoa, Cryptosporidium, Giardia and Entamoeba histolytica-associated diarrheal illness was negatively associated with the growth of preschool children.
Abstract: The enteric protozoa, Cryptosporidium, Giardia and Entamoeba histolytica, cause diarrhea in children. We investigated the association of enteric protozoan-associated diarrheal illness with the nutritional status and growth of preschool children in Dhaka, Bangladesh. The subjects were 221 children aged 2-5 years who were followed prospectively for diarrheal illness for 3 years. The weight and height of the children were measured at entry and at 4-month intervals. Cryptosporidium and E. histolytica were diagnosed with commercially available stool antigen detection kits. Giardia was diagnosed by conventional microscopy. Cryptosporidium- and Giardia-associated diarrheal illness was not associated with the growth of the children. Children with E. histolytica-associated diarrheal illness had lower weight for age Z-score changes (-0.103+/-0.120 vs. 0.176+/-0.052, P=0.038). Similarly, the change in height for age Z-score was lower in children with E. histolytica-associated diarrheal illness (-0.348+/-0.186 vs. 0.142+/-0.08, P=0.018). Children with E. histolytica-associated diarrheal illness were 2.93 times (95% CI 1.01-8.52, P=0.047) more likely to be malnourished and 4.69 times (95% CI 1.55-14.18, P=0.006) more prone to be stunted. Entamoeba histolytica-associated diarrheal illness was negatively associated with the growth of preschool children.
TL;DR: It is demonstrated that males are more susceptible than females to develop skin lesions when exposed to As in water from tube wells.
Abstract: The discovery of arsenic in drinking water in many areas of the world has caused widespread public health concern. Close to 100 million people in the world, including about 13 million in the United States, are chronically exposed to inorganic As [International Agency for Research on Cancer (IARC) 2004]. The As problem in Bangladesh is perhaps the most devastating, because about half of the total 6–11 million hand-pumped tube wells yield drinking water with As concentrations > 10 μg/L, the drinking-water guideline recommended by the World Health Organization (WHO) [British Geological Survey (BGS) 2001; Smith et al. 2000].
Inorganic As is an established potent human carcinogen (IARC 2004). In addition, ingestion of As through drinking water has been implicated in several noncancer diseases, for example, peripheral vascular disease; hypertension; respiratory, neurologic, and liver disorders; and diabetes mellitus [IARC 2004; National Research Council (NRC) 2001; WHO/IPCS (International Programme on Chemical Safety) 2001]. Early effects of exposure to As in drinking water include pigmentation changes and hyperkeratosis (IARC 2004; Smith et al. 2000), which reportedly appear after 5–10 years of exposure (Guha Mazumder et al. 1998). These skin lesions may develop into more serious and disabling forms, including cancer (Guha Mazumder et al. 1998; Haque et al. 2003; IARC 2004; NRC 2001; Tondel et al. 1999; Tseng 1977; WHO/IPCS 2001). Because of the magnitude of the problem and the difficulties involved in mitigation (Jakariya et al. 2005), it is essential to identify risk groups in the population (NRC 2001). Numerous studies on As-related health effects have been performed, particularly in recent years. Still, few have focused on susceptibility factors.
Our ongoing studies on As-induced health effects in Matlab, Bangladesh, showed that the highest prevalence of As-induced skin lesions occurred in middle-aged men (Rahman et al. 2006), suggesting variation in susceptibility by sex and age. A few previous reports have indicated that men are more affected by As-related skin effects, including skin cancer, than women (Chen et al. 2003; Ferreccio et al. 2000; Guha Mazumder et al. 1998; Kadono et al. 2002; Tseng 1977; Watanabe et al. 2001), whereas other studies found women to be more susceptible than men (Ahmad et al. 1999) or did not identify any difference (Ahsan et al. 2000; Hadi and Parveen 2004; Tondel et al. 1999). However, none of these studies was designed to study differences between the sexes.
The present population-based case–referent study aims at determining the sex-specific risk of As-induced skin lesions in Matlab, Bangladesh, an area with high prevalence of elevated concentrations of As in tube-well water (Rahman et al. 2006). Further, it aims at assessing whether a start of exposure before 1 year of age compared with later periods is associated with a higher risk of developing the disease. We took advantage of the comprehensive ICDDR, B Health and Demographic Surveillance System (HDSS) in Matlab. By defining the study base as all people > 4 years of age who lived in the demographic surveillance area, the design allowed a novel approach to assess lifetime As exposure and evaluate sex- and age-related differences in risk of obtaining As-related skin effects.
TL;DR: Deaths from cholera are again making news, this time in Angola, and Drs.
Abstract: Deaths from cholera are again making news, this time in Angola. Drs. David Sack, Bradley Sack, and Claire-Lise Chaignat discuss whether there is hope for controlling cholera.
01 Jan 2006
TL;DR: It is shown that Vibrio cholerae shed in human ‘rice‐water’ stools have a 10‐fold lower oral infectious dose in an animal model than in vitro grown V. cholerae, which may aid in transmission during outbreaks.
Abstract: Summary
Factors that enhance the transmission of pathogens are poorly understood. We show that Vibrio cholerae shed in human ‘rice-water’ stools have a 10-fold lower oral infectious dose in an animal model than in vitro grown V. cholerae, which may aid in transmission during outbreaks. Furthermore, we identify a bacterial factor contributing to this enhanced infectivity: The achievement of a transient motile but chemotaxis-defective state upon shedding from humans. Rice-water stool V. cholerae have reduced levels of CheW-1, which is essential for chemotaxis, and were consequently shown to have a chemotaxis defect when tested in capillary assays. Through mutational analyses, such a state is known to enhance the infectivity of V. cholerae. This is the first report of a pathogen altering its chemotactic state in response to human infection in order to enhance its transmission.
TL;DR: Serovar Typhi antigens identified by IVIAT warrant further evaluation for their contributions to pathogenesis, and they may have diagnostic, therapeutic, or preventive uses.
Abstract: We applied an immunoscreening technique, in vivo-induced antigen technology (IVIAT), to identify immunogenic bacterial proteins expressed during human infection with Salmonella enterica serovar Typhi, the cause of typhoid fever. We were able to assign a functional classification to 25 of 35 proteins identified by IVIAT. Of these 25, the majority represent proteins with known or potential roles in the pathogenesis of S. enterica. These include proteins implicated in fimbrial structure and biogenesis, antimicrobial resistance, heavy metal transport, bacterial adhesion, and extracytoplasmic substrate trafficking as well as secreted hydrolases. The 10 remaining antigens represent proteins with unknown functions. Of the 35 identified antigens, four had no immunoreactivity when probed with control sera from individuals never exposed to serovar Typhi organisms; these four included PagC, TcfB, and two antigens of unknown function encoded by STY0860 and STY3683. PagC is a virulence factor known to be upregulated in vivo in S. enterica serovar Typhimurium infection of mice. TcfB is the major structural subunit of a fimbrial operon found in serovar Typhi with no homolog in serovar Typhimurium organisms. By examining differential immunoreactivities in acute- versus convalescent-phase human serum samples, we found specific anti-PagC and anti-TcfB immunoglobulin G responses in patients with serovar Typhi bacteremia. Serovar Typhi antigens identified by IVIAT warrant further evaluation for their contributions to pathogenesis, and they may have diagnostic, therapeutic, or preventive uses.
TL;DR: Multilocus sequence typing (MLST) analysis using nine genetic loci showed that the Mozambique isolates have the same sequence type (ST) as O1 El Tor N16961, a representative of the current seventh cholera pandemic.
Abstract: Vibrio cholerae O1 isolates belonging to the Ogawa serotype, El Tor biotype, harbouring the classical CTX prophage were first isolated in Mozambique in 2004. Multilocus sequence typing (MLST) analysis using nine genetic loci showed that the Mozambique isolates have the same sequence type (ST) as O1 El Tor N16961, a representative of the current seventh cholera pandemic. Analysis of the CTX prophage in the Mozambique isolates indicated that there is one type of rstR in these isolates: the classical CTX prophage. It was also found that the ctxB-rstR-rstA-rstB-phs-cep fragment was PCR-amplified from these isolates, which indicates the presence of a tandem repeat of the classical CTX prophage in the genome of the Mozambique isolates. The possible origin of these isolates and the presence of the tandem repeat of the classical prophage in them implicate the presence of the classical CTX phage.
TL;DR: This study aims to explore current patterns of diagnosis and treatment, quantify household economic impact and identify household strategies to cover the costs of visceral leishmaniasis care in rural Bangladesh.
Abstract: The objectives were to explore current patterns of diagnosis and treatment quantify household economic impact and identify household strategies to cover the costs of visceral leishmaniasis (VL) care in rural Bangladesh. Structured interviews with 113 VL patients from 87 households documenting all provider visits and expenditures for health care for VL and the ways in which the expenditures were covered. Patients paid a median of 7 visits to six different providers before beginning VL treatment. All visited the subdistrict government hospital at least once. While health care including antileishmanial drug therapy is officially available free of charge at government facilities 79% of patients reported making informal payments for provider access diagnostics and drug administration; only 14% of patients received their full drug course from this source. For the 58% of patients who purchased the full treatment course drug cost constituted 34% of direct expenditure. Median direct expenditure for one VL patient was US$87 and median income lost was $40; median total expenditure was 1.2 times annual per capita income of our study population. Households employed multiple coping strategies to cover expenditures most commonly sale or rental of assets (62%) and taking out loans (64%). Visceral leishmaniasis treatment causes a major economic burden in affected families. Control strategies for VL should facilitate timely affordable diagnosis and treatment of patients to decrease the infection reservoir and to alleviate the economic burden of VL on households. (authors)
TL;DR: The responsive feeding framework, once operationalized, has the potential to identify specific behaviours that support or impede mother-child interaction during complementary feeding.
TL;DR: The Matlab variants of Vibrio cholerae O1, defined as hybrids between the classical and El Tor biotypes, were first isolated from hospitalized patients with acute secretory diarrhoea in Matlab, a rural area of Bangladesh.
Abstract: The Matlab variants of Vibrio cholerae O1, defined as hybrids between the classical and El Tor biotypes, were first isolated from hospitalized patients with acute secretory diarrhoea in Matlab, a rural area of Bangladesh. These variants could not be categorized as classical or El Tor biotypes by phenotypic and genotypic tests, and had representative traits of both the biotypes. A number of virulence-associated genes and/or gene clusters were screened by PCR and DNA sequencing. El Tor-specific gene clusters, Vibrio seventh-pandemic islands (VSP)-I and -II and repeat toxin (RTX) were present in the genome of these variants, indicating their El Tor lineage, whereas the nucleotide-sequence-derived CtxB amino acid sequence of these strains grouped them under the classical biotype. Matlab variants possessed all the necessary genes to initiate pandemics. The genetic relatedness of Matlab variants to the V. cholerae strains recently isolated in Mozambique is another important observation of this study, which underscores the epidemiological significance of Matlab variants.