Biomedical subjects

M J Albert

Publications and source records attributed to M J Albert.

At least 73 records · Page 4Linked to original sources

PubMed1997

Anticipating rotavirus vaccines: hospital-based surveillance for rotavirus diarrhea and estimates of disease burden in Bangladesh.

OBJECTIVES: Rotavirus is the most common cause of severe diarrhea in children worldwide, and a vaccine may soon be licensed and available for use in immunization programs. To assess the need for a rotavirus vaccine in Bangladesh, we estimated the disease burden of rotavirus diarrhea from national vital statistics for births and diarrheal deaths, together with hospital surveillance data on the proportion of severe childhood diarrhea attributed to rotavirus. METHODS: From 1990 through 1993, hospital surveillance was conducted of a systematic, random 4% sample of >80,000 patients with diarrhea who sought care each year at the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B). RESULTS: Rotavirus was detected in 20% (1561 of 7709) of fecal specimens from children with diarrhea <5 years of age; 92% of all cases (1436) occurred in children <2 years of age, but only 3% (50) of cases occurred in infants <3 months of age. Children infected with rotavirus were more likely to have watery stools (P < 0.001), severe vomiting (P < 0.001) but less severe dehydration (P = 0.007) than children infected with other enteropathogens. CONCLUSIONS: We estimate that in this setting, where 18% of children die by age 5 and about 25% of these succumb to diarrhea, between 14,850 and 27,000 of the 3 million Bangladeshi children born in 1994 will die of rotavirus by the age of 5 years, equivalent to 1 rotavirus death per 111 to 203 children. The estimated burden of rotavirus diarrhea in Bangladesh is sufficiently great to warrant field testing of rotavirus vaccines for possible inclusion in the current immunization program.

Bangladesh↗

PubMed1997

Immune response to the mannose-sensitive hemagglutinin in patients with cholera due to Vibrio cholerae O1 and O0139.

The mannose-sensitive hemagglutinin (MSHA) is a type 4 pilus present in Vibrio cholerae O1 strains of the El Tor biotype, as well as in strains of serogroup O139. It has been shown to be a colonization antigen in animal models. The aim of this study was to investigate systemic and local antibody responses to MSHA in adult patients with cholera due to V. cholerae O1 and O139. Twenty-four of 28 (86%) patients with O1 cholera and 11 of 17 (65%) patients with O139 cholera showed significant increases in MSHA-specific immunoglobulin A (IgA) and IgM antibody-secreting cells (ASCs) 7 days after the onset of disease. However, the magnitude of the ASC response in O1 cholera patients was significantly higher than that in the O139 cholera patients in both IgA-producing (P = 0.015) and IgM-producing (P = 0.029) cells. Both groups of patients responded with antibody responses to MSHA in plasma, seroconverting with both IgA (63 to 70% of patients) and IgG (43 to 59% of patients) antibodies. Compared to the MSHA-specific antibody levels determined in healthy controls (n = 10), more than 90% of O1 and O139 cholera patients showed responses to MSHA of both the IgA and the IgG isotypes. About 70% of the patients in both groups also had antibody responses to MSHA in their feces. In summary, we demonstrated that MSHA is immunogenic, giving rise to both systemic and local antibodies in patients with cholera due to both O1 and O139 serogroups.

Adolescent↗

PubMed1997

Comparison of immune responses in patients infected with Vibrio cholerae O139 and O1.

Vibrio cholerae O139 has recently emerged as the second etiologic agent of cholera in Asia. A study was carried out to evaluate the induction of specific immune responses to the organism in V. cholerae O139-infected patients. The immune responses to V. cholerae O139 Bengal were studied in patients by measuring antibody-secreting cells (ASC), as well as vibriocidal and antitoxic antibodies in the circulation. These responses were compared with those in patients with V. cholerae O1 disease. Strong immunoglobulin A (IgA) and IgM ASC responses were seen against the homologous lipopolysaccharide or serogroup of V. cholerae. The magnitude and isotype of the responses were similar in O139- and O1-infected patients. Vibriocidal antibody responses were seen against bacteria of the homologous but not heterologous serogroup, and these responses reflect the lack of cross-protection between the infections caused by the two serogroups. The two groups of patients showed comparable cholera toxin-specific ASC responses, with the IgG isotype dominating over the IgA isotype, as well as comparable antitoxic immune responses in plasma. These results suggest that despite having a polysaccharide capsule, V. cholerae O139 induces systemic and intestine-derived ASC responses in peripheral blood comparable to those seen in patients with V. cholerae O1 disease.

Adult↗

PubMed1997

Phenotypic and genotypic changes in Vibrio cholerae O139 Bengal.

To find reasons for the recent decline of Vibrio cholerae O139 Bengal cholera in Bangladesh, phenotypic and genotypic changes in O139 isolates obtained from patients with cholera from 1993 to 1996 were studied. The isolates were tested for the presence of ctx and tcpA genes, hemagglutinin/protease (HA/P), capsule, D-mannose-sensitive hemagglutinin (MSHA), L-fucose-sensitive hemagglutinin (FSHA), tube test (tube) and CAMP test (CAMP) hemolytic activities, resistance to 2,4-diamino-6,7-diisopropyl pteridine (O/129) and trimethoprim-sulfamethoxazole (TMP-SMX), and genotype by pulsed-field gel electrophoresis (PFGE). All isolates possessed ctx and tcpA genes, HA/P, and a capsule. Most isolates were negative for FSHA, but although the majority of the isolates were positive for MSHA, no discernible trend in the activity was found during the study period. All early isolates were CAMP hemolysin positive and resistant to the vibriostatic compound O/129 and TMP-SMX, the two properties that could be used for the presumptive diagnosis of O139 cholera. However, subsequently, isolates that were CAMP hemolysin negative and susceptible to TMP-SMX and O/129 were increasingly encountered, with all the 1996 isolates being so, which suggested that these properties can no longer be used for the presumptive diagnosis of O139 cholera. V. cholerae O139 isolates that were CAMP hemolysin positive and resistant to O/129 and TMP-SMX produced a disease of greater severity than that caused by the CAMP hemolysin-negative and susceptible isolates on the basis of the lengths of stay of the hospitalized patients. The study period witnessed the evolution of four different genotypes by PFGE. All of these data suggested that the V. cholerae O139 isolates have undergone changes in some properties. However, how these changes influenced their prevalence relative to that of V. cholerae O1 in human infection is not clear. Studies of the environmental factors will provide the key for an understanding of the relative abundance of these vibrios.

Adult↗

PubMed1997

Characterization of Aeromonas spp. isolated from humans with diarrhea, from healthy controls, and from surface water in Bangladesh.

Aeromonas isolates from patients with diarrhea in Bangladesh (n = 69), from healthy controls (n = 11), and from surface water (n = 40) were analyzed with respect to their hybridization groups (HGs) by the aid of fatty acid methyl ester (FAME) characterization and DNA fingerprinting by AFLP, biochemical phenotypes (Phe-nePlate [PhP] types), and the production of hemolysin and cytotoxin. The aim of the investigation was to find out whether certain strains carrying virulence factors predominated among patient isolates. According to FAME and/or AFLP analysis, most human isolates were allocated to DNA HGs 4 (Aeromonas caviae) and 1 (A. hydrophila). Most environmental strains were allocated to HG8 (A. veronii biogroup sobria) and HG4 (A. caviae), and only one was of HG1. According to PhP typing, the diversity among patient isolates was lower than that among other strains, and two dominating PhP types (types BD-1 and BD-2) were identified in 29 and 30% of the patient isolates, respectively. PhP type BD-1 was also common among the environmental isolates, whereas PhP type BD-2 was only identified in two of the other isolates. Twenty-five of 26 isolates belonging to HG1 were of the same PhP type (BD-2), whereas isolates of other common HGs were more diverse according to their PhP types. Hemolytic and cytotoxin-producing strains occurred more frequently among the environmental isolates than among patient isolates. However, the hemolytic and cytotoxic activities among human isolates was strongly correlated to the HG1/BD-2 type, which, in addition, showed high cytotoxin titers (median values, 1/512 compared to 1/128 for cytotoxin-positive isolates belonging to other types). Thus, the HG1/BD-2 type may represent a pathogenic A. hydrophila type that is able to produce diarrhea in humans.

Aeromonas↗

PubMed1997

Emergence of a new clone of toxigenic Vibrio cholerae O1 biotype El Tor displacing V. cholerae O139 Bengal in Bangladesh.

The emergence of Vibrio cholerae O139 Bengal in 1993, its rapid spread in an epidemic form, in which it replaced existing strains of V. cholerae O1 during 1992 and 1993, and the subsequent reemergence of V. cholerae O1 of the El Tor biotype in Bangladesh since 1994 have raised questions regarding the origin of the reemerged El Tor vibrios. We studied 50 El Tor vibrio strains isolated in Bangladesh and four other countries in Asia and Africa before the emergence of V. cholerae O139 and 32 strains isolated in Bangladesh during and after the epidemic caused by V. cholerae O139 and 32 strains isolated in Bangladesh during and after the epidemic caused by V. cholerae O139 to determine whether the reemerged El Tor vibrios were genetically different from the El Tor vibrios which existed before the emergence of V. cholerae O139. Analysis of restriction fragment length polymorphisms in genes for conserved rRNA, cholera toxin (ctxA), and zonula occludens toxin (zot) or in DNA sequences flanking the genes showed that the El Tor strains isolated before the emergence of V. cholerae O139 belonged to four different ribotypes and four different ctx genotypes. Of 32 El Tor strains isolated after the emergence of O139 vibrios, 30 strains (93.7%) including all the clinical isolates belonged to a single new ribotype and a distinctly different ctx genotype. These results provide evidence that the reemerged El Tor strains represent a new clone of El Tor vibrios distinctly different from the earlier clones of El Tor vibrios which were replaced by the O139 vibrios. Further analysis showed that all the strains carried the structural and regulatory genes for toxin-coregulated pilus (tcpA, tcpI, and toxR). All strains of the new clone produced cholera toxin (CT) in vitro, as assayed by the GM1-dependent enzyme-linked immunosorbent assay, and the level of CT production was comparable to that of previous epidemic isolates of El Tor vibrios. Further studies are required to assess the epidemic potential of the newly emerged clone of V. cholerae O1 and to understand the mechanism of emergence of new clones of toxigenic V. cholerae.

Bacterial Typing Techniques↗

PubMed1997

Rapid detection of Vibrio cholerae O139 Bengal from stool specimens by PCR.

In a previous study using pure bacterial cultures in a PCR assay, a primer pair corresponding to a unique chromosomal region of Vibrio cholerae O139 Bengal generated an amplicon from only V. cholerae O139 Bengal. PCR with the same primer pair was used to screen 180 diarrheal stool specimens. All the 67 V. cholerae O139 culture-positive stool specimens were positive by PCR, and the remaining specimens, which contained either other recognized enteric pathogens or no pathogens, were all negative by PCR.

Cholera↗

PubMed1997

Molecular analysis of toxigenic Vibrio cholerae O139 Bengal strains isolated in Bangladesh between 1993 and 1996: evidence for emergence of a new clone of the Bengal vibrios.

Vibrio cholerae O139 Bengal emerged in 1992 and rapidly spread in an epidemic form, in which it replaced existing strains of V. cholerae O1 in Bangladesh during 1992 and 1993. The subsequent emergence of a new clone of V. cholerae O1 of the El Tor biotype that transiently displaced the O139 vibrios during 1994 to 1995 and the recent reemergence of V. cholerae O139 and its coexistence with the El Tor vibrios demonstrated temporal changes in the epidemiology of cholera in Bangladesh. We studied clonal diversity among V. cholerae O139 strains isolated from cholera patients and environmental surface water since their first appearance until their transient disappearance in 1994 as well as the O139 strains that reemerged during 1995 to 1996 and were isolated in the capital Dhaka and four rural districts of Bangladesh to investigate the origin of the reemerged strains. Analysis of restriction fragment length polymorphisms in genes for conserved rRNA and cholera toxin (CT) (ctxA) or in DNA sequences flanking these genes revealed four different ribotypes and four different ctx genotypes among the 93 strains of V. cholerae O139 studied. Ribotypes I and II and ctx genotypes A through C were shared by strains isolated from the epidemic outbreak during 1992 and 1993 in Bangladesh and India, ribotype III was represented by a single CT-negative O139 strain from Argentina, and 16 of 27 (59.2%) of the reemerged strains isolated during 1995 and 1996 belonged to a new ribotype of O139 vibrios designated ribotype IV. All 16 strains belonging to ribotype IV also belonged to a new ctx genotype (genotype 4). These results provide evidence for the emergence of a new clone of toxigenic V. cholerae O139 in Bangladesh. Further analysis of the rfb gene cluster by PCR revealed the absence of a large region of the O1-specific rfb operon and the presence of an O139-specific genomic region in all O139 strains. The PCR amplicon corresponding to the rfaD gene of a CT-negative O139 strain from Argentina was smaller in length than those of the toxigenic O139 strains but was identical to those of seven non-O1 and non-O139 strains. All O139 strains except the CT-negative strain carried structural and regulatory genes for CT and toxin-coregulated pili (ctxA, tcpA, tcpI, and toxR). These results suggest that the O139 Bengal strains possibly emerged from an El Tor strain but that the CT-negative non-Bengal O139 strain might have emerged from a non-O1, non-O139 strain. Thus, strains belonging to the O139 serogroup may have emerged from similar serotype-specific genetic changes in more than one progenitor strain of V. cholerae.

Bacterial Outer Membrane Proteins↗

PubMed1997

The role of food in the epidemiology of cholera.

Cholera is an acute dehydrating diarrhoeal disease, traditionally caused by vibrio cholerae O1, and also more recently by V. cholerae O139 (Bengal). Traditionally, water was recognized as the primary vehicle for transmission of cholera, but in the past 30 years, outbreaks of cholera associated with eating contaminated food have demonstrated that food also plays an important role, although in many instances water is the source of contamination of foods. Most commonly associated with cholera is seafood, both molluscan shellfish and crustaceans. Seafood may be contaminated in its natural environment or during preparation. Other food items associated with outbreaks are fruit and vegetables, meat, cooked grains, etc. Vegetables are usually contaminated by contact with sewage in soil and fruits when injected with contaminated water to increase weight and turgor. Food items initially free from V. cholerae organism may become contaminated when mixed with water, or other contaminated food, or through handling by infected persons who have not observed proper hygiene. Refrigeration, freezing, alkaline pH, high concentration of carbohydrate, humidity and absence of competing flora enhance the survival of V. cholerae in food. Survival of V. cholerae is shorter in food with acidic pH. Foodborne cholera can be averted by the hygienic preparation of food and its consumption. However, since the vehicles of transmission vary markedly from place to place, being affected by local customs and practices, selected control and preventive measures that are most important locally must be implemented. To this end, application of the Hazard Analysis and Critical Control Point system to food preparation is essential in order to identify the practices which may present a risk. Restrictions on importation of foods which do not present a risk of being contaminated from areas where cholera is endemic is not warranted.

Cholera↗

PubMed1997

Detection of non-culturable Shigella dysenteriae 1 from artificially contaminated volunteers' fingers using fluorescent antibody and PCR techniques.

Epidemiological studies have demonstrated that hands may be an important vehicle for transmission of shigellosis. The present study was carried out to find out the survival potential of Shigella dysenteriae 1 on fingers of volunteers. Finger surface was inoculated with 10(5) cfu of S. dysenteriae 1 and then the bacteria were detected using conventional culture, PCR and fluorescent antibody (FA) techniques after different time intervals. It was found that S. dysenteriae 1 survived for up to one hour in culturable form but up to four hours in non-culturable form on human fingers. The non-culturable S. dysenteriae was detected by PCR and FA techniques. This study elaborates on the role that fingers have in the transmission of shigellae.

DNA, Bacterial↗

PubMed1996

Structural studies of the O-antigenic polysaccharide from an Aeromonas caviae strain.

The structure of the O-antigenic polysaccharide from a strain of Aeromonas caviae, isolated from the stools of a patient with diarrhoea, has been investigated. Sugar analysis, methylation analyses, and a uronic acid degradation together with NMR spectroscopy were the principal methods used. The sequence of the sugar residues could be determined by NOESY and HMBC experiments. It is concluded that the polysaccharide is composed of pentasaccharide repeating units with the following structure: [sequence: see text]

Aeromonas↗

PubMed1996

Structure of the O-specific polysaccharide of an Aeromonas trota strain cross-reactive with Vibrio cholerae O139 Bengal.

The O-specific polysaccharide of an Aeromonas trota strain was isolated by hydrolysis of the lipopolysaccharide at pH 4.5 followed by gel-permeation chromatography and found to consist of hexasaccharide repeating units containing D-galactose, L-rhamnose, 3,6-dideoxy-L-xylo-hexose (colitose, Col), 2-acetamido-2-deoxy-D-glucose and 2-acetamido-2-deoxy-D-galactose in the ratios 1:1:2:1:1. Partial hydrolysis of the polysaccharide with 48% hydrofluoric acid resulted in selective removal of colitose to give a modified polysaccharide containing the other four sugar constituents. On the basis of methylation analysis and NMR spectroscopic studies of the initial and modified, colitose-free polysaccharide, it was concluded that the repeating unit of the O-specific polysaccharide has the following structure [sequence: see text] The known cross-reactivity between the strain studied and Vibrio cholerae O139 Bengal is substantiated by the presence of a common colitose-containing epitope shared by the O-specific polysaccharide of A. trota and the capsular polysaccharide of V. cholerae, which is thought to carry determinants of O-specificity.

Aeromonas↗

PubMed1996

A Klebsiella pneumoniae strain that shares a type-specific antigen with Shigella flexneri serotype 6. Characterization of the strain and strain and structural studies of the O-antigenic polysaccharide.

A strain of Klebsiella pneumoniae was found as the only isolate with pathogenic potential from the stool of a two-year old patient with diarrhoea. A strong serological cross-reactivity with Shigella flexneri serotype 6 was demonstrated. The cross-reacting antigens were shown to reside in the cell wall lipopoly-saccharide. Studies of the pathogenic potential of the Klebsiella strain showed low level of invasion of HEp-2 cells. However, tests for adherence to HEp-2 cells as well as tests for toxin production were negative. The strain had several small plasmids and was multidrug resistant. These data do not form a sufficient basis for estimating the pathogenic potential of the organism. No K antigen was detected. The structure of the O-antigenic polysaccharide from the K. pneumoniae strain was investigated using methylation analysis, NMR spectroscopy, and Smith degradation as the principal methods. The O-antigenic polysaccharide has the following pentasaccharide repeating unit: -->3)- alpha -L-Rhap-(1-->3)- alpha -L-Rhap-(1-->2)- alpha-L-Rhap- (1-->2)- alpha-L-Rhap-(1-->2)- alpha-L-Rhap-(1-->. This structure is not identical to any of the previously described O-antigens of K. pneumoniae. The strong serological cross-reactivity with the Shigella flexneri serotype 6 O-antigen can most likely be attributed to the structural element alpha-L-Rhap-(1-->2)- alpha -L-Rhap present in the O-polysaccharide repeating unit of this serotype. Antiserum raised against the K. pneumoniae strain also agglutinated S. dysenteriae serotype 1 and strains of all different serotypes of S. flexneri. The Shigella strains contain the structural element alpha-L-Rhap-(1-->3)- alpha-L-Rhap in their O-antigen polysaccharides which may be responsible for the observed cross-reactivity.

Bacterial Adhesion↗

PubMed1996

Serum antibacterial and antitoxin responses in clinical cholera caused by Vibrio cholerae O139 Bengal and evaluation of their importance in protection.

Vibrio cholerae O139 Bengal strain was the causative agent of the recent epidemics of cholera in India and Bangladesh. We studied antibacterial and antitoxin immune responses in acute and convalescent phase paired sera collected from seven of these cholera patients. Significant rise in the levels of both antibacterial and antitoxin antibodies was demonstrable in the sera of convalescent cholera patients. Antibacterial antibodies, directed primarily against O139 lipopolysaccharides (LPS), belonged to IgM class, while antitoxin antibodies were of IgG and IgA class and neutralized cholera toxin. The convalescent sera, however, showed no increase in the reactivity towards V. cholerae O1 whole cells or their LPS preparation. Immunoblotting experiments revealed that the convalescent, but not the acute, phase serum recognized the truncated form of LPS characteristics of O139 strains. Convalescent serum also induced definite protection against O139, but not O1, challenge in experimental animal model. Further studies showed that such protection was probably mediated by antibodies inhibiting intestinal colonization of O139 organisms. These results suggest that critical difference(s) exists between the immunogenic somatic components of V. cholerae O1 and O139 organisms that are of considerable importance in protection against cholera.

Antibodies, Bacterial↗

PubMed1996

Changing epidemiology of cholera due to Vibrio cholerae O1 and O139 Bengal in Dhaka, Bangladesh.

At the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B) Dhaka we studied the trends in cholera for the period January 1992 to May 1995. Vibrio cholerae O139 Bengal emerged as a second aetiologic agent of cholera in Dhaka in January 1993. In 1993, the majority of cholera cases was due to V. cholerae O139, with V. cholerae O1 accounting for a small proportion of cases. During the latter part of the study period (Jan 1994-May 1995), V. cholerae O1 re-emerged as the predominant cholera strain. The predominant age group affected in endemic cholera due to V. cholerae O1 was children 2-9 years old, and the organism was isolated from more females than from males at all ages. In contrast, cholera due to V. cholerae O139 caused disease mostly in adults 15 years and older, which indicated that this organism was new in this population. As with V. cholerae O1, V. cholerae O139 was isolated from more females than males. The initial rapid emergence and predominance of V. cholerae O139 was considered possibly to herald the start of the eighth pandemic of cholera. However, just after a year, the prevalence of V. cholerae O139 decreased dramatically with V. cholerae O1 resuming the role of the dominant cholera strain. The factor(s) contributing to the dramatic decline in prevalence of V. cholerae O139 is not well understood.

Adolescent↗

PubMed1996

Neonatal rotavirus infection in Bangladesh: strain characterization and risk factors for nosocomial infection.

BACKGROUND: Rotavirus (RV) diarrhea is an important cause of childhood morbidity and mortality in Bangladesh and is responsible for 24% of hospital admissions for diarrhea in children from 3 months to 2 years of age. However, the prevalence of neonatal RV infections and characteristics of RV strains infecting neonates have not been explored in Bangladesh. METHODS: We investigated neonates at six hospitals in Bangladesh to determine the prevalence of neonatal RV infection, to identify risk factors for infection and to characterize neonatal RV strains by reverse transcription-polymerase chain reaction. RESULTS: Of 381 neonates screened at 6 hospitals 61 of 146 infants (42%) at 2 hospitals in Dhaka were RV-positive. Of these 62% were detected within the first 5 days of life. We found an increased risk for neonatal RV infection among infants whose mothers reported no handwashing during care of the neonate (P = 0.03). Analysis of RV strains in enzyme-linked immunosorbent assay-positive specimens identified P[6]G4 and P[6]G1 genotypes to be most common; 7% (2 of 27) of strains were nontypable. A concurrent analysis of RV strains circulating in Bangladesh suggested that RV genotypes infecting neonates had a distinct P genotype, because most community strains were P-nontypable compared with neonatal strains, which carried the P[6] genotype. CONCLUSIONS: Hospitalized neonates in Dhaka have increased risk for infection with RV as early as the first week of life with strains having the unusual P[6] genotype. Our findings confirm studies in India showing that neonatal RV infection can be common and may occur with strains distinct from those circulating in the community. Neonatal RV infections could alter a child's response to the RV vaccine as well as the calculation of RV vaccine efficacy in these populations.

Bangladesh↗

PubMed1996

Sociodemographic, hygienic and nutritional correlates of Helicobacter pylori infection of young Bangladeshi children.

BACKGROUND: By the age of 10 years most children in developing countries have been infected by Helicobacter pylori Identification of clues to modes of transmission of this organism to children, as well as evaluation of the sequelae of childhood infections, constitute important research priorities for developing countries. OBJECTIVES: To evaluate demographic, socioeconomic and hygienic factors associated with acquisition of infection by H. pylori early in childhood among Bangladeshi children ages 2 to 5 years and to assess whether infection by H. pylori was associated with poor nutritional status in these children and in an older group ages 6 to 9 years. METHODS: A random population-based survey of 257 rural Bangladeshi children ages 2 to 5 years and 312 children ages 6 to 9 years. Seropositivity for H. pylori, as manifested by the presence of serum IgG anti-H. pylori antibodies, was correlated with nutritional status of the sampled children and with sociodemographic features and access to clean water and latrine facilities among families of the children. RESULTS: Among children ages 2 to 5 years, the 123 (48%) who were infected by H. pylori were similar to the 134 noninfected children with respect to socioeconomic level, family access to tube well water and family ownership of a latrine. However, families of infected children had more persons per sleeping room in the home (3.8 vs. 3.2, P < 0.05) and were more likely to be Hindu (20% vs. 10%, P < 0.05). Infected children did not differ significantly from noninfected children in Z scores for weight-for-age (-2.66 vs. -2.78), weight-for-height (-1.17 vs. -1.28) or height-for-age (-3.58 vs. -3.56). Analysis of survey children ages 6 to 9 years also revealed similar nutritional indexes among infected vs. noninfected children. CONCLUSIONS: Household crowding and behaviors that differ between Hindus and Muslims, but not lack of access to clean water and latrines, may enhance the transmission of H. pylori to rural Bangladeshi children. Although confirming the high frequency of infections in young Bangladeshi children, our findings do not support the notion that H. pylori is responsible for the high prevalence of malnutrition in this setting.

Age Distribution↗

PubMed1996

Alterations in lymphocyte phenotype and function in children with shigellosis who develop complications.

This study was designed to see whether alterations occur in peripheral blood mononuclear cell phenotype and function in children with Shigella dysenteriae 1 infection with complications (leukemoid reaction and/or hemolytic-uremic syndrome) and whether there are any alterations prior to the development of complications. The following groups of children (ages, 12 to 60 months) were compared: children without any infection (n = 51), children with uncomplicated shigellosis (n = 65), children admitted with complicated shigellosis (leukemoid reaction and/or hemolytic-uremic syndrome) (n = 29), and children with shigellosis who developed complications after enrollment (subsequently complicated shigellosis) (n = 12). Tests for the peripheral blood mononuclear cell phenotype (CD3, CD4, CD8, CD57 [corrected], CD20, and CD25), spontaneous proliferation, and the proliferative response to phytohemagglutinin, pokeweed mitogen, and the lipopolysaccharide of S. dysenteriae 1 were performed, as were skin tests for delayed-type hypersensitivity (DTH). Children who subsequently developed complications differed from other groups of children as follows: (i) the numbers of CD3+ and CD4+ cells were lower than in uninfected children (P < 0.05), (ii) the CD4/CD8 ratio was lower than in children with uncomplicated shigellosis (P < 0.05) and in uninfected children (P < 0.05), and (iii) the levels of spontaneous proliferation of peripheral blood mononuclear cells were higher and DTH responses were lower than those in children with uncomplicated shigellosis (P < 0.05 and P < 0.017, respectively). Children with complications differed by having (i) increased numbers of CD3- CD57- [corrected] CD20- cells (P < 0.05) compared with those in other groups of children and (ii) lower CD4/CD8 ratios (P < 0.05), higher levels of spontaneous proliferation (P < 0.05), and lower DTH responses (P = 0.005) than children with uncomplicated shigellosis. Three to five days after enrollment, the number of CD4+ cells increased in children who subsequently developed complications (P = 0.025), i.e., when they developed complications and at this time their CD4+ cell number was similar to that of other groups of children. Thus, lymphocyte phenotype and function are altered prior to the development of complications in children with shigellosis, and once complications develop, the pattern of alterations changes. Whether these alterations have a role in precipitating complications or whether they reflect early events underlying the development of complications remains to be elucidated.

Antigens, CD↗