Diagnosis and management of dysentery by community health workers

Evaluation of fecal occult blood testing for rapid diagnosis of invasive diarrhea in young children

Antimicrobials are only indicated in acute childhood diarrhea if it is invasive or persistent. Rapid screening for invasive diarrhea can therefore inform treatment decisions but pathogen identification by culture is slow, expensive and cumbersome. This study aimed to assess the diagnostic utility of stool microscopy and immunochromatographic fecal occult blood test (FOBT) kits for identifying invasive or potentially invasive diarrhea in Ibadan, Nigeria. Fecal specimens from 46 children under 5 years old with diarrhea, collected as part of ongoing case-control studies, were subjected to stool microscopy for erythrocytes and leucocytes, and FOBT using the innovator's product and four locally procurable generic immunochromatographic kits, each according to manufacturers' instructions. Stool specimens were cultured for enteric bacterial pathogens using standard procedures. Presumptive pathogen isolates were identified biochemically and by PCR, and then confirmed by whole genome sequencing. Shigella, enteroinvasive Escherichia coli and Yersinia, pathogens that invariably cause invasive diarrhea, were detected in five of 46 specimens. Occult blood detection by microscopy was 55.6% sensitive and 78.4% specific, while the innovator's FOBT product was respectively 62.5% and 81.6% sensitive and specific compared to strict invasive pathogen recovery. Microscopy and FOBT testing were less sensitive in identifying specimens that contained pathogens that do not always elicit invasive diarrhea. Generic FOBT tests compared well with the innovator's product. Microscopy and FOBT testing have some value for delineating likely invasive diarrheas. They could inform treatment and serve as early warning indicators for dysentery outbreaks in resource limited settings. Inexpensive, generic FOBT kits that are locally procurable in Nigeria performed as well as the innovator's product.

Identification and management of Shigella infection in children with diarrhoea: a systematic review and meta-analysis

BACKGROUND

Shigella infections are a leading cause of diarrhoeal death among children in low-income and middle-income countries. WHO guidelines reserve antibiotics for treating children with dysentery. Reliance on dysentery for identification and management of Shigella infection might miss an opportunity to reduce Shigella-associated morbidity and mortality. We aimed to systematically review and evaluate Shigella-associated and dysentery-associated mortality, the diagnostic value of dysentery for the identification of Shigella infection, and the efficacy of antibiotics for children with Shigella or dysentery, or both.

METHODS

We did three systematic reviews (for mortality, diagnostic value, and antibiotic treatment of Shigella and dysentery), and meta-analyses where appropriate, of studies in resource-limited settings. We searched MEDLINE, Embase, and LILACS database for studies published before Jan 1, 2017, in English, French, and Spanish. We included studies of human beings with diarrhoea and accepted all study-specific definitions of dysentery. For the mortality and diagnostic value searches, we excluded studies that did not include an effect estimate or data necessary to calculate this estimate. The search for treatment included only randomised controlled trials that were done after Jan 1, 1980, and assessed antibiotics in children (aged <18 years) with dysentery or laboratory-confirmed Shigella. We extracted or calculated odds ratios (ORs) and 95% CIs for relative mortality and did random-effects meta-analysis to arrive at pooled ORs. We calculated 95% CIs assuming a binomial distribution and did random-effects meta-regression of log-transformed sensitivity and specificity estimates for diagnostic value. We assessed the heterogeneity of papers included in these meta-analyses using the I2 statistic and evaluated publication bias using funnel plots. This review is registered with PROSPERO (CRD42017063896).

FINDINGS

3649 papers were identified and 60 studies were included for analyses: 13 for mortality, 27 for diagnostic value, and 20 for treatment. Shigella infection was associated with mortality (pooled OR 2·8, 95% CI 1·6-4·8; p=0·000) whereas dysentery was not associated with mortality (1·3, 0·7-2·3; p=0·37). Between 1977 and 2016, dysentery identified 1·9-85·9% of confirmed Shigella infections, with sensitivity decreasing over time (p=0·04). Ten (50%) of 20 included antibiotic trials were among children with dysentery, none were placebo-controlled, and two (10%) evaluated antibiotics no longer recommended for acute infectious diarrhoea. Ciprofloxacin showed superior microbiological, but not clinical, effectiveness compared with pivmecillinam, and no superior microbiological and clinical effectiveness compared with gatifloxacin. Substantial heterogeneity was reported for meta-analyses of the Shigella-associated mortality studies (I2=78·3%) and dysentery-associated mortality studies (I2=73·2%). Too few mortality studies were identified to meaningfully test for publication bias. No evidence of publication bias was found in this analysis of studies of diagnostic value.

INTERPRETATION

Current WHO guidelines appear to manage dysentery effectively, but might miss opportunities to reduce mortality among children infected with Shigella who present without bloody stool. Further studies should quantify potential decreases in mortality and morbidity associated with antibiotic therapy for children with non-dysenteric Shigella infection.

FUNDING

Bill & Melinda Gates Foundation and the Center for AIDS Research International Core.

Prevalence and determinants of diarrhoea among infants in selected primary health centres in Kaduna north local government area, Nigeria

Introduction

Despite efforts toward the prevention and management of diarrhoea, associated mortality among infants has remained high in Northern Nigeria. This study was designed to determine the prevalence and identify determinants of diarrhoea among infants in Kaduna North Local Government Area (KNLGA), Nigeria.

Methods

In a cross-sectional survey 630 mothers of infants attending three primary health care centers were interviewed. Data was collected on socio-demo graphic characteristics, infant care practices, infant diarrhoea history and mothers knowledge of causes, symptoms and management of diarrhea. Data were analyzed using descriptive statistics, Chi-square, and logistic regression tests at 5% level of significance.

Results

Mothers' mean age was 27±5.5 years and 46.1% had secondary education. Infants' mean age was 22.4± 12.8 weeks and 50% were females. Prevalence of diarrhoea in the two weeks preceding the study was 21.1%. Only 11.7% of mothers had poor knowledge of diarrhoea. About 76.3% of mothers always washed their hands with soap after cleaning infants' perineum. Majority of infants (84.6%) completed age appropriate immunization while 31.6% were exclusively breastfed. Infants whose mothers sometimes (OR=2.32; 95% CI: 1.4-3.87) or never washed (OR=2.64; 95% CI: 1.19-5.82) their hands with soap after cleaning the infants perineumand those with incomplete age appropriate immunization (OR=1.87, 95% CI: 1.2-2.896) were more likely to have diarrhoea.

Conclusion

Promotion of hygiene and nutrition education for mothers particularly on proper infant feeding practices, hand washing practices and complete immunization of infants is needed to address the diarrhea determinants.

Randomized intervention study of solar disinfection of drinking water in the prevention of dysentery in Kenyan children aged under 5 years

We report the results of a randomized controlled intervention study (September 2007 to March 2009) investigating the effect of solar disinfection (SODIS) of drinking water on the incidence of dysentery, nondysentery diarrhea, and anthropometric measurements of height and weight among children of age 6 months to 5 years living in peri-urban and rural communities in Nakuru, Kenya. We compared 555 children in 404 households using SODIS with 534 children in 361 households with no intervention. Dysentery was recorded using a pictorial diary. Incidence rate ratios (IRR) for both number of days and episodes of dysentery and nondysentery diarrhea were significantly (P < 0.001) reduced by use of solar disinfection: dysentery days IRR = 0.56 (95% CI 0.40 to 0.79); dysentery episodes IRR = 0.55 (95% CI 0.42 to 0.73); nondysentery days IRR = 0.70 (95% CI 0.59 to 0.84); nondysentery episodes IRR = 0.73 (95% CI 0.63 to 0.84). Anthropometry measurements of weight and height showed median height-for-age was significantly increased in those on SODIS, corresponding to an average of 0.8 cm over a 1-year period over the group as a whole (95% CI 0.7 to 1.6 cm, P = 0.031). Median weight-for-age was higher in those on SODIS, corresponding to a 0.23 kg difference in weight over the same period; however, the confidence interval spanned zero and the effect fell short of statistical significance (95% CI -0.02 to 0.47 kg, P = 0.068). SODIS and control households did not differ in the microbial quality of their untreated household water over the follow-up period (P = 0.119), but E. coli concentrations in SODIS bottles were significantly lower than those in storage containers over all follow-up visits (P < 0.001). This is the first trial to show evidence of the effect of SODIS on childhood anthropometry, compared with children in the control group and should alleviate concerns expressed by some commentators that the lower rates of dysentery associated with SODIS are the product of biased reporting rather than reflective of genuinely decreased incidence.

Dipstick test for rapid diagnosis of Shigella dysenteriae 1 in bacterial cultures and its potential use on stool samples

BACKGROUND

We describe a test for rapid detection of S. dysenteriae 1 in bacterial cultures and in stools, at the bedside of patients.

METHODOLOGY/PRINCIPAL FINDINGS

The test is based on the detection of S. dysenteriae 1 lipopolysaccharide (LPS) using serotype 1-specific monoclonal antibodies coupled to gold particles and displayed on a one-step immunochromatographic dipstick. A concentration as low as 15 ng/ml of LPS was detected in distilled water and in reconstituted stools in 10 minutes. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 1.6×10⁶ CFU/ml and 4.9×10⁶ CFU/ml of S. dysenteriae 1, respectively. Optimal conditions to read the test have been determined to limit the risk of ambiguous results due to appearance of a faint yellow test band in some negative samples. The specificity was 100% when tested with a battery of Shigella and unrelated strains in culture. When tested on 328 clinical samples in India, Vietnam, Senegal and France by laboratory technicians and in Democratic Republic of Congo by a field technician, the specificity (312/316) was 98.7% (95% CI:96.6-99.6%) and the sensitivity (11/12) was 91.7% (95% CI:59.8-99.6%). Stool cultures and the immunochromatographic test showed concordant results in 98.4 % of cases (323/328) in comparative studies. Positive and negative predictive values were 73.3% (95% CI:44.8-91.1%) and 99.7% (95% CI:98-100%).

CONCLUSION

The initial findings presented here for a simple dipstick-based test to diagnose S. dysenteriae 1 demonstrates its promising potential to become a powerful tool for case management and epidemiological surveys.

Changing species distribution and antimicrobial susceptibility pattern of Shigella over a 29-year period (1980-2008)

We studied changes in species distribution and antimicrobial resistance patterns of Shigella during 1980-2008, using the Diarrhoeal Diseases Surveillance system of Dhaka Hospital of ICDDR,B. In hospitalized patients Shigella prevalence decreased steadily from 8-12% in the 1980s to 3% in 2008. Endemic S. flexneri was the most commonly isolated species (54%). Epidemic S. dysenteriae type 1 had two peaks in 1984 and 1993, but was not found after 2000, except for one case in 2004. The therapeutic options are now limited: in 2008 a total of 33% of S. flexneri were resistant to ciprofloxacin and 57% to mecillinam. In the <5 years age group, severely underweight, wasted and stunted children were more at risk of shigellosis compared to well-nourished children (P<0·001). Although hospitalization for Shigella diarrhoea is decreasing, the high levels of antimicrobial resistance and increased susceptibility of malnourished children continue to pose an ongoing risk.

Structural and genetic evidence that the Escherichia coli O148 O antigen is the precursor of the Shigella dysenteriae type 1 O antigen and identification of a glucosyltransferase gene

Shigella dysenteriae type 1 is the most virulent serotype of Shigella. Enterotoxigenic Escherichia coli O148 is pathogenic and can cause diarrhoea. The following structure was established for the tetrasaccharide repeating unit of the E. coli O148 O antigen: -->3)-alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-D-Glcp-(1-->3)-alpha-D-GlcpNAc-(1-->. This differs from the structure reported earlier for S. dysenteriae type 1 by having a glucose (Glc) residue in place of a galactose (Gal) residue. The two bacteria also have the same genes for O antigen synthesis, with the same organization and high level of DNA identity, except that in S. dysenteriae type 1 wbbG is interrupted by a deletion, and a galactosyltransferase gene wbbP located on a plasmid is responsible for the transfer of galactose to make a novel antigenic epitope of the O antigen. The S. dysenteriae type 1 O antigen was reconstructed by replacing the E. coli O148 wbbG gene with the wbbP gene, and it had the LPS structure and antigenic properties of S. dysenteriae type 1, indicating that the S. dysenteriae type 1 O antigen evolved from that of E. coli O148. It was also confirmed that wbbG of E. coli O148 is a glucosyltransferase gene, and two serotype-specific genes of E. coli O148 and S. dysenteriae type 1 were identified.

Considerations for development of whole cell bacterial vaccines to prevent diarrheal diseases in children in developing countries

Enteric pathogens constitute a major pediatric threat in the developing world through their impact on morbidity and mortality, physical and cognitive development and cause and effect relationship with malnutrition. Although many bacterial pathogens can cause diarrheal diseases, a group of less than 10 including Shigella spp., enterotoxigenic Escherichia coli (ETEC), Vibrio cholerae, and possibly, Campylobacter jejuni account for a significant percentage of these diseases in developing countries. Rotavirus is also a major cause of diarrheal diseases. Vaccines against these agents offer a potentially effective control measure against these diseases, but safe, practical, and effective vaccines for many of these agents have yet to be realized. Many vaccine development approaches are under investigation, but the one that is currently most advanced and that has been most widely applied to enteric pathogens is the use of orally administered live or killed whole pathogen preparations. If inactivated, these vaccines will probably be administered as multiple doses with approximately 10(10) to 10(11) total particles per dose, but they are relatively safe for oral administration. Further, they may not require a buffer for delivery and can be stored in liquid formulations. Fewer doses may be required for some live attenuated pathogen vaccines, but a buffer will most likely be required for oral delivery and the product must be stored in a dried formulation. Also, safety becomes more of a concern with live pathogens depending on the degree of attenuation, host immunocompetence, and the total number and kinds of attenuated pathogens which may be present in a combined agent vaccine. Both live and killed whole pathogen vaccines can be immunogenic and have the possibility to serve as vectors for other antigens. Although many organisms and serotypes are clinically important, by exploiting antigenic cross reactivity and using some pathogen components as vectors for cloned antigens of other pathogens, it could be possible to induce immunity against major enteric pathogens/serotypes with <10 whole pathogen components in a multi-agent vaccine. Safe and effective mucosal adjuvants may in the future be useful in whole pathogen vaccines, but they do not seem to be essential for immunization. Further, dietary supplements such as zinc, mixed routes of delivery and new regimens are under study which may in the future enhance further the effectiveness of the whole pathogen vaccines which now seem realizable in the near term. For this to happen, however, a coordinated and committed effort is necessary now to address the immunologic, regulatory, manufacturing, testing and implementation issues which will be involved in the realization of this important product to benefit children's health worldwide.

Community-based treatment of multidrug-resistant tuberculosis in Lima, Peru: 7 years of experience

Programs implementing community-based directly observed therapy (DOT) have demonstrated success in the treatment of patients with tuberculosis. However, given complexities in the management and treatment of patients infected with multidrug-resistant tuberculosis (MDR-TB), the utilization of community-based DOT to treat MDR-TB patients has only recently been successfully attempted. We describe the first such program and highlight the crucial components and most critical challenges to creating a successful community-based MDR-TB treatment program.

Shigella dysenteriae type 1-specific bacteriophage from environmental waters in Bangladesh

Shigella dysenteriae type 1 is the causative agent of the most severe form of bacillary dysentery, which occurs as epidemics in many developing countries. We isolated a bacteriophage from surface water samples from Bangladesh that specifically lyses strains of S. dysenteriae type 1. This phage, designated SF-9, belongs to the Podoviridae family and has a 41-kb double-stranded DNA genome. Further screening of water samples for the prevalence of the phage revealed 9 of 71 (12.6%) water samples which were positive for the phage. These water samples were also positive in PCR assays for one or more S. dysenteriae type 1-specific genes, including ipaBCD and stx1, and live S. dysenteriae type 1 was isolated from three phage-positive samples. The results of this study suggest that phage SF-9 may have epidemiological applications in tracing the presence of S. dysenteriae type 1 in environmental waters.

Diagnostic accuracy of stool assays for inflammatory bacterial gastroenteritis in developed and resource-poor countries

Because acute bacterial gastroenteritis is often inflammatory, rapid stool assays that detect intestinal inflammation might be used to distinguish between bacterial and nonbacterial gastroenteritis. We performed meta-analyses to determine the discriminatory power, in developed and in resource-poor countries, of rapid stool assays that test for lactoferrin, fecal leukocytes, fecal erythrocytes, and occult blood. In developed countries, the area under the summary receiver operating characteristic curve (AUC/SROC) was 0.89 for fecal leukocytes and 0.81 for occult blood. In resource-poor countries, the AUC/SROC was 0.79 for lactoferrin, 0.72 for fecal leukocytes, 0.63 for occult blood, and 0.61 for fecal erythrocytes. In developed countries, positive and negative likelihood ratios (LR+ and LR-, respectively) for fecal leukocytes were 4.56 and 0.32 when a threshold of >5 cells/high-power field was used, compared with 2.94 and 0.6 in resource-poor countries; for lactoferrin, LR+ was 1.34 and LR- was 0.17 in resource-poor countries when the threshold was an agglutination rating of "+" and a dilution of 1:50. In developing countries, rapid stool assays performed poorly, whereas in developed countries, tests for fecal leukocytes, lactoferrin, and occult blood were moderately useful and could identify patients who were more likely to benefit from empirical antibiotic therapy.

Protective efficacy of oral immunization with heat-killed Shigella flexneri 2a in animal model: study of cross protection, immune response and antigenic recognition

Oral immunization of rabbits with four doses of 10(11) heat-killed Shigella flexneri 2a showed 100% protection against challenge with virulent S. flexneri 2a. After orally immunizing Guinea pigs with four doses of heat-killed S. flexneri 2a 100% protection could be shown against ocular challenge with the same virulent S. flexneri 2a strain but this conferred no protection against challenge with Shigella dysenteriae type 1. In enzyme-linked immunosorbent assay (ELISA) and immunoblot experiments both whole cell lysate-envelope (WCL-E) fraction and outer membrane proteins (OMPs) were recognized by the antisera. Though protective mechanism in shigellosis is not established with certainty, outer membrane proteins (specially 38, 34, 23 and 20kDa proteins) may be the major antigens in the induction of protective immune responses as indicated by this observation.

[Changes in child health indicators in a municipality with community health workers: the case of Itapirapuã Paulista, Vale do Ribeira, São Paulo State, Brazil]

Twelve community health workers (CHWs) were trained to offer basic health care for children under five years of age through household visits in Itapirapuã Paulista, a municipality in Vale do Ribeira, São Paulo State, Brazil. Their tasks included diagnosis, initial treatment, and management of diarrhea and acute respiratory diseases at the household level, growth monitoring, incentives to complete basic immunization, and counseling on infant food supplementation. An average of 409 (396-417) children were visited weekly by CHWs in their homes over the course of three years. In this period, the hospitalization rate dropped drastically, and the use of oral rehydration therapy during bouts of diarrhea increased greatly. However, prevalence of stunting and incidence of low birth weight did not change. Child health indicators (CHI) in this municipality were better than those in a municipality chosen as a control. CHWs may have contributed to improved local CHI, but the results should be interpreted with caution for two reasons: (1) CHI is improving in Brazil countrywide and (2) it is a small program implemented in an area with high morbidity and mortality rates and low availability of health services.

Isolation of Shigella dysenteriae type 1 and S. flexneri strains from surface waters in Bangladesh: comparative molecular analysis of environmental Shigella isolates versus clinical strains

Bacillary dysentery caused by Shigella species is a public health problem in developing countries including Bangladesh. Although, shigellae-contaminated food and drinks are often the source of the epidemic's spread, the possible presence of the pathogen and transmission of it through environmental waters have not been adequately examined. We analyzed surface waters collected in Dhaka, Bangladesh, for the presence of shigellae by a combination of PCR assays followed by concentration and culturing of PCR-positive samples. Analysis of 128 water samples by PCR assays for Shigella-specific virulence genes including ipaBCD, ipaH, and stx1 identified 14 (10.9%) samples which were positive for one or more of these virulence genes. Concentration of the PCR-positive samples by filtration followed by culturing identified live Shigella species in 11 of the 14 PCR-positive samples. Analysis of rRNA gene restriction patterns (ribotype) showed that the environmental isolates shared ribotypes with a collection of clinical isolates, but in contrast to the clinical isolates, 10 of the 11 environmental isolates were either negative or carried deletions in the plasmid-encoded invasion-associated genes ipaB, ipaC, and ipaD. However, all environmental Shigella isolates were positive for the chromosomal multicopy invasion-associated gene ipaH and all Shigella dysenteriae type 1 isolates were positive for the stx1 gene in addition to ipaH. This study demonstrated the presence of Shigella in the aquatic environment and dispersion of different virulence genes among these isolates which appear to constitute an environmental reservoir of Shigella-specific virulence genes. Since critical virulence genes in Shigella are carried by plasmids or mobile genetic elements, the environmental gene pool may contribute to an optimum combination of genes, causing the emergence of virulent Shigella strains which is facilitated in particular by close contact of the population with surface waters in Bangladesh.

Safety and immunogenicity of improved Shigella O-specific polysaccharide-protein conjugate vaccines in adults in Israel

Data suggest that the O-specific polysaccharide (O-SP) domain of the lipopolysaccharide (LPS) of Shigella species is both an essential virulence factor and a protective antigen and that a critical level of serum immunoglobulin G (IgG) to this antigen will confer immunity to shigellosis. Because covalent attachment of polysaccharides to proteins increases their immunogenicity, especially in infants and in young children, the O-SP of Shigella species were bound to medically useful proteins, and the safety and immunogenicity of the resultant conjugates were confirmed in adults and 4- to 7-year-old children. Succinylation of the carrier protein improved the immunogenicity of Shigella conjugates in mice and increased their yield. Based on these results, a clinical trial of O-SP conjugates of Shigella sonnei and Shigella flexneri 2a bound to succinylated mutant Pseudomonas aeruginosa exotoxin A (rEPAsucc) or native or succinylated Corynebacterium diphtheriae toxin mutant (CRM9 or CRM9succ) was conducted in healthy adults. The conjugates were safe and immunogenic. S. sonnei-CRM9, S. sonnei-CRM9succ, and S. sonnei-rEPAsucc elicited significant rises of geometric mean (GM) IgG anti-LPS within 1 week of injection (P < 0.001). At 26 weeks, the GM anti-LPS levels elicited by these three conjugates were similar and higher than their prevaccination levels (P < 0.0001). GM IgG anti-LPS levels elicited by S. flexneri 2a-rEPAsucc were significantly higher than those elicited by S. flexneri 2a-rCRM9succ at all intervals after injection. At 26 weeks, the levels of IgG anti-LPS in vaccinees were higher than their prevaccination levels (P < 0.0001). The serum antibody responses were specific, as there was no significant rise of anti-LPS to the heterologous O-SP in any vaccinee. Both conjugates elicited statistically significant rises of serum antibodies to the injected carrier protein. At 6 months, these five Shigella conjugates elicited higher fold rises than similar conjugates (D. N. Taylor et al., Infect. Immun. 61:3678-3687, 1993). Based on these data, we chose S. sonnei-CRM9 and S. flexneri 2a-rEPAsucc for evaluation in children.

Shigella and Salmonella strains isolated from children under 5 years in Gaborone, Botswana, and their antibiotic susceptibility patterns

We isolated Shigella from 43/221 (21%) and Salmonella 8/221 (3%) rectal swabs from children under 5 years with diarrhoea, and found Shigella in two of 100 specimens from children without diarrhoea. Sh. boydii (13%) was the most prevalent Shigella species followed by Sh. flexneri (6%) and Sh. sonnei (2%). The prevalence of various types of Sh. boydii was type 7, 5%; type 9, 3%; type 12 and 16, 2%; and type 18, 1%. Other Shigella serotypes encountered were Sh. flexneri type 6 (4%), type 4 (2%), with Sh. sonnei phase II isolated from 2% of the specimens. The Salmonella species were S. typhimurium and S. paratyphi. The high rate of isolation of Shigella species from children with diarrhoea is indicative of a definite role of this enteropathogen in causing endemic diarrhoea in Gaborone, Botswana. Antibiograms of the predominant isolates showed that most Shigella species were resistant to ampicillin but susceptible to chloramphenicol, and with the exception of Sh. flexneri type 6, also susceptible to gentamicin. The Salmonella species were susceptible to chloramphenicol, collistin-sulphate, gentamicin, cotrimoxazole, and ampicillin.

Treatment with succinic anhydride improves the immunogenicity of Shigella flexneri type 2a O-specific polysaccharide-protein conjugates in mice

Seroepidemiological data and a clinical trial with a Shigella sonnei O-specific polysaccharide (O-SP)-Pseudomonas aeruginosa recombinant exoprotein A (rEPA) conjugate provide evidence that a critical level of immunoglobulin G (IgG) lipopolysaccharide (LPS) antibodies in serum confers protection against shigellosis. We evaluated the immunogenicity of conjugates whose carrier proteins and O-SPs were treated with succinic anhydride (SA), which reacts with amino groups at neutral pH to form amide-linked carboxyls (succinylation). Conjugates were synthesized with either of two genetically inactivated medically useful toxins, the diphtheria protein CRM9 or rEPA, bound to the O-SP of Shigella flexneri type 2a. Conjugates composed of the succinylated protein, succinylated O-SP, or both succinylated components were administered to mice by a clinically relevant scheme, and their levels of serum IgG anti-LPS and anti-proteins were assayed 7 days after the second and third injections. CRM9 served as a more immunogenic carrier than rEPA. Conjugates composed of succinylated components were more immunogenic than the conjugates composed of the native components. SA treatment of both the carrier protein and the O-SP did not confer an advantage over the succinylated protein alone. Conjugates prepared with native proteins, in general, elicited slightly higher levels of IgG protein antibodies than conjugates composed of the SA-treated proteins.

Vaccination against shigellosis with attenuated Shigella flexneri 2a strain SC602

The Shigella flexneri 2a SC602 vaccine candidate carries deletions of the plasmid-borne virulence gene icsA (mediating intra- and intercellular spread) and the chromosomal locus iuc (encoding aerobactin) (S. Barzu, A. Fontaine, P. J. Sansonetti, and A. Phalipon, Infect. Immun. 64:1190-1196, 1996). Dose selection studies showed that SC602 causes shigellosis in a majority of volunteers when 3 x 10(8) or 2 x 10(6) CFU are ingested. In contrast, a dose of 10(4) CFU was associated with transient fever or mild diarrhea in 2 of 15 volunteers. All volunteers receiving single doses of >/=10(4) CFU excreted S. flexneri 2a, and this colonization induced significant antibody-secreting cell and enzyme-linked immunosorbent assay responses against S. flexneri 2a lipopolysaccharide in two-thirds of the vaccinees. Seven volunteers who had been vaccinated 8 weeks earlier with a single dose of 10(4) CFU and 7 control subjects were challenged with 2 x 10(3) CFU of virulent S. flexneri 2a organisms. Six of the control volunteers developed shigellosis with fever and severe diarrhea or dysentery, while none of the vaccinees had fever, dysentery, or severe symptoms (P = 0. 005). Three vaccinees experienced mild diarrhea, and these subjects had lower antibody titers than did the fully protected volunteers. Although the apparent window of safety is narrow, SC602 is the first example of an attenuated S. flexneri 2a candidate vaccine that provides protection against shigellosis in a stringent, human challenge model.

Shigellosis in children: a clinico-epidemiological comparison between Shigella dysenteriae type I and Shigella flexneri

We reviewed the clinical and epidemiological features of 390 children under 5 years of age infected with either Shigella dysenteriae type I or Shigella flexneri attending a diarrhoea treatment centre from 1993 to 1995 in Dhaka, Bangladesh. Older age (24 months or more), underweight and wasting but not stunting were the host factors significantly more associated with Shigella dysenteriae type I infection than in Shigella flexneri-infected children. Moreover, use of antibiotics at home, use of water from tubewells or pipe-water for drinking and lack of sanitary facilities for defaecation were the behavioural and environmental factors strongly associated with S. dysenteriae type I infection. Children with diarrhoea due to S. flexneri presented with more watery/liquid stools and had a shorter duration of illness. Duration of diarrhoea for 4 or more days was typical of S. dysenteriae type I infection. Interventions to address malnutrition and to promote environmental hygiene would be predicted to offer greater protection against shigellosis due to S. dysenteriae than S. flexneri.

Epidemiological and clinical profiles of acute invasive diarrhoea with special reference to mucoid episodes: a rural community-based longitudinal study

A study was carried out in 3 villages near Calcutta, India, having a population of 5464, between August 1992 and December 1994. A cohort of rural children below 4 years of age was prospectively observed to determine the clinico-epidemiological aspects of mucoid diarrhoea and examine propensity to invasiveness. Overall, the incidence of diarrhoea was 1.7 episodes/child/year, and that of mucoid and bloody dysentery was 0.8 and 0.2 episodes/child/year, respectively. Children aged 6-11 months had a higher incidence of mucoid diarrhoea (1.3 episodes/child/year) and the peak season occurred in June and July. Multivariate analysis using logistic regression showed that mucoid diarrhoea and bloody dysentery were closely similar in both clinical and laboratory findings, including raised faecal leucocyte count (> 10/high power microscope field [hpf]). However, abdominal pain occurred more frequently in bloody dysentery than in mucoid diarrhoea. Faecal leucocyte count (> 10/hpf) can therefore be used as an indicator for invasiveness of mucoid diarrhoea at the community level.

Risk factors for deaths in under-age-five children attending a diarrhoea treatment centre

Few case-control studies have examined possible risk factors for diarrhoeal deaths in under-age-five children in the developing countries. We analysed data from the surveillance system of our diarrhoea treatment centre/hospital for the period 1990-94 on 928 children less than 5 years of age. In univariate analysis, 11 factors were significantly associated with death: lack of breastfeeding, severe malnutrition, complicated diarrhoea, pneumonia, xerophthalmia, duration of diarrhoea 7-14 days, moderate or severe dehydration, recent history of measles, Shigella flexneri infection, maternal illiteracy, and very low household income. Rotavirus diarrhoea was negatively associated with fatal outcome. In the assessment of severe malnutrition, weight-for-height measurement discriminated mortality risk better than weight-for-age or height-for-age indices. Only two factors retained their significance, severe malnutrition and non-breastfeeding in the multivariate analysis with adjusted odds ratio (95% confidence interval) of 84.2 (9.1, 775.9) and 4.2 (1.3, 13.2) respectively.

Fecal screening tests in the approach to acute infectious diarrhea: a scientific overview

OBJECTIVE

To evaluate the value of fecal leukocytes, fecal occult blood, fecal lactoferrin and combination of fecal leukocytes with clinical data in the workup of patients with inflammatory diarrhea.

DATA IDENTIFICATION

A systematic literature search in all languages using MEDLINE (1970 to 1994), reference lists of articles primarily retrieved and of review articles and correspondence with experts in the field.

STUDY SELECTION

The search identified 2603 references, 81 of which were deemed relevant on the basis of prespecified selection criteria. Of these 25 contained sufficient data for further analysis and thus were finally included.

DATA EXTRACTION

All data from the selected articles were extracted by one observer whereas the second reviewer checked these data for accuracy. True positive rates and false positive rates were calculated from each 2 x 2 table.

RESULTS OF DATA ANALYSIS

The study summarizes the diagnostic accuracy of the signaled tests as predictors of inflammatory diarrhea as defined by stool culture (the reference test). Plots of true positive rates against false positive rates demonstrated widely scattered points, indicating heterogeneity. A summary receiver operating characteristic curve was fitted to the data with the use of logistic transforms and weighted least squares linear regression. Of the 25 studies analyzed 38 data points were used to construct summary receiver operating characteristic curves for index tests.

CONCLUSIONS

Fecal lactoferrin was the most accurate index test. Fecal leukocytes showed the lowest performance as assessed by the area under the curve. Occult blood and combination of fecal leukocytes with clinical data yielded intermediate curves. A limited number of studies (fecal lactoferrin, and fecal leukocytes with clinical data) and methodologic flaws identified in the assessed studies must be solved in future primary studies to improve the usefulness of the metaanalytic approach used here.

Shigella infections

Shigella dysentery is a major public-health problem in many tropical areas. Despite improvements in water supplies and sanitation, it continues to be a disease of poor rural and urban communities and in populations affected by migration and crowding following disasters. Pathogenesis is due to colonic invasion, endotoxin, and, in Shigella dysenteriae 1, shiga toxin. As well as the local manifestations of dysentery, systemic complications include convulsions, haemolytic-uraemic syndrome, hyponatraemia and hypoglycaemia. The spread of shigella infection is most commonly person-person, although water and food-borne outbreaks have been reported. Since 1970, multiple antimicrobial resistance, particularly in Sh. dysenteriae 1, has complicated strategies for management. Multiply resistant strains have occurred in Latin America, Central Africa and southern and south-eastern Asia. No vaccines are currently available, and prevention and control will depend on public-health improvements and improved case management.

High frequency of strains multiply resistant to ampicillin, trimethoprim-sulfamethoxazole, streptomycin, chloramphenicol, and tetracycline isolated from patients with shigellosis in northeastern Brazil during the period 1988 to 1993

The occurrence and antimicrobial resistance pattern of Shigella isolates obtained from persons in community and hospital-based studies of diarrhea and matched controls in northeastern Brazil were studied. The isolation rate of Shigella spp. from patients with diarrhea during 1988 to 1993 varied from 4.5% (26 of 575) for the urban community of Gonçalves Dias to 6.7% (12 of 179) and 5.9% (7 of 119) for Hospital Infantil and Hospital Universitário, respectively. Of the 55 Shigella isolates (45 from patients with diarrhea, 8 from controls, and 2 undetermined) 73% (40 of 55) were Shigella flexneri, 16% (9 of 55) were S. sonnei, 7% (4 of 55) were S. boydii, and 4% (2 of 55) were S. dysenteriae. Of 39 S. flexneri strains, over half were resistant to ampicillin, trimethoprim-sulfamethoxazole, or both. Over 64% were resistant to streptomycin, chloramphenicol, and tetracycline. Overall, 82% of all S. flexneri isolates were resistant to four or more antimicrobial agents tested. As elsewhere, in the northeast of Brazil, ampicillin and trimethoprim-sulfamethoxazole are no longer reliable for treatment of S. flexneri infection. Most Shigella strains were resistant to four or more antimicrobial agents. Nalidixic acid was still useful for treatment of infections due to S. flexneri.

Shigellosis in neonates and young infants

To determine the clinical features and outcome of shigellosis in young infants, we reviewed the hospital records of 159 infants < or = 3 months of age (including 30 neonates) and 159 children 1 to 10 years of age with shigellosis who were admitted to the Diarrhoea Treatment Centre in Dacca, Bangladesh. Infants more commonly had a history of nonbloody diarrhea (82.8% vs 42.7%; p < 0.001), moderate or severe dehydration (59.9% vs 32.1%; p < 0.001), or bacteremia (12.0% vs 5.0%; p = 0.027) and less commonly had fever (32.7% vs 58.6%; p < 0.001), abdominal tenderness (1.9% vs 12.6%; p < 0.001), or rectal prolapse (0% vs 8.3%; p = 0.001). Infections caused by Shigella boydii (20.8% vs 6.3%; p < 0.001) and Shigella sonnei (7.5% vs 1.3%; p = 0.006) were more common, and Shigella dysenteriae type 1 (9.4% vs 31.4%; p < 0.001) infections were less common in infants than in older children; the proportion of Shigella flexneri infections was equivalent in the two groups (59.1% vs 60.4%). Infants were twice as likely to die as older children (16.4% vs 8.2%; p = 0.026). Only 17 infants (14.3%) were being exclusively breast fed at the onset of their illness. In a multiple logistic regression analysis, independent predictors of death in infants were gram-negative bacteremia, ileus, decreased bowel sounds, hyponatremia, hypoproteinemia, and a lower number of erythrocytes detected on microscopic examination of stool specimens. Diarrhea management algorithms that rely only on clinical findings of dysentery to diagnose and treat shigellosis are likely to be unreliable in this high-risk age group.

Prescribing pattern in acute diarrhoea in three districts in Bangladesh

Irrational use of drugs is a serious problem in the management of diarrhoea in developing countries. Many studies have been conducted in many different countries to document the prescribing pattern in diarrhoeal diseases in the hope of promoting rational use of drugs and thereby improve patient care. In only a few of these studies have standard drug use indicators been used to quantify the extent and nature of irrational prescribing. We report here the findings of a prescribing survey in acute diarrhoea (prescriptions written by graduate doctors) in the government health facilities (GHF) and private dispensaries (PD) in the districts of Dhaka, Tangail and Serajgonj of Bangladesh. In the study a set of standard indicators concerning prescribing, patient care and drug supply developed by the International Network for Rational Use of Drugs (INRUD; and later adopted by WHO) has been employed. Twelve prescriptions given in acute diarrhoea cases in children under 5 years old were prospectively collected on a random basis from each of the 10 centres from three districts. They were analysed by the methods suggested in the INRUD manual.

Synthesis, characterization, and clinical evaluation of conjugate vaccines composed of the O-specific polysaccharides of Shigella dysenteriae type 1, Shigella flexneri type 2a, and Shigella sonnei (Plesiomonas shigelloides) bound to bacterial toxoids

The theoretic basis for developing conjugate vaccines, to induce immunoglobulin G (IgG) lipopolysaccharide (LPS) antibodies for the prevention of shigellosis, has been described (J. B. Robbins, C.-Y. Chu, and R. Schneerson, Clin. Infect. Dis. 15:346-361, 1992). The O-specific polysaccharides (O-SPs) of Shigella dysenteriae type 1, S. flexneri type 2a, and S. sonnei were covalently bound to carrier proteins. Alone, the O-SPs were not immunogenic in mice. Conjugates of these O-SPs, injected into young outbred mice subcutaneously as saline solutions containing 2.5 micrograms of saccharide, elicited serum IgG and IgM antibodies with booster responses; adsorption onto alum enhanced their immunogenicity. Injection of 25 micrograms of these conjugates into adult volunteers elicited mild local reactions only. Each conjugate induced a significant rise of the geometric mean serum IgG, IgM, and IgA LPS antibody levels. A second injection 6 weeks later did not elicit booster responses, and adsorption of the conjugates onto alum did not enhance their immunogenicity. Conjugate-induced levels of IgA, but not IgG or IgM, declined to preimmunization levels at day 56. The levels of postimmunization antibodies of the three immunoglobulin classes were similar to or higher than those of recruits in the Israel Defense Force following shigellosis caused by S. flexneri type 2a or S. sonnei. These data provide the basis for evaluating these conjugates to prevent shigellosis.

Childhood diarrhoea and acute respiratory infections in developing countries

In 1990 childhood diarrhoea and acute respiratory infections together accounted for 7.5 million deaths of children younger than five years of age in developing countries. To decrease mortality and treatment costs associated with these illnesses, the World Health Organization has developed standard diagnostic and treatment procedures for health staff, and is working on strategies for disease prevention. Immunisation against measles, adequate nutrition, including exclusive breastfeeding for the first four to six months, and improved water supplies and sanitation are the most important preventive measures. The 1990 World Summit for Children has set goals of a 50% reduction in childhood mortality from diarrhoea and a 33% reduction in mortality from acute respiratory diseases by the year 2000. These goals can be achieved by political commitment and a major investment of resources, but sustained support for these efforts from the medical professions is crucial.

Rapid detection of Shigella dysenteriae and Shigella flexneri in faeces by an immunomagnetic assay with monoclonal antibodies

A rapid and sensitive method for the detection of Shigella dysenteriae type 1 and Shigella flexneri serotypes in faeces based on capture of the bacteria with immunomagnetic particles is described. The particles were coated with either of two different monoclonal antibodies specific for the O-antigens of Shigella dysenteriae type 1 and Shigella flexneri serotypes. Captured bacteria were detected by an enzyme immunoassay with O-antigen specific rabbit antiserum. The whole assay required 2 to 3 hours to perform and the sensitivity limit was 10(3) cfu/ml as determined by viable cell counting. One hundred and fifty enterobacteria strains, including 100 Shigella strains from a strain collection, and 302 fresh faecal samples were used for the study. All Shigella dysenteriae type 1 and Shigella flexneri culture-positive faecal samples were positive in the immunomagnetic assay. In addition 18 of 252 culture-negative faecal samples were positive. The immunomagnetic assay was compared with latex agglutination and indirect immunofluorescence using culture as the reference method. The immunomagnetic assay had a sensitivity of 100%, latex agglutination a sensitivity of 72% with 28% false-negative results, and indirect immunofluorescence a sensitivity of 95%. The immunomagnetic assay was superior in sensitivity since it also detected Shigella in faecal samples up to two days after antibiotic therapy had been started, which both latex agglutination and indirect immunofluorescence failed to do. The high sensitivity in detecting live and dead bacteria, and the ease of performance of the immunomagnetic assay render it an attractive method for detection of Shigella.

Detection of Shigella dysenteriae type 1 and Shigella flexneri in feces by immunomagnetic isolation and polymerase chain reaction

A combination of immunomagnetic separation (IMS) and a polymerase chain reaction (PCR) procedure was used for direct isolation and identification of Shigella dysenteriae type 1 and Shigella flexneri from feces. Immunomagnetic particles were coated with monoclonal antibody MASFB, which is specific for a common epitope of the O polysaccharides of S. dysenteriae type 1 and S. flexneri. Bacteria bound to the beads were boiled in water, and target DNA was amplified with a primer pair specific for a gene coded on the invasion-associated locus (ial) of the large virulence plasmid of all four Shigella spp. and enteroinvasive strains of Escherichia coli. A 320-bp DNA fragment was generated and detected by an alkaline phosphatase-conjugated probe. Nonviable cells were also captured and detected by this technique. The method is simple and fast (7 h) and has a detection limit of ca. 10 Shigella organisms per g in fecal samples. The combined IMS-PCR assay correctly identified all 57 samples carrying S. dysenteriae type 1 and 68 samples carrying S. flexneri from 238 fecal specimens and also permitted detection of 17 samples carrying Shigella spp. from 113 specimens from diarrheal patients in whom shigellae were not detected by conventional culture.

Care of HIV-risk infants: nursing outreach by PNPs

In this prospective study, HIV-risk infants (infants born to women with a history of intravenous drug use, prostitution, or who is a sexual partner of an intravenous drug user) were followed during home visits by a pediatric nurse practitioner. Analysis of home visit records indicated that significant medical problems were detected in one out of every 12 visits, requiring referral of the infant for immediate medical attention. The most frequent problems/maternal concerns encountered during the home visits were infectious disease symptoms and skin conditions. The type of problems/maternal concerns did not differ by infant HIV status. With an increase in incidence of HIV infection in children, outreach by specialized nurses including PNPs is necessary to provide the intensive medical services required by these children.

Fluorescent antibody staining test for rapid diagnosis of Shigella dysenteriae 1 infection

An indirect fluorescent antibody test for rapid detection of Shigella dysenteriae 1 in diarrheal stools was developed. A diagnosis could be made within 90 min of submission of specimens to the laboratory. On comparison with culture results, the test had a sensitivity of 92%, a specificity of 93%, and positive and negative predictive values of 94% and 92%, respectively.

Intestinal obstruction during shigellosis: incidence, clinical features, risk factors, and outcome

To determine the incidence and outcome of intestinal obstruction during shigellosis, the authors assessed 1211 consecutive patients with shigellosis admitted during a 15-month period to a diarrhea treatment center in Dhaka, Bangladesh. Obstruction was identified in 30 (2.5%) patients. Ten (33.3%) of these patients died, compared with 97 (8.2%) of the 1181 patients without obstructions (P less than 0.001; RR = 4.1). In a case-control study, patients with obstructions were compared with 30 control patients with shigellosis but without obstructions. Case and control patients were similar in age (median, 18 months vs. 24 months; NS). Before admission to the hospital, case patients had less often been breast-fed than control patients (33% vs. 85%; P = 0.006) and had more often received antimicrobial agents (53% vs. 13%; P = 0.001). Case patients more often had abdominal tenderness (73% vs. 13%; P less than 0.001), altered consciousness (50% vs. 17%; P = 0.006), and Shigella dysenteriae type 1 infection (73% vs. 27%, P = 0.001) and had a higher median blood leukocyte count (40 x 10(3)/microL vs. 14 x 10(3)/microL; P = 0.007) and serum potassium concentration (5.0 mmol/L vs. 4.3 mmol/L; P = 0.016), and lower median serum sodium (123 mmol/L vs. 131 mmol/L; P = 0.003) and total protein (52 g/L vs. 60 g/L; P = 0.025) concentrations than did control patients. Eight (27%) patients with obstructions developed the hemolytic-uremic syndrome, compared with none of the control patients (P = 0.003). It was concluded that obstruction is an ominous complication of shigellosis and that therapies in addition to provision of antimicrobial agents need to be evaluated.

Effect of duration of diarrhoea and predictive values of stool leucocytes and red blood cells in the isolation of different serogroups or serotypes of Shigella

Diarrhoeal stools from 11,358 patients were microscopically examined for the presence of white and red blood cells (WBC and RBC) and cultured for enteric pathogens. Of the 3895 patients who had Shigella as sole pathogens, 2681 (72.3%) showed the presence of both WBC and RBC and the remainder had only WBC (P less than 0.001). The presence of both WBC and RBC was as good a predictor of shigellosis as the presence of greater than 25 WBC per high power field (hpf) of the microscope with or without RBC. However, the best predictor of shigellosis (positive predictive value 85%, negative predictive value 83%) was the presence of greater than 25 WBC/hpf and the presence of RBC regardless of their number. More patients infected with S. dysenteriae 1, S. flexneri and S. boydii shed both WBC and RBC than those infected with S. sonnei, most of whom shed WBC only (P less than 0.001). A greater number of patients infected with S. dysenteriae 1 shed more WBC and RBC than those infected with S. flexneri (P less than 0.001). The same trend was found when patients infected with S. flexneri were compared with those infected with S. boydii (though the difference was not statistically significant) and when patients infected with S. boydii were compared with patients infected with S. sonnei (P less than 0.001). There was a progressive decline in the isolation rate of Shigella as the duration of dysentery, before stool culture, increased.

Zymodemes of Entamoeba histolytica in Dhaka, Bangladesh

Stool samples containing Entamoeba histolytica were obtained from two sources: an urban hospital and an urban slum. Using the enzyme patterns of three enzymes (E.C.2.7.1.1 hexokinase, E.C.5.3.1.9 glucose phosphate isomerase and E.C.2.7.5.1 phosphoglucomutase) stained after cellulose acetate electrophoresis, four zymodemes (I, II, XIV and XVI) were identified in 71 isolates. Zymodemes considered to be pathogenic (II and XIV) were identified from 31 of 34 isolates from the urban hospital, and these zymodemes were strongly associated with dysentery and trophozoites containing ingested red blood corpuscles. Blood visible to the naked eye was more commonly seen in stools from which zymodeme XIV was isolated than in those containing zymodeme II (P less than 0.001). Zymodemes considered to be non-pathogenic (I and XVI) were identified in 34 of 37 isolates from slum dwellers and were not associated with blood in the stools.

The effect of maternal and child health and family planning services on mortality: is prevention enough?

OBJECTIVE

To examine the impact on mortality of a child survival strategy, mostly based on preventive interventions.

DESIGN

Cross sectional comparison of cause specific mortality in two communities differing in the type, coverage, and quality of maternal and child health and family planning services. In the intervention area the services were mainly preventive, community based, and home delivered.

SUBJECTS

Neonates, infants, children, and mothers in two contiguous areas of rural Bangladesh.

INTERVENTIONS

In the intervention area community health workers provided advice on contraception and on feeding and weaning babies; distributed oral rehydration solution, vitamin A tablets for children under 5, and ferrous fumarate and folic acid during pregnancy; immunised children; trained birth attendants in safe delivery and when to refer; treated minor ailments; and referred seriously ill people and malnourished children to a central clinic.

MAIN OUTCOME MEASURES

Overall and age and cause specific death rates, obtained by a multiple step "verbal autopsy" process.

RESULTS

During the two years covered by the study overall mortality was 17% lower among neonates, 9% lower among infants aged 1-5 months, 30% lower among children aged 6-35 months, and 19% lower among women living in the study area than in those living in the control area. These differences were mainly due to fewer deaths from neonatal tetanus, measles, persistent diarrhoea with severe malnutrition among children, and fewer abortions among women.

CONCLUSIONS

The programme was effective in preventing some deaths. In addition to preventive components such as tetanus and measles immunisation, health and nutrition education, and family planning, curative services are needed to reduce mortality further.

Hypoglycemia during diarrhea in childhood. Prevalence, pathophysiology, and outcome

To determine the frequency and outcome of hypoglycemia during diarrhea in childhood, we screened 2003 consecutive patients less than 15 years of age who were admitted to a diarrhea treatment center in Dhaka, Bangladesh. Hypoglycemia, defined as a blood glucose concentration less than 2.2 mmol per liter, was found in 91 patients (4.5 percent), 39 (42.9 percent) of whom died. We also measured the plasma concentrations of glucoregulatory hormones and gluconeogenetic substrates in 46 of the patients with hypoglycemia who were 2 to 15 years old and in 25 normoglycemic patients matched with them for age and weight. The patients with hypoglycemia had had diarrhea for less time than the normoglycemic patients (median, 12 vs. 72 hours; P less than 0.05), and their last feeding had been 18 hours before admission, as compared with 9 hours for the normoglycemic patients (P less than 0.05). The groups were similar in terms of nutritional status, the proportion of patients who had fever, and the types of pathogens recovered from stool samples. The plasma C-peptide concentrations were low (less than 0.30 nmol per liter) in all the hypoglycemic patients. As compared with the normoglycemic patients, the patients with hypoglycemia had elevated median plasma concentrations of glucagon (44 vs. 11 pmol per liter; P = 0.001), epinephrine (3400 vs. 1500 pmol per liter; P = 0.012), norepinephrine (7500 vs. 2900 pmol per liter; P = 0.002), and lactate (3.5 vs. 2.1 mmol per liter; P = 0.020) and similar alanine and beta-hydroxybutyrate concentrations. Eighteen hypoglycemic patients with severe malnutrition had been ill longer than 26 better-nourished patients with hypoglycemia (median duration of illness, 18 vs. 10 hours; P = 0.023) and had lower median plasma concentrations of lactate (1.9 vs. 3.9 mmol per liter; P = 0.021) and alanine (173 vs. 293 micromol per liter; P = 0.040). We conclude that hypoglycemia is a major cause of death in association with diarrhea. Because the glucose counterregulatory hormones were appropriately elevated in the children with diarrhea and hypoglycemia, whereas the gluconeogenetic substrates were inappropriately low, we further conclude that the hypoglycemia observed in such patients is most often due to the failure of gluconeogenesis.