Shiga-like toxin-producing Escherichia coli O111 and associated hemolytic-uremic syndrome: a family outbreak.

OBJECTIVE: To describe a family cluster of Shiga toxin-producing Escherichia coli O111ac:NM infection. STUDY DESIGN: The index case was identified as part of a United States prospective study of hemolytic-uremic syndrome. Epidemiologic investigation was conducted through interviews. E. coli O111:NM infection was characterized through culture and serology. Shiga toxin 1 and 2 gene sequences were determined with oligonucleotide DNA probes. RESULTS: All three children and both parents had nonbloody diarrhea, vomiting and abdominal cramps, and one child developed hemolytic-uremic syndrome. Shiga toxin 1- and 2-producing E. coli O111ac:NM was isolated from two children. IgG antibodies to E. coli O111 were detected in all three children. CONCLUSIONS: To our knowledge this is the first reported cluster of O111 infection and only the second caused by non-O157 Shiga toxin-producing E. coli in North America.

Comparison of the effects of anaerobic and micro-aerophilic incubation on resistance of Helicobacter pylori to metronidazole.

To assess the influence of incubation conditions on the resistance of Helicobacter pylori this study compared the effect of micro-aerophilic and anaerobic incubation followed by micro-aerophilic incubation on the measurement of metronidazole resistance of 102 H. pylori isolates, by both disk diffusion and Epsilometer (E)-tests. Anaerobic incubation for 24 h before micro-aerophilic incubation for 48 h consistently increased metronidazole activity in both assay methods. Although statistically significant, this was microbiologically less significant, as only 4 of 102 isolates gave discrepant readings (all four were resistant in micro-aerophilic conditions but susceptible in anaerobic/micro-aerophilic conditions). In all four cases variation was by a few millimeters in zone size (i.e., all were close to the cut-off point). There was 100% agreement between disk diffusion and E-test results. Of 104 observations (52 duplicate assays: 13 strains, two atmospheric conditions, two methods of determining resistance) there was 100% intra-observer and inter-observer agreement with regard to susceptibility and resistance status for both E-test and disk diffusion methods. Anaerobic incubation followed by micro-aerophilic incubation had little effect on the estimation of prevalence of metronidazole resistance and seemed to add little, if any, significant advantage over micro-aerophilic incubation alone.

Cost-effectiveness analysis of the russian treatment scheme for tuberculosis versus short-course chemotherapy: results from Tomsk, Siberia.

SETTING: Tomsk Oblast, Siberia. OBJECTIVE: To assess the cost-effectiveness of individualised Russian treatment and short-course chemotherapy (SCC) regimens for new WHO Category I tuberculosis patients. DESIGN: Analysis of costs incurred by the provider, the household and society as a whole for both treatment approaches, and a sensitivity analysis for SCC with hospitalisation for 2 weeks (patients theoretically at low risk of defaulting) and 2 months (patients theoretically at risk of defaulting). Outcomes were measured as cost per case cured and year of life saved, with cure rates based on a locally conducted trial. RESULTS: The cost per cure using the individualised Russian treatment was US $2,295, vs. US $1,901 when using SCC. The costs per year of life saved were respectively US $123 and US $103. The cost per cure was US $1,457 for SCC with 2 months hospitalisation and US $556 for SCC with 2 weeks hospitalisation, with costs per year of life saved of US $79 and US $30, respectively. CONCLUSION: Major financial savings for both the provider and the household, with cure rates similar to those obtained with the Russian treatment scheme, can be achieved in Tomsk when embarking on SCC with 2 weeks and 2 months hospitalisation.

Developing nursing practice as part of the collaborative TB control programme, Tomsk, Siberia.

SETTING: Review of nursing practice, identification of training needs and implementation of training for nurses working in the Tomsk Oblast' Tuberculosis Services (TOTBS), Russia. OBJECTIVE: Preparation of TOTBS nurses for the implementation of a WHO-style TB control programme in January 1997. METHODS: Nursing services and training needs were assessed through observation visits to a number of institutions providing care for TB patients, semi-structured interviews, and discussions at staff meetings. Training sessions focused on the WHO DOTS strategy, patient education and default tracing. An evaluation visit focused on nurses' attitudes and levels of treatment completion. RESULTS: Out of a total of 165 TB cases notified in Tomsk Oblast' between January and March 1997, 53 were started on DOTS on an ambulatory basis. Five patients who defaulted returned to treatment within five days (range 2-5) and no patients were lost to follow up. Improved compliance was attributed to better patient education offered by nurses and a reliable supply of medication. Quarterly reports continue to show satisfactory levels of treatment completion. CONCLUSIONS: Obstacles to the development of nursing practice included resistance to change and low morale due to enormous workloads, no pay and staff shortages. Motivation improved through the setting of achievable targets.

Conservation of the cytotoxin-associated (cagA) gene of Helicobacter pylori and investigation of association with vacuolating-cytotoxin activity and gastroduodenal disease.

Polymerase chain reaction (PCR) amplification and DNA hybridization analyses were used to test for the presence of the cytotoxin-associated (cagA) gene in 108 strains of Helicobacter pylori. Fifty-two geographically diverse strains of known vacuolating cytotoxin activity, and 56 recent UK clinical isolates from patients with duodenal ulceration (n = 28) and from healthy individuals who were endoscopically normal (n = 28) were studied. Overall, cagA was detected by PCR in 74 (69%) strains and DNA hybridization provided evidence of gene homologues in a further eight strains. For 96% of the cytotoxin-producing strains and 46% of the non-cytotoxin producing strains, there was a close association either with presence or absence of cagA. At the genomic level, Southern blot DNA hybridization showed that cagA was probably present in a single copy in most of the H. pylori tested, and that HaeIII restriction site variation within and around the gene provided additional markers of diversity for the species. As 40% of the cagA containing strains did not produce an active cytotoxin, and no significant association between cagA presence and DU-disease was observed, we concluded that the presence of the cagA gene in H. pylori could not be used as a single reliable predictor of higher risk patients.

Migration and Helicobacter pylori seroprevalence: Bangladeshi migrants in the U.K.

Helicobacter pylori, an infectious agent of worldwide public health importance, has higher seroprevalence in developing countries than in developed countries. We investigated whether Bangladeshi women, born in Bangladesh, have a greater H. pylori seroprevalence than Bangladeshi women born in the U.K. and, in addition, whether there is an association between H. pylori seropositivity and age of migration to the U.K. amongst Bangladeshi women. Women attending antenatal clinics at the Royal London Hospital were screened using ELISA for anti-H. pylori IgG. In Bangladeshi individuals born in the U.K., 13/16 (81%, 95% confidence interval (CI) 54%-96%) and, in Bangladeshi individuals born in Bangladesh 91/137 (66%, 95% CI 59%-74%) had antibodies to H. pylori. No significant association was found between H. pylori seropositivity and country of birth, or age at migration to the U.K. Public health strategies concerning H. pylori should consider migrant populations with high seroprevalence of H. pylori.

Mortality and morbidity among Rwandan refugees repatriated from Zaire, November, 1996.

INTRODUCTION: Following renewed ethnic violence at the end of September 1996, conflict between Tutsi rebels and the Zairian army spread to North Kivu, Zaire where approximately 700,000 Rwandan Hutu refugees resided following the 1994 genocide. After a major rebel offensive against the camps' militia groups on 15 November, a massive movement of refugees towards Rwanda through Goma town, the capital of North Kivu, began. Massive population movements such as this are likely to be associated with substantial mortality and morbidity. OBJECTIVE: To study patterns of mortality, morbidity, and health care associated with the Rwandan refugee population repatriation during November 1996. METHODS: This study observed the functioning of the health-care facilities in the Gisenyi District in Rwanda and the Goma District in Zaire, and surveyed mortality and morbidity among Rwandan refugees returning from Zaire to Rwanda. Patterns of mortality, morbidity, and health care were measured mainly by mortality and health centre consultation rates. RESULTS: Between 15 and 21 November 1996, 553,000 refugees returned to Rwanda and 4,530 (8.2/1,000 refugees) consultations took place at the border dispensary (watery diarrhea, 63%; bloody diarrhea, 1%). There were 129 (0.2/1,000) surgical admissions (72% soft tissue trauma) to the Gisenyi hospital in the subsequent two weeks. The average number of consultations from the 13 health centres during the same period was 500/day. Overall, the recorded death rate was 0.5/10,000 (all associated with diarrhea). A total of 3,586 bodies were identified in the refugee camps and surrounding areas of Goma, almost all the result of trauma. Many had died in the weeks before the exodus. Health centres were overwhelmed and many of the deficiencies in provision of health care identified in 1994 again were evident. CONCLUSIONS: Non-violent death rates were low, a reflection of the population's health status prior to migration and immunity acquired from the 1994 cholera outbreak. Health facilities were over stretched, principally because of depleted numbers of local, health-care workers associated with the 1994 genocide. Health-care facilities running parallel to the existing health-care system functioned most effectively.

Helicobacter pylori: a predominantly childhood infection--predominantly adult disease.

It is now 12 years since Helicobacter pylori was first cultured in an Australian laboratory. During these years significant understanding of the organism, its epidemiology and its disease associations have been made. Diagnostic methods and therapeutic regimens have appeared and been refined. In this article microbiological, epidemiological and clinical aspects of adult and childhood H. pylori are linked to present and future public health problems.

The epidemiology of Helicobacter pylori: missing pieces in a jigsaw.

Gastric colonisation with Helicobacter pylori is common throughout the world. Although most infected individuals remain well, H. pylori is involved in the pathogenesis of type B gastritis and peptic ulcer disease. There is also an epidemiological association with gastric cancer. Person-to-person spread is the most likely form of transmission but it is not clear whether this is faecal-oral or oral-oral. The risk factors for developing disease following infection are poorly understood. The development of diagnostic techniques suited to epidemiological studies, as well as microbiological typing methods, should help to resolve these uncertainties.

The frequency of culturing stools from adults with diarrhoea in Great Britain.

Utilizing the Office of Population Censuses and Surveys (OPCS) Omnibus Survey, it was possible to measure the frequency with which a stool culture was obtained following episodes of diarrhoea in adults. Interviewing over 8000 adults, over a 4-month period between October 1992 and January 1993, 633 persons (7.9%) reported one episode of diarrhoea in the previous month, and 5.4% of these individuals with diarrhoea reported that a stool had been requested for examination. No significant regional differences were observed with the sample size available. The estimate of the rate of diarrhoea in adults was just under one episode per person per year.

European framework to decrease the burden of TB/HIV.

Tuberculosis (TB) in Europe is declining in countries in western and central Europe, but the burden is still high and increasing in eastern Europe. HIV/AIDS is increasing dramatically in eastern Europe. HIV-related tuberculosis (TB/HIV) morbidity and mortality are expected to accelerate significantly in the future. This framework aims to guide European countries in developing their national plan for reducing TB/HIV morbidity and mortality. It results from an extensive consultation process undertaken by the World Health Organization Regional Office for Europe and by those responsible for HIV/AIDS and TB programmes and their partners. It builds on strategies developed globally and in Europe for TB control and for HIV/AIDS prevention and care. This framework sets out the rationale for effective collaboration between HIV/AIDS and tuberculosis national programmes. It identifies five strategic components (political commitment, collaborative prevention, intensified case-finding, coordinated treatment and strengthened surveillance) and eight key operations (central coordination, policy development, surveillance, training, supply management, service delivery, health promotion and research).

The cohort effect and Helicobacter pylori.

A total of 631 serum samples collected in 1969, 1979, and 1989 from adults and children were screened for Helicobacter pylori by Western blot analysis. Results showed that H. pylori seroprevalence has become less frequent over the 20-year period. By studying seropositivity by year of birth, the magnitude of a cohort effect of H. pylori seropositivity was estimated. The odds of being seropositive decreased by 26% per decade, P = .008 (95% confidence interval, 8%-41%). Estimates of seroprevalence adjusted for both age-specific variation and the cohort effect suggest that most seropositivity in adults occurs by the age of 15 years. The implication of these findings is that H. pylori infection is becoming less frequent and is predominantly acquired in childhood.

Helicobacter pylori acquisition in infancy after decline of maternal passive immunity.

We evaluated the natural history of Helicobacter pylori infection and the host immune response in 80 infants, and determined seroprevalence of H. pylori infection in their Taiwanese mothers. Decline in passively transferred maternal anti-H. pylori IgG antibodies and subsequent H. pylori infection was assessed in infants over 14 mo. A sensitive and specific, 96-well microtiter ELISA for the detection of H. pylori IgG antibodies was used to evaluate maternal serum (single specimen) and their infants (birth, 1, 2, 3, 6, 12, and 14 mo). Sera were also evaluated by ELISA for the presence of anti-H. pylori IgM antibodies in the infants. Maternal H. pylori IgG seroprevalence was 62.5% [50/80; 95% confidence intervals (CI), 51-73%]. All infants born to the 50 seropositive mothers passively acquired maternal H. pylori IgG. Transplacentally transferred maternal anti-H. pylori IgG lasted until about the 3rd mo of life, and disappeared in nearly all the infants by 6 mo of age. Seven and one-half percent of infants (6/80; 95% CI, 3-16%) acquired H. pylori infection; two were born to H. pylori-negative mothers. Among the six IgG seropositive infants, an IgM response specific for H. pylori antigens was detected and appeared to precede the rise in IgG in five. We conclude that maternal passive transfer of IgG antibodies occurs in the infant and disappears by 6 mo of age. H. pylori infection is acquired in infancy in this population; IgM antibodies against H. pylori are detectable, seem short-lived, and appear to precede IgG antibody development.

Hypogammaglobulinaemia associated with normal or increased IgM (the hyper IgM syndrome): a case series review.

The clinical and immunological aspects of 16 children with the syndrome of hypogammaglobulinaemia associated with normal or increased IgM (the hyper IgM syndrome) and their responses to treatment are reviewed. Increased concentrations of IgM, neutropenia, and recurrent infections could usually be controlled by antimicrobial and intravenous immunoglobulin treatment. Together with the bacterial infections characteristic of hypogammaglobulinaemia, these patients often developed opportunistic infections, including Pneumocystis carinii pneumonia, often presenting in the first year of life. The occurrence of sclerosing cholangitis, neurological complications, and neutropenia may be a result of an underlying cell mediated immune deficiency, autoimmunity, or infection. Despite a high incidence of opportunistic infections, immunological investigations did not show any abnormality of T cell function. These findings are discussed in the light of the recent demonstration that the lack of expression of a T lymphocyte activation antigen is the molecular basis of the X linked form of the disorder.