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F Scheutz

Publications and source records attributed to F Scheutz.

At least 37 records · Page 2Linked to original sources

Determining causation in epidemiology.

Epidemiology uses many methods to identify the causes of disease, although it remains impossible to provide proof that any specific factor is a cause. We are only able to present supporting evidence. We subscribe to the pragmatic view that a factor is indeed a cause if its elimination improves health. We describe a deterministic causal model, where disease develops when the necessary component causes exist in one of several possible constellations of causes, each of which constitutes a sufficient set of component causes. If we accept this concept of disease causation, the notion of multifactorial disease becomes meaningless. We should rather turn our attention to component causes that we can eliminate in order to improve public health. The complex nature of diseases and the fact that it is only possible to present supporting evidence for a causal relationship are some of our reasons for basing the identification of causes on a theoretic model or framework. The purpose is to construct and present a model that is complex enough to formalize basic intuitions concerning cause and effect. Finally, conceptual frameworks provide guidance for the use of multivariable statistical techniques and may assist in the interpretation of the results.

Causality↗

Immunoglobulin profile in HIV-1 infected children in Dar es Salaam.

OBJECTIVE: To determine immunoglobulin levels in HIV-1 seronegative and HIV-1 seropositive children at different clinical stages of HIV infection. DESIGN: Cross-sectional study. SETTING: Lugalo and Mwanayamala mother and child clinics in Dar es Salaam. SUBJECTS: Two hundred and ninety-nine children aged 18 months to five years. MAIN OUTCOME MEASURES: Estimation of immunoglobulin classes (IgG, IgA, IgM, IgD and IgE). RESULTS: Mean serum levels of all immunoglobulin classes were significantly higher (p < 0.0001) among the HIV-1 seropositive children (IgG = 22.9 g/l, IgA = 2.2 g/l, IgM 2.7 g/l, IgD 101.5 IU/ml and IgE 887.7 IU/ml) than among the HIV-1 seronegative children (IgG = 11.3 g/l, IgA = 1.0 g/l, IgM = 1.5 g/l, IgD = 27.8 UI/ml and IgE 341.3 UI/ml). The percentages of HIV-infected children with immunoglobulin concentrations above mean level were 83% for IgG, 77% for IgA, 78% for IgM, 73% for IgD and 78% for IgE. CONCLUSION: HIV seropositive children have higher levels of immunoglobulin than seronegative children. There was no correlation between the levels of immunoglobulin classes and CDC clinical staging.

Case-Control Studies↗

Dental caries in Danish children and adolescents 1988-1997.

OBJECTIVE: To describe the occurrence of dental caries in Danish children and adolescents from 1988 to 1997. DESIGN: Cross-sectional data collected by the Danish National Board of Health. RESULTS: The earlier trend of a marked annual decline in caries now appears to have halted, especially in respect of the permanent dentition of 7-year-old children. The distributions show marked positive skewness for all age groups, which may give rise to considerations of implementing high risk strategies in order to obtain further reductions in DMFS in the population. CONCLUSION: Calculations indicate, that the effect of a hypothetical high risk strategy on the occurrence of caries at the population level will be limited.

Adolescent↗

Job satisfaction amongst rural medical aides providing emergency oral health care in rural Tanzania.

OBJECTIVE: To investigate to what extent the rural medical aides (RMAs) in Tanzania were satisfied with their new (added) role of providing emergency oral health care services, and to analyse factors influencing job satisfaction amongst them. DESIGN: Cross-sectional survey using a self-administered job satisfaction questionnaire. SETTING AND SUBJECTS: All 40 RMAs providing emergency oral health care in rural health centres and dispensaries in Mbeya and Tanga regions, Tanzania. MAIN OUTCOME MEASURE: RMAs ratings of their overall satisfaction with the job of providing emergency oral health care. RESULTS: Overall, 95% of the RMAs were satisfied with providing emergency oral health care. Patient relations, personal time and stress were significantly correlated with overall job satisfaction in providing emergency oral health care. CONCLUSIONS: The RMAs' newly added role of providing emergency oral health care does not seem to generate problems with job satisfaction.

Allied Health Personnel↗

A tooth per child?

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Attitude of Health Personnel↗

The use of an IpaC-specific ELISA to identify enteroinvasive Escherichia coli strains of unusual serogroups.

Twenty five Escherichia coli isolates expressing O antigens different from the conventionally recognized enteroinvasive E. coli were tested in the Sereny test, with an invasion plasmid-specific DNA probe, and by an enzyme-linked immunosorbent assay recognizing the secreted IpaC antigen. These results indicate that the IpaC enzyme-linked immunosorbent assay is a sensitive method to recognize enteroinvasive E. coli, irrespective of their serogroups.

Antibodies, Bacterial↗

Patient satisfaction with emergency oral health care in rural Tanzania.

Emergency oral health care, as conceived in Tanzania, is an on-demand service provided at a rural health center or dispensary by a Rural Medical Aide. The service includes: simple tooth extraction under local anesthesia, draining of abscesses, control of acute oral infection with appropriate drug therapy, first aid for maxillo-facial trauma, and recognition of oral conditions requiring patient referral for further care at the district or regional hospital dental clinic. The objective of the present study was to describe patient satisfaction with emergency oral health care services in rural Tanzania and determine the relative importance of factors influencing patient satisfaction. The study was carried out as a cross-sectional interview survey between April 1993 and May 1994 using a patient satisfaction questionnaire in rural villages in the Rungwe district of Tanzania. It included 206 patients aged 18 years or more who had received emergency oral health care between April 1993 and March 1994. Overall, 92.7% of the respondents reported that they were satisfied with the service. Patients who were married, had no formal education and lived more than 3 km from the dispensary were more likely to be satisfied with treatment. In a logistic regression model, a good working atmosphere at the dispensary, a good relationship between care provider and patients (art of care) and absence of post-treatment complications significantly influenced patient satisfaction with odds ratios of 10.3, 17.4 and 6.2, respectively.

Adolescent↗

Household survey of access to and utilisation of emergency oral health care services in rural Tanzania.

BACKGROUND: Emergency oral health care, as conceived in Tanzania, is an on demand free-of-charge service provided by primary health workers called Rural Medical Aides(RMAs). OBJECTIVE: To evaluate accessibility and utilisation of emergency oral health care services. DESIGN: Cross-sectional household questionnaire survey. SETTING: Rural villages forming a catchment area for rural health centres and dispensaries providing emergency oral health care in Rungwe district, Mbeya region, Tanzania. SUBJECTS: Two hundred households containing about 1,106 persons. Half the households were randomly selected from a village where the dispensary or health centre was located. The other households were from a village distant from the health centre or dispensary. MAIN OUTCOME MEASURES: Self-reported use of emergency oral health care in a household and perceived barriers to the utilisation of this service. RESULTS: More than 90% of the respondents knew that emergency oral health care was available at the health centre or dispensary. In 40% of the households surveyed, there was a person who had used emergency oral health care. Half the respondents perceived that there were some barrier in using emergency oral health care. Lack of money to pay for treatment or transportation and fear of dental treatment were mentioned as the perceived barriers for using emergency oral health care by thirty and seven per cent respectively. In a logistic regression model, use of emergency oral health care was explained by a positive history of dental problems in the household (OR = 4.3) and the age of the household informant being more than 40 years (OR = 4.5). CONCLUSIONS: The majority in the rural Tanzanian villages surveyed knew about the availability of emergency oral health care services. The proportion of households which had used these services were relatively high compared to the time span. Inability to pay for the services was one of the perceived barriers to their utilisation.

Adolescent↗

Characterization of Escherichia coli serotype O12:K1:H7 isolates from an immunocompetent carrier with a history of spontaneous abortion and septicemia.

Escherichia coli isolates from an immunocompetent woman with a history of repeated amnion infections and spontaneous abortion were characterized. Escherichia coli were isolated from stool, blood and cervix swab samples taken over a 21-month period after the last abortion which followed septicemia during pregnancy. All samples except the last cervix swab contained isolates of serotype O12:K1:H7, which produced adhesins, P fimbriae, type I fimbriae and the iron-chelator aerobactin. Pulsed-field gel electrophoresis revealed identical Xbal restriction patterns of the O12:K1:H7 isolates, suggesting that one particular Escherichia coli strain was responsible for the severe extraintestinal infections during pregnancy. The strain was able to persist in the intestine of the woman despite antibiotic therapy.

Abortion, Spontaneous↗

Origin and characteristics of enteroinvasive strains of Escherichia coli (EIEC) isolated in Germany.

Thirty-five E. coli strains belonging to O-serogroups with enteroinvasive types of Escherichia coli (EIEC) isolated in Germany between 1989 and 1995 were investigated for invasivity-associated DNA sequences. Only 11 strains were positive for ipaH and thus confirmed as EIEC. All 11 EIEC isolates originated from human infections which were imported to Germany from Eastern Europe. EIEC O124 were most frequent and originated from asymptomatic Romanians arriving at Rostock, Germany in 1992 and 1993. In January 1993, EIEC O124 were isolated from faeces of a laboratory technician with diarrhoea working at the enteric pathogen department of the Institute of Hygiene in Rostock. By comparing her E. coli O124 isolate with recently imported O124 strains for Xba I restriction fragment length polymorphisms (RFLP) the probable source of infection could be determined. Four major RFLP patterns were found in the group of O124 strains. O124 strains with identical RFLP patterns were found in the group of 0124 strains. 0124 strains with identical RFLP patterns were isolated from people who were in close contact to each other.

DNA Primers↗

Discovery of disseminated J96-like strains of uropathogenic Escherichia coli O4:H5 containing genes for both PapG(J96) (class I) and PrsG(J96) (class III) Gal(alpha1-4)Gal-binding adhesins.

The pyelonephritis-associated adhesin gene papG of Escherichia coli occurs in three variants. Whereas the class II and class III variants are common among human urinary tract infection isolates, the class I allele, despite being the first cloned, has previously been found only in source strain J96. Five strains have been discovered from geographically diverse locales that, like J96, contain both the class I and class III papG alleles. One strain caused bacteremia, whereas 4 caused cystitis. Like J96, all 5 had group III capsule genes, expressed the H5 flagellar antigen and the F13 fimbrial antigen, and exhibited similar genomic patterns and virulence factor profiles. These findings demonstrate that the class I papG allele is not unique to J96 but is present in a group of extraintestinal isolates of E. coli O4:H5 that represent a disseminated virulent clonal group.

Adhesins, Escherichia coli↗

The role of lipopolysaccharide and Shiga-like toxin in a mouse model of Escherichia coli O157:H7 infection.

The role of lipopolysaccharide (LPS) and Shiga-like toxin (SLT) in the pathogenesis of hemolytic uremic syndrome (HUS) was studied in a mouse model. Mice inoculated intragastrically with Escherichia coli O157:H7 developed gastrointestinal, neurologic, and systemic symptoms, necrotic foci in the colon, glomerular and tubular histopathology, and fragmented erythrocytes. LPS-responder (C3H/HeN) mice developed a combination of neurologic and systemic symptoms, whereas LPS-nonresponder (C3H/HeJ) mice had a biphasic course of disease, first developing systemic symptoms and later severe neurologic symptoms. Mice inoculated with SLT-II-positive strains developed severe neurotoxic symptoms and a higher frequency of systemic symptoms and glomerular pathology compared with SLT-II-negative strains. Anti-SLT-II antibodies protected against these symptoms and pathology. These results demonstrate that this model could be used to study aspects of human HUS and that both LPS and SLT are important for disease development.

Animals↗

Is there an association between periodontal condition and HIV infection?

Individuals in Tanzania who have limited access to medical and dental treatment provide an opportunity to study the natural association between periodontal condition and HIV infection and the stage of infection. 119 HIV-infected adult individuals and 73 individuals with AIDS from the AIDS Clinical Trial Clinic at Muhimbili Medical Centre (MMC) in Dar-es-Salaam participated as cases. Mean age was 35.3 and 35.1 years, respectively. 156 individuals with a mean age of 28.3 years, confirmed as HIV-seronegative, served as controls. There were no significant differences in bleeding on probing, pocket formation or attachment loss among the HIV-seronegative individuals, HIV-seropositive and AIDS patients. We applied multiple logistic regression to calculate odds ratios for presence of periodontal conditions adjusting for age, gender and DMFT. Our odds ratios did not reveal any significant associations between bleeding on probing, pocket formation or attachment loss with regard to lymphocyte and CD4+ T-cell counts among the HIV-infected individuals and AIDS patients. When associations were investigated with regard to HIV-serostatus (HIV-seronegative, HIV-seropositive or AIDS), our adjusted odds ratios were insignificant, too. In fact, most odds ratios were close to 1. Thus, our study supports recent views that the presence, extent and severity of periodontal disease among HIV-infected individuals, may be less that hitherto thought.

Acquired Immunodeficiency Syndrome↗

Association between carriage of oral yeasts, malnutrition and HIV-1 infection among Tanzanian children aged 18 months to 5 years.

The objective was to determine whether there is an association between carriage of oral yeasts, malnutrition and HIV-1 infection among Tanzanian children. A case-control study design within a cross-sectional study was used, and the outcome was carriage of oral yeasts. The exposure variables were malnutrition and HIV-1 antibody, and confounders to be adjusted for were age, sex, and breastfeeding. The study was carried out in Dar-es-Salaam, Tanzania, in two maternal and child health (MCH) clinics that offer routine medical checkups to all expectant mothers and children aged between 0 and 5 years in the catchment area. A total of 882 children aged between 18 months and 5 years participated. Smears from the tongue and buccal mucosa were examined for oral yeasts. Malnutrition was categorized according to standards on the MCH chart and World Health Organization/Centers for Disease Control (WHO/CDC) standards as weight-for-height (wasted), weight-for-age (underweight), and height-for-age (stunted). HIV-1 infection was determined by an enzyme-linked immunosorbent assay. Reactive sera were confirmed by Western Blot. About 27% of the children were slightly or severely malnourished according to standards on the MCH chart. According to WHO/CDC standards, 2.6% were wasted, 16.3% were underweight, and 29.6% were stunted. Fourteen (1.6%) were seropositive for HIV-1 antibody. Hyphal forms and blastospores were much more frequent among children infected with HIV-1 with odds ratios ranging from 3.8 (95% CI: 1.3;11.2) to 6.2 (95% CI: 2.1;18.4) depending on categorization of malnutrition. Malnutrition was a risk factor, too, albeit to a much lesser and insignificant degree. The study supports our previous findings that malnutrition may predispose to carriage of oral yeasts and subsequent infection. However, in this study population HIV infection was clearly the predominant risk factor.

AIDS-Related Opportunistic Infections↗

Characteristics and prevalence within serogroup O4 of a J96-like clonal group of uropathogenic Escherichia coli O4:H5 containing the class I and class III alleles of papG.

The recent discovery of a geographically dispersed clonal group of Escherichia coli O4:H5 that includes prototypic uropathogenic strain J96 prompted us to determine the prevalence of J96-like strains within serogroup O4 and to further assess the characteristics of such strains. We used O:K:H;F serotyping, PCR-based genomic fingerprinting, pulsed-field gel electrophoresis (PFGE), multilocus enzyme electrophoresis (MLEE), and PCR detection of the three papG alleles and of the cytotoxic necrotizing factor 1 (cnf1) and aerobactin (aer) gene sequences to characterize the 15 O4 strains among 336 E. coli isolates from three clinical collections (187 from mixed-source bacteremia, 75 from urosepsis, and 74 from acute cystitis). J96-like strains constituted approximately half of the O4 strains, or 2% of the total population. In contrast to other O4 strains, the J96-like strains characteristically exhibited specific group III capsular antigens, the H5 flagellar and F13 fimbrial antigens, a distinctive PCR genomic fingerprint, the class III papG allele (plus, in 50% of strains, the enigmatic class I papG allele), and cnf1 but lacked aer. A subset of these strains was remarkably homogeneous with respect to all these characteristics and exhibited a distinctive PFGE fingerprint and MLEE pattern. These findings clarify the epidemiological relevance of J96 as a model extraintestinal pathogen, provide further evidence of the class I papG allele outside of strain J96, and offer insights into the evolution of E. coli serogroup O4.

Adhesins, Escherichia coli↗

Nutritional status of under fives attending maternal and child health clinics in Dar es Salaam, Tanzania.

We designed a study to assess the nutritional status of children under five years of age attending MCH clinics in Dar es Salaam. This was a cross-sectional anthropometric study involving children 6-24 months who from July to August 1993 were attending Magomeni MCH clinic and those aged 18 months to five years who were attending Lugalo and Mwananyamala MCH clinics for routine growth monitoring and for vaccination between May to August 1994. The data collected included age, birthweight, sex, weight, height, breastfeeding status and HIV-1 serostatus. Of the 1854 children enrolled (961 boys and 893 girls) 31.6% were stunted, 14.6% were underweight and 2.9% were wasted. The highest percentage of stunting and wasting was observed between 11 and 25 months and 36 to 40 months. Of the 849 children tested for HIV-1, 14 (1.7%) were seropositive and two out of 770 (0.3%) were born with low weight. HIV seropositivity and low birthweight were both associated with stunting and wasting. We conclude that malnutrition is still a sizeable problem among children attending urban MCH clinics in Dar es Salaam especially among those aged less than three years, to whom special malnutrition control strategies should be targeted. There is also a need to identify factors responsible for the observed decline in MCH attendance with age and correct the situation.

Age Distribution↗