Biomedical subjects
H Friis
Publications and source records attributed to H Friis.
An arm-chair study of diagnostic decision-making in gastroenterological out-patients.
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[Index Medicus Danicus. Past--Present--Future].
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[Deaths due to parathion poisoning in Denmark].
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[Medical information retrieval].
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Regional variation in the use of antibiotics in four Danish hospitals.
The increasing use of antibiotics contributes to the selection of resistant bacteria and to the cost of health care. Large regional differences in the use of antibiotics between and within countries exist. This study describes such usage in four Danish hospitals, and includes a comparison with that of the average of 450 US hospitals. Compared to the Danish hospitals, the US hospitals used approximately double the amount of antibiotics in defined daily dosages (DDD)/100 bed days. In contrast to the comparison with the American hospitals no real differences were found comparing the four Danish hospitals. The four Danish hospitals differed in degree of specialization, presence of a clinical microbiological department or a hospital pharmacy. Use of antibiotics, in DDD/100 bed days, was highest in the hospital without a department of clinical microbiology, while the highest cost of antibiotics/admission was found in the hospital with the highest degree of specialization. Restraint in antibiotic usage calls for the joint efforts of the department of clinical microbiology, the hospital pharmacy and the local drug committee - the most important tools being: continuous education, audits of antibiotic use, provision of guidelines and recommendations, facilities for rapid diagnosis of infectious diseases, and limitation of the number of antibiotics used in routine sensitivity testing.
Bacteremia in patients suffering from cirrhosis.
In a five-year retrospective study, there were 57 episodes of bacteremia among 1623 admissions (3.5%) of patients suffering from cirrhosis. Gram-positive bacteria were found in 70% of the episodes, gram-negative bacteria in 30%. All of the gram-positive bacteria found were fully sensitive to methicillin and to gentamicin. The gram-negative bacteria found were all sensitive to gentamicin, but only 50% were sensitive to ampicillin. The distribution between gram-positive and gram-negative bacteria was the same, irrespective of whether the patients acquired the infection inside or outside the hospital. More than 50% of the patients suffered from one or more of the following complications of cirrhosis: ascites, encephalopathy and haematemesis. Twenty-one patients died within seven days after the bacteremia was diagnosed. Bacteremia is a serious complication of advanced cirrhosis, and it is recommended that adequate antibiotic treatment is started when septicemia is suspected.
Antibacterial activity of cefotaxime, desacetylcefotaxime, and the combination of the two.
Cefotaxime (CTX) is metabolized to desacetylcefotaxime (dCTX), which is antibacterially active. The combination of CTX and dCTX is synergistic in a 1:1 ratio, but in this study, a combination of CTX:dCTX in a fixed ratio of 5:1 was not found synergistic when tested on 120 recently isolated clinical strains. Zone diameters of disks containing pure CTX or dCTX 30 micrograms or the combination of CTX/dCTX in micrograms: 25/5, 20/10, 15/15, and 10/20, were compared. The correlation between the zone size of the pure CTX disk and the 25/5, 20/10, and 15/15 disks were high with correlation coefficients (r) 0.98 to 0.96. Regardless of the metabolism and the potential synergy, no differences were found in the zone sizes comparing the pure CTX disk with the combination with a ratio from 5:1 to 1:1. The clinical microbiological laboratory can go on using the pure 30 micrograms CTX disk for routine susceptibility testing.
The impact of iron supplementation on reinfection with intestinal helminths and Schistosoma mansoni in western Kenya.
A randomized, placebo-controlled, double-blind trial was carried out in 1994-96 among 231 children and 181 adults in order to determine the effects of iron on reinfection rates and intensities of hookworm, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mansoni. Adults given 60 mg elemental iron twice-weekly for 12 months had significantly lower reinfection rates of A. lumbricoides (16.7% vs 31.9%, P = 0.046), T. trichiura (6.9% vs 20.6%, P = 0.03) and S. mansoni (38.3% vs 61.8%, P = 0.008) compared to adults given placebo. In contrast, adults allocated to iron had a significantly higher reinfection rate of hookworm at the 4-month examination (11.1% vs 0%, P = 0.009), but the difference was not significant at 8- and 12-month follow-up examinations. Iron supplementation had no effect on reinfection intensities in adults. Surprisingly, iron supplementation had no effect on either reinfection rates or intensities in children. Multiple logistic regression analyses controlling for baseline infection status confirmed the effect in adults of iron on A. lumbricoides, T. trichiura and S. mansoni reinfection rates. The effect is suggested to be due to reduced risk behaviour, to improved immune function or to unfavourable host gut conditions caused by an increased oxidative stress. In each case, the lack of effect in children remains to be explained. In contrast, iron supplementation apparently was short-lived in favour of hookworm infection, an effect that needs further clarification. The findings suggest that iron supplementation has a role to play in helminth control programmes and that intraluminal factors may contribute to the regulation of some helminth infections.
Does Schistosoma haematobium co-infection reduce the risk of malaria-induced splenomegaly?
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Marginal vitamin A deficiency in pigs experimentally infected with Trichuris suis: a model for vitamin A inadequacy in children.
The development of an experimental model for marginal vitamin A deficiency in humans is of major interest, enabling the elucidation of possible interactions with helminth infections. We established a useful experimental model for human vitamin A deficiency in young pigs; deficiency was induced through a depletion method encompassing both sow and offspring. We report on a 2 x 2 study in which 18-week-old vitamin A deficient pigs and vitamin A sufficient littermates were infected with both of the intestinal nematodes Trichuris suis and Ascaris suum and followed for 14 weeks through 32 weeks of age. Forty-nine pigs were followed with respect to bodyweight, liver biopsies and blood samples for retinol concentration and faecal samples for parasite eggs and worms. Liver and serum concentrations of vitamin A were significantly diminished in the vitamin A deficient (VAD) group as compared to the vitamin A sufficient (VAS) group both before (P < 0.001) and after inoculation with T. suis and A. suum (P < 0.02). A significant correlation between retinol content in micro-biopsy needle samples and gross liver content was found (r = 0.457, n = 48, P = 0.001). The adult T. suis worms in the VAD group were marginally smaller (36.7 vs 40.2 mm; P = 0.08), more orally located (section 2.9 vs 3.9; P = 0.08) and had a higher proportion of males (0.58 vs 0.50; P = 0.08) whereas there were no effects of diet treatment on fecundity. The proportion of pigs with faecal T. suis egg excretion 12 weeks post inoculation (p.i.) was significantly lower in the VAD group compared with the VAS infected group (21 vs 78%; P = 0.036). In addition, faecal T. suis egg excretion was significantly lower in the VAD group at both week 11 (P = 0.040) and week 12 p.i. (P = 0.021). Vitamin A deficiency may have altered the functional integrity of the mucosal intestinal epithelium, disrupting the normally delicate attachment of T. suis and leading to the premature termination of infection. However, a possible antagonistic interaction, if verified, should not preclude interventions to improve vitamin A status, i.e., treatment should accompany anthelmintic treatment.
The contribution of hookworm and other parasitic infections to haemoglobin and iron status among children and adults in western Kenya.
A cross-sectional study of 729 children and adults in western Kenya investigated the impact of infection with hookworm, Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni and malaria on iron status. In bivariate analyses, hookworm intensities as low as 300 eggs/g of faeces were negatively related to levels of haemoglobin (Hb) and serum ferritin (SF). Malaria parasitaemia was negatively related to Hb and positively related to SF, while S. mansoni intensities were negatively related to SF. Multivariate regression analysis was done to identify predictors of Hb and SF levels. In children, age (in years) was the only predictor for Hb (B = 1.7 g/L) and only malaria parasitaemia (negative, light, moderate, heavy) was retained in the model for log10 SF (B = 0.097 microgram/L). In adults, hookworm infection and malaria parasitaemia together with age, sex, pregnancy, SF levels < 12 micrograms/L and elevated body temperature were significant predictors of low Hb. The regression coefficient for hookworm egg count (for increments of 100 eggs/g) was -1.3 g/L. Significant interactions between sex and age and between sex and malaria parasitaemia were revealed. Age and malaria parasitaemia were significant predictors only among females, with a regression coefficient for malaria parasitaemia of -6.9 g/L. The regression coefficient for hookworm did not change when SF < 12 micrograms/L was taken out of the model, indicating that the effect of hookworm cannot be explained by low iron stores alone. Using SF as the dependent variable, hookworm and S. mansoni intensities together with age and sex were retained in the model. The regression coefficients for hookworm egg count (increments of 100 eggs/g) and S. mansoni egg count (increments of 10 eggs/g) were -0.011 microgram/L and -0.012 microgram/L, respectively. Iron deficiency was a problem in this population and hookworm infections contributed significantly to this situation.
Geophagy, iron status and anaemia among pregnant women on the coast of Kenya.
In a cross sectional survey based in an antenatal clinic at Kilifi District Hospital, Coast Province, Kenya, 154 of 275 pregnant women (56%) reported eating soil regularly. Geophagous women had lower haemoglobin and serum ferritin concentrations than non-geophagous women (mean haemoglobin level 9.1 vs. 10.0 g/dL, P < 0.001; median ferritin level 4.5 vs. 9.0 micrograms/L, P < 0.001). In multiple linear regression analyses, geophagy was a significant predictor of haemoglobin (beta = -6.4, P = 0.01) and serum ferritin concentrations (beta = -6.6, P = 0.002), while controlling for gestational age and malaria and hookworm infection. Another 38 pregnant women, who reported eating soil regularly, participated in focus group discussions and were interviewed on geophagy. The most commonly eaten soil was from the walls of houses. The median estimated daily intake was 41.5 g (range 2.5-219.0 g). Twenty-seven of these women assisted in the collection of soil samples which were then analysed for their content of iron, zinc and aluminium after extraction with 0.1 M HC1. The average daily soil intake supplied the geophagous women with 4.3 mg of iron, corresponding to 14% of the recommended dietary allowance of iron for pregnant women. The study revealed a strong negative association between geophagy and both haemoglobin and ferritin status. At the same time it demonstrated the potential of soil as a source of dietary iron for geophagous women. These seemingly contradictory results might be due to other components in the soil interfering with iron uptake or metabolism. Alternatively, it may be that the geophagous women had extremely depleted iron stores before starting to eat soil. From these cross-sectional data, no inference about causality could be made.
Geophagy as a risk factor for geohelminth infections: a longitudinal study of Kenyan primary schoolchildren.
Geophagy among primary schoolchildren and its impact on geohelminth infection were studied in western Kenya. In a cross-sectional survey, 204 children aged 10-18 years were interviewed about geophagy and examined for helminth infections (Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni, hookworm). Children found infected were treated with albendazole (600 mg in a single dose) and/or praziquantel (40 mg/kg in a single dose). The children were re-examined after 4, 8 and 11 months. In the initial cross-sectional survey, 77% of the children ate soil daily and 48% of all soil samples were contaminated with eggs of A. lumbricoides (median egg count in contaminated samples was 3/2 g of soil; range 1-15). Twenty-nine children (14.2%) were infected with A. lumbricoides and 87 (42.6%) with T. trichiura. Significant associations between geophagy and infection intensity with A. lumbricoides and T. trichiura, but not S. mansoni or hookworm, were found. Re-infection with A. lumbricoides was twice as common among geophagous children as among non-geophagous children (27.4% vs. 12.0%; P = 0.030). The intensity of reinfections was higher in geophagous children (median 773 eggs/g vs. 95 eggs/g; P = 0.027). The relative risk for A. lumbricoides reinfection was 2.28 for geophagous children (95% confidence interval [95% CI] 1.02-5.11), and the fraction of reinfection attributable to geophagy was 56.0% (95% CI 1.7%-80.4%). There was a significant difference in T. trichiura infection intensity between geophagous and non-geophagous children (median no. of eggs/g 68 vs. 20; P = 0.049), but not in reinfection rates. No difference between the groups was seen in S. mansoni or hookworm reinfection rate or intensity, or in the families' socioeconomic or educational status. Geophagy was associated with an increased risk of reinfection with A. lumbricoides and possibly with T. trichiura. Neither family background nor infection with non-orally transmitted helminths was associated with geophagy, suggesting that this association was not due to confounding, but causal. Geophagy is therefore likely to be a source of ascariasis and possibly trichiuriasis among primary schoolchildren.
Assessment of eosinophil cationic protein as a possible diagnostic marker for female genital schistosomiasis in women living in a Schistosoma haematobium endemic area.
Eosinophil cationic protein (ECP) levels were measured in vaginal lavage extracts from 518 Zimbabwean reproductive women, age range 15-49 years, to assess the potential use of ECP as a diagnostic marker for female genital schistosomiasis (FGS). One hundred and fifty women had confirmed FGS status. These included 77 (cases) women who had ova in genital tissue and 73 (controls) women who had no ova in genital tissue. Participants were examined at baseline, 3 and 15 months post-treatment with praziquantel. ECP levels were determined using the enzyme linked immunosorbent assay (ECP-ELISA). ECP levels from 18 Norwegian women were used to calculate the diagnostic values of the test. FGS was diagnosed from the study population using genital biopsy and smears. Women were also diagnosed for urinary schistosomiasis using the urine filtration technique. The prevalence of urinary schistosomiasis was 39 % at baseline and this declined to 8% and 6% at 3 and 15 month post-treatment surveys, respectively. There was a higher mean ECP level in women with FGS, 889.3 ng/mL (95% CI: 457.0-1327.5) compared to the endemic control group, 359.1 ng/mL (95%, CI: 227.3-490.9), P = 0.027. Mean ECP levels declined at 3 months following treatment of infected individuals. There was no correlation between ECP levels and tissue ova density, and urine egg intensity. The sensitivity, specificity, positive and negative predictive values for the ECP-ELISA test were 35%, 80%, 65% and 53%, respectively. Our results indicate that FGS causes an inflammatory immune response that increases ECP levels in genital fluid. Treatment of schistosomiasis results in a regression of pathology and a decline in ECP levels. However, other factors such as allergy and microbial infection could also be responsible for increased ECP levels in genital mucosa. These conditions will affect the validity of the test in diagnosis of FGS.
Predictors and reference values of CD4 and CD8 T lymphocyte counts in pregnancy: a cross sectional study among HIV negative women in Zimbabwe.
OBJECTIVE: To identify predictors and define reference values for T lymphocyte subsets in HIV negative pregnant black women. DESIGN: Cross sectional study. SETTING: Edith Opperman Martenity Hospital, Harare, Zimbabwe. STUDY POPULATION: 1113 HIV negative women 22 to 35 weeks pregnant registering for routine antenatal care. METHODS: A questionnaire was used to collect demographic and obstetric data. CD4 and CD8 T lymphocyte counts were determined by manual immunocytochemistry. Concentrations in serum, of retinol, beta-carotene, ferritin, folate and 1-antichymotrypsin were also measured. Multiple linear regression analysis was employed to identify and estimate effects of potential predictors. MAIN OUTCOME MEASURES: CD4 and CD8 T lymphocyte levels, demographic, obstetric data and micronutrient status. RESULTS: Predictors of CD4 counts were gestational age, serum retinol and season. CD4 counts declined by 25 (95% confidence interval [CI]; 11 to 40; p = 0.001) cells/L for each week's increase in gestation among women with low serum retinol, while low serum retinol was independently associated with lower CD4 counts (-127; 95% CI, -233 to 20 cells/L; p = 0.02) at 35 weeks gestation. The late rainy season was associated with higher CD4 counts (137; 95% CI, 67 to 207 cells/L; p < 0.001). CD8 counts were higher in women with low serum folate (87; 95% CI, 6 to 166 cells/L; p = 0.036) and were slightly higher in gravida 4+ compared to gravida one to three. Reference values of CD4 but not CD8 count and percentage markedly differed from flow cytometry values of pregnant and non-pregnant women in developed and developing countries reported in the literature, even after controlling for the differences in methods of T lymphocyte subset immunophenotyping. CONCLUSION: Gestational age, gravidity, micronutrient status and season influence T lymphocyte subset levels and need to be considered when designing clinical management and intervention strategies for pregnant women. The data underscores the need for local reference values.