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Introducción de nuevos métodos de control de calidad de baciloscopia de esputo BAAR, en el Laboratoria Nacional de Referencia del Instituto de Medicina Tropical "Pedro Kourí"
No full textDoes hyponatremia have a value in the diagnosis of extrapulmonary tuberculosis in HIV-1 infected patients in Cambodia?
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Bridging the gap between clinical practice and diagnostic clinical epidemiology: pilot experiences with a didactic model based on a logarithmic scale
No full textRationale From general practitioners to academic staff, clinicians continue to have difficulties in applying clinical epidemiology in their everyday work. They do not fully understand the logical rules behind the numbers and they do not recognize these rules in their work. We present a new model where the pre-test and the post-test probabilities are converted to log10 of odds, and the likelihood ratio (LR) to its own log10. Methods Following Bayes' theorem, adding the log10LR to the log10 pre-test odds gives the log10 post-test odds, which can easily be represented on a logarithmic scale. In addition, by rounding the log10LR to half the unit, we create classes of discriminative power of tests, close to intuitive estimation. This model generates also a user-friendly diagram, adding considerably to the understanding of Bayes' theorem. We evaluated the effect of the rounding, the current use of the classical model and the acceptability of the new model. Results Rounding 10 disease characteristics to half the unit gives an absolute error of less than half a unit. After six explanations of Bayes' theorem, only 6/16 medical students were capable of answering simple questions about predictive value. When asked about weight of disease characteristics, no one of the 50 clinicians mentioned sensitivity, specificity, predictive value or LR. With the new model, more than 80% of trainees found medical decision making easier to understand and recognized the theory in their practice. Conclusions We conclude that our model of diagnostic clinical epidemiology offers a logical environment for an easy and rapid assessment of the evolution of disease probability with consecutive tests, providing a scientific format for 'qualitative' clinical estimations
Teken-encefalitis (frühsommer-meningo-enzephalitis (fsme); tick-borne encephalitis (tbe); russian spring-summer encephalitis (rsse); central european encephalitis (cee))
No full textSpatial modelling and the prevention of Loa loa risk: decision making under uncertainty
No full textHealth decision-makers working in Africa often need to act for millions of people over large geographical areas on little and uncertain information. Spatial statistical modelling and Bayesian inference have now been used to quantify the uncertainty in the predictions of a regional, environmental risk map for Loa loa (a map that is currently being used as an essential decision tool by the African Programme for Onchocerciasis Control). The methodology allows the expression of the probability that, given the data, a particular location does or does not exceed a predefined high-risk threshold for which a change in strategy for the delivery of the antihelmintic ivermectin is required
Reducing the burden of malaria in pregnancy by preventive strategies
No full textMalaria is one of the most common and preventable causes of adverse birth outcomes. In Africa, important progress has been made in the past decade with the introduction of a preventive strategy for malaria in pregnancy consisting of intermittent preventive treatment in pregnancy (IPTp) and insecticide-treated nets, yet their coverage is still unacceptably low and malaria continues to demand a huge toll on pregnant women and their newborn babies. Increasing the frequency of dosing of IPTp with sulfadoxine-pyrimethamine might provide temporary respite, but increasing resistance to sulfadoxine-pyrimethamine makes research into safe, efficacious, and affordable alternatives for IPTp one of the highest priorities for the control of malaria in pregnancy. A number of promising alternatives are, or will soon be, available that need to be evaluated as IPTp after their safety and pharmacokinetics in pregnancy have first been assessed in parasitaemic women. Little is known about appropriate control strategies in Asia and Latin America for Plasmodium falciparum and Plasmodium vivax malaria in pregnancy, which in most countries rely on responsive case management approaches. The role of case management based on proactive screening for malaria infection of women attending antenatal care or preventive approaches with insecticide-treated nets or IPTp are urgently needed. To achieve these objectives, multicentre and multidisciplinary approaches are required across the range of malaria transmission settings that include assessment of immunological effect of successful preventions, the perceptions and acceptability of different preventive approaches, and their cost-effectiveness
Gastrointestinal protozoa in non-human primates of four zoological gardens in Belgium
No full textGastrointestinal parasites are important infectious causes of diarrhoea in captive non-human primates (NHP). However, prevalence data of gastrointestinal parasites in zoological gardens are scarce. Therefore, a cross-sectional survey was conducted to estimate the occurrence of gastrointestinal parasites in NHP of four zoological gardens in Belgium. Between August 2004 and April 2006, 910 faecal samples were collected from 222 animals housed in 39 groups. The 31 species involved were representatives of prosimians, New World (NW) monkeys, Old World (OW) monkeys and apes. Because individual sampling was impossible, a statistical simulation was performed to estimate a sufficient sample size. All samples were microscopically examined after an acetic acid-ether concentration. Differences in host species susceptibility were examined by non-parametric tests. Entamoeba spp. (44%) and Giardia spp. (41%) were the most prevalent species. Other parasites detected were Endolimax nana (36%), Chilomastix mesnili (21%), Balantidium coli (13%), Trichuris spp. (10%), Iodamoeba bütschlii (5%) and Strongyloides spp. (5%). Parasites for which a significant difference in susceptibility at the level of host taxonomy was noted were Entamoeba spp. (p<0.001) and C. mesnili (p<0.05). Samples containing Entamoeba spp. were the most prevalent in OW monkeys (p<0.0083). Samples collected from OW monkeys contained the highest number of parasite species (p<0.0083)
Heterogeneity in the trypanosomosis incidence in Zebu cattle of different ages and sex on the platteau of eastern Zambia
No full textOn the plateau of eastern Zambia, trypanosomosis is endemic. Glossina morsitans morsitans Westwood (Diptera: Glossinidae), the only tsetse species present, is almost entirely dependent on livestock as its source of food with cattle being the most preferred host. To determine if tsetse challenge is distributed equally over the various age categories and sexes within a cattle herd, a longitudinal study of trypanosomosis incidence was conducted during the rainy season. A total of 354 head of cattle consisting of 40% oxen, 30% cows, 15% young stock, 13% calves and 2% bulls were sampled for three consecutive months and their infection statuses determined using the PCR-RFLP technique as diagnostic method. Results indicated that there were significant differences (P<0.001) in the proportion of infected animals between the various categories. In oxen, the risk of infection was 5.6 times higher than in calves. Those results suggest heterogeneity in the challenge by tsetse flies and are in line with entomological observations on the feeding preference of tsetse on cattle. The implications of these results for the control of trypanosomosis in Eastern Province and other epidemiologically related areas are discussed