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Biomedical subjects

A Van Gompel

Publications and source records attributed to A Van Gompel.

At least 19 recordsLinked to original sources

Recurrence of blackwater fever: triggering of relapses by different antimalarials.

Five cases of blackwater fever (BWF) are described, all of whom had a history of recent quinine therapy. In two cases a second haemolytic crisis was induced by halofantrine, in one case also a third. Increasing frequency of this syndrome with its dramatic clinical presentation is to be expected as imported P. falciparum infection, parasite resistance to chloroquine and the use of quinine and other related antimalarials become more frequent.

Adult↗

[The principal arthropod vectors of disease. What are the risks of travellers' to be bitten? To be infected?].

Many blood-sucking arthropods are potential vectors of disease. To become a vector, the arthropod must be susceptible to the infective agent and must survive the incubation period so as to transmit the pathogens to a host. While some arthropod associated diseases affect only man (e.g. malaria) most of these diseases are (anthropo-) zoonoses with man often an accidental host. The risk of contamination depends on the one hand on the biting behaviour of the vector, its biology and distribution, and on the other hand on the sites visited by the traveller, the length of his stay, his activities, the conditions of sleeping accommodation. The risk of contracting malaria is very high in tropical Africa, in the forest area of South America and South East Asia, in Papua New Guinea. Malaria can be prevented if measures (e.g. pyrethroid impregnated bed nets, repellents) are taken to avoid bites of Anopheline mosquitoes between sunset and sunrise, but appropriate chemoprophylaxis must not be neglected. Lethal cases of yellow fever among unvaccinated travellers still occur despite a strict international regulation on vaccination requirements. Dengue is a major health problem in intertropical areas. As no vaccine is available, personal protection measures are recommended against daytime-biting mosquitoes, including the use of protective clothing, repellents. Other arthropod borne diseases among travellers are less common but the risks increase during adventure trips (e.g. zoonotic leishmaniasis, tick-borne relapsing fever) and humanitarian actions (e.g. risk of louse-borne typhus during visits of overcrowded prisons). Tick-borne diseases receive nowadays more attention. These diseases are not only restricted to some occupations (farmers, veterinarians) but also ramblers and campers are at risk. Attached ticks should be removed rapidly and carefully, since several hours of attachment are needed for transmission of spirochetes of LYME disease.

Animals↗

Kabisa: an interactive computer-assisted training program for tropical diseases.

In Europe, tropical pathology is usually taught in special short courses, intended for those planning to practise in developing countries. The theoretical knowledge to be assimilated during this short period is considerable, and turning such newly acquired knowledge into competence is difficult. Kabisa is a computer-based training program for tropical diseases. Instead of concentrating on strictly tropical diseases, students are trained in recognizing diseases in patients presenting randomly in an imaginary reference hospital in a developing country. Databases are compiled by experts from experiences in various parts of Africa, Asia and tropical America. Seven languages and three levels of competence can be chosen by the student. Updating of all databases is possible by teachers who want to describe a particular setting. A 'consistency checker' verifies the internal consistency of a new configuration. The logical engine is based upon both a 'cluster' and a Bayesian logic, with built-in corrections for related disease characteristics. This correction allows calculated probabilities to stay closer to real probabilities, and avoids the 'probability overshoot' that is inherent to 'idiot Bayes' calculations. The program provides training in diagnostic skills in an imaginary second-line setting in a tropical country. It puts tropical and cosmopolitan diseases in perspective and combines applied clinical epidemiology and pattern recognition within varying sets of presenting symptoms. Students are guided in searching for the most relevant disease characteristics, in ranking disease probability, and in deciding when to stop investigating.

Belgium↗

[Information communication to travelers, the French and Belgian experiences].

Providing relevant and up-to-date information to professionals and the general public is possible through many existing as well as developing means of communication including telephone and faxing, databases, answering machines and internet. Professionals may use information networks in order to harmonize advice given to their patients or clients. An exchange may also be established among all types of travel medicine professionals for keeping up with the latest relevant news and information or for sharing new ideas. Because travellers are now more proactive on their health than ever before, basic information designed for the general public is also becoming necessary. Examples of the various uses of communications in France and in Belgium are considered below.

Belgium↗

Eosinophilic myositis resulting from sarcocystosis.

Muscle sarcocystosis is a parasitic infection acquired by ingestion of sporocysts of Sarcocystis species. A case is described where symptoms of fever, chronic myositis and eosinophilia were present. Diagnosis was made via muscle biopsy. Improvement and cure coincided with treatment with cotrimoxazole. A limited review of human muscle sarcocystosis and an outline of the gaps in the knowledge of this infection is presented.

Adult↗

Severe myoclonus in a patient recovering from falciparum malaria.

Isolated myoclonus has rarely been reported as a complication of Plasmodium falciparum malaria. We describe the development of chaotic myoclonic jerks in an afebrile and conscious patient, the fourth day of treatment with quinine for P. falciparum infection. The myoclonus finally resulted in a generalized tonic-clonic seizure and coma, which resolved without further antimalarial treatment.

Adult↗

Clinical training for tropical doctors in the nineties.

Together with economic causes, the declining belief in the relevance of clinical skills, the omission of the hospital from the health system, and the erroneous generalisation of a complaint centred approach enhanced the decline in clinical medicine in several developing countries over the last decades. Despite a growing interest and important efforts in continuous education, basic training remains generally knowledge-directed. Clinical training should start from a realistic job description, and aim at acquiring skills instead of knowledge. Basics of clinical epidemiology can help refine clinical logic both at the health centre and the hospital level. the district hospital should be awarded a key role in pre-graduate and continuous clinical training. Awaiting a revival of the economy in most tropical countries, and especially in tropical Africa, an effective way for improving clinical practice is to invest in training, at all levels, with an emphasis on continuous medical training.

Clinical Competence↗

Diagnosis of amoebic infection of the liver: report of 36 cases.

The classical clinical picture of amoebic infection of the liver consists of fever, right upper quadrant pain and hepatomegaly. In recent years, the widespread availability of ultrasound and serology made an early diagnosis possible, which could result in less prominent clinical pictures. Thirty six cases of liver amoebiasis diagnosed in Antwerp between 1985 and 1992, were reviewed. Three patients acquired their infection in Belgium. For the other patients, the average delay between arrival in Belgium and the first symptoms was 5.64 months. The classical triad of clinical signs (fever, right upper quadrant pain and hepatomegaly), was observed in only 13.9% of the patients, whereas it was much more frequent in earlier studies (68-75%). The right lobe was the most frequently affected (94%). The colour of the liquid, obtained by puncture, was brown in 61% of patients in whom it was reported. Amoebic cysts were found in the stools of only one patient. Amoebic serology was initially negative in only one patient, but became positive on second testing. Chest X-rays were abnormal in 34% of the patients. All patients who develop unexplained fever during the year after a stay in tropical countries should undergo an abdominal ultrasound examination and serological testing for Entamoeba histolytica.

Adult↗

Likelihood ratios: a real improvement for clinical decision making?

The concept of likelihood ratio has been advocated for several years as one of the better means to evaluate diagnostic tests and as a practical and valuable tool in clinical decision making. In this paper we review the basic concepts underlying the evaluation of diagnostic tests and we explore the properties and usefulness of both positive and negative likelihood ratios compared with sensitivity and specificity. Particular attention is given to the use of likelihood ratios in the clinical setting. Likelihood ratios have three main advantages: they are intuitive, they simplify the predictive value calculation and the overall evaluation of sequential testing. Disadvantages are the non-linearity and the necessity to recalculate probabilities in odds. Although they summarize the information contained in sensitivity and specificity, these characteristics are still necessary for certain clinical decisions. Since likelihood ratios have been promoted among physicians and medical students, we discuss examples of inappropriate use and misunderstandings in the medical literature: the frequent omission of confidence intervals, the choice of cut-off points based on likelihood ratios for positive test results only and the confusion between likelihood ratios for ranges and those for cut-off points.

Decision Support Techniques↗

Twelve patients with severe malaria treated with partial exchange transfusion. Comparison between mathematically predicted and observed effect on parasitaemia.

Imported malaria is increasing in Western countries, which results in considerable morbidity and mortality, the latter mainly due to delayed diagnosis and treatment. Partial exchange transfusion has been proposed as a therapy for very severe falciparum malaria, but the utility of this procedure has not been proven. We report on 12 patients with severe Plasmodium falciparum malaria, treated with exchange transfusion in 5 Belgian hospitals between 1987 and 1991. The mean parasitaemia before exchange was 17.2% (range 6-35%). An average of 3.1 l was exchanged within 3 to 7 hours. Ten of the 12 patients survived. One patient recovered initially, but died as a consequence of a cascade of complications of dialysis. Three patients developed the adult respiratory distress syndrome (ARDS), two had less serious pulmonary involvement, and five had temporary renal failure; none of the survivors had sequelae. A formula is proposed to calculate the expected reduction in parasitized erythrocytes by exchange transfusion in function of the initial parasitaemia, the initial haemoglobin level and the volume of blood exchanged. Comparison between the mathematically predicted and the observed decline in parasitaemia shows on average a 25% excess of observed over predicted efficacy per unit of blood exchanged. After introducing this correction the formula enables the clinician to estimate roughly the volume of blood that has to be exchanged in order to bring the initial parasitaemia down to a desired level.

Adult↗

Development of hyperreactive malarious splenomegaly in an 8 year-old Caucasian boy, 18 months after residence in Africa.

Hyperreactive malarial splenomegaly (the former tropical splenomegaly syndrome) refers to a combination of splenomegaly, high antimalarial antibodies and high serum IgM content, a condition resulting from an aberrant immunological response to malaria. It has rarely been described in expatriates. We report the case of an 8 year-old Dutch boy who developed this syndrome 18 months after returning from Zaire. Treatment with mefloquine resulted in gradual improvement of all laboratory abnormalities. The spleen did not decrease in size, but became normal for age as height increased.

Animals↗