Search

Asiatic dengue was detected in nine tourists. In eight patients it was of the classical benign type, the ninth case being associated with severe thrombopenia (4 000/mm3), but without signs of shock. A brief summary is given of the physiopathology of the hemorrhagic forms of the disease: acquired sensitivity from a primary attack and reinfection with a heterologous virus; selection of virulent strains by an atypical vector; genetic recombination producing a strongly pathogenic virus.

In a patients with P. falciparum malaria contracted in Thailand, the course of the disease under treatment suggested resistance to both chloroquine and pyrimethamine-sulfadoxine, as well as reduced sensitivity to quinine. This was confirmed by in vitro tests on continuous culture of the strain. Therapeutic success was obtained with a quinine-cycline combination. The problems raised by the emergence of P. Falciparum strains resistant to polychemotherapy are emphasized.

A study of 100 cases of malaria in France, 98 of which were imported, shows the strong predominance (83%) of Plasmodium falciparum and of contamination in Africa (86%). The reasons why malaria is rare among tourists returning from Asia are given. The risk of re-introduction of the disease into France seems to be slight, especially for P. falciparum. Chemoprophylaxis is easy when aminoquinolines can be recommended, but much more complicated otherwise, the reasons for failure being the lack of effect of other drugs on pre-erythrocytic forms, resistance to chemotherapy and lack of information or carelessness.

In a 26-year-old man who had spent time in a trypanosome endemic zone, lesions of erythema marginatum progressing by acute exacerbations for 2 years despite various forms of treatment led to the discovery of a multiple lymphadenopathy and a greatly accelerated sedimentation rate. These findings suggested a diagnosis which was confirmed by the discovery of Trypanosoma gambiense in the blood and lymph node aspirate. In addition, there was an albumino-lymphocytic reaction in the cerebrospinal fluid. Finally, an atrioventricular block was discovered. All these symptoms and signs responsed to treatment with melarsoprol but a pericardial reaction developed, possibly of immunoallergic origin.

Plasmodium ovale as the causative parasite in attacks of malaria is rare. Nevertheless, the number of cases seen in France would seem to be on the increase. In 137 attacks of malaria collected between 1967 and 1978, Plasmodium ovale was found on 13 occasions. The main characteristics of this form of malaria are, apart from its benign nature, the usual absence of any recurrence and a very variable incubation period, ranging from fifteen days to several months or even a year (with an average of 3.2 months). It is thus important to bear this diagnosis in mind, even if a long period elapsed since return from an endemic area, and it will be realised that adequate chemoprophylaxis using a schizonticide does not offer protection from forms with a long incubation period. Genetic control of the duration of the period of maturation of exo-erythrocytic forms, i.e. the incubation period, is suggested, identical to that recently advanced in the case of Plasmodium vivax. This would account for the variability and possible long duration of incubation periods. A usual monoclonal character of these infections could explain the virtual absence of recurrences.

Epidemiology of tropical Burkitt's lymphoma shows the concomitant existence of the three following characteristics in endemic areas: - fairly dense rural population with a low standard of living; - early occurrence of primary infection by the Epstein-Barr virus (whose genome is always present in all tumour cells); - stable malaria. The social and economic level of these areas accounts for the specific features of the viral infection. Climatic factors determine permanent of prolonged transmission of malaria which could be mediated through a mitogen. Eradication of malaria could be a useful way to induce a fall in Burkitt's lymphoma incidence.