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Human-to-human transmission of Entamoeba histolytica is rare in industrialized countries. We describe an outbreak of amebiasis in a family in The Netherlands, demonstrating that even with Western standards of hygiene, persistent cyst passage may result in the transmission of E. histolytica to household contacts. If E. histolytica is isolated from a person living in an area of nonendemicity, it may be worthwhile to test all family members for cyst passage.

Schistosomiasis in travelers often remains unrecognized because doctors are unfamiliar with the clinical presentation and diagnosis of this imported disease. We describe the epidemiological, clinical, and laboratory characteristics associated with an outbreak of schistosomiasis among nonimmune travelers. Of 30 travelers in two consecutive groups, 29 who had swum in freshwater pools in the Dogon area of Mali, West Africa, were followed for 12 months. Twenty-eight (97%) of those 29 became infected; 10 (36%) of the 28 had cercarial dermatitis, and in 15 (54%), Katayama fever developed. Eggs were found in 22 (79%) of the infected travelers: eggs of Schistosoma mansoni or terminally spined eggs (probably of Schistosoma intercalatum) were in the stools of 19 and 10 patients, respectively, and eggs of Schistosoma haematobium were in the urine of 7 patients. The eggs of 2 of these Schistosoma species were present in 6 cases, and in 4 cases eggs of all 3 species were found. The limited exposure of this group of travelers resulted in a high rate of infection with all three of the Schistosoma species that are prevalent in Africa. A diagnosis of schistosomiasis should be considered for any traveler with a history of exposure to fresh water in an area of endemicity. The only effective method of prevention is avoiding all contact with fresh water in these areas.

A 45-year-old woman in the period 1988-1995 suffered three episodes of acute pancreatitis associated with the use of metronidazole. On each occasion the pancreatitis subsided after withdrawal of metronidazole. Pancreatitis is a very infrequent, but potentially dangerous adverse effect of metronidazole. The exact pathogenetic mechanism of metronidazole-induced pancreatitis remains to be determined.

Of the four most dangerous protozoal infections acquired in (sub)tropical regions, falciparum malaria, amoebic abscess of the liver, visceral leishmaniasis (kala azar) and African trypanosomiasis (sleeping sickness) only the fourth was up to now unreported in the Dutch medical literature. Two case histories are presented: a Cameroonian woman, resident in the Netherlands for two years, suffering from West African type sleeping sickness, and a Dutch tourist who acquired East African trypanosomiasis while travelling through Zimbabwe. Although the parasites are morphologically identical, clinical and epidemiological characteristics are distinctly different. The West African type, rarely if ever observed in Europeans, has an insidious chronic course leading to the features of classical sleeping sickness. Differential diagnosis is difficult. The East African variety runs an acute course in Europeans leading to death within days due to myocarditis. It is therefore mandatory for the diagnosis to be made as soon as possible in order to initiate specific therapy. Both patients recovered after specific therapy.

Amoeboma was diagnosed in three patients: a Bengal seaman aged 40 and two Dutch citizens who had lived in the tropics, a man aged 41 and a woman aged 56. The first-mentioned patient had a rectal tumour easily inspected by sigmoidoscopy; a biopsy sample contained Entamoeba histolytica. The faeces contained no cysts. The two other patients had coecal amoebomas. They had been operated elsewhere on suspicion of appendicitis and had been treated with metronidazole, which had failed to eliminate the amoebae. The faeces still contained cysts. One patient had trophozoites in a biopsy sample. The serum of all three patients contained anti-amoeba antibodies. Two patients were treated successfully with a combination of metronidazole (a tissue amoebicide) and diloxanide (a lumenal amoebicide). In one patient this combination failed, and emetine had to be substituted for the metronidazole, also because of an allergic reaction. Amoeboma of colon or rectum is one of the many manifestation forms of amoebiasis, but it is rare. While in amoebic colitis tissue necrosis (histolysis) is encountered almost exclusively, in amoeboma there is a violent inflammatory reaction with formation of a pseudotumour by granulation tissue, possibly due to secondary bacterial infection. Endoscopy and determination of circulating antibodies against the causative agent E. histolytica have by now improved the diagnosis so much that adequate treatment without surgical intervention is possible in principle. As with so many exotic diseases, a stay in the tropics is the key to the diagnosis.

From 1986 to 1990 we have treated 215 patients with falciparum malaria. In 8 patients (4%) who had not returned to any malarial area, malaria attacks recurred after 6-20 weeks. Curiously these were now caused by different species: Plasmodium vivax (4 patients) and P. ovale (4 patients). After proper management of malignant tertian malaria caused by P. falciparum, patients are considered cured, provided the treatment has been in accordance with the resistance pattern of the parasite in the country of origin. Yet, in a small number of patients attacks of malaria recur after different time intervals. The explanation of this seemingly paradoxical phenomenon is that these were delayed primary attacks of benign tertian malaria rather than recrudescences of malignant tertian malaria. Consequently the patients must have been infected by two different species of malaria at a time. In P. vivax and P. ovale hypnozoites occur (notably absent in P. falciparum), dormant stages in the liver that are not susceptible to the antimalarials in use for the eradication or prophylaxis of the blood stages which cause the acute attacks of malaria. After a variable amount of time the blood is then (re)invaded and the patient suffers a delayed primary attack or a relapse. Physicians should be aware that definite cure of malignant tertian malaria does not prevent future attacks of benign tertian malaria. They should inform their patients accordingly.

A patient with Q fever is described who had been ill for a year before the diagnosis was made on the basis of serological data. In addition it was possible to isolate Coxiella burnetii, the causative agent by culture from the urine. This is very exceptional and is to our knowledge only the second case in which this has been achieved. The patient made a full recovery after lengthy treatment with tetracycline. Q fever should be considered in patients with pyrexia of unknown origin, particularly in travellers.

Tropical eosinophilia was diagnosed in two patients from India. This appears to be the first report on this exotic condition in the Netherlands. Tropical eosinophilia is characterised by hypereosinophilia, asthma-like attacks of wheezing and non-productive cough, non-specific findings on the chest X-ray in combination with general malaise, subfebrile temperatures, weight loss and lymphadenopathy. Although the syndrome is caused by an infection with Filaria, classical symptoms of filarial infection are characteristically absent. The main diagnostic criteria are hypereosinophilia and asthma-like attacks in subjects from regions where Filaria is endemic, high IgE titers, high antifilarial antibody titers and cure following one or more treatment courses with diethylcarbamazine. These case reports illustrate the importance of the assessment of the number of eosinophil cells in the peripheral blood in the diagnosis of tropical disease.

Schistosomiasis is a very frequent import infection in the Netherlands. The serotesting for schistosomiasis in Leyden affords reasonable insight into the prevalence of this import infection among different groups of the population in the Netherlands. Out of 3032 serum samples submitted in the period from 1983 to April 1986, 40% was positive. Most people with positive serum tests were of Surinam origin. Currently, there is a shift toward more infections among Dutch travellers. Many of these patients have high IFA titres indicating a recently incurred infection. Often no ova are found in spite of positive serotest: this phenomenon was seen in 36% of the Dutch travellers and in 48% of the Surinam people.

Between 1980 and 1985, 40 patients were treated surgically for hydatid disease of the liver. In 4 cases (10%) jaundice was the first and most conspicuous sign of this disease. The patients originated from Spain, Morocco, Turkey and Lebanon. In 2 of these cases the initial diagnosis was hepatitis; one patient was operated on for suspected acute cholecystitis. All 4 patients had an eosinophilia and positive hydatid serology. Hydatid material was found in the biliary tract in two cases, while bile-stained hydatid fluid proved that there was a communication between cystic cavity and biliary tract in the other two patients. Obstruction of the common bile duct by hydatid elements causes jaundice and probably also cholangitis. Calcifications in the cyst are no guarantee against future complications. Surgery is the treatment of choice. When patients from an endemic area present with jaundice, hydatid disease of the liver should be suspected, particularly if eosinophilia also exists.

As an imported disease acute schistosomiasis (Katayama fever) is typically a condition of the uninformed, inexperienced traveller [1] or the more adventurous type taking part in certain expeditions [2]. With the enormous increase of people travelling to the tropics it was to be expected that the number of patients with acute schistosomiasis would rise accordingly [1]. Since the first experience with this syndrome in our hospital in 1982, twenty patients have been recognized, all them infected with Schistosoma mansoni. It has been stated that this syndrome is seldomly [3–5) if ever [2, 6, 7] seen in primary infection with the species S. haematobium. However, recently we have observed six patients with severe acute schistosomiasis caused by S. haematobium.

A case of falciparum malaria from Malawi is reported. RII resistance to chloroquine according to WHO standards is proven. This is the first case of chloroquine-resistance, assessed according to WHO standards, reported from Malawi.

Resistance of P. falciparum to the two groups of antimalaria drugs commonly used for prophylaxis, i.e. folate antagonists and 4-aminoquinolines has become a matter of great concern, also in Africa. After 1978, P. falciparum developed resistance to the group of 4-aminoquinolines, which was first reported from East Africa. Chloroquine resistant infections are now spreading into Central Africa. Similar developments are now appearing with the combination sulfadoxine/pyrimethamine. With the increasing reports of multiple drug resistance in P. falciparum from Africa, no single drug or combination of drugs in use for chemoprophylaxis can give a complete protection under all circumstances any longer. Until new effective drugs become available, it is advised to use the combination of chloroquine or amodiaquine and proguanil; the traveller should be prepared for action in the event of a breakthrough. A written instruction is suggested to be inserted in the "International Certificate of Vaccination".

Patients with amoebiasis who receive steroid treatment may suffer adverse affects including acute amoebic dysentery and exacerbation of the amoebiasis. In some cases the presenting symptoms are initially misdiagnosed and steroids prescribed, which provokes fulminating progression of hepatic amoebiasis. Repeated stool examinations often yield negative results. Any patient being considered for treatment with corticosteroids who has lived in the tropics should be investigated for amoebiasis serologically and by repeated stool examination. Even after negative results the possibility of amoebiasis should be reconsidered if diarrhoea or fever develops during or after steroid treatment.

3 observations chez des adultes ayant fait un voyage au Mali. Positivite des examens de selles pour Schistosoma mansoni et S. haematobium