Search

Only a few drugs are available for the treatment of malaria. Artemisinin combination treatment is advocated because of its efficacy and to prevent the development of resistance. In the Netherlands, falciparum malaria is treated with atovaquone-proguanil or artemether-lumefantrine, both registered as 3-day treatments. In a recent study, 21 patients were treated with artemether-lumefantrine for 5 days. There are arguments in favour of a 5-day course: absorption of lumefantrine is dependent on food intake and the serum levels of lumefantrine are higher on day 7 after a 5-day course than after a 3-day course. As shown by studies in Thailand, the serum level is related to the relapse rate, although these studies revealed no difference in relapse rate between the 3- and 5-day courses. In endemic countries, short courses of treatment are favoured to further patient compliance. Artesunate for i.v. administration is urgently needed.

A 27-year-old woman was admitted to the hospital with a depression, anaemia and fatigue. She had come from Angola to the Netherlands as a refugee 2 years before this evaluation. As an explanation for her symptoms tropical infectious diseases of parasitic origin were considered, but no clues were found in this direction. The test for trypanosomiasis was considered to be suggestive for an infection in the past (persistent titre 1:200). She was discharged but readmitted 6 months later because of a deterioration of her clinical condition. Magnetic resonance imaging showed bilateral signal abnormalities within the white matter of the brain. On examination no neurological signs or abnormalities were found. Again, no definite diagnosis could be made and the patient was discharged. Because of a further deterioration of her clinical condition she was readmitted a short time later for the third time. On the MRI the white matter lesions had increased. The serum protein electrophoresis was markedly abnormal with an elevated IgM Level. Finally, at a repeated lumbar puncture mobile trypanosomes were found. The diagnosis of 'West African sleeping sickness' was made and the patient was treated with eflornithine. She recovered completely during the next 18 months.

Three new antimalarial drugs have recently been registered in the Netherlands: atovaquone-proguanil, artemether-lumefantrine and artemotil. These drugs are effective against parasites with multiple resistance. Atovaquone-proguanil and artemether-lumefantrine seem in practice to be equivalent for the treatment of non-severe Plasmodium falciparum infections for respectively persons of more than 11 kg and persons aged 12 years and older (35 kg). Artemotil (intramuscular injection) is registered for the treatment of severe malaria in children up to 17 years of age. Atovaquone-proguanil is also registered for prophylactic use in adults. The intravenous administration of quinine is preferable in the case of seriously ill patients. In patients with non-severe malaria for whom parenteral treatment is indicated, artemotil is a good alternative for quinine.

In Central Africa, the number of people suffering and dying from sleeping sickness is the same as it was in 1920, whereas the disease was under control in the 1950s. In Zaire (Congo), Gambiense sleeping sickness was virtually under control by 1960. Due to war, chaos, population movements, lack of resources, and collapse of public health, the situation is now as it was 80 years ago and some years ago it was even more bleak as the supply of drugs seemed to halt. Due especially to the action of Médecins sans Frontières, the availability of the four essential drugs pentamidine, suramine, melarsoprol and eflornithine is now secure until 2006. Control of the epidemic in Central Africa can be achieved once peace and order and a basic infrastructure have been restored, and under the condition that adequate resources will be available.

Three Dutch tourists, a man aged 57 and two women aged 55 en 52 years, acquired African trypanosomiasis in the national parks of Tanzania. Two, without central nervous system involvement, were cured after treatment in the Netherlands, albeit one after having suffered a relapse. In the third patient, involvement of the central nervous system was diagnosed in Africa and she was treated with melarsoprol. After an apparently uneventful recovery she was readmitted with cerebral complaints and symptoms. While being treated with melarsoprol she lapsed into coma. She died following repatriation. An epidemic of trypanosomiasis is currently raging through Central Africa. In several western countries, trypanosomiasis has been diagnosed recently in tourists who visited Tanzania.

A 27-year-old man had 'furuncles' after a one-month stay in Gambia, which proved to be cutaneous myiasis due to Cordylobia anthropophaga.

A 39-year-old man, who had made a cycling tour from Tibet to Nepal, visited the outpatients' clinic one month later because of prolonged diarrhoea, abdominal complaints and serious weight loss. Parasitological examination of the stool revealed oocysts of Cyclospora cayetanensis and the patient was treated with trimethoprim-sulfamethoxazole (co-trimoxazole) with good result. C. cayetanensis has only recently been discovered as a protozoal cause of diarrhoea. Infections are primarily reported from areas with a low hygienic standard e.g. Central and South America, the Indian subcontinent (Nepal), Indonesia and South-East Asia. Clinical symptoms of infection are diarrhoea (usually watery), abdominal cramps and discomfort. The infection can have a prolonged course. Diagnosis is made by parasitological examination of the stool (one should be cautious not to confuse with cryptosporidia) and treatment with trimethoprim-sulfamethoxazole is effective.

In a mouse model of river blindness it was demonstrated that Wolbachia bacteria, endosymbionts of filarial nematodes, play an important role in the inflammatory process leading to the disease and that this process depends on Toll-like receptor 4. Wolbachia is found in many arthropods and in all filariae pathogenic for man. Treatment with doxycycline depletes female filariae of Wolbachia and renders them infertile for at least 18 months. Chemotherapy of filarial nematodes should be studied for the reduction and possibly prevention of pathology due to filariae, and for a contribution to control and eradication programmes.

Two patients, a woman aged 24 and a man aged 86, had suffered from recurrent, itchy, linear, creeping skin lesions, notably on the thighs, buttocks and lower abdomen, for 9 months and more than 50 years, respectively. The woman had been in South America, and the man had worked on the Burma railway as a prisoner of war during World War II. In both patients 'larva currens' was observed. The clinical diagnosis of 'strongyloidiasis' was supported by eosinophilia and raised antibody titres against Strongyloides stercoralis in the blood. No larvae could be detected in either patient. Treatment with albendazole, and ivermectin, respectively, resulted in disappearance of the complaints. S. stercoralis is found in many parts of the world. In the Netherlands the major risk groups in which strongyloidiasis should be considered are people from, and visitors to, South-America (Surinam) and South-East Asia (Indonesia, former prisoners of war).

During a flight to Kenya, a 42-year-old man took a therapeutic dose of chloroquine because of fever. He regularly travelled to Africa and always took chloroquine and proguanil for malaria prophylaxis. The fever disappeared but he did not fully recover. He complained of malaise and weight loss. Fourteen years previously he had suffered from amoebic dysentery. One month after the onset of the patient's complaints, an amoebic liver abscess was suspected on the basis of his medical history, an elevated ESR and a slight leukocytosis. The diagnosis was confirmed by ultrasonography and serology.

Despite treatment for malaria two travellers who acquired fever in Africa continued to have complaints: a 25-year-old Dutch woman and a 25-year-old Australian man. On questioning they appeared to have swum in Lake Malawi and a diagnosis of acute schistosomiasis was made, confirmed by serological tests. This syndrome, also called Katayama fever, is characterized by fever, oedema, urticaria and eosinophilia. The aetiology is not fully elucidated but it is supposed to be caused by immune complexes initiated by maturing worms and eggs. Patients who acquired fever in an endemic area must be questioned about contact with fresh water. Serological tests are important for the diagnosis. Treatment is with praziquantel but it is advised to treat only after the acute phase. During the acute manifestations corticosteroids may be necessary. Prevention is by avoiding contact with infected water. There is no vaccine. The role of artemisinin drugs in prevention is currently being studied.

Two weeks after rafting on a river in Thailand a Dutch 54-year-old male experienced chills and high fever. While rafting he had wounded his hand. Because of the history (water contact, the wound, high fever with chills), of the findings at examination (fever, conjunctivitis) and of the laboratory findings (leukocytosis, albuminuria, disturbance of liver enzymes), a clinical diagnosis of 'leptospirosis' was made. This was confirmed by serological tests and culturing of Leptospirae from the blood. Leptospirosis is a zoonosis, in man associated with certain occupations, water sports and inundations. The clinical picture varies from a mild febrile disease (sometimes pyrexia of unknown origin) to a severe condition with kidney and liver failure, bleeding tendency, lung oedema (Weil's syndrome). In travellers with fever, water contact, leukocytosis and neutrophilia, leptospirosis must be considered and specific diagnostic tests applied.

A 26-year-old woman, who had visited the Krugerpark in South Africa 5 days before, presented with fever, a skin lesion with a black crust (eschar), lymphadenopathy and a vesiculo papular rash. The clinical diagnosis 'Rickettsia africae infection' was confirmed by specific serological tests. A second patient aged 43 years, whose vesicular rash did not respond to flucloxacillin had been in the Krugerpark one week before and on examination was found with 2 eschars. Based on epidemiological and clinical grounds African tick fever can be distinguished from Mediterranean spotted fever (fièvre boutonneuse). In the Netherlands specific diagnostic tests are not available. For treatment the distinction is not necessary; treatment is with tetracycline or doxycycline. Both patients recovered upon this treatment.

Objective: To describe an analysis of the patients seen at the Outpatient Department (OPD) for Tropical Diseases in the Academic Medical Centre, Amsterdam, during 1996 and 1997., Design: Descriptive cross-sectional study., Method: From our database of OPD-patients the following data were analysed: age, country of birth, travel destination and most frequent complaints at presentation. These were further analysed in relation to travel destination, diagnosis and need of admission., Results: In 1996 and 1997 1763 patients visited the OPD. Abdominal complaints, fever, general malaise and skin diseases were the main problems. Abdominal complaints were more often acquired in Asia, fever in sub-Saharan Africa and skin problems in South America. General malaise was not related to a specific travel destination. Abdominal complaints, fever and general malaise were more often caused by parasites, and skin problems by bacteria. Plasmodia were the most frequently encountered microbial cause. Malaria was found in 1 out of every 3 Dutch, and 9 out of every 10 Ghanaian patients with fever from Africa., Conclusion: The analysis of the database yielded useful information regarding patients with import diseases in the Netherlands and with respect to travellers to tropical areas.

In Africa malaria parasites are increasingly developing resistance to the 3 affordable and tolerable drugs: chloroquine, amodiaquine and sulfadoxine-pyrimethamine. Alternative products are much more expensive and more toxic. A malaria disaster is looming. On the contrary, in Vietnam a disaster appears to have been averted. Data on malaria epidemiology, on the mosquito, the parasite and the host, man, give insight into the differences and the possibilities of control. Artemisinin derivatives can play an important role in malaria control, also in Africa. Without improvement of care which will require considerable investment and attention, the prospects are bleak.

In a general practice in Amsterdam Southeast in 1998 a delayed first attack of Plasmodium ovale infection was diagnosed in a 13-year-old girl from Ghana, malaria tropica with a low parasitaemia index in a 43-year-old Ghanaian man and a 8-year-old Ghanaian girl, and Plasmodium vivax infection in a 44-year-old Surinam woman. The Ghanaian patients had visited their native country, the Surinam woman had contracted the infection during a visit to India. All patients responded well to antimalaria medication. These patients were among a total of 6 patients of non-Dutch origin diagnosed with malaria in 1998 in this general practice. Four patients had not taken any prophylactic drug and two had not used the drugs properly. A relative increase of malaria in immigrants has been seen in the Netherlands and elsewhere in Europe in recent years. Underestimation of the risks and lack of knowledge of malaria and of the changing epidemiology make people of ethnic minorities travel without taking appropriate precautions. New, creative ways of communication and information will have to be explored to reach these migrant communities.

The Netherlands has been free from malaria since the early 1960, due to a combination of factors: active search and treatment of patients and parasite carriers, targeted use of insecticides, changes in farming and in housing of man and cattle, pollution of surface water with phosphates and the fact that surface waters became fresher. These factors reduced the mosquito population that is dependent on brackish water. The Dutch malaria mosquito cannot transmit the parasite of tropical malaria. The mosquito population could possibly increase due to measures to 'develop nature' but the number of parasite carriers, the acute disease manifestations, the quality and organization of the health care system make it extremely unlikely that local transmission will occur. Fears that malaria may become endemic and that the population in the western parts of the country will have to apply malaria chemoprophylaxis in the near future, are unfounded.

The management of poisonous snake bites includes first aid and clinical medical treatment. First aid consists of reassurement of the patient, immobilisation of the bitten limb and rapid transport to the nearest hospital to monitor the vital functions. In no case suction, incision or tight bandages should be applied. The degree of envenomation can be classified in three categories depending on the spread of the symptoms: no symptoms, only local non-progressive symptoms, and systemic or local rapidly progressive symptoms (severe envenomation). Antivenin therapy is indicated in severe envenomation. Because of the risk of anaphylactic reactions or serum sickness, antivenin should be given with great caution. Antibiotic therapy and tetanus prophylaxis are advised in all cases. Immediate consultation with the National Intoxication Centre of the Rijksinstitut voor Volksgezondheid en Milieu (RIVM) is always warranted; telephone: 030-2748888. In a national protocol, which is available at the RIVM, the Harbour Hospital Rotterdam, the Academic Medical Centre and Artis Zoo Amsterdam, the correct management of snake bites is described. An overview of all antivenins available in the Netherlands is also given in this protocol.

The anthelminthics registered in the Netherlands include albendazole, mebendazole and praziquantel. Available but not registered are ivermectin and diethylcarbamazine. With these five drugs nearly all indigenous and imported helminth infections in the Netherlands can be treated effectively. Neurocysticercosis is difficult to treat with medication, surgery may be needed.

Viral haemorrhagic fevers, such as Lassa fever and yellow fever, cause tens of thousands of deaths annually outside the Netherlands. The viruses are mostly transmitted by mosquitoes, ticks or via excreta of rodents. Important to travellers are yellow fever, dengue and Lassa and Ebola fever. For yellow fever there is an efficacious vaccine. Dengue is frequently observed in travellers; prevention consists in avoiding mosquito bites, the treatment is symptomatic. Lassa and Ebola fever are extremely rare among travellers; a management protocol can be obtained from the Netherlands Ministry of Health, Welfare and Sports. Diagnostics of a patient from the tropics with fever and haemorrhagic diathesis should be aimed at treatable disorders such as malaria, typhoid fever, rickettsiosis or bacterial sepsis, because the probability of such a disease is much higher than that of Lassa or Ebola fever.

The natural products quinine and artemisinine have been effective antimalarials for centuries. Most synthetic antimalarials were developed because of pressure of war; against all some degree of resistance has developed. The newer drugs are too expensive for large-scale use. Development of new antimalarials is financially too risky for the pharmaceutical industry. Co-operation among industries, research institutes, governments and international organizations is coming off the ground. Dutch researchers should contribute to international malaria research for humanitarian reasons and out of self-interest, for the benefit of public health.

The diagnosis of malaria should include the species involved and in case of P. falciparum infection the parasitaemia index: the percentage of the infected red cells. P. vivax, ovale and malariae infection are treated with chloroquine, in case of P. vivax and ovale malaria followed by primaquine. Mefloquine and halofantrine are indicated for chloroquine-resistant vivax infections. Advice on management and treatment is different for mild and severe (> or = 5% infected erythrocytes or presence of complications) P. falciparum infections. Mild infections may be treated on an outpatient basis. In severe infections quinine has to be started immediately, while frequent checks of vital functions and blood parameters are indicated. New treatment options are the use of artemisinine (preparations) or atovaquone, both efficacious and low in adverse effects and toxicity.

In a 45-year-old Swiss male, who had been living in the Netherlands for 20 years, alveolar echinococcosis was diagnosed. He had probably been infected during his youth in Switzerland. His illness became symptomatic more than 20 years later. The diagnosis was reached by microscopic examination of material obtained from a necrotic mass in the liver. Imaging revealed that the disease had spread diffusely throughout the liver, spleen and abdomen. Curative resection was impossible. Percutaneous drainage of the hepatic necrotic mass was complicated by a bacterial infection for which he was treated with antibiotics. Treatment with high doses of albendazole resulted in considerable improvement. The patient represents the first case of Echinococcus multilocularis infection diagnosed in the Netherlands.

Unilocular hydatid disease occurs in humans after oral intake of eggs of the dog tapeworm, Echinococcus granulosus. Cysts develop mostly in the liver, but sometimes also in the lung. The diagnosis of Echinococcus infection is based on history-taking, physical examination, ultrasound and CT examination and serological testing; the diagnosis is confirmed by parasitological examination of cystic fluid. Treatment until some 15 years ago consisted in operation. Subsequently, treatment with initially mebendazole, later with albendazole or with percutaneous drainage (puncture, aspiration, injection of a scolicidal, respiration (PAIR)), or with combinations of the same, became accepted forms of management. The PAIR method is reported to give high proportions of success, low proportions of recurrence and few complications. However, adequate evaluation is not yet possible because of the short follow-up period. For the prevention of leakage it is recommended to perform the PAIR method with a transhepatic puncture under continuous ultrasonographic or CT guidance; for avoidance of recurrences, one week's pretreatment and 1-4 weeks' after-treatment with albendazole are recommended. The results of albendazole monotherapy are hard to predict and highly variable: success: 30-88% (median: 71%); failure: 22-32% (median: 25%); recurrences: 9.5-31% (median: 16%). Both albendazole therapy and the PAIR management should be followed by protracted follow-up to check regression of cysts and detect recurrences. It is not clear which treatment is the best one.

Drug resistance is a major problem in malaria. The resistance mechanism remains unresolved but contributing factors are probably heavy drug use, parasite selection, cross resistance and genetic influences of drugs. Plasmodium ovale en P. malariae are sensitive to the current antimalarial drugs. P. vivax has some chloroquine resistant strains, notably on Papua New Guinea, Irian Jaya and other islands in the Pacific. The geographical distribution of P. falciparum strains resistant to proguanil and pyrimethamine is not well known. Chloroquine-resistant strains are found in South East Asia, the Amazon region (almost 100% resistance in both regions) and in Africa south of the Sahara (resistance not everywhere 100%). Sulfadoxine-pyrimethamine is not an effective treatment in South East Asia and the Amazon region; it is useful in tropical Africa. Mefloquine resistance is a problem mainly confined to Thailand. There is cross resistance between halofantrine and mefloquine. Decreased sensitivity to quinine was reported from Thailand, but it remains an effective drug, notably when given in combination with tetracycline or doxycycline. In cases of severe or complicated malaria intravenous quinine is still the preferred therapy. Resistance to artemisinine has not yet been reported. Pharmaceutical companies show little interest in antimalarial drug development, which in view of the increasing drug resistance is a matter of great concern.

Objective: To determine how and where malaria was diagnosed in a forestry area in South-Vietnam and how it was treated., Design: Descriptive., Setting: Hieu Liem, Dong Nai province, Vietnam., Method: In the government hospital and health posts malaria diagnosis and treatment were free of charge while treatment had to be paid for in four private clinics. A population survey was carried out in the forestry area and outside this area: the people were examined for splenic enlargement and a blood sample was analysed., Results: Most patients went to private clinics and it was here that malaria was most frequently diagnosed. In 7.5% of the population in the forest area parasites were found while 1.8% of those living outside the forest appeared to have parasites in the blood. None of the persons with parasitaemia had splenomegaly. Splenomegaly was found in 2.9% of the population, 6.7% in and 0.9% outside the forest area., Conclusion: Recent changes in the health sector in Vietnam have liberalized malaria treatment, possibly control. The wide distribution and extensive use of effective drugs like artesunate and mefloquine have probably contributed to reduction of (severe) malaria, but development of resistance to these drugs is to be feared. Control of drug distribution and of prescription practices is urgently needed.

In a retrospective study the data concerning 49 patients with cutaneous leishmaniasis were analysed. The group included 39 patients seen in Amsterdam in the period 1979-1988 in the Royal Institute for the Tropics and the University Medical Centre and 10 patients seen in the University Hospital of Leiden in the period 1970-1982. Mediterranean countries, especially Spain, were important sources of infection. In 26 patients, one skin lesion was found. All but one of the patients had (papulo)nodules, nodules with central scab formation and/or ulcerative skin lesions. In most cases the lesions were localized on the face and extremities, one patient had a mucosal lesion of the nose, three had sporotrichoid extension and six, lymphadenitis. For demonstration of the parasite, aspiration, smear, biopsy and culture were used with varying frequencies. The biopsy and culture methods contributed most to the diagnosis. The treatment in 22 patients consisted in parenteral administration of sodium stibogluconate while 13 received primary cryotherapy. In addition, four patients were subjected to cryotherapy because of a recurrence after, or side effects of the treatment with sodium stibogluconate. In three patients, spontaneous healing was awaited. Owing to incomplete follow-up, the ultimate condition was not known of all patients; the skin lesions treated with cryotherapy all healed. In case of nodular and ulcerative skin lesions in a person who has lived in the (sub)tropics, cutaneous leishmaniasis should be considered; the geographical anamnesis is of great importance in this respect.