Malaria in Nonimmune Travelers

Background: With the current increase of international travel to tropical endemic areas, the incidence of malaria being imported into nonendemic countries has increased significantly. Disagreement concerning malaria chemoprophylaxis and inadequate knowledge of malarious areas, morbidity, and pretravel advise has led to confusion among both health professionals as well as travelers. Therefore, this study was conducted to investigate malaria imported into Germany by identifying the high-risk endemic areas, clinical presentations, and chemoprophylactic and therapeutic regimens related to reported cases. Methods: Between 1990 and 1993, the 160 nonimmune travelers, all German nationals or residents for more than 10 years, presenting to our travel clinic with microscopically confirmed malaria were investigated. For each, the travel history, chemoprophylaxis used during travel, symptoms, pathological diagnosis, and treatment efficacy were analyzed. Results: Africa (73%), Asia (21%), and Central South America (6%) were the endemic countries visited by our patients, of whom only 3% used the chemoprophylaxis recommended for their destination. Plasmodium falciparum was the most common pathogen, found in more than half of our patients, and P. vivax (29%), P. ova le (6%), P. malariae(6%), a mixed infection with P.falciparum and P vivax (3%) were also detected. All patients presented with fever and headaches, a majority with profuse night sweats, insomnia, arthralgias, and myalgias, and diarrhea and abdominal cramps were experienced in 13% and 8%, respectively. In falciparum malaria, a recrudescence was observed in all patients who received chloroquine only, whereas quinine, halofantrine, and mefloquine were highly effective. In vivax malaria, a relapse rate of 14% was noted in the patients treated with the currently recommended regimen of chloroquine and primaquine. Conclusions: Visitors to endemic countries, especially to Africa, are of significant risk. Given the low compliance rate of chemoprophylaxis, a high percentage of malaria in our patients could have been avoided by an appropriate prophylaxis regimen and optimal pretravel counseling

Cutaneos larva migrans in travelers

The symptoms, medical history, and treatment of 98 patients with cutaneous larva migrans (creeping eruption) who attended a travel-related-disease clinic during a period of 4 years are reviewed. This condition is caused by skin-penetrating larvae of nematodes, mainly of the hookworm Ancylostoma braziliense and other nematodes of the family Ancylostomidae. Despite the ubiquitous distribution of these nematodes, in the investigated group only travelers to tropical and subtropical countries were affected; 28.9% of the patients had symptoms for > 1 month, and for 24.5% the probable incubation period was > 2 weeks. The efflorescences typically were on the lower extremities (73.4% of all locations). The buttocks and anogenital region were affected in 12.6% of all locations, and the trunk and upper extremities each were affected in 7.1%. Only a minority of patients presented with eosinophilia or an elevated serum level of IgE. No other laboratory data appeared to be related to the disease. Therapy with topical thiabendazole was successful for 98% of the patients. Systemic antihelmintic therapy was necessary in two cases because of disseminated, extensive infection

Folgen importierter Tropenkrankheiten in Deutschland

20-50% of all travellers to tropical and subtropical countries experience health problems during or after travel. Mainly respiratory tract infections or gastrointestinal disorders are predominant. As specific disorders imported from the tropics traveller's diarrhoea is prevailing, however amebic and helminthic infections, hepatitis A, malaria, sexually transmitted diseases as well skin disorders are rather common. Classical tropical diseases such as cholera, sleeping sickness or trachoma play only a very minor role as imported infections. The majority of health impairments during or after travel are uncomplicated or self limiting. However, falciparum malaria, viral hepatitides, typhoid fever, tropical viral infections and infections of the CNS can take a malicious course. Early diagnosis and treatment generally can provide complete cure without sequels. Sequels are most commonly seen following hepatitis B and C as well as HIV infection but also as a result of CNS infections (e.g. encephalitis) and of imported tuberculosis. For medical expert opinion it is essential that sequels were present already during the acute phase of illness. The socio-economical impact of infections imported from the tropics is considerable due to the high morbidity figures. Preventive measures before and after a stay in tropical countries could markedly reduce the health risks involved

Praziquantel in clonorchiasis and opisthorchiasis

A single stool examination revealed pathogenic intestinal parasites in 462 (58%) of 796 vietnamese and cambodian refugees. 56 (7.0%) were infected with Clonorchis sinensis and/or Opisthorchis viverrini. These patients received Praziquantel in a dosage of 20 mg/kg bwt. p.day on 3 consecutive days. Parasitological controls were completed after 12 months. No further excretion of eggs could be detected in 88% of the patients. Concurrent infections with other trematodes and cestodes were also cured. Nematode infections remained uninfluenced. No change of haematological and biochemical parameters could be observed during therapy. Diarrhea and epigastric pain were common side effects, which are probably not effects of the drug itself. They rather seem to be due to the release of parasitic antigens. This is also indicated by a further increase of circulating Ig E after therapy

Komplizierte Malaria tropica

Bei elf von 43 nichtimmunen Patienten mit Malaria tropica traten eine oder mehrere Organkomplikationen auf: zerebrale Malaria, akute respiratorische Insuffizienz, akutes Nierenversagen, Sekundärinfektion, Autoimmunhämolyse, spontane Milzruptur und akute Pankreatitis. Die Parasitämie betrug 0,1 bis 60 %. Initiale antiparasitäre Therapie mit Chinin parenteral führte in neun Fällen zu rascher Rückbildung der Parasitämie. Zusätzlich wurde ein zweites schizontozides Mittel entsprechend der Resistenzlage gegeben. Die supportive Therapie umfaßte intensivmedizinische Überwachung mit Bilanzierung von Elektrolyt- und Wasserhaushalt sowie gegebenenfalls eine frühzeitige Hämodialyse und (oder) endotracheale Intubation mit PEEP-Beatmung. In einem Fall mit exzessiver Parasitämie wurde eine Austauschtransfusion durchgeführt. Heparin wurde nur bei nachgewiesener disseminierter intravasaler Gerinnung gegeben, Corticosteroide nur bei persistierender Autoimmunhämolyse. Alle Patienten überlebten ohne zurückbleibende Defekte. Die retrospektive Analyse zeigt, daß neben einer raschen spezifischen Therapie die supportive Behandlung der einzelnen Organkomplikationen für Verlauf und Prognose der komplizierten Malaria tropica mitentscheidend ist

Schlafkrankheit bei deutschen Tropenreisenden

Zwei deutsche Tropenreisende erkrankten nach einer zweitägigen Safari im Akagera-Nationalpark in Ruanda an ostafrikanischer Trypanosomiasis (Schlafkrankheit). Leitsymptome waren Fieber, Lymphadenopathie und eine typische Primärläsion (Trypanosomenschanker). Die Diagnose konnte durch den Nachweis von Trypanosomen im peripheren Blut gesichert werden. Das Zentralnervensystem war in beiden Fällen nicht beteiligt. Unter dem Einfluß einer Therapie mit Suramin, 1 g pro Woche intravenös über 6 Wochen, bildeten sich die Symptome und die Parasitämie rasch zurück. Nach der Zahl der seit 1970 berichteten Fälle ergibt sich für deutsche Tropenreisende ein Infektionsrisiko von 0,3 pro 100 000. Aufgrund der teilweise erheblichen Wiederzunahme der Schlafkrankheit in einigen afrikanischen Ländern kann mit einer Zunahme des Infektionsrisikos auch für Touristen gerechnet werden

Halofantrin zur Behandlung der importierten Malaria bei nicht-immunen Reisenden

Im Rahmen einer prospektiven Multizenterstudie wurden die Wirksamkeit (Kriterien: Heilungsrate, Zeit bis zur Entfieberung oder Parasitenfreiheit) und Verträglichkeit (Kriterien: klinische Nebenwirkungen, veränderte Laborparameter) von Halofantrin bei 96 nicht-immunen Malaria-Patienten (71 Männer, 25 Frauen, mittleres Alter 34,3 [21-62] Jahre) untersucht, die aus Hochresistenzgebieten nach Deutschland oder in die Schweiz zurückgekehrt waren. 63 Patienten wurden mit einer Eintagestherapie behandelt (dreimal 500 mg Halofantrin); die folgenden 33 Patienten erhielten einen zusätzlichen Therapiezyklus nach einer Woche. In der zweiten Gruppe war die Therapie in allen Fällen wirksam, während bei der Eintagestherapie fünf von 41 Patienten (12,2 %) mit Malaria tropica einen Rückfall erlitten. Die Zeit bis zur Entfieberung betrug 45 Stunden, die Zeit bis zur Parasitenfreiheit 66 Stunden. Bei fünf Behandelten kam es unter der Therapie zu leichten Transaminasenanstiegen, die jedoch spontan innerhalb weniger Tage zurückgingen und am ehesten infektionsbedingt waren. - Bei guter Verträglichkeit ist Halofantrin für die Therapie und Stand-by-Therapie von multiresistenten Plasmodien-Infektionen geeignet. Die Behandlung muß nach 7 Tagen wiederholt werden.The efficacy (criteria: cure rate, time to resolution of fever or absence of parasites) and safety (criteria: clinical side effects, altered laboratory parameters) of halofantrin were investigated in a multi-centre study of 96 non-immune patients (71 men, 25 women, mean age 34.3 [21-62] years) with malaria imported from regions of high resistance into Germany or Switzerland. The initial 63 patients received one-day treatment (three doses of 500 mg halofantrin), while the last 33 patients received an additional course of treatment one week later. Treatment was curative in all patients in the second group, but relapses occurred in five of the 41 patients (12.2 %) with falciparum malaria who received one-day therapy. Fever resolved after a mean of 45 hours and parasites were absent after a mean of 66 hours. There were small increases in transaminase values (most probably because of the infection) in five patients, but all became normal again within a few days. - Halofantrin is a safe drug and is suitable for both therapy and stand-by therapy of resistant Plasmodium infections. Treatment should be repeated after 7 days

Visual saliency and semantic incongruency influence eye movements when inspecting pictures

Models of low-level saliency predict that when we first look at a photograph our first few eye movements should be made towards visually conspicuous objects. Two experiments investigated this prediction by recording eye fixations while viewers inspected pictures of room interiors that contained objects with known saliency characteristics. Highly salient objects did attract fixations earlier than less conspicuous objects, but only in a task requiring general encoding of the whole picture. When participants were required to detect the presence of a small target, then the visual saliency of nontarget objects did not influence fixations. These results support modifications of the model that take the cognitive override of saliency into account by allowing task demands to reduce the saliency weights of task-irrelevant objects. The pictures sometimes contained incongruent objects that were taken from other rooms. These objects were used to test the hypothesis that previous reports of the early fixation of congruent objects have not been consistent because the effect depends upon the visual conspicuity of the incongruent object. There was an effect of incongruency in both experiments, with earlier fixation of objects that violated the gist of the scene, but the effect was only apparent for inconspicuous objects, which argues against the hypothesis