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

Aktueller Malariaschutz bei Kurzzeitaufenthalt

Zusammenfassung: In Deutschland werden jährlich ca. 800Malariafälle gemeldet. Für ca.1% der nicht immunen Reisenden endet die Krankheit tödlich. Um diese Situation zu verbessern, ist die Information durch die beratenden Ärzte entscheidend: das Risikobewusstsein der Reisenden vor, während und nach einer Reise in endemische Gebiete muss geschärft werden. Ein konsequenter Mückenschutz vermindert das Infektionsrisiko der Malaria sowie anderer durch Arthropoden übertragener Krankheiten zusätzlich. Die regelmäßige Einnahme von Medikamenten zur Malariachemoprophylaxe in Hochrisikogebieten sowie das rasche Handeln im Falle von Fieber in Gebieten mit mäßigem oder kleinem Malariarisiko (Aufsuchen eines Arztes zur Diagnosestellung, notfalls Selbsttherapie) tragen wesentlich zur Reduktion schwerer Malariaerkrankungen be

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

Texton segregation by associated differences in global and local luminance distribution.

Perceptual segregation of visual textures has been attributed to certain features ('textons') such as (elongated) blobs of given size and orientation, line crossings, and line ends. Differences in the spatial distribution of these features were assumed to be detected pre-attentively and to provide the instantaneous impression of segregating texture areas and of borders between them. This paper questions the validity of this general view and, in particular, the role of some of these features in texture discrimination. It is demonstrated that for some textons, perceptual segregation is independent of detection and discrimination of the texton itself. In addition, segregation can be strongly affected by positional or luminance jitter of texture elements or by other modifications that change the luminance distribution in the pattern but do not affect the supposed texton differences. From the textons reported in the literature, only differences in orientation were found to be fairly robust against such modifications

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

Influence of the ultrasonic vibration amplitude on the melt pool dynamics and the weld shape of laser beam welded EN AW-6082 utilizing a new excitation system for laser beam welding

Laser beam welding is a commonly used technology for joining similar and dissimilar materials. In order to improve the mechanical properties of the weld, the introduction of ultrasonic vibration into the weld zone has been proposed [5]. The ultrasonic system consists of an electronic control, a power supply, a piezoelectric converter and a sonotrode, which introduces the vibration into the weld zone. Its proper design is of great importance for the process performance. Furthermore, the effects of ultrasound in a melt pool need to be understood to evaluate and optimize the process parameters. In addition, it is important to find out the limits of ultrasonic excitation with respect to a maximum vibration amplitude. Therefore, firstly different methods of ultrasonic excitation are investigated and compared with respect to their performance. A system which is based on using longitudinal vibrations turns out to be the best alternative. Secondly, the system design is described in detail to understand the boundary conditions of the excitation and finally, simulations about the influence of ultrasonic vibrations are done by using a simplified model. The system is used to perform experiments, which aim at detecting the maximum vibration amplitude doing bead on plate welds of EN AW-6082 aluminum alloy. The experiments reveal a significant change of the weld shape with increasing ultrasonic amplitude, which matches the simulative findings. If the amplitudes are small, there is a marginal effect on the weld shape. If the amplitudes are high, melt is ejected and the weld shape is disturbed. In the present case, amplitudes over 4 µm were found to disturb the weld shape. © 2021, The Author(s)