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

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

Pushing Purcell-enhancement beyond its limits

Purcell-enhanced emission from a coupled emitter-cavity system is a fundamental manifestation of cavity quantum electrodynamics. Starting from a theoretical description we derive a scheme for photon emission from an emitter coupled to a birefringent cavity that exceeds hitherto anticipated limitations. Based on a recent study and experimental investigation of the intra-cavity coupling of orthogonal polarisation modes in birefringent cavities, we now decouple the emitter and the photon prior to emission from the cavity mode. Effectively, this is "hiding" the emitter from the photon in the cavity to suppress re-excitation, increasing the overall emission through the cavity mirrors. In doing so we show that tailored cavity birefringence can offer significant advantages and that these are practically achievable within the bounds of present-day technology. It is found that birefringence can mitigate the tradeoff between stronger emitter-cavity coupling and efficient photon extraction. This allows for longer cavities to be constructed without a loss of performance -- a significant result for applications where dielectric mirrors interfere with any trapping fields confining the emitter. We then generalise our model to consider a variety of equivalent schemes. For instance, detuning a pair of ground states in a three-level emitter coupled to a cavity in a Lambda-system is shown to provide the same enhancement, and it can be combined with a birefringent cavity to further increase performance. Additionally, it is found that when directly connecting multiple ground states of the emitter to form a chain of coupled states, the extraction efficiency approaches its fundamental upper limit. The principles proposed in this work can be applied in multiple ways to any emitter-cavity system, paving the way to surpassing the traditional limits of such systems with technologies that exist today.Comment: 8 pages, 8 figures plus 3 page appendi