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Biomedical subjects

T Löscher

Publications and source records attributed to T Löscher.

At least 19 recordsLinked to original sources

[33 year old Libanese woman with recurrent haemoptysis and cystic lesion of the lung].

A 33 year old woman from Lebanon presented with recurrent hemoptysis, subfebrile temperature, dyspnoe in stress, fatigue, weight loss, and pruritus. Serological tests and results from chest X-ray and computer tomography revealed cystic echinococcosis with pulmonary involvement. After refusal of surgical therapy a medical treatment with albendazole was implemented. Two months after the start of the therapy only a small fibrotic residuum in the lung was seen. A spontaneous healing success seems unlikely because of the duration of the pulmonary cyst and the progressive symptoms before treatment.

Adult↗

[Tsutusgamushi fever after travel to Southeast Asia].

HISTORY AND CLINICAL FINDINGS: A 49-year-old travel guide fell ill during his return from a 6-week-stay in Vietnam, Myanmar and Thailand. He developed high fever and severe headache. On admission, the body temperature was at 39.5 degrees C with relative bradycardia. A black, crusted skin lesion of approximately 5 mm diameter was noted on the chest wall and was interpreted as an insect bite. INVESTIGATIONS: CRP and liver enzymes were elevated. Total leucocyte count was normal but the differential count showed a left shift and aneosinophilia. Imaging procedures revealed splenomegaly and small pleural effusions on both sides. TREATMENT AND COURSE: The patient was treated with a parenteral quinolone based on the initial suspicion of typhoid fever. Failure of this treatment and negative blood cultures raised concerns about the possibility of Tsutsugamushi fever, based on travel history and a re-evaluation of the skin lesion as an eschar. Tsutsugamushi fever was suspected on epidemiological and clinical grounds and was confirmed by the detection of specific IgM to Orienta tsutsugamushi and by seroconversion of IgG antibodies during follow-up. Even before immunodiagnostic confirmation was available, a course of doxycycline was started. This led to rapid improvement of the patient's condition. CONCLUSION: In febrile travellers returning from Southeast Asia, Tsutsugamushi fever has to be considered in the differential diagnosis. The causative agent, Orienta tsutsugamushi is transmitted by larvae of trombiculid mites (chiggers). Leading symptoms are fever continua, cephalgia, and a primary lesion (eschar) at the site of cutaneous inoculation. The Eschar is easily overlooked and has to be searched carefully. Diagnosis is confirmed by the detection of specific antibodies. However, serology may be negative in the beginning. Therefore, treatment with doxycycline should be initiated on clinical grounds.

Anti-Bacterial Agents↗

[52-year-old patient with subcutaneous space-occupying lesion in immunosuppression].

We report the case of a 52-years-old male patient, who was diagnosed with subcutaneous alveolar echinococcosis 6 months after liver transplantation for HCV-related cirrhosis. Nether the explanted nor the transplantated liver revealed an echinococcus focus. Therefore a rare primary extrahepatic manifestation was likely. Interestingly, the echinococcal larvae had developed protoscolices. The development of mature tapeworms in human is a rarity, which could be related to the immunosuppressive therapy after liver transplantation. The patient was curatively treated by surgical removal of the subcutaneous tumor and a postoperative therapy with albendazole. Furthermore, HCV reinfection (genotype 2b) was successfully treated with interferone alpha 2b and ribavirine for 6 months.

Biopsy↗

Fatal malaria in a German couple returning from Burkina Faso.

We report on a German couple found dead at home 7 days after returning from Burkina Faso. Postmortem evaluation revealed Plasmodium falciparum infection with a parasitemia of approximately 80% in both cases. No pathological findings of the organs were present at autopsy except moderate splenomegaly in both cases and myocarditis in one case. Typical findings of fatal malaria like petechial hemorrhages of the brain or other organs, or sequestration of parasitized erythrocytes in venules and capillaries were absent. Lack of sequestration with excessive hyperparasitemia leading to systemic hypoxemia and host cytokine release may have contributed to the rapid fatal course in these nonimmune patients.

Animals↗

Prophylaxis failure due to probable mefloquine resistant P falciparum from Tanzania.

Failures of mefloquine prophylaxis in travellers returning from Africa have been reported repeatedly. Non-compliance to chemoprophylaxis is considered to be a major factor for failure. Only few reports on mefloquine prophylaxis failure in sub-Saharan Africa were able to report blood levels of the drug that were sufficient for prophylactic effectiveness. We report the case of a 44-year-old German female who travelled to Tanzania for 3 weeks. The patient reported that she never missed a dose of mefloquine during her weekly prophylaxis schedule. Four weeks after returning from Tanzania, the patient presented with fever, headache and myalgia. Only a few trophozoites of Plasmodium falciparum were found in a thick film. Blood levels of mefloquine at that stage were at 1400 ng/ml, thus largely excluding non-compliance and malabsorption. To our knowledge, this is the first case of confirmed prophylaxis failure due to mefloquine resistance in East Africa.

Adult↗

Sensitivity and specificity of ELISA and immunoblot for diagnosing neurocysticercosis.

In patients with neurocysticercosis (NCC), clinical manifestations and the results of neuroimaging procedures vary widely and often do not facilitate a definite diagnosis. In order to determine the value of immunodiagnosis for NCC, 222 serum and cerebrospinal fluid samples from patients with NCC and healthy subjects were examined. The samples represented patients from various endemic regions, those with other neurological disorders from an endemic area (Mexico), persons with various helminth infections other than NCC, and a group of healthy volunteers. All specimens were tested by enzyme-linked immunosorbent assay and immunoblot for the presence of Taenia solium-specific antibodies. The sensitivities of the enzyme-linked immunosorbent assay and the immunoblot test in NCC patients were almost identical (80% and 81.7%, respectively). For both tests, the sensitivity was higher when cerebrospinal fluid (86%) was tested compared with serum (75%). The overall specificity of enzyme-linked immunosorbent assay was only 75.3% because of frequent false-positive results in patients with other helminth infections, especially in those with echinococcosis. The specificity (99.4%) of the immunoblot test was clearly superior. It is concluded that enzyme-linked immunosorbent assay as a screening method and immunoblot as a confirmatory test contribute considerably to the diagnosis of NCC.

Animals↗

Diagnostic significance of blood eosinophilia in returning travelers.

This study was conducted to investigate the predictive value of blood eosinophilia (total white blood cell count with > or =8% eosinophils) for the diagnosis of travel-related infections in 14,298 patients who returned from developing countries. The data show that blood eosinophilia in travelers returning from developing countries has only limited predictive value for the presence of travel-related infections. However, the likelihood of the presence of helminth infections increases considerably with the extent of eosinophilia.

Adolescent↗

Detection of embB codon 306 mutations in ethambutol resistant Mycobacterium tuberculosis directly from sputum samples: a low-cost, rapid approach.

Substitutions of codon 306 in the gene embB are the most common mutations found in ethambutol resistant Mycobacterium tuberculosis. The characterization of these mutations has been hampered by the need for prior cultivation of the mycobacteria, or the need for DNA sequencing, or both. Here, we describe a simple and culture-independent technique to detect embB codon 306 mutations directly from sputum samples, requiring little more than a PCR machine and a simple agarose minigel. There is no need for labelled probes or DNA sequencing. In a preliminary test of feasibility, interpretable results were obtained from 21 of 24 selected sputum samples, 12 of which were determined to contain ethambutol resistant M. tuberculosis after culture. All of six samples with embB codon 306 mutations were correctly identified. Although an exact validation of this technique is beyond the scope of this technical report, we conclude from well-known embB codon 306 mutation prevalence figures that approximately one half of EMB resistant cases could already be predicted within 2 working days, with little equipment or hands-on time needed, instead of weeks required for conventional resistance testing.

Chemistry, Clinical↗

Patterns of Plasmodium falciparum drug resistance in nonimmune travellers to Africa.

Falciparum malaria is a major cause of morbidity and mortality among tourists returning from endemic areas. Treatment of infected travellers is frequently standardised, and resistance tests are rarely done as they are difficult to perform and interpret. In vitro tests of resistance to chloroquine, mefloquine, quinine, halofantrine, tetracycline, and sulfadoxine/pyrimethamine were performed on Plasmodium falciparum isolates obtained from 52 German travellers returning from malarious areas in sub-Saharan Africa. All patients were treated successfully with a standard dose of mefloquine. No in vivo resistance was observed. Although 20 (38.5%) isolates showed no signs of in vitro resistance, the remaining 32 (61.5%) were resistant to at least one of the tested antimalarial agents. Of these 32 isolates, 11 were multiresistant. Resistance to chloroquine was most frequently observed (55.8%), followed by sulfadoxine/pyrimethamine (11.5%), mefloquine (9.6%), quinine (3.8%), and halofantrine (1.9%). In vitro resistance to tetracycline was not detected in this study group. Treatment of falciparum malaria without resistance testing appears to be effective in most cases, but possible therapeutic failure due to emerging drug resistance should be kept in mind.

Adolescent↗

[Malaria--rapid diagnostic tests and emergency self-medication].

WHO recommendations have adopted the option of stand-by emergency treatment (SBT) for travellers to areas where malaria is endemic and medical attention may not be obtained within 24 hours after onset of symptoms. Indication and choice of drugs for SBT depend on use and kind of a chemoprophylactic regimen, situation of plasmodial resistance at the destination, and contraindications and tolerability in the individual traveller. However, the diagnosis of malaria on clinical grounds alone is unreliable, and fever occurs frequently during travel to malaria endemic areas from various reasons. The possibility of malaria has to be considered in all cases of unexplained fever that starts after the 7th day of stay in an endemic area. Studies in European travellers have shown that only 0.5-1.4% of all travellers to whom SBT medication has been prescribed, will finally use it. SBT use in febrile travellers (8.1-10.4% of all travellers) has been 4.9-17%, but plasmodial infection could be confirmed retrospectively in 10.8-16.7% of SBT-users only. The recent introduction of rapid diagnostic tests (RDT) for malaria has provided a potential tool to self-diagnose and treat a possible malaria attack when medical attention or microscopic diagnosis is not available. However, the utilisation of currently available RTDs by travellers has been shown to be technically problematic. Healthy volunteers were able to learn how to perform the tests, especially when standard written instructions were supplemented with verbal information (75 vs. 90% successful performance). But their interpretation of test results was unsatisfactory, with a high rate of false-negatives (14.1%). In another study in febrile European tourists in Kenya, only 68% of patients were able to perform the RDTs correctly, and 10 out of 11 with microscopically confirmed malaria failed to diagnose themselves accurately. Thus, besides appropriate training before departure, technical improvements are required before such RDT kits can be recommended for self-use by travellers.

Africa↗

Zoonotic potential of Enterocytozoon bieneusi.

The reservoirs and the modes of transmission of the most frequent microsporidial species in humans, Enterocytozoon bieneusi, are still unknown. We have examined fecal samples of 26 humans and 350 animals from 37 species to find 18 samples containing this parasite from humans, cats, pigs, cattle, and a llama. Genotypic characterization of the internal transcribed spacer of the rRNA gene resulted in 14 different genotypes, 6 of them previously undescribed. Phylogenetic analysis revealed the lack of a transmission barrier between E. bieneusi from humans and animals (cats, pigs, and cattle). Thus, E. bieneusi appears to be a zoonotic pathogen.

Animal Diseases↗

Heteroresistance in Mycobacterium tuberculosis.

SETTING: Drug resistance in Mycobacterium tuberculosis is often linked to specific mutations in a limited number of resistance genes. Detection of these mutations in a cultured isolate can predict the resistant phenotype. Genotypic analysis of the mycobacteria directly in a clinical specimen would result in considerable time saving for resistance prediction. OBJECTIVE: To find out whether resistance-predicting genotypes of mycobacteria found after cultivation always give a good reflection of those in the original clinical sample. DESIGN: Restriction fragment length polymorphisms of repetitive polymerase chain reaction (PCR) amplification and cloning of PCR products were used as nonintegrative methods to describe the composition of katG, rpsL and embB genotypes involved in resistance to isoniazid, streptomycin and ethambutol, respectively, in the original sample. This result was then compared to the phenotypic resistance profile after cultivation. RESULTS: Using both methods, mixed, heteroresistant populations could be detected in almost every fifth analyzed sample (katG: 5 of 16; rpsL: 3 of 17; embB: 1 of 21). Direct sequencing, a widely used integrative method, repeatedly failed to detect heteroresistance. CONCLUSION: Heteroresistance is a valid phenomenon in clinical tuberculosis. It is not rare and not restricted to a particular resistance gene, and is obscured by cultivation as well as by some, not all, culture-independent resistance prediction tests.

Antitubercular Agents↗