Bedside diagnosis of imported malaria using the Binax Now malaria antigen detection test.

Malaria may be misdiagnosed in non-endemic countries when the necessary experience for rapid expert microscopy is lacking. Rapid diagnostic tests may improve the diagnosis and may play a role as a bedside diagnostic tool. In a multicentre study we recruited patients suspected of malaria over a period of 14 months. The Binax Now Malaria rapid test was used at the bedside and in the clinical microbiology laboratory. The training of clinical staff was monitored and their experience with the use of the test was recorded. 542 patients were included, 80 of whom had malaria diagnosed by microscopy. The rapid test used at the bedside had a sensitivity of 88% for the detection of P. falciparum compared to 95% when the test was performed in the microbiology laboratory. The risk of technical problems and invalid tests was highest when the test was used at the bedside. The rapid diagnostic test may be useful for the diagnosis of P. falciparum malaria when used by routine laboratory staff, but could lead to misdiagnoses when used at the bedside. Microscopy is still essential in order to identify the few missed diagnoses, to determine the degree of parasitaemia, and to ensure species diagnosis, including mixed infections.

Antibiotic susceptibility of Listeria monocytogenes in Denmark 1958-2001.

In order to see whether the susceptibility of Danish Listeria monocytogenes strains has changed over the years we examined a collection of human isolates from the period 1958-2001. We, furthermore, wanted to compare L. monocytogenes susceptibility testing using a disc diffusion assay with MIC measurements performed by the E-test. 106 strains isolated predominantly from blood cultures and cerebrospinal fluids were examined together with three reference strains. Susceptibility to the following antibiotics was tested by the E-test and by Oxoid discs using Iso-sensitest agar: penicillin G, ampicillin, meropenem, gentamicin, sulphamethoxazole, trimethoprim, ciprofloxacin, erythromycin, vancomycin, linezolid, chloramphenicol and tetracycline. The strains were in the main sensitive to all antibiotics examined using both methods, except for ciprofloxacin, where the strains were intermediate sensitive. However, for penicillin, ampicillin and sulphamethoxazole, while the disc diffusion assay found the strains to be sensitive, MIC measurements generally placed the strains one dilution above the breakpoint for sensitivity in the intermediate sensitive group. Based on the MIC measurements, the antibiotic susceptibility of L. monocytogenes has not changed in Denmark from 1958 to 2001, and the multiresistant strains found in human infections elsewhere have not been found in Denmark.