Comparison between five PCR techniques for the diagnosis of SARS-CoV-2.

OBJECTIVE: Since the first cases of SARS-CoV-2 appeared, there have been numerous techniques that have been developed for the diagnosis or monitoring of infection, both direct and serological techniques. Choosing a good diagnostic tool is essential for epidemiological control. The objective was to compare five commercialized RT-PCR techniques in real time, in sensitivity, specificity and agreement for the detection of SARS-CoV-2. METHODS: Five commercial RT-PCR kits for the detection of SARS-CoV-2 were compared. Eight known positive samples were taken and subjected to seven different dilutions or concentrations, and another 135 negative samples were used to determine sensitivity, specificity, and agreement values. RESULTS: The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the Palex, Roche and GeneXpert techniques with respect to Seegene were identical, corresponding to 98.21%, 100%, 100% and 99.26% respectively. For Becton Dickinson the sensitivity was 89.28%, the specificity of 100%, the PPV of 100% and the NPV of 95.74%. The agreement using the Kappa index for Palex, Roche and GeneXpert was 0.9892, while the agreement for Becton Dickinson was with a Kappa index of 0.9215. CONCLUSIONS: All commercial RT-PCR kits had high sensitivities and specificities, as well as PPV, NPV, and concordance.

Clinical spectrum of fever of intermediate duration in the south of Spain.

Fever of intermediate duration (FID) is a new nosologic entity defined as fever higher than 38 degrees C that has a duration of between 1 and 4 weeks and that after an initial approach has not been diagnosed. It has clinical similarities with fever of unknown origin, but because of characteristic etiologies it requires the term FID. We describe the clinical characteristics and etiology of FID in the south of Spain and create a treatment algorithm. Retrospective study of the medical charts of patients attending at our Service during 2000 and 2005 who had an initial diagnosis of FID and who had a complete follow-up until the resolution of symptoms. Two hundred and thirty-three patients met the inclusion criteria, of whom 164 were men. Median number of days before being referred to our service was 9 (range 2-28). Half of the patients had elevation of transaminases, and CRP and ESR were slightly elevated, 2.8 mg/dl (range 0.1-50) and 16 mm/h (range 1-131) respectively. A final diagnosis was made in 80 patients, with infection with coxiella (32 patients), CMV (16 patients), rickettsial species (11 patients), VEB virus (6 patients), and brucella (5 patients) being the more frequent entities. Doxycycline was the antibiotic most frequently prescribed. Among patients with Q fever, CMV, and rickettsial infection, the majority had abnormal hepatic function, (87%, 93%, and 55% respectively). In FID, a diagnosis is reached in a minority of patients, although the prognosis is excellent in most of them. In our patients the clinical picture of Q fever, CMV, and rickettsial infections included abnormal hepatic function. In addition, these three infections are the most frequently diagnosed so when treating a patient with FID, if elevation of liver enzymes is present patients should start on doxycycline.

Septic arthritis due to Absidia corymbifera in a patient with HIV-1 infection.

We report the first case described of septic arthritis caused by Absidia corymbifera in the setting of cellular immune deficiency associated with HIV-1 infection. Isolation of this organism from sterile fluids as synovial fluid should be regarded as pathogenic.