Radiological Findings Increased the Successful of COVID-19 Diagnosis in Hospitalized Patients Suspected of Respiratory Viral Infection but with a Negative First SARS-CoV-2 RT-PCR Result.

SARS-CoV-2 is the etiological agent of COVID-19 and may evolve from asymptomatic disease to fatal outcomes. Real-time reverse-transcription polymerase chain reaction (RT-PCR) screening is the gold standard to diagnose severe accurate respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but this test is not 100% accurate, as false negatives can occur. We aimed to evaluate the potential false-negative results in hospitalized patients suspected of viral respiratory disease but with a negative previous SARS-CoV-2 RT-PCR and analyze variables that may increase the success of COVID-19 diagnosis in this group of patients. A total of 55 hospitalized patients suspected of viral respiratory disease but with a previous negative RT-PCR result for SARS-CoV-2 were included. All the participants had clinical findings related to COVID-19 and underwent a second SARS-CoV-2 RT-PCR. Chest-computed axial tomography (CT) was used as an auxiliary tool for COVID-19 diagnosis. After the second test, 36 patients (65.5%) were positive for SARS-CoV-2 (COVID-19 group), and 19 patients (34.5%) were negative (controls). There were differences between the groups in the platelet count and the levels of D-dimer, procalcitonin, and glucose (p < 0.05). Chest CT scans categorized as COVID-19 Reporting and Data System 5 (CO-RADS 5) were more frequent in the COVID-19 group than in the control group (91.7% vs. 52.6%; p = 0.003). CO-RADS 5 remained an independent predictor of COVID-19 diagnosis in a second SARS-CoV-2 screening (p = 0.013; odds ratio = 7.0, 95% confidence interval 1.5−32.7). In conclusion, chest CT classified as CO-RADS 5 was an independent predictor of a positive second SARS-CoV-2 RT-PCR, increasing the odds of COVID-19 diagnosis by seven times. Based on our results, in hospitalized patients with a chest CT classified as CO-RADS 5, a second SARS-CoV-2 RT-PCR test should be mandatory when the first one is negative. This approach could increase SARS-CoV-2 detection up to 65% and could allow for isolation and treatment, thus improving the patient outcome and avoiding further contagion.

Atmospheric pollen count in Monterrey, Mexico.

There are few reports of pollen count and identification in Mexico; therefore, it is important to generate more information on the subject. This study was designed to describe the prevalence of pollen in the city of Monterrey, Mexico, during the year 2004. Atmospheric pollen was collected with a Hirst air sampler, with an airflow of 10 L/minute during 2004. Pollen was identified with light microscopy; the average monthly pollen count as well as total was calculated from January 2004 to January 2005. The months with the highest concentration of pollen were February and March (289 and 142 grains/m(3) per day, respectively), and July and November had the lowest concentration (20 and 11 grains/m(3) per day, respectively). Most of the pollen recollected corresponded to tree pollen (72%). Fraxinus spp had the highest concentration during the year (19 grains/m(3) per day; 27.5% of the total concentration of pollen). Tree pollen predominated from January through March; with Fraxinus spp, Morus spp, Celtis spp, Cupressus spp, and Pinus spp as the most important. Weed pollen predominated in May, June, and December and the most frequently identified, were Amaranthaceae/Chenopodiaceae, Ambrosia spp, and Parietaria spp. The highest concentration of grass pollen was reported during the months of May, June, September, October, and December with Gramineae/Poaceae predominating. Tree pollen was the most abundant during the year, with the ash tree having the highest concentration. Weed and grass pollen were perennial with peaks during the year.

Osteomielitis de rótula y artritis séptica de rodilla por Pseudomonas aeruginosa / Pseudomonas aeruginosa-associated osteomyelitis of the patella and septic arthritis of the knee

Introducción. La osteomielitis de rótula es una infección poco frecuente que afecta principalmente a los niños. En la mayoría de los casos la causa es Staphylococcus aureus. El diagnóstico se sospecha si hay dolor e hinchazón perirrotuliano, celulitis, bursitis prerrotuliana (séptica o no), o artritis séptica que no responde al tratamiento estándar. Caso clínico. Paciente diabético tipo 1 de 14 años de edad con dolor e inflamación de la rodilla izquierda por una herida superficial con un objeto metálico punzante sin respuesta a antibióticos orales y antiinflamatorios. Se confirmó infección de articulación y de rótula por gammagrafía y ultrasonido músculo-esquelético, así como por estudio histológico del tejido sinovial obtenido por cirugía. El cultivo reveló Pseudomonas aeruginosa. El tratamiento con ceftazidima seguido de ciprofloxacina fue efectivo con resolución del proceso infeccioso. Conclusión. Se requiere de un alto nivel de sospecha y de un abordaje exhaustivo para el diagnóstico de osteomielitis de rótula, asociado o no a artritis séptica.

Introduction. Osteomyelitis of the patella is an infrequent infection that predominantly affects children. The most frequent microorganism is Staphylococcus aureus. Diagnosis should be considered in patients with pain and swelling around the patella, cellulitis, prepatellar bursitis (septic or not), and in patients with septic arthritis with no response to the standard treatment. Case report. We report the case of a 14-year-old male patient with type 1 diabetes mellitus with pain and swelling of the left knee after being injured with a sharp metallic object. No response was obtained with oral antibiotics and anti-inflammatory drugs. Surgery, gammagraphy, and musculoskeletal ultrasound, together with the histology, confirmed septic arthritis of the knee and osteomyelitis of the patella due to Pseudomonas aeruginosa. Treatment with ceftazidime and subsequent ciprofloxacin resulted in total remission of symptoms. Conclusion. A high level of suspicion and an exhaustive approach are required for definitive diagnosis of osteomyelitis of the patella, associated or not with septic arthritis.