BackgroundMultidrug-resistant tuberculosis has emerged as a global threat. The aim of this work was to compare the CT findings of primary multidrug-resistant tuberculosis and drug-sensitive tuberculosis in non-AIDS adults.Material and methodsFrom January 2012 to February 2016, 89 patients with primary multidrug-resistant tuberculosis were retrospectively reviewed, and 89 consecutive drug sensitive TB patients with no history of anti-tuberculous chemotherapy from January 2014 to November 2014 were enrolled as control group. All patients were seronegative for HIV. The patients’ demographic data and the locations, frequency and patterns of lung lesions on chest CT were compared.ResultsGender and frequency of diabetes were similar between the two groups. The mean age of primary multidrug-resistant tuberculosis patients was younger than that of drug-sensitive tuberculosis (39.0 vs 47.5, P = 0.005). Lung cavitary nodules or masses were more frequently observed and also showed greater extent in primary multidrug-resistant tuberculosis compared with drug-sensitive tuberculosis. The extent of bronchiectasis was significantly greater in primary multidrug-resistant tuberculosis than in drug-sensitive tuberculosis. Calcification, large nodules and calcified lymph nodes were more frequent in drug-sensitive tuberculosis.ConclusionCharacteristic chest CT findings may help differentiate between primary multi-drug resistant tuberculosis and drug-sensitive tuberculosis in patients without HIV infection.

In the face of the coronavirus disease 2019 (COVID-19), strong and long-lasting immunity is required to protect the host from secondary infections. Recent studies revealed potential inadequacy of antibodies against SARS-CoV-2 in some convalescent patients, raising serious concerns about COVID-19 reinfection. Here, from 273 COVID-19 patients, we identified six reinfections based on clinical, phylogenetic, virological, serological, and epidemiological data. During the second episode, we observed re-emergence of COVID-19 symptoms, new pulmonary lesions on CT images, increased viral load, and secondary humoral immune responses. The interval between the two episodes ranged from 19 to 57 days, indicating COVID-19 reinfections could occur after a short recovery period in convalescent patients. More importantly, reinfection occurred not only in patients with inadequate immunity after the primary infection, but also in patients with measurable levels of neutralizing antibodies. This information will aid the implementation of appropriate public health and social measures to control COVID-19, as well as inform vaccine development.

Highlights The incidence of venous thromboembolism is high among mild/moderate COVID-19 cases. Despite of thrombosis, tests for inflammatory, coagulation and biochemistry parameters were all in normal scope. The conventional method by Doppler ultrasound tend to underestimate the rate of thrombosis in comparisons to CTPA + CTV method.