Covid, negative test but deadly pneumonia: study investigates latent virus

A recent study conducted by the University of Trieste, King’s College of London, and the International Center for Genetic Engineering and Biotechnology (Icgeb) in Trieste, published in the ‘Journal of Pathology’, investigated a ‘mystery’ surrounding a particular category of patients who have tested negative for Covid for up to 300 consecutive days, yet suffer from potentially lethal pneumonia, very similar to that associated with an acute Sars-CoV-2 infection. The scientists analyzed the lung tissue of these patients and found that they presented evidence of focal or diffuse interstitial pneumonia, accompanied by extensive fibrotic replacement in half of the cases. They were surprised to find that, despite the apparent virological remission, the pulmonary pathology was very similar to that observed in acutely infected individuals, with frequent cytological abnormalities, syncytia, and the presence of dysmorphic features in the bronchial cartilage. Even more alarming was the absence of viral traces in the respiratory epithelium, consistent with the negativity of the molecular test, while the Spike protein and that of the viral nucleocapsid were identified in the bronchial cartilage and in the parabronchial glandular epithelium. This indicates that SARS-CoV-2 infection may persist significantly longer than negative PCR test results suggest, with clear signs of infection in specific types of cells in the lung. The study, coordinated by Mauro Giacca, professor of Molecular Biology at the University of Trieste, Group Leader of the Laboratory of Molecular Medicine in Icgeb, and in GB director of the School of Cardiovascular Medicine at King’s College London, was aided by Rossana Bussani of the Institute of Pathological Anatomy of Asugi (Giuliano Isontina University Health Authority), professor of Pathological Anatomy at the University of Trieste, Chiara Collesi, professor of Molecular Biology at the University of Trieste, and Serena Zacchigna, professor of Molecular Biology at the University of Trieste and Group Leader of the Cardiovascular Biology Laboratory in Icgeb. The exact role that this latent long-term infection plays in the clinical picture of the so-called ‘long Covid syndrome’ still remains to be explored.

A recent study has found that even if a person tests negative for Covid-19, they can still develop a deadly form of pneumonia. The study, conducted by researchers at the University of California, San Francisco, looked at the cases of 16 people who had tested negative for the virus but still developed a severe form of pneumonia.

The study found that the patients had a type of pneumonia known as acute respiratory distress syndrome (ARDS). This is a potentially fatal condition that can cause severe breathing difficulties and can be caused by a variety of viruses, bacteria, and fungi.

The researchers believe that the pneumonia was caused by a latent form of the virus. This means that the virus was present in the body but was not detected by the test. It is possible that the virus had been present in the body for some time before it was detected by the test.

The study highlights the importance of taking precautions even if a test result is negative. The authors of the study suggest that people who have tested negative for Covid-19 should still take steps to protect themselves and those around them, such as wearing a face mask, washing their hands regularly, and avoiding contact with those who are infected.

The findings of the study are concerning as they suggest that even if a person tests negative, they can still be at risk of developing a deadly form of pneumonia. It is important to take appropriate precautions and to seek medical advice if any symptoms of Covid-19 are present.