It is not just the lungs, it affects the heart, kidneys, brain... this is making treatment—and a lasting cure—difficult.
The central government’s new guidelines advising home isolation for Covid-19 patients with ‘very mild symptoms’—as certified by a doctor—will give the healthcare system more room to deal with moderate and severe infections, but it is not clear this is the best way forward since both researchers and doctors do not yet have a complete picture on how SARS-CoV-2 attacks the body. While it is true that risks are different for different populations, incidence of co-morbidities and even vaccine coverage, this could be a reason why different lines of treatment—like HCQ that US president Trump held out as a likely cure—are reported to have worked in some cases and failed in others. Based on global experience, the Indian government asked industry to help dramatically ramp up production of ventilators, but 30,000+ infections later, India has put just 80 patients on ventilators. The post-mortem of many victims, on the other hand, has shown that many died of kidney failure.
An article in New York, a Vox Media owned magazine, talks about how “the clinical shape of the disease (Covid-19), long presumed to be a relatively predictable respiratory infection, is getting less clear…” Indeed, while fever, dry cough, and impaired respiration are nearly universally accepted as symptoms, and the US Centers for Disease Control lists fever as a top symptom, according to a report in The Washington Post, as many as 70% of the Covid-19 patients considered sick enough to be admitted to New York hospitals didn’t have fever. The New York article reports that, in the case of Boston’s Brigham and Women’s Hospital, as few as 44% of Covid-19 patients had fever, while cough was present in 68-83% of the patients, and shortness of breath in 11-40%. Nausea and diarrhoea, at the higher end of the range for this symptom (17%), is just as common as shortness of breath (at the lower end of its range).
An article in Science magazine talks of pathologists and clinicians beginning to realise that though the lungs are “ground zero”, the heart, blood vessels, kidneys, intestines, and even the brain are vulnerable to the virus. Researchers at the Wellcome Sanger Institute and elsewhere have highlighted the role of a cell-surface receptor called ACE-2, which normally helps the body regulate blood pressure, in facilitating the virus’s attack. A paper in JAMA Cardiology talks about how a fifth of the patients in a group of 416 admitted in a Wuhan hospital showed heart damage, while another Wuhan study talks of arrhythmia in 44% of the patients it considered. Another study talks of how blood clotted abnormally in 38% of the 184 Covid-19 patients in a Dutch hospital’s ICU—clots carry a compounded risk as they could get lodged in the brain and cause a stroke, or block vital arteries.
Some patients have also reported low blood oxygen levels without any shortness of breath, which, researchers believe, could be due to the virus possibly altering the balance of hormones regulating blood pressure and causing arterial constriction. As per a pre-print article in medRxiv, 27% of 85 patients hospitalised in Wuhan had kidney failure, while another from the same pre-print server reported incidence as high as 59% among 200 patients.
Covid-19 patients have also exhibited several central nervous system dysfunctions and complications. With viral RNA found in 53% of stool samples indicating an attack on the intestines, as per a study published in the American Journal of Gastroenterology, researchers believe there could be many more signs of the disease, as well as sites of attack in the body. That makes it difficult to judge whether those manifesting ‘mild symptoms’ aren’t masking a deeper onslaught within, or won’t worsen.