It had been over a month since Mirabai Nicholson-McKellar was infected with the coronavirus, and the 35-year-old filmmaker thought she was on her way to recovery. Then the shortness of breath came back, followed by chest pains. A visit to the emergency room and a second test for Covid-19 gave another positive result. Just three days earlier, she’d been cleared by health authorities in Australia’s New South Wales state, and was allowed to end her home quarantine after going 72 hours without symptoms. “When is this going to end? I think about that constantly,” she said of the twists and turns in her health. “Am I still contagious? How do I know if I’m not contagious?” Her experience adds to a growing number of reports of patients appearing to have a reactivation of symptoms, testing positive again, or even potentially being reinfected. Such incidents don’t align with the generally accepted understanding of how virus infections work and spread. False Dawn This so-called false-dawn phenomenon is puzzling health experts as they try to come to grips with the mysterious pathogen that emerged only five months ago. Solving the puzzle will inform a broad range of challenges, from the development of an effective vaccine to how soon governments may be able to safely end lockdowns and allow normal life to resume. More immediately, the situation is taking a personal toll, making the journey of recovery a complex and frustrating ordeal for some of the more than 1 million survivors of the pandemic. So far, there hasn’t been enough research to conclude why symptoms seem to re-emerge in some people, and whether they experience reinfection or if the virus persists for weeks. One possibility is that Covid-19 causes blood clots that may cause potentially dangerous complications unless treated with anticoagulant medications, said Edwin J.R. van Beek, chair of clinical radiology at the University of Edinburgh’s Queens Medical Research Institute. Dead Virus South Korean researchers also offered some clues this week when they reported that so-called nucleic acid tests might be positive based on the detection of dead viral particles that could give the false impression that a patient is still infectious when they’re not. “Everyone’s trying to figure this out,” said Yvonne Maldonado, an infectious diseases professor at Stanford Medical School. “What happens when people have been sick and infected -- are we going to consider them immune and, therefore, not susceptible at all? Or are they immune and serve as potential points of infection for other people?” Officials in countries that managed to suppress an initial wave of the pandemic are dreading the possibility that the virus may have a seasonal pattern and could return in the fall and repeat the nightmare scenario. Strained Hospitals Hospitals already strained beyond their limits could see further demand if patients return. It also poses long-term implications for social safety nets and insurers as some struggle with the lingering effects of the coronavirus on their day-to-day life and health. Severe cases that require ventilators and ICU stays would need continued follow-up care as they recover from the ordeal, further pressuring health-care systems. There can also be a growing psychological cost. Governments may try to isolate survivors for longer in fear that they are still infectious, adding more anxiety to patients already suffering from the uncertainty of when they will be deemed healthy again. “A lot of patients will suffer mental health issues,” said Michelle Biehl, a critical-care pulmonary doctor at Cleveland Clinic in Ohio. “They’ll have anxiety, depression, PTSD.” As the number of recovered patients expand, the burden will begin to shift down the medical practice chain, Biehl said. More primary care doctors, mental health specialists and physical therapists will be seeing survivors. “You send them home and what happens then?” asked Maldonado. “From the outpatient side, we’re just starting to get to that point where we’re seeing people in the longer term.” Herd Immunity There’s consensus that so-called herd immunity is key to ending the pandemic, but with a vaccine unlikely to be widely available this year, it will depend on factors such as how long people who’ve recovered have immunity and what percentage of people must be immune to protect the “herd.” There’s “a lot of unknowns and uncertainty in the development of individual immunity,” said Kentaro Iwata, a professor of infectious diseases at Japan’s Kobe University. “Development of antibody inside the body is not necessarily development of immunity against this disease.” The unknowns concerning infectiousness, immunity and lingering symptoms create frustrating dilemmas for patients like Daniela Alves. The London resident paid 200 pounds ($251) for a private test that told her she was positive. Like Nicholson-McKellar, she was never hospitalized but had coughs, shortness of breath and aches that came and went for weeks, never in a straight path toward recuperating, leaving her uncertain of the state of her health. “I don’t know when I’m going to be negative so I can go outside,” she said. “Do I have to pay another 200 pounds so I know I’m safe to others?” Source