[ ]there is a fact that I feel has been significantly neglected the past few months since the pandemic really gained so much momentum, and that is the emotional impact In the United States, there have been 5,600,107 cases and 174 647 deaths (case fatality rate of 3 12%) 11 I emphasize confirmed because many countries may be underreporting cases and/or deaths 12 Some countries, like North Korea, refuse to even report data to the World Health Organization (WHO) 13 Viral shedding and the period of greatest infectiousness seems to be earlier in the stages of illness, when viral RNA levels in respiratory droplets are highest 14 Is this person asymptomatic (does not have symptoms but is infected and will never develop symptoms), or pre-symptomatic (the phase when an individual is infected and may be shedding virus but hasn't yet developed symptoms), and can one tell the difference? No, since symptoms may show up between 2 to 14 days after exposure, with infectiousness starting about 2 days prior to symptom onset, peaking about 0 7 days before symptom onset, then declines within seven days, but can occur up to 21 days after exposure This is where nucleic acid amplification (NAAT), most commonly with reverse-transcription polymerase chain reaction (RT-PCR) tests can be valuable, since they can detect the viruses about a week before any symptoms even show up 15,16,17 Serological testing (IgA, IgM and IgG) seem to be a more precise diagnostic tool after day 14 of symptom onset, with IgA and IgM titers tending to dissipate after 3 weeks, while IgG confers long-term immunity, approaching 100% seropositivity by 16 to 20 days 18,19 Recently, The Infectious Diseases Society of America (IDSA) released a statement stating that 3 to 4 weeks after exposure, is optimal 20 It should be noted that these are "general" statistics, in that antibody produced with SARS-CoV-2 are predicated upon how seriously ill the individual (i e , less severe disease has been shown to lead to smaller antibody production21) became and underlying immune competence Complications can be seen in the form of respiratory failure, arrhythmias, and thromboembolisms 24 Certain lab values have now been associated with worse outcomes: elevations in D-dimer, ferritin, CRP, lactate dehydrogenase (LDH), creatine phosphokinase (CPK), troponin, as well as lymphopenia and thrombocytopenia 25,26,27 Convalescence appears to be around two weeks for mild infections and three to six weeks for severe disease 28 The most common persistent symptoms were fatigue (53 percent), dyspnea (43 percent), joint pain (27 percent), and chest pain (22 percent) 29 Recovery course is variable and depends on age and pre-existing comorbidities in addition to illness severity
A Pragmatic Approach to Immunity & Respiratory Viral Infections