Abstract

In 2019, a novel virus emerged in Wuhan, China that caused a febrile respiratory illness, sometimes rapidly fatal and thought to be transmitted by droplet contact. It likely originated from another species (possibly the bat), but later, spread occurred from human-to-human. Over a period of months, this disease disseminated to more than 100 nations as a highly infectious pandemic, reminiscent of disease associated with other coronavirus agents in 2002 (SARS) and 2012 (MERS). This COVID-19 virus also caused other forms of clinical illness, albeit in the minority, and most infected patients (over 50%) had few symptoms or remained completely asymptomatic. Prominent in some patients was watery diarrhea, often lasting less than a week, but sometimes without any respiratory features, such as fever, cough or shortness of breath. It is believed that fecal-oral transmission may result. The virus attaches to the surface of human respiratory and intestinal cells, gains entry into these cells, ultimately leading to production of new virions intraluminally. Fecal shedding may occur for extended periods, even after respiratory secretions become negative. Apart from preventive measures, vaccine development remains the most important strategy.