The case of SARS It came seemingly out of nowhere: In the winter of 2002/2003, more and more people in Asia suddenly fell ill with a mysterious, new type of pneumonia. They developed high fevers, coughs, shortness of breath and their lungs were severely inflamed. As it turned out, no antibiotic helped against the highly contagious infection, and medical experts were also unable to find common pathogens. Not a few patients died.
From China to the whole world
While doctors were still puzzling over this strangely atypical pneumonia, the new disease continued to spread: Within weeks, the number of cases rose first in southern China, then in the rest of the country, Hong Kong and other countries in East Asia. People hardly dared to go out on the streets for fear of infection, and the Hong Kong metro remained deserted even during rush hour.
The world first became aware of the epidemic in February 2003, when a U.S. citizen and a Canadian woman contracted the disease in Asia and died from the infection. By this time, however, thousands in Asia had already fallen ill with the unknown disease and a good 500 had died from it. In the meantime, there were also new cases in Europe. North America – the infection had become a pandemic. Now the World Health Organization (WHO) has also reacted: it triggered a worldwide pandemic alert at the beginning of March. Christened the new disease "Severe Acute Respiratory Syndrome" – SARS. Teams of disease experts traveled to Asia to coordinate quarantine measures and search for the cause of SARS.
From bats to humans
A short time later, the pathogen was found: It was a coronavirus that had never before been detected in humans. From genetic analysis, researchers concluded that the virus originally came from bats found in China. From them, it was transmitted via feces or saliva to wild creeping cats, which in turn were caught, traded in markets, and consumed by people in southern China.
The SARS virus has managed to cross the species barrier from animals to humans – and is now rampant in a host species that is in no way armed against this new pathogen. Although the pandemic was contained after a few months by rigorous quarantine measures, by then more than 8.000 people fell ill and a good 700 died. There is no vaccine or cure for SARS to date.
Map of the areas affected by the SARS epidemic in the period 01.11.2002 – 07.08.Countries affected in 2003. Black: states with confirmed deaths, red: states with confirmed infections © Maximilian Dorrbecker/ CC-by-sa 4.0
"Dramatic case study"
"SARS dramatically demonstrates the devastating global consequences that an emerging infectious disease can cause," WHO stated in a 2003 report. To this day, SARS is considered the first pandemic of the 21st century. A disease of the twenty-first century – and as a classic example of an emerging disease. This term is used by physicians to describe infectious diseases that have never been seen before in humans or that suddenly penetrate completely new areas.