STERN SAID that all of the coronavirus in the country originated from abroad. In the beginning, this included many cases that entered Israel via Europe and Southeast Asia. However, “they did not spread so much: They quarantined early – and very effectively.” To reach this conclusion, Stern and a team of other researchers mapped the spread of the virus into and within Israel by decoding the genomic sequence of the coronavirus strain in Israel. A release explained that the scientists harnessed their genomic map to pinpoint mutations indicating from where the virus originated within Israel – and later, to where it spread. “The novel coronavirus is characterized by mutations that occur at a set pace,” she explained. “These mutations do not affect the virus,” but they “can help us trace the chain of infection from country to country. After the pandemic broke out in Wuhan, for example, one or two mutations occurred, and one virus with a mutation may have migrated to Europe where it experienced additional mutations, and from there it traveled to the United States, and so on. “We can look at these mutations as a kind of bar code that helps us keep track of the progression and transformation of the coronavirus as it moves from country to country,” she continued. The researchers compared the genomic sequences of local patients to some 4,700 genomic sequences taken from patients around the world. Until now, any assessment of the spread of infection relied on such subjective parameters as patient feedback.
Moreover, the study showed that “super-spreaders” were responsible for most of the coronavirus cases in Israel – around 80% of cases were infected by only between 1% and 10% of patients, or at “super-spreading events, such as large parties or other social gatherings.” Stern believes that no more than 1% of the Israeli population contracted the virus – “a far cry from herd immunity.” Data from the novel statistical model may be used to reveal the rate of infection in specific locations, including homes, apartment buildings, schools or even neighborhoods, and could also help inform closure and quarantine policies in the future. “This technology and the information it provides is of great importance for understanding the virus and its spread in the population, as a scientific and objective basis for local and national decision-making,” Stern said. “Going forward, the data obtained from genomic sequencing will serve as an important basis for informed decisions about which institutions to close, for what amount of time, and in which format.” She said that closing borders and social distancing are two obvious and very important measures that would need to be implemented in any future spike. However, “we have developed tools that will allow us to cope, in real time, with the next outbreak that may occur.” The study will be published in medRxiv.org. Stern’s team partnered with scientists at Emory University; Gertner Institute; Sheba Medical Center; the Holon Institute of Technology; Samson Assuta Ashdod University Hospital; Hadassah Medical Center, Ein Kerem; Soroka Medical Center; Barzilai Medical Center; Baruch Padeh Medical Center; and the Genome Center at the Technion Institute of Technology.