Different epidemic waves are caused by different variants of SARS-CoV-2. The main sources of these variants can cross borders and exist in animal reservoirs, according to one article.
The article published this week on News Medical, an open-access medical and life sciences center, showed that a bell-shaped curve, typical of a seasonal viral respiratory infection, has been observed in Asia. In comparison, the bell curve recorded in Western countries has seen one or two peaks.
Citing a recent study published in the medRxiv preprint server, the article revealed the role of globalization and zoonosis in the emergence and spread of SARS-CoV-2 variants.
The results of the present study indicate that geographically or politically isolated countries only experienced one epidemic episode and therefore only had one bell curve. While in Europe and the United States, several epidemics have occurred successively involving different viral variants.
The study also found that the role of epizootics in animal herds was not taken into account in the generation of new variants of SARS-CoV-2 and their transmission to humans. Mink was found to play a major role in the spread of the pandemic.
Thus, effective border control and regular surveillance of flocks can help reduce the incidence of new variants of SARS-CoV-2 and the emergence of new epidemics, the authors concluded in the article.