|Animal viruses cause various types of infection. In lytic infections, the virus will break open or lyse the host cell, resulting in the destruction of the host cell. Other viruses may cause persistent infections. In this type of infection, the virus may go dormant and be reactivated at a later time. The host cell may or may not be destroyed. Some viruses can cause persistent infection in different organs and tissues at the same time. Latent infections are a type of persistent infection in which the appearance of disease symptoms does not happen immediately, but follows after a period of time. The virus responsible for the latent infection is reactivated at some later point, usually prompted by some type of event such as infection of the host by another virus or physiological changes in the host. HIV, Human Herpes viruses 6 and 7, and the Epstein-Barr Virus are examples of persistent virus infections that are associated with the immune system. Oncogenic viral infections cause changes in host cells, turning them into tumour cells. Journal impact factor is an index or a criteria devised by Eugene Garfield to categorize journals based on their citations. Impact factor is considered as a putative marker to indicate the journal quality. But the recent policies being adopted to improve the impact factor is becoming a topic of controversies today. This current scenario questions the reliability of impact factor. The citation index cannot be considered to determine the scientific quality of an article because the technicalities are not considering the scientific quality. Knowing or reading an article is not enough to determine their quality validating the content and approving the findings and revalidating the facts is vital in scientific research. It is highly impossible to do a scholar check in each and every article to detect fraudulent or unsubstantial citations.