The emergence of viral diseases has become one of the major concern in public health, and the factors behind their occurrence have been analyzed extensively by various scientists. Virologic and environmental factors are responsible for the emergence and re-emergence of viral diseases (Ennaji, 2019). The nature of viruses does not allow them to exist in a permanent environment conservatively. Somewhat due to their ability to change, they keep on mutating and adapting to different ecological niche depending on their level of fitness. Viruses have the potential of mutating and parasitizing alternative host only to occur as a new form of viral infection after a while. The molecular combination of events that occur as a result of mutation, genome segment assortment and recombination give birth to a complex and phenotypically differentiating class of viruses. Many emerging infections affecting the human population are of the zoonotic origin. The sociological and ecological factors provide a good condition for the mutation and survival of viruses causing infectiuos diseases. Majority of the scientist have cited genetic variation as the major cause of viral disease emergence. The scientist has also described the interspecies transmission as the leading factor behind viral traffic. The emergence and re-emergence of viral diseases can be considered as the occurrence of virus adaptation to the new ecological niche. The adjustment of the virus can be identified in its replicative fitness which is the ability of the virus to produce infectious progeny in a specific environment. Most of the RNA viruses can mutate and occupying an alternative host for their survival and existence. These are the factors that have led to the periodical occurrences of new viral infections.
The influenza virus, commonly known as the flue, is a perfect example of viral diseases that has ever affected the human population. The virus emerged in 1918, and it became one of the most severe global pandemics in history. The disease was caused by the H1N1 virus that had genes of avian origin. However, the origin of the disease could not be traced to any specific place though it spread globally between 1918 and 1919. The United States of America was one of the most affected countries as the disease claimed the lives of many people compared to other countries. The first infection in America was identified in a military soldier in 1918. The virus infected an estimated population of 500 million people globally and claimed lives of over 50 million people worldwide with the U.S. registering about 675,000 deaths. The mortality rate caused by the influenza virus was high among the young population. It claimed the lives of healthy young people who existed in the age bracket of 20-40 years. The properties of the virus that made it devastating were not identified.
The influenza virus become a deadly virus globally due to lack of vaccines or alternative antibiotic to help in dealing with it (Sutton, et al., 2017) Human population was forced to take non-pharmaceutical interventions that included quarantine, isolation, and proper personal hygiene, restriction of public gathering and use of disinfectants. However, the genome and the sequence of the virus was later identified and reconstructed by a group of researchers and virus hunters from Mount Sinai School of Medicine. The virus was reconstructed in a safe, highly regulated CDC laboratory for study and future preparation. The virus also had a socio-economic impact on the lives of people globally (Ojo, 2020). All the business come into a standstill since isolation was used as one of the preventive measures. Different countries were also forced to use a lot of resources in fighting the spread of the disease. In some cases, the employed population received a pay cut of their salary while others were laid off. Socially people were forced to separate from each other for a specific period of time, while others also lost their love ones to the pandemic.