Viral Pandemics in the Past Two Decades

Abstract

An epidemic that occurs worldwide, involving many countries and affecting a large population is called as a pandemic. The ongoing corona virus disease (COVID-19) pandemic has not only adversely affected the global healthcare infrastructure, but has significantly impacted world economy, socio-political and cultural environment. There are 219 different types of viruses, known at present to be able to infect human beings. This number is just a tip of the iceberg, with the possibility of a substantial pool of undiscovered human viruses and millions of other virus species (which affect plants and non-human animals) that can be potentially infectious to humans as well. Throughout human history there have been numerous pandemics and disease outbreaks that have not only led to huge loss of life, but also hindered economic growth and development. Therefore, in this review article we wanted to highlight major viral pandemics that have occurred in the last two decades, to understand factors contributing to their emergence, transmission and suggest ways to curb future outbreaks.

Ocular manifestations of recent viral pandemics: A literature review

“…Zika and MRES viruses can be transmitted through ocular secretions, especially conjunctival secretions (89,113). Influenza A viruses can replicate in the conjunctiva of infected people, which could be its route of access to the respiratory mucosa (79). In COVID-19, the eye is suspected to be a potential route of transmission (50).…”

“…H1N1 could replicate in the human conjunctiva, making the ocular surface an important route of infection. In addition, the virus was also isolated from other ocular tissues like cornea, trabecular meshwork, and RPE cells (79). It nearly affects all eye parts starting with the conjunctiva causing direct conjunctival invasion by the influenza virus and presents most commonly as bilateral acute conjunctivitis in 58 cases (65%).…”

“…Acute conjunctivitis was linked to significant eyelid edema, conjunctival hyperemia, watery discharge, and moderate chemosis. As to the cornea, 18 cases presented with bilateral multiple corneal erosions that subsided by the 7th day of the illness (79).…”

Applicability and Psychometric Comparison of the General-Population Viral Anxiety Rating Scales among Healthcare Workers in the COVID-19 Pandemic

“…Until the early 2000s, with the development of vaccines and communicable diseases control, concerns about viral diseases decreased [ 1 ]. However, new viral infections such as the Ebola virus epidemic in 2014 and the MERS virus epidemic in 2015 [ 2 ] started to appear. In December 2019, an outbreak of COVID-19 in Wuhan, China, swept the world, with 572,239,451 confirmed cases and 6,390,401 deaths recorded as of 29 July 2022 [ 3 ].…”

Viral pandemics do not follow Newtonian laws of linear motion

“…Bhadoria et al . [ 1 ] publish their overview of viral pandemics in the last two decades in August 2021 issue of the Journal. They chronicle important pandemics of 21 st century, recollect their important milestones, compile lessons learnt, and suggest ways to prevent emergence of newer ones in future.…”