With exploding human population, the prevalence of infectious diseases has also increased. Survival has never been easy especially amidst the constant outbreaks of various diseases. Time to time, human population has witnessed onset of deadly infectious diseases that have claimed a significant number of lives. One of the major reasons behind the spread of illnesses has been human and animal interaction. Increasing number of non-vegetarian population has a significant role in the outbreak of most of the pandemics that humans have witnessed until now. A close proximity to animals, poor sanitation and nutrition actually provide breeding grounds for infectious diseases. Even after a huge development in health sector, spread of novel infections creating global pandemic has not ended. The current example is the novel coronavirus that has reportedly claimed lives of over 9000 people worldwide. Here, we tell you about world’s 5 deadly pandemics that took lives of millions of people. Also Read - Coronavirus Crisis: IIT Delhi Makes Their Own Hand Sanitizers After Facing Shortage

Plague of Justinian

Killing half of the world’s human population in 541 CE, plague of Justinian was caused due to a bacterium called Yersinia pestis. It claimed lives of around 30 to 50 million people globally. This deadly bacterial infection was transmitted by infected fleas causing symptoms including swollen lymph, fever, chills, fatigue, muscle ache etc. Plague of Justinian is considered to be the first ever recorded incident of the bubonic plague that afflicted the Byzantine Empire and Mediterranean port cities. Also Read - 'Weak Immune System' Forcing Jack Leach to Lay Low Amid Coronavirus Pandemic

The Black Death

The outbreak occurred between 1346 and 1353. Thought to have originated in Asia, the black death reached Africa and Europe through fleas living on rats via merchant ships. It killed approximately 75 to 200 million people worldwide and ravaged three continents at a time. This is the time when quarantine was exercised for the first time by people and it emerged as the most significant way to contain the disease. Also Read - Coronavirus: US Approves COVID-19 Diagnostic Test That Can Deliver Result in Just 45 Minutes

Third Cholera Pandemic

Lasting from 1852 to 1860, third cholera pandemic was deadly and it washed away around one million human population. It was originated in India and reached Asia, Europe, North America and Africa. Contaminated water was/is the source of transmission of this infectious disease that causes severe diarrhea that can potentially lead to dehydration and even death. Notably, cholera is caused due to a bacterium called Vibrio cholerae.

Flu Pandemic

Occurring between 1918 and 1920, flu pandemic claimed lives of around 20 to 50 million people across the world. Around 5 million people succumbed to this flu in just the first 25 weeks of the pandemic alone. It affected not only children and elderly people but also the young adults.

HIV/AIDS Pandemic

This pandemic was at its peak between 2005 and 2012. HIV/AIDS was first discovered in 1976 in Democratic Republic of the Congo. Since 1981, the disease has killed more than 36 million people worldwide. Majorly a sexually transmitted disease, AIDS occur when human immunodeficiency virus infects a person and interferes with his body’s ability to fight against common infections. The deadly virus can be transmitted through semen, vaginal fluid, and blood too.