Deadliest viruses in history 25th February 2022 – Tags: Virus, viruses

According to Peter Crosta (UoI), “viruses are microscopic organisms that exist almost everywhere on the planet. They can infect animals, plants, fungi and even bacteria…

Humans have witnessed some of the deadliest viral pandemics, with far-reaching consequences. However, vaccines and antiviral drugs have helped to reduce the risk and spread of disease, as well as prevent serious illness and death. Vaccines help the body to safely develop immunity against a disease. There have been outbreaks of diseases that have threatened humanity such as

Influenza virus

Influenza pandemic causes a worldwide outbreak of a new flu that is different from the current or recently circulating human seasonal flu. The 1918 influenza pandemic (Spanish flu) caused by an H1N1 micro-organism of avian origin was the most severe in recent history. It is estimated to have killed more than 50 million people worldwide. In 1957-1958, the Asian influenza caused by the H2N2 virus emerged and triggered a pandemic. The 1968 pandemic was caused by influenza A (H3N2) and was followed by SARS-CoV in 2002 and H1N1 in 2009. Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in 2019, and the current COVID-19 virus in 2020. The viruses have higher case fatality rates in men and in older populations with comorbidities.

HIV/AIDS

Human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS) were discovered in the 1980s. It was first discovered in gay communities in the United States, but is believed to have originated from a microscopic chimpanzee organism from Africa in the 1920s. This microscopic organism has grown to pandemic proportions with more than 65 million infections and 25 million deaths worldwide.

Zika viruses

It is caused by a viruses transmitted by day-biting Aedes mosquitoes. It was first discovered in Uganda in 1947 in monkeys and later in humans in 1952 also in Uganda and Tanzania. During pregnancy, Zika infections cause microcephaly and other birth defects in the developing foetus and newborn. It can also cause foetal loss, stillbirth or premature delivery. It can also trigger Guillain-Barré syndrome, neuropathy and myelitis, especially in adults and older children.

Marburg virus

Marburg disease is very virulent. The disease causes haemorrhagic fever and has a mortality rate of up to 88%. Symptoms include convulsions and haemorrhages of the mucous membranes, skin and organs. It is common in West Africa

Ebola virus

Ebola virus disease is also known as Ebola haemorrhagic fever. It is similar and deadly to Marburg viruses disease. However, the Zaire Ebola viruses is the most deadly, with a mortality rate of up to 90%.

Hantavirus

Hantavirus causes Hantavirus Pulmonary Syndrome (HPS), a severe, sometimes fatal, respiratory disease in humans. Rodents are the main risk of exposure to Hantavirus.

Junin viruses

Junin virus is a major public health problem, especially in Argentina. Junin virus is an endemic rodent-borne zoonosis that has been listed as a biological threat agent. The virus is associated with haemorrhagic fever and people infected with the virus suffer from tissue inflammation, sepsis and skin haemorrhages.

Chromea-Congo Fever virus

This virus is transmitted by ticks and is similar to Ebola and Marburg. Infected persons have pin-sized haemorrhages in the face, mouth and pharynx.

Machupo viruses

Also known as Bolivian haemorrhagic fever. First detected in Bolivia in 1952. A forest rodent is the reservoir host of the Machupo virus. Infections cause high fever accompanied by heavy bleeding.

Kyasanur Forest Virus (KFD)

Kyasanur Forest Virus Disease (KFD) is a tick-borne viral haemorrhagic fever endemic to southwest India. People infected with the virus experience high fever, severe headaches and muscle aches that can lead to haemorrhage.

Dengue

Dengue disease is transmitted by mosquitoes. Infections cause mild flu-like illnesses that can develop into life-threatening complications. The virus is common in tropical and subtropical climates worldwide and in most urban and semi-urban areas.

 

Rotavirus

Rotavirus is a contagious virus that causes severe watery diarrhoea and vomiting in young children and infants. Children infected with rotavirus must be hospitalised and may even die.

Smallpox

Smallpox or variola virus is a contagious and deadly virus that disfigures and affects humans. Patients present with fever and a progressive rash. During the pandemic, most recovered, but about 3 in 10 died from the disease.

Rabies

Rabies is a deadly virus transmitted to humans through the saliva of infected animals. This microscopic organism infects the central nervous system of the infected mammal causing disease in the brain and death.