While human beings across the globe are caught in the whirlpool of Covid19 pandemic, scientists believe that we are a long way from winning the fight against viruses.
According to scientists, Covid19 has lower fatality rates, but there are more than a dozen other viruses that are even deadlier and can wipe out huge human population.
Scientists have identified Marburg virus in 1967 when lab workers in Germany were exposed to infected monkeys imported from Uganda. Marburg virus cause hemorrhagic fever — high fevers, bleeding throughout the body, and lead to shock, organ failure and death.
The mortality rate was more than 80 percent between 1998 and 2000 outbreak in Congo, as well as in the 2005 outbreak in Angola.
The first known Ebola outbreaks were reported in Sudan and Congo in 1976. Ebola is spread through contact with blood or other body fluids, or tissue from infected people or animals.
For the Bundibugyo strain, the fatality rate is 50 percent, and it is up to 71 percent for the Sudan strain.
Although rabies vaccines for pets were introduced in the 1920s, the condition continues to remain as a serious problem in India and parts of Africa. It destroys the brain. If a patient doesn’t get treatment, there is 100 percent possibility of death.
It is the deadliest virus and is still the biggest killer. An estimated 32 million people have died from HIV since the disease was first recognized in the early 1980s.
The disease continues to devastate many low- and middle-income countries, where 95 percent of new HIV infections occur. Nearly 1 in every 25 adults within the African region is HIV-positive.
In 1980, the World Health Organisation (WHO) declared the world free of smallpox. But before that, humans battled smallpox for thousands of years. It is estimated that 90 percent of the native population of the Americas died from smallpox. In the 20th century alone, smallpox killed 300 million people.
Hantavirus pulmonary syndrome (HPS) first gained wide attention in the US in 1993. The virus is transmitted through the droppings of infected mice. Hantavirus outbreak was reported during the Korean War, more than 3,000 troops were infected, and about 12 percent of them died.
When a new flu strains emerges, a pandemic result, with higher mortality rates. The most deadly flu pandemic has been the Spanish Flu, began in 1918 and sickened up to 40 percent of the world’s population, killing an estimated 50 million people.
Dengue virus first appeared in the 1950s in the Philippines and Thailand. Up to 40 percent of the world’s population now lives in areas where dengue is endemic.
Dengue sickens 50 to 100 million people a year. Although the mortality rate for dengue fever is lower than some other viruses. The virus can cause an Ebola-like disease called dengue hemorrhagic fever, and has a mortality rate of 20 percent if left untreated.
A vaccine for Dengue was approved in 2019 by the US Food and Drug Administration for use in children 9 to16 years where dengue is common and with a confirmed history of virus infection.
The virus causes severe diarrhea illness among babies and young children. The virus can spread rapidly, through what researchers call the fecal-oral route. Although children in the developed world rarely die from rotavirus infection, the disease is a killer in the developing world. More than 453,000 children died from Rotavirus infection in 2008.
The virus that causes severe acute respiratory syndrome, or SARS, first appeared in 2002 in the Guangdong province of southern China. The virus likely emerged in bats and finally infecting humans.
The virus causes fever, chills and body aches, and often progresses to pneumonia, a severe condition in which the lungs become inflamed and fill with pus. It has an estimated mortality rate of 9.6 percent. However, no new cases of SARS have been reported since the early 2000s.
SARS-CoV-2 belongs to the same family of viruses as SARS-CoV, and was first identified in December 2019 in Wuhan in China. The virus likely originated in bats, like SARS-CoV, and passed through an intermediate animal before infecting people.
The disease caused by SARS-CoV-2 is called COVID19. Common symptoms include fever, dry cough and shortness of breath, and the disease can progress to pneumonia in severe cases.
The virus that causes Middle East respiratory syndrome, or MERS, sparked an outbreak in Saudi Arabia in 2012 and another in South Korea in 2015.
The MERS virus belongs to the same family of viruses as SARS-CoV and SARS-CoV-2 and originated in bats. The disease infected camels before passing into humans and triggers fever, coughing and shortness of breath in infected people.
MERS often progresses to severe pneumonia and has an estimated mortality rate between 30 and 40 percent, making it the most lethal of the known coronaviruses that jumped from animals to people.