Kerala is on high alert over the Nipah virus infection. Dead bats found in a well in the family's home are believed to have caused the infection. Until now, 10 Nipah deaths have been confirmed in the state and two are in critical state.
The disease has potentially lethal effects but it is not the only one to emerge to the surface in this age. Here's a list of some of the deadliest viruses that put the world on the edge in the 21st century.
1. Ebola: caused by Ebola virus (Hemorrhagic fever)
Ebola virus disease (EVD) or better known as Ebola is a rare but deadly virus that causes fever, body aches, diarrhoea and sometimes bleeding inside/outside the body.
It first emerged in 1976 with two simultaneous outbreaks in Africa. The first outbreak happened in Nzara in Sudan and the other in Yambuku in Republic of Congo (Zaire). The virus takes its name from Ebola river.
According to the WHO, the fruit bats of the Pteropodidae family are natural Ebola virus hosts. Ebola is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.
Ebola then spreads through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.
2. Marburg virus (Hemorrhagic fever)
First noticed in the 1960s, Marburg virus is very much like the Ebola. The site of its outbreak was the German cities of Marburg and Frankfurt. It was between 1998 and 2000 when the first signs of its fatal nature came to the surface.
Of the 154 cases reported in two locales of the Democratic Republic of Congo, Durba and Watsa, 128 resulted in deaths. In 2004, a Marburg virus took 227 lives from the 252 reported cases.
Transmission of these viruses occurs by direct contact with infected body fluids from animals and humans, such as blood, saliva, vomitus, respiratory droplets, urine and stool, and contact with virus-contaminated objects (e.g., needles, syringes).
Persons who prepare, cook, and eat contaminated animals may become infected. Person-to-person transmission occurs, as does infection from direct inoculation. Transmission via semen may occur weeks after recovery
3. Swine Flu: caused by the H1N1 virus
WHO declared its first ever Public Health Emergency of International Concern for the H1N1 virus in April 2009. About 284,500 people were reported to have been killed by the epidemic while the actual number may be much higher.
The virus has its origins in an influenza pandemic (also known as the Spanish Flu) in 1918-1919. Researchers once hailed the pandemic as the mother of all pandemics.
As per a report of Science Daily, about 500 million people (nearly a third of the world's population back then) were infected, with total deaths estimated at approximately 50 million and were arguably as high as 100 million.
Though the virus itself was a human influenza virus, researchers found that the virus, causing the pandemic was able to infect and replicate in pigs but did not kill them.
4. SARS: caused by the SARS coronavirus
Severe Acute Respiratory Disease (SARS), caused by the SARS coronavirus, came to light in November 2002. The first case was reported in Chinas Guangdong province and it spread to nearly 37 countries within weeks.
According to WHO, as of July 2003, there were 8,096 reported cases of SARS, with 774 confirmed deaths, most of them coming in China (349), and Hong Kong (299).
Effects of this outbreak included uncertainties and fear that, in some cases, resulted in debates and policies against students returning to their U.S. universities from Asia after spring break, and travel restrictions to Hong Kong, parts of China (such as Beijing), Toronto, Canada, and Taiwan. Restrictions had political and economic consequences.
5. Avian Flu: caused by H5N1 virus
Centres for Disease Control and Prevention classified the Avian flu as a highly pathogenic avian flu virus. In 1997, several outbreaks of highly pathogenic H5N1 were reported in poultry at farms and live animal markets in Hong Kong.
One of the worst impacts of these outbreaks has been in economic terms, leading to the closure of many a poultry farm in these countries, hitting poultry exports and international trade severely.
It was also during this time that human got affected with the virus. A total of 18 people were reported to have contracted the virus, of which six died. The virus re-emerged in 2003 when several cases in Asian countries like China and South Korea came to light.
According to WHO, as of July 2014, 667 cases of humans infected with H5N1 have been reported which caused deaths of 393 people.
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