Infectiousness, Lethality and Biohazard Levels for 6 viruses

Contagiousness of 6 diseases including Ebola


Hepatitis C virus persists chronically in the liver in about 85% of those infected. This chronic infection can be treated with medication. Overall, 50–80% of people treated are cured. The primary route of transmission in the developed world is intravenous drug use, while in the developing world the main methods are blood transfusions and unsafe medical procedures.  No vaccine is available.

HIV is transmitted primarily via unprotected sexual intercourse, contaminated blood transfusions, hypodermic needles, and from mother to child during pregnancy, delivery, or breastfeeding. Some bodily fluids, such as saliva and tears, do not transmit HIV. There is no cure or vaccine; however, antiretroviral treatment can slow the course of the disease and may lead to a near-normal life expectancy. Without treatment, the average survival time after infection is 9 to 11 years.


Ebola affects humans and other primates that causes an acute illness that is one of the most lethal on the planet. Fruit bats are believed to be a carrier and may spread the virus without being affected. Once human infection occurs, the disease may spread between people, as well. Male survivors may be able to transmit the disease via semen for nearly two months. Symptoms start two days to three weeks after contracting the virus, with a fever, sore throat, muscle pain, and headaches. Typically, vomiting, diarrhea, and rash follow, along with decreased function of the liver and kidneys. Around this time, affected people may begin to bleed both within the body and externally. The virus may be acquired upon contact with blood or bodily fluids of an infected human or other animal. Spreading through the air has not been documented in the natural environment. No specific treatment for the disease is yet available. Depending on the outbreak, lethality has been recorded at between 30% and 70%.

SARS (Severe acute respiratory syndrome) is a viral respiratory disease of zoonotic (animal) origin. Between November 2002 and July 2003, an outbreak of SARS in southern China spread rapidly to other countries, causing 8,273 cases and 775 deaths in multiple countries. As of 2013,  there is no cure or protective vaccine for SARS that is safe for use in humans.


Mumps typically starts with a few days of fever, headache, muscle aches, tiredness, and loss of appetite, and is followed by swelling of salivary glands. Before the routine vaccination program was introduced in the United States, mumps was a common illness in infants, children and young adults. It is now a rare disease in the United States. There is no specific treatment for mumps; most people recover fully, but some (particularly adults) may develop complications as serious as deafness.

Measles is caused by one of the most contagious viruses out there.  In 1980, before widespread vaccination, measles caused an estimated 2.6 million deaths each year globally.  Vaccination programs have resulted in a massive reduction in measles deaths worldwide.  In 2012, there were 122,000 measles deaths globally. Death rate in infected individuals is 1%-3%, but the actual rate varies widely by age, health and quality of medical care.


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