Many diseases have high mortality rates. The true answer depends upon the geographic location you are concerned with. In many underdeveloped countries infectious gastroenteritis due to water born or food born microorganisms cause a very high death rate. In more developed countries diseases like cancer, heart disease, and diabetes have very high death rates. In the United States cardiovascular disease has always ranked high on the list of culprits. Some authorities attribute this fact to our nutrition and lifestyle habits.
HIV AIDS is one of the most dangerous diseases for humans. It does not have its causes or symptoms but it simply pave the way for more diseases. We know that white blood corpuscle is like the soldier, they stop diseases causing microbe into the body. But AIDS but disables and kills WBC in our body because of this many diseases starts entering the body continueously and attack the body and affect it seriously . Since due to the death of WBCs their is no one to kill them. The ultimate result is the death of the victim not due to AIDs but through other microbes
The most deadly infectious disease in history was the pneumonic form of the plague, the so-called Black Death of 1347 to 1351. The pneumonic plague, which was a bacterial lung infection, had a mortality (death) rate of 100 percent.
Today, the disease with the highest mortality rate in humans (almost 100 percent) is rabies. A person who contracts rabies from being bitten by a rabid animal develops an inability to swallow water. With immediate attention, the rabies virus, introduced by a bite, can be prevented from invading the human nervous system. The survival rate in this circumstance is 95 percent.
The high-mortality disease receiving the most attention today is AIDS (acquired immunodeficiency syndrome). First reported in 1981, AIDS is caused when a person is infected with HIV (human immunodeficiency virus). HIV works by seriously weakening the victim's immune system, leaving the body unequipped to fight off a wide range of illnesses.
In 1993, HIV infection became the most common cause of death among persons aged 25 to 44 years. In 1994, an estimated 41,930 U.S. residents died from HIV infection, based on information recorded from death certificates; this number may have actually been as high as 60,000.
Sources: The Guinness Book of Records 1996, p. 17; MMWR: Morbidity and Mortality vol. 45, no. 6 (February 1996), pp. 121-23.