An epidemic occurs when an infectious disease spreads rapidly to many people. Here’s a list of diseases responsible for taking millions of lives around the world.
It existed for thousands of years. It is highly infectious disease which mainly targets young children. The virus is transmitted from person to person by fecal oral route and spreads by contaminated water and targets human nervous system that usually cause irreversible paralysis in legs . Symptoms of polio include headache, fever, fatigue, stiffness in the neck, vomiting and most visibly pain in the limbs. In 1952 polio outbreak occurred in united states and around 57628 cases were reported throughout the nation.Though there is no cure for polio but it can be prevented through immunization by giving polio drops multiple times.
It stands for Acquired immune deficiency syndrome. Its is caused by a virus called HIV (human immunodeficiency virus). The illness alters the immune system making people much more vulnerable to infections and diseases. HIV is passed from one person to another through blood to blood and sexual contact. An infected pregnant woman can pass HIV to their babies during pregnancy, delivery and breast feeding.The development of numerous opportunistic infections in an AIDS patient can ultimately lead to death. AIDS spread widely throughout the world in 1980”s and has taken lives of more than 25 million people. There is still no cure for AIDS. Only awareness and prevention can stop AIDS from spreading further.
Basically caused by species of plasmodium microbes common to 2 species mosquito and human. When infected mosquitos feed on human blood , they pass on the microbes. These microbes destroy Red blood cells. The symptoms usually begin 10 to 15 days after being bitten. The symptoms include fever, fatigue, vomiting and headaches. In severe cases it can cause yellow skin, coma or death.This disease appeared in South America from 1600 to 1650. It is one of the longest surviving threats as the disease first occurred 400 years back and still people suffer from this disease like in Africa where 350 to 500 million cases of malaria occur each year. Malaria became epidemic and was spread to many countries in world war I and II killing over a 100 thousand American soldiers. The risk of disease can be reduced by preventing mosquito bites by using mosquito nets and insect repellants or by spraying insectides and draining standing water.
This disease moved from India to other parts of the world in 19th century. The largest cholera outbreak happened in Haiti in 2010 killing more than 8000 people. It is an acute diarrhoea infection caused by intake of food or water contaminated by bacteria vibrio cholerae. The short incubation period of 2hrs to 5 days enhance the potentially explosive pattern of outbreaks.The transmission of cholera is related to inadequate environmental management. People living in rural area where minimum requirement of clean water and sanitation are not met are at very high risk of this disease. Symptoms include dehydration which in turn is marked by low blood pressure, thirst, muscle cramp, dry mucus membrane, rapid heart rate and loss of skin elasticity.
Smallpox epidemic occurred in 1500. It caused death of nearly 90 million native Americans where as it killed around 4 hundred thousnad Europeans per year at the end of 18th century though a vaccine was invented in 1796.Not only that the disease persists as in late 1960’s 2 million people died worldwide due to smallpox. After vaccination campaigns through 19th and 20th centuries WHO certified the eradication of smallpox in 1979. Smallpox is a contagious deadly disease that has affected humans for thousands of years. The symptoms of smallpox appear 12 to 14 days of getting infected. The Symptoms include fever, overall discomfort, headache, severe fatigue, severe back pain and possibly vomiting. After few days flat red spots appear first on face, hands, and forearms and then on the whole body. Within a day or two these turn into small blisters filled with clear fluid and turn into pus. Scabs begin to form 8/9 days later and fall leaving pitted scars.
It is an acute viral disease also known as yellow jack, yellow plague or bronze john. The symptoms include fever, loss of apetite, chills, nausea, muscle pain in back and headaches.symptoms improve within 5 days. In some people within a day of improving fever comes back abdominal pain occurs and liver is damaged causing yellow skin. The disease is caused by mosquitoes carrying yellow fever virus. Yellow fever caused 2 lakh infections and 30000 deaths every year with 90% occurring in Africa alone. Vaccination against yellow fever is available. During Nepoleon’s regime yellow fever took away lives of millions of people. The yellow fever epidemic occurred in 1793in the united states when over 4000 people died in 4 months.
The Black Death
Also known as Bubonic Plague. It is considered to be 1st true pandemic on earth. It cut population in half through parts of the world like Asia, Europe in the 14th century. Symptoms of Black Death includes swollen Lymph glands, fever, cough, bloody sputum and difficulty in breathing. 200 plus million deaths occurred due to black death in Europe Asia and middle east. Some scientists have considered the black death as hemorrhagic virus similar to EBOLA.
Influenza epidemic of 1918 or commonly known as spanish flu disease caused as many as 100 million plus death worldwide between 1918 to 1920. After world war I a new illness emerged called Spanish flu or flu of 1918. It wasn’t the typical influenza virus we encountered every year. This was a new strain of microbe the H1N1 Avian Influenza, a virus which moved from birds to humans in America Midwest. It got its name as Spanish flu as it killed 8 million people in Spain itself. The virus got spread to other continents with the massive troop transport and the supply lines at the close of world war I. Influenza symptoms include fever, fatigue, muscle and joint pain, headache and lack of appetite.
Tuberculosis is a bilateral infection that can spread through the lymph nodes and bloodstream to any organ in your body. Tuberculosis bacteria causes death of tissue in the organ they infect. If left untreated TB bacteria can be fatal. Tuberculosis can be contagious as the bacteria are transmitted through air. TB has been wreaking havoc on humanity for thousands of years. In the 19th century TB killed as much as one quarter of the adult population of Europe. In 1918 one in six deaths in France were caused by TB. TB has been around and is responsible for death of 2 million people out of 8 million affected every year. Symptoms of TB include internal weakness, chest pain, night sweats and terrible fits of coughing.
Camp Fever also known as Epidemic typhus got spread in 1600’s. It spread throughout Europe during war in 1600 and claimed 100 million plus deaths and again in World War I, it caused several million deaths in Russia, Poland and Romania. The symptoms include headache, high fever, chills and rash. It is caused by rickettsiae bacteria which is transmitted by arthropods like flea, mite, ticks bites. It is not transmitted from person to person. Prevention of Typhus is easier than treatment as prevention focuses on destroying arthropod infestation. Antibiotics are used to treat Typhus.
Severe Acute Respiratory Syndrome is what SARS stands for. It is a viral respiratory illness caused by a corona virus called SARS associated corona-virus. It was first reported in Asia in 2003.The disease spread to more than 20 countries in North America, South America, Europe and Asia. Between November 2002 and July 2003 an outbreak of SARS in southern China caused 8096 cases and 774 deaths. Within weeks SARS spread from Hongkong to 37 countries. Symptoms of SARS include flu like, fever, myalgia, lethargy, cough, sore throat and other non specific symptoms.
Ebola epidemic is the largest in history affecting multiple countries in west Africa with over 4500 deaths. Ebola virus disease (EVD) also known as Ebola hemorrhagic fever is a severe often fatal illness in humans. The virus is transmitted to people from animals and spread in the human population through human to human transmission.EVD first appeared in 1976 in Nzara, Sudan and the other Yambuku, Democratic Republic of Congo in a village near the Ebola river. The current outbreak in west Africa in march 2014 is the largest and most complex Ebola outbreak since the first outbreak. The symptoms of Ebola appear between 2 to 21 days of Ebola virus invading the human body. The symptoms include sudden onset of fever, fatigue, muscle pain, headache and sore throat followed by vomiting, diarrhea, rash, symptoms of impaired kidney and liver functions and in some cases internal and external bleeding. There is as yet no proven treatment available for EVD. However a range of potential treatment including blood products, immune therapies , drug therapies are currently being evaluated. No liscensed vaccines are available yet but 2 potential vaccines are undergoing human safety.
Swine flu is a respiratory disease caused by influenza virus that infect the respiratory tract of pigs. The symptoms include fever, nasal secretions fatigue and headache. Swine flu is transmitted from person to person by inhalation or injection of droplets containing from people sneezing or coughing. The human respiratory infection caused by particular influenza virus H1N1 strain was first recognized in spring 2009.The pandemic was declared in August 2010. Two antiviral agents Relenza and Tamiflu have been reported to help prevent or reduce the effects of swine flu if taken within 48 hours of onset of symptoms.