Coronaviruses are a large family of viruses that cause respiratory illnesses. Because nCoV is so new, many unknowns remain about the virus, including exactly how easily it spreads, how deadly it is and whether it will cause a global pandemic.
The World Health Organization has declared the nCoV outbreak a "public health emergency of international concern," but has not yet declared it a pandemic. Studies suggest nCoV likely originated in bats, but made it's "jump" to people through a yet-to-be-identified animal, which acted as a bridge between bats and humans. Scientists think that smallpox , which causes skin lesions, emerged about 3, years ago in India or Egypt, before sweeping across the globe.
The Variola virus, which causes smallpox, killed as many as a third of those it infected and left others scarred and blinded, according to the World Health Organization. A photo taken in shows the village cemetery in the Bangladesh countryside where smallpox victims were buried.
The disease is believed to have killed 46 percent of its victims at a hospital in the Dacca, Bangladesh, ravaging the country for centuries. In , the WHO declared the disease officially eradicated, after a decade-long vaccination campaign.
The last remaining samples of the virus are being held in facilities in the United States and Russia. Unlike smallpox, this ancient killer is still with us. Caused by a bacterium carried by fleas, plague has been blamed for decimating societies including 14th-century Europe during the Black Death , when it wiped out roughly a third of the population, including in Basel, Switzerland, depicted in this painting from The disease comes in three forms, but the best known is bubonic plague, which is marked by buboes, or painfully swollen lymph nodes.
Although it is preventable and curable, malaria has devastated parts of Africa, where the disease accounts for 20 percent of all childhood deaths, according to the World Health Organization. It is present on other continents as well. A parasite carried by blood-sucking mosquitoes causes the disease, which is first characterized by fever, chills and flu-like symptoms before progressing on to more serious complications.
By , the disease was eliminated from the U. A subsequent WHO campaign to eradicate malaria was successful only in some places, and the goal was downgraded to reducing transmission of disease, according to the U. Centers for Disease Control and Prevention. The WHO has distributed so-called long-lasting insecticidal nets in order to reduce bites from malaria-carrying mosquitoes, including in Cambodia shown in image. A seasonal, respiratory infection, flu is responsible for about 3 million to 5 million cases of severe illness, and about , to , deaths a year across the globe, according to the World Health Organization.
Periodically, however, the viral infection becomes much more devastating: A pandemic in killed about 50 million people worldwide. As became apparent from "swine flu" and "bird flu" scares in recent years, some influenza viruses can jump between species. Potentially fatal, tuberculosis or "TB" is caused by the bacterium Mycobacterium tuberculosis , which usually attacks the lungs and causes the signature bloody coughs.
In patients suffering from an advanced stage of TB, you can see the effects in a lung X-ray shown in image. The bacterium does not make everyone it infects sick, and up to one-third of the world's population currently carries the bacterium without showing symptoms. At the end of , about While many of the worst offenders on this disease list have a long-standing relationship with humans, HIV is a recent arrival.
HIV's decimating effect on certain immune system cells was first documented in By destroying part of the immune system , HIV leaves its victims vulnerable to all sorts of opportunistic diseases. Cholera causes acute diarrhea that if left untreated can kill within hours.
People catch the disease by eating or drinking substances containing the bacterium Vibrio cholerae. The bacteria tend to contaminate food and water through infected feces. Since it can take 12 hours to 5 days to show symptoms, people can unwittingly spread the disease through their feces.
Thanks to improved sanitation, cases of cholera have been rare in industrialized nations for the last years, but worldwide it kills between 21, and , individuals every year, the WHO estimates. During the 19th century, however, cholera spread from its home in India, causing six pandemics that killed millions of people on all continents, according to the World Health Organization.
During a cholera epidemic in Peru in , a hospital waiting room shown in image was converted to an emergency cholera ward. More recently, a cholera outbreak in Haiti, which began after that country's devastating earthquake, had sickened more than people and killed nearly 9,, according to a report published in in The Journal of Infectious Diseases.
No longer a significant threat in the United States, rabies is still a deadly problem in other areas of the world. Rabies causes "tens of thousands" of deaths every year in countries in Africa and Asia, according to the WHO. Approximately two people die yearly in the U. The initial symptoms of rabies can be hard to detect in humans, as they mimic that of the flu and include general weakness, discomfort and fever. But as the disease progresses, patients may experience delirium, abnormal behavior, hallucinations and insomnia, according to the Centers for Disease Control and Prevention CDC.
To date, fewer than 10 people who have contracted rabies and started to exhibit symptoms have survived. However, a rabies vaccine does exist and is usually very effective in both preventing infection with the virus and treating infected individuals before they begin to show symptoms. Pneumonia might not conjure up the same dread as diseases like rabies or smallpox, but this lung infection can be deadly, especially for those older than 65 or younger than 5. The disease can be caused by bacteria, a virus or a combination of both, according to Dr.
A person can also get pneumonia from a fungal infection, parasites or reactions to certain medicines, Adalja told Live Science in September Rotavirus, the most common cause of viral gastroenteritis inflammation of the stomach and intestines , is a diarrheal disease that can be deadly. In , rotavirus killed , children under the age of 5 globally, according to the WHO. About 22 percent of those deaths occurred in India alone; and overall most of the deaths occur in children living in low-income countries.
The virus causes dehydration, brought upon by severe, watery diarrhea and vomiting. There are four rotavirus vaccines that are considered highly effective at preventing the disease, the WHO says.
Though rare, Ebola virus disease EVD is an often fatal infection caused by one of the five strains of the Ebola virus. The virus spreads very rapidly, overcoming the body's immune response and causing fever, muscle pain, headaches, weakness, diarrhea, vomiting and abdominal pain. Nearly 60, children were infected and more than 3, died. Three years later vaccination began to prevent the communicable disease.
That same year the deadly disease killed more than 5, people in the United States. Today more than 35 million people around the world are living with an HIV infection.
More than 25 million people have died of AIDS since the first cases were reported. By July more than 8, cases and deaths had been reported. The global H1N1 flu pandemic may have killed as many as , people, though only 18, deaths were confirmed. The H1N1 virus is a type of swine flu, which is a respiratory disease of pigs caused by the type A influenza virus. An epidemic of cholera killed at least 10, people in Haiti in following a deadly earthquake that paralyzed the nation.
The outbreak hampered efforts to rebuild. The United Nations would later apologize for initially denying claims that Nepalese peacekeepers brought the deadly disease to the country following the earthquake. In , approximately , people worldwide died from the measles, a highly contagious disease caused by a virus. Typhoid fever kills around , people a year. Tuberculosis, an infectious bacterial disease, killed an estimated 1.
These are some of the infectious diseases that most concern health officials today. Parks like this one were closed to prevent further infection.
This tick-borne bacterial disease is not limited to the Rocky Mountains; it occurs in many states and most commonly reported in North Carolina, Tennessee, Missouri, Arkansas and Oklahoma. Symptoms include fever, body aches and a spotted rash. Adults rarely die from this mosquito-transmitted disease. There have been no reported mosquito-born cases of Zika in the United States since That year, seven people were infected by mosquitoes in the U.
In the 14th and 15th centuries, around half of Europe's population was wiped out by this contagious bacterial infection. While modern medicine has driven the plague's mortality rate down significantly, outbreaks of plague still happen. In , the World Health Organization warned of an outbreak in Madagascar.
In the 14th century, doctors sometimes wore long trench coats and beak masks filled with aromatic substances like herbs, spices or onions. This costume was thought to protect the doctors from infection. Treatments for the plague in the Middle Ages included everything from drinking urine to eating the heart of a stag. Diphtheria is a contagious respiratory infection spread by bacteria in a cough or a sneeze.
It is particularly dangerous to children. In Indonesia, where outbreaks are common, these students waited nervously before receiving diphtheria vaccinations in October Botulism infections are rare, but potentially fatal. Bacteria enter the body through improperly processed foods or through an open wound and produce a dangerous neurotoxin. Legionnaires disease is an atypical pneumonia spread by inhaling mist from bacteria-ridden water. An outbreak killed at least 12 people in Flint in and Scientists allege that low chlorine levels in the city's municipal water supply were to blame.
This illness became a household name in when letters containing anthrax spores were mailed to news media and to two U. Five people died. The most common way anthrax is spread, however, is through contact with infected animals or animal products. In , at least ten buffalo died from an outbreak in Kenya.
Severe Acute Respiratory Syndrome , or SARS, is a strain of coronavirus that reached epidemic levels in , infecting more than 8, people in 29 countries and killing The monkeypox virus is most often spread through contact with the bodily fluids of an infected animal, though human-to-human transmission is possible.
It occurs most often in rainforests of Central and West Africa. People suffering from the virus will experience fever and swollen lymph nodes followed by a rash that concentrates on the face and extremities. Toxic shock is a dangerous bacterial infection most commonly associated with the use of tampons, but it also occurs in other settings such as post-surgical infections, burns and catheters.
The disorder causes the immune system to attack the nervous system. Scientists have linked cases to the presence of other pathogens like the Zika virus and influenza. Fun fact: That old story that tetanus is caused by stepping on rusty nails is not altogether accurate. Rust does not cause tetanus. Rusty objects are often found outdoors where bacteria live.
And while the rough, porous rust does provide a convenient habitat for dangerous bacteria, you can also contract tetanus from a nail with no rust at all — or from an animal bite. It's the low-oxygen environment under the skin that provides the perfect breeding ground for dangerous toxins. This is a severe bacterial infection of the thin layer of tissue that surrounds the brain. Tony Nassif shows a photo of his daughter, Jenah, who died of the disease after she was misdiagnosed.
Tuberculosis causes respiratory symptoms like a severe cough with occasional blood. It is curable, but it remains one of the top 10 causes of death, globally. The exact cause of this severe brain disease is not known, but it often occurs in children recovering from a virus — like chickenpox — especially if aspirin was administered. This correlation led to warnings against aspirin use in children in the s and '80s. When children's aspirin use declined, so did instances of Reye sydnrome.
Smallpox causes severe flu-like symptoms in addition to a rash and large lesions on mucous membranes. The disease was declared globally eradicated in and administration of the vaccine was halted. These women in Kolkata, India perform a ritual for the goddess Shitala, the folk deity believed to cure smallpox and similar diseases.
Staph infections are notoriously difficult to treat, especially the antibiotic-resistant strain known as MRSA. Listeriosis, the illness caused by the listeria bacteria , is primarily transmitted through contaminated foods. Listeria is particularly dangerous for pregnant women and the elderly. In , 33 people died from eating Listeria-contaminated cantaloupe. This rare brain infection is spread by mosquitoes and affects both humans and animals.
0コメント