Cancer is a large group of diseases that can start in almost any organ or tissue of the body when abnormal cells grow uncontrollably, and go beyond their usual boundaries to invade adjoining parts of the body. According to the World Health Organization (WHO), it is the second most common cause of death globally, accounting for millions of deaths every year. Lung, prostate, colorectal, stomach and liver cancer are the most common types of cancer in men, while breast, colorectal, lung, cervical and thyroid cancer are the most common among women. However, these are not necessarily the deadliest forms of cancer.

What makes cancer the deadliest depends upon how many people have it and what percentage of those people actually survive. Cancer researchers determine this on the basis of five-year relative survival. This is the percentage of people who are expected to survive the effects of a given cancer, excluding their risk of other possible causes of death, for five years past a diagnosis. It is also important to note that what makes cancer really deadly is that practically no cure for it. A cure for cancer would imply that there are no cancerous cells remaining in the body.

Here are the 5 deadliest cancers in the U.S., according to SEER five-year relative survival data for cases diagnosed between 2014 and 2020.

1. Pancreatic cancer occurs when cells in your pancreas, a gland in your abdomen that aids digestion, mutate and multiply out of control, forming a tumour. Major risk factors include smoking, obesity, diabetes, chronic pancreatitis, certain genetic mutations and environmental chemical exposure.

2. Esophageal cancer develops in the oesophagus, which is the tube that connects your throat to your stomach.

3. Liver cancer and intrahepatic bile duct cancer originate in the liver or bile ducts, often linked to hepatitis infections, heavy alcohol use, obesity, and aflatoxin exposure.

4. Lung and bronchus cancer primarily caused by smoking, secondhand smoke, and environmental pollutants, affects the lungs and airways, making it the leading cause of cancer death in the US.

5. Acute myeloid leukaemia (AML) is an aggressive blood and bone marrow cancer that progresses rapidly, often linked to genetic mutations, radiation exposure, and certain chemicals.

ALSO READ: Why Are Lifestyle Factors Making Millennials Vulnerable To Cancer?

The 17th outbreak of Ebola virus in the Democratic Republic of Congo has been identified as the rare Bundibugyo strain.

Bundibugyo virus disease is a rare and deadly illness that has caused outbreaks in several African countries in the past. It is different from other known ebolaviruses such as the Zaire ebolavirus and the Sudan ebolavirus.

Bundibugyo virus was first identified during an outbreak in 2007 in Uganda, which resulted in 131 cases and 42 deaths.

Another Bundibugyo outbreak was reported in 2012, killing 50 per cent of the people infected in Uganda and 34 per cent in DR Congo.

As per the US CDC, as of May 17, there are reports of 10 confirmed cases and 336 suspected cases, including 88 deaths, in DRC.

Uganda has reported 2 confirmed cases, including 1 death, among people who travelled from DRC. No further spread has been reported. These numbers are subject to change as the outbreak evolves.

How Does Ebola Bundibugyo Spread?

Also read: WHO Calls Ebola Outbreak In DR Congo And Uganda An International Public Health Emergency

The Bundibugyo virus spreads through contact with the blood or bodily fluids of a person infected with or who has died from the rare Ebola strain.

It can also spread through contact with contaminated objects such as clothing, bedding, needles, and medical equipment, or through contact with infected animals such as bats and nonhuman primates.

Historically, Bundibugyo virus outbreaks have recorded fatality rates ranging from 25 per cent to 50 per cent.

Symptoms To Watch For

Symptoms of Bundibugyo virus disease are similar to other forms of Ebola and include:

• Fever
• Headache
• Muscle pain
• Weakness
• Diarrhea
• Vomiting
• Stomach pain
• Unexplained bleeding or bruising, usually in later stages of illness

The WHO has described the current outbreak as “extraordinary” because there are no approved Bundibugyo virus-specific therapeutics or vaccines, unlike the Ebola-Zaire strain. Most of the country’s previous outbreaks were caused by the Zaire strain.

Prof Trudie Lang from the University of Oxford also described dealing with Bundibugyo as “one of the most significant concerns” in the current outbreak, the BBC reported.

Symptoms are believed to appear between two and 21 days after infection.

With no approved drugs specifically targeting the Bundibugyo virus, treatment currently depends on supportive care, including managing pain, treating secondary infections, maintaining fluids, and ensuring adequate nutrition. Early medical care improves survival chances.

CDC Issues Travel Guidelines

The CDC advised people traveling to Uganda and the DR Congo to follow routine precautions. These include:

• Consider travel insurance, including medical evacuation coverage.
• Avoid contact with people showing symptoms such as fever, muscle pain, or rash.
• Avoid contact with blood, bodily fluids, or contaminated objects.
• Avoid contact with bats, forest antelopes, and nonhuman primates such as monkeys, chimpanzees, and gorillas.
• Avoid entering caves or mines where bats may live.

Travellers should monitor themselves for symptoms while in outbreak areas and for 21 days after leaving. If symptoms develop:

• Isolate immediately
• Do not travel
• Contact local health authorities or a healthcare facility before visiting in person

At least six Americans who are in the Democratic Republic of the Congo are believed to have been exposed to the Ebola virus, amid the latest outbreak in the African nation that has killed over 80 people and infected nearly 300, according to a media report.

Citing sources, STAT News said that one of the individuals may also have developed symptoms.

Although there are no test results yet for any of the individuals, the US government is reportedly trying to arrange for their transportation out of the DRC to a location where they can be safely quarantined and cared for, if they are found to have been infected.

It is also not clear if that would be in the US. As per sources, it may be an American military base in Germany, the report said.

Meanwhile, the US CDC, in a statement said, it is supporting interagency partners "who are actively coordinating the safe withdrawal of a small number of Americans who are directly affected by this outbreak."

"At this time, the risk to the American public remains low," the CDC said. "CDC continues to closely monitor the situation and has systems in place to detect and respond rapidly to potential public health threats."

The health agency has also issued travel advisories for Americans traveling in Congo and Uganda, telling them to "practice enhanced precautions" and avoid people who have symptoms, which include fever, muscle pain, and rash.

The latest Ebola outbreak, the 17th in DR Congo, has also spread to Uganda. On May 17, the World Health Organization declared it a "public health emergency of international concern."

According to the Africa CDC, the outbreak is caused by a rare strain Bundibugyo virus, for which there is no vaccine available currently.

Also read: WHO Calls Ebola Outbreak In DR Congo And Uganda An International Public Health Emergency

What Is Ebola?

The US CDC explains that the Ebola disease is caused by a group of viruses, known as orthoebolaviruses (formerly ebolavirus).

These viruses can cause serious illness that, without treatment, can cause death. Orthoebolaviruses were discovered in 1976 in the Democratic Republic of the Congo and are found primarily in sub-Saharan Africa.

The four types of orthoebolaviruses cause illness in people are:

• The Ebola virus (species Orthoebolavirus zairense)
• Sudan virus (species Orthoebolavirus sudanense)
• Taï Forest virus (species Orthoebolavirus taiense)
• Bundibugyo virus (species Orthoebolavirus bundibugyoense)

The CDC notes that two other types of orthoebolaviruses have not affected people to date. They are:

• Reston virus (species Orthoebolavirus restonense) has caused disease in non-human primates like macaques.
• Bombali virus (species Orthoebolavirus bombaliense) was more recently identified in bats.

Read More: More Americans Exposed To Hantavirus; 41 Under Monitoring, Says CDC

How Ebola Infection Spreads and Turns Deadly

People sick with Ebola disease can spread the virus to others when they start having symptoms like fever, aches, pains, and fatigue. It can be spread through direct contact with infected bodily fluids.

As the person becomes sicker, the illness causes diarrhea, vomiting, and unexplained bleeding. In severe cases, the virus can damage blood vessels, weaken the immune system, and lead to organ failure, internal bleeding, and shock.

However, the virus can persist in certain bodily fluids, such as semen, even after recovery, meaning transmission may still be possible in rare cases despite the absence of symptoms.

"This happens when the virus remains in certain parts of the body that are shielded from the immune system. For example, the virus can remain in semen even after someone recovers. Whether the virus is present in these body parts, and for how long, varies by survivor," the CDC said.

The World Health Organization today declared the Ebola outbreak in the Democratic Republic of the Congo and Uganda a “public health emergency of international concern” (PHEIC), citing the risk of spread to neighboring countries.

The WHO defines a Public Health Emergency as an extraordinary event or crisis that poses a substantial risk of widespread illness, injury, or death to a population, such as pandemics, severe pollution events, or natural disasters.

However, the WHO clarified that the outbreak, caused by the Bundibugyo virus, does not meet the criteria for a pandemic emergency. Countries sharing land borders with the DRC were described as being at high risk for further spread.

“The Ebola disease caused by Bundibugyo virus in the Democratic Republic of the Congo and Uganda constitutes a public health emergency of international concern (PHEIC), but does not meet the criteria of pandemic emergency, as defined in the International Health Regulations (2005) (IHR),” the WHO said in a statement.

Ebola Outbreak: Cases And Deaths

The UN health agency said the outbreak has caused 80 deaths, with eight laboratory-confirmed cases and 246 suspected Ebola cases reported in Ituri Province in the DR Congo, across Bunia, Rwampara, and Mongbwalu.

In addition, two laboratory-confirmed cases — including one death — with no apparent link to each other were reported in Kampala, Uganda, within 24 hours of each other, indicating international spread. Both individuals had travelled separately from the DR Congo.

A laboratory-confirmed case has also been reported in Kinshasa, DR Congo, involving a person returning from Ituri.

The WHO further noted unusual clusters of community deaths and said the outbreak poses a public health risk to other countries through international spread, which has already been documented.

Also read: World Hypertension Day 2026: Why Switching Salt May Be India’s Simplest Weapon Against High Blood Pressure

What Is Bundibugyo Virus Disease?

Bundibugyo virus disease is a rare and deadly illness that has caused outbreaks in several African countries in the past. It is different from other known ebolaviruses such as the Zaire ebolavirus and Sudan ebolavirus.

The virus was first identified during an outbreak in 2007, which resulted in more than 100 cases before being declared over in early 2008.

The WHO described the current outbreak as “extraordinary” because there are no approved Bundibugyo virus-specific therapeutics or vaccines, unlike the Ebola-Zaire strain. Most of the country’s previous outbreaks were caused by the Zaire strain.

How The Virus Spreads

According to US Centers for Disease Control and Prevention (CDC), the Bundibugyo strain spreads through contact with the blood or body fluids of infected individuals or people who have died from the disease.

Transmission can also occur through contact with contaminated objects such as clothing, bedding, needles, and medical equipment, or through infected animals including bats and nonhuman primates.

Symptoms include fever, headache, muscle pain, weakness, diarrhea, vomiting, stomach pain, and unexplained bleeding or bruising in the later stages of illness.

Read More: Can Hantavirus Spread Through Semen And Breast Milk? What Experts Say

WHO Issues Guidelines

The WHO advised immediate isolation of confirmed cases and daily monitoring of contacts. It also recommended restricting national travel for exposed individuals and avoiding international travel until 21 days after exposure.

At the same time, the agency urged countries not to close borders or restrict travel and trade out of fear, warning that such measures could lead to unmonitored informal border crossings.