This week, more than 1,000 people got sick and 16 died in an outbreak of HUS – a disease related to the bacteria E. coli. Initially cucumbers imported from Spain were blamed to be contaminated with the bacteria, but today this theory was proved wrong, and the source of the infection remains a mystery. What exactly is HUS, and what can you do to avoid it?

Initially, Germans have been warned not to eat cucumbers. (Photo by kobiz7)

Danger Level: High

What is it?

Hemolytic Uremic Syndrome (HUS) is a disease that causes anemia, renal failure and a low platelet count in the blood.

Who gets it?

Most cases of HUS develop in young children, but it can certainly happen in adolescents and adults as well.

It can affect men and women alike.

It’s usually not very common, occurring to 0.5-2 people out of 100,000 in the US per year.

What causes it?

The most common cause for HUS is infection with E. Coli bacteria. E. coli (or by its full name, Escherichia coli) is actually a large group of germs, some of them live in the intestines of healthy people. The type of E. coli which causes HUS is a violent type, which produces a toxin called Shiga-Like Toxin. The toxin is absorbed to the blood through the intestines, and damages the cells that create the most internal layer of blood vessels – especially in the kidney but also in other organs. This damage causes all the symptoms of HUS.

You can get infected with this type of E. coli by eating contaminated and undercooked meat or produce, drinking unpasteurized contaminated milk or swimming in contaminated pools and lakes. It can also be transferred by contact with infected people, for example – in day-cares.

E. coli (Photo by Phil Moyer)

There are other not-common causes for HUS, including:

• Other infections: Some other bacterial and viral infections can also cause HUS, but this is much less common.
• Medications: Several medications can (rarely) cause HUS, including birth control pills, some chemotherapy drugs and cyclosporine – which is used to suppress the immune system (for example after an organ transplant).
• Other diseases: Systemic Lupus Erythematosus (SLE), Preeclampsia and inflammation in the kidneys after radiation treatments.
• Some cases are genetic.

How does it feel?

1. Food Poisoning: The first symptoms are food-poisoning symptoms caused by the E. coli bacteria themselves. This can include abdominal pain, a fever, vomiting and diarrhea which usually becomes bloody at some point. these symptoms appear 5-10 days before all the other symptoms.
2. Anemia: This causes the sick person to look pale and be pretty tired, weak and irritable.
3. Bleeding: There might be external bleeding (from the nose of mouth) or bleeding under the skin, which looks like small unexplained bruises. this is caused by a low number of platelets, which are the cells in our body responsible for blood clots.
4. Kidney Failure: Can cause the body to produce less urine.

The story of 16-year-old Aly, who recovered from HUS

How is it discovered?

When suspecting HUS, the doctors will draw some blood. They will check several things: Complete Blood Count will let them know if there is anemia or low platelets, and kidney function tests will determine if there is kidney failure. They will also look at the blood under a microscope. Other tests that might be needed are a urine test (to look for blood in the urine) and a stool sample (to look for the germs).

How is it treated?

The treatment is given in the hospital, and the goal is to relieve the symptoms:

• The most important part of the treatment is dialysis treatments until the kidneys start working again. If the disease is diagnosed early enough, dialysis might not be needed. The doctors can save the kidneys from failing by giving a lot of fluids.
• The anemia is treated with blood transfusions, and the bleeding problems with platelet transfusions.
• Another possible treatment is plasma-exchange (also called plasmapheresis) – in which blood is removed from the body and blood from a donor is returned back. This is used to remove elements that cause the disease from the blood.

Although the cause is an infection, antibiotics are not part of the treatment.

Dialysis treatment.

What happens after treatment?

In most cases (about 90%, and especially in children), if the disease is discovered early enough and treated correctly, the patient recovers. The other 10% might die or remain with chronic kidney failure which will require dialysis treatments for the rest of their life or a kidney transplant. Some of the people who recover will develop kidney problems or hypertension later in life.

The bottom line – how do I avoid it?

The best way to avoid HUS is to avoid food-poisoning with E. coli – this can be done in several ways:

• Treating foods carefully: You should wash hands often when cooking, keep meat in the refrigerator or freezer, wash fruit and vegetables under running water, cook meat thoroughly without leaving pink areas (if you have a thermometer for cooking, cook to a temperature of at least 160°F [70°C]).
• Avoiding certain foods: Especially undercooked meat, unpasteurized milk and cider. Drink only clean water. Remember that the contaminated food will not necessarily look spoiled of taste bad.
• Avoid swimming in dirty lakes and pools.
• If you have diarrhea – wash hands often.

Related posts:

1. Everything You Need To Know About Fast Food – An Infographic
2. In the News – Hodgkin’s Disease
3. Naphthalene Poisoning – When Mothballs Kill More Than Just Moths (As Seen on House MD)

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)
On episode 23 of season 7 (the season finale, named “Moving On”), Afsoun Hamidi, a performance artist, collapses during filming one of her projects. Later she has pancreatitis, something resembling a tumor in her brain, and a skin rash. Biopsy of the rash reveals that her symptoms are related to a condition called Wegener’s granulomatosis.

Photo by NBCUniversal

Danger level: High

What is it?

Wegener’s Granulomatosis (WG for short) is an inflammation of blood vessels, restricting blood flow to various organs in the body.

Who gets it?

WG is quite rare. In the United States, for example, it’s estimated that about 3 out of every 100,000 people are sick with it. It’s more common in people of Northern European origins, and is less common in black people. It can occur in any age, but is most common in middle age (the average age when it appears is around 40). Men and women are affected equally.

What causes it?

In WG there is an inflammation of blood vessels in the body, meaning it’s a vasculitis (the medical term for inflammation of blood vessels. There are other diseases in this group – such as temporal arteritis and kawasaki, which we covered before).

Our blood vessels generally come in 3 sizes, much like clothing. Small, medium and large. WG is an inflammation of small and medium sized blood vessels.

It happens because the body actually attacks its own blood vessels. The process isn’t completely understood, but probably involves a change in the body’s immune system which triggers the body destroying its own blood vessels.

WG tends to affect mostly 3 systems in the body: The upper airways, the kidney, and the lungs. They are affected since the arteries that supply them with blood are damaged in the disease.

How does it feel?

There are some general symptoms in WG which include loss of appetite, fever, fatigue, and even weight loss.

Usually the first specific symptoms involve the upper airways and can include nosebleeds, nasal congestion, collapse of the bridge of the nose (causing a deformity called saddle nose, seen in this picture), a hole in the nasal septum (which separates our right side of the nose from the left), inflammation of the sinuses (sinusitis), ear infections, difficulty breathing, and coughing (sometimes a bloody cough).

When the disease is in the lungs people may feel shortness of breath (which may be caused by bleeding in the lungs), or cough. When the kidneys are involved, kidney failure can occur, which may be life threatening.

Other organs may be involved, such as the skin (a rash may appear, like the one on House), the joints – which can become inflamed as well, and the nerves (something which can also affect vision – like the patient on House told that had happened to her).

Believe it or not, but there are even more possible symptoms, into which we won’t get here (including, rarely, pancreatitis, which for some reason was a main manifestation on House).

How is it discovered?

The disease resembles many other diseases, making the diagnosis difficult. A blood test checking for a component in the body called ANCA can be used, since it’s elevated in the disease. A physical exam, x-ray, and urine test, among others, can help with the diagnosis. The definitive way is performing a biopsy (taking a piece of an organ to look at under a microscope) on one of the involved organs, which will show something like this:

WG under a microscope. The round area on the left is called a granuloma, which is a mass of immune cells (that’s how the disease got its name). Photo by Nephron.

How is it treated?

Drugs that suppress the immune system (which attacks the body here) are used in WG. This includes steroids and chemotherapy.

What happens after treatment?

With treatment given on time, symptoms may disappear altogether. Still, in about half of patients, the disease may return. Before the disease was understood and the right treatments were given, about half of all patients died within 5 months. Today more than 75% get to live longer.

The bottom line – How do I avoid it?

Unfortunately, there is no known way to prevent WG.

Related posts:

1. Behçet’s Disease – Inflammation of Your Blood Vessels, Throughout the Body (As Seen on House MD)
2. Waldenström’s macroglobulinemia – A Rare Blood Cancer That Can Lead To Strokes
3. Peripheral Arterial Disease – A Narrowing of Blood Vessels that Will Shorten Your Life

This is part of our House MD Project series.

Click here to read the connection to the episode (spoiler alert!)


On last night’s episode (season 7, episode 15), named “Bombshells”, a mass is found on Cuddy’s kidney. After seeing findings in her lungs on imaging it’s presumed she has a malignant tumor in her kidneys that has metastasized to the lungs. A biopsy from the tumor reveals something different, though: She has a benign tumor, called an oncocytoma.

Danger level: Medium

What is it?

Renal oncocytoma is a type of tumor that can be found in the kidney.

Who gets it?

There are many types of kidney cancers, the most common of which is called a renal cell carcinoma. Renal oncocytomas, on the other hand, aren’t that common. They account for about 3-7% of tumors in the kidney.

They are about 2-2.5 times more common in men than in women. They’re usually discovered around age 62.

What causes it?

Sometimes, renal oncocytomas can run in families. This tends to occur more in families in which a syndrome by the long name of Birt-Hogg-Dube syndrome (BHD) is running, due to a genetic mutation.

In other cases, the tumor just appears. There is currently no theory to explain why.

Our kidneys are made of little units called nephrons. There are about 1.5 million (!) nephrons in one kidney. The nephron itself has many tubules and parts, as can be seen in this drawing:

Renal oncocytomas arise from the collecting ducts of the nephron (called in the drawing “collecting tub.” (short for tubule)).

As in other tumors, it occurs when the cells in the area continue dividing without stopping, creating a mass.

How does it feel?

Most people don’t feel anything, and in most cases the tumor is found accidentally after taking an image of the abdomen for some other reason.

In other cases there may be bloody urine (called hematuria), or flank pain.

It’s important to note that this tumor is benign, meaning that it doesn’t tend to spread throughout the body like a malignant tumor does, and so poses less threat.

How is it discovered?

After such a tumor is found in imaging (such as ultrasound or a CT scan), a biopsy is usually needed to know which type of tumor it is. A biopsy is a procedure in which a piece of tissue (in this case, the kidney) is taken and looked at under a microscope. Each tumor has a distinct appearance which can differentiate it from other types. This is how a renal oncocytoma looks under the microscope:

Photo by Nephron

How is it treated?

Most patients are treated with surgery, in which the tumor (or the whole kidney) is taken out.

What happens after treatment?

Like mentioned above, this tumor is benign. Taking it out by surgery should provide cure.

The bottom line – How do I avoid it?

There is currently no known way to prevent this tumor.

Related posts:

1. Astrocytoma (Butterfly Tumor)–A Brain Tumor That Spreads To Both Sides (As Seen On Grey’s Anatomy)
2. Nesidioblastoma – A Tumor of the Pancreas That Can Secrete Hormones (As Seen on House MD)
3. TTP Explained Again (As Seen on House MD)

Anyone who watched last night’s season finale of Grey’s Anatomy has two different questions on their mind right now (and to not spoil it for anyone who didn’t, neither of them involves either IL-2 or anterograde amnesia). But tradition is tradition, and so you get to learn about two subjects for the price of one today.

IL-2

What is it?

IL-2 (or by its long name interleukin-2) is a chemotherapy used to treat melanomas and kidney cancer.

How does it work?

Interleukins are molecules in our immune system. They help in our body’s response to infections.

The cells that fight infections in our body are the white blood cells. The interleukins attach to these cells by connecting to a special receptor on them, and by this they activate them.

The good news is that the white blood cells can kill not only bacteria and viruses, but also cancer cells. IL-2 causes the body to make more of the immune system cells and makes the cells more effective.

The IL-2 molecule.

When is it used?

IL-2 is used to treat advanced stages of kidney cancer (called renal cell carcinoma) or melanoma, when these tumors metastasize (spread to other parts of the body).

How successful is it?

About 10-20% of people treated with IL-2 respond to the treatment. In a study done in 1999, 270 people with metastatic melanoma were given the treatment. 16% of them (43 people) improved with the treatment. Another study was done in 2000, in which again 16% of people improved.

It’s important to understand, though, that only 6% of these people were completely cured with this drug, while in the others it only helped partially.

Danger level: Medium

What is it?

Amnesia  is a Greek word which means forgetfulness or loss of memory. Anterograde amnesia is the inability to remember new facts.

Who gets it?

There are two types of things which can cause anterograde amnesia:

1. Drugs – No, not the ones that make you high. A group of drugs called benzodiazepines (which are usually used for anxiety or to induce sleep) can cause you to forget things. This can be seen in people receiving them before undergoing surgeries, who can’t recollect the minutes around taking the drug.
2. Physical damage to the brain – The damage can be the result of an injury (such as after an accident) or after a surgery to the brain. Such surgeries may be needed in some types of seizures, or when a tumor is in that part of the brain.

What causes it?

The area in our brain responsible for storing memories is called the hippocampus. Damage to the area of the hippocampus can cause a problem with learning new things and retaining them.

The hippocampus. Lose it and you’ll stop remembering new things.

How does it feel?

People with anterograde amnesia lose the ability to learn new facts. It’s important to understand, though, that they can learn how to do new things, such as talk on the phone. They won’t, whoever, remember who they talked to.

If the amnesia was caused by a drug, it usually goes away after a short time. If the amnesia is a result of damage to the brain, however, the chances of gaining the remembering ability back are much slimmer.

This video is a good example. It’s a part of a documentary about Clive Wearing, who suffers from anterograde amnesia:

You can see more examples by watching the (fictional) movies Memento and 50 First Dates.

How is it treated?

Unfortunately, once an area of the brain is damaged, there is currently no known way to recover that area.

Related posts:

1. As Seen on Grey’s Anatomy – Melanoma – You Can Avoid It if It’s Found on Time
2. As Seen on Grey’s Anatomy – Normal Pressure Hydrocephalus (NPH)
3. Astrocytoma (Butterfly Tumor)–A Brain Tumor That Spreads To Both Sides (As Seen On Grey’s Anatomy)