Cholera

*Brain tumor facts Medically Edited by: Charles P. Davis, MD, PhD

Primary brain tumors can be either malignant (contain cancer cells) or benign (do not contain cancer cells). A primary brain tumor is a tumor which begins in the brain. If a cancerous tumor which starts elsewhere in the body sends cells which end up growing in the brain, such tumors are then called secondary or metastatic brain tumors. This discussion is focused on primary brain tumors.
Brain tumors can occur at any age.
The exact cause of brain tumors is not clear.
The symptoms of brain tumors depend on their size, type, and location.
The most common symptoms of brain tumors include headaches; numbness or tingling in the arms or legs; seizures, memory problems; mood and personality changes; balance and walking problems; nausea and vomiting; changes in speech, vision, or hearing.
Physicians group brain tumors by grade (the way the cells look under a microscope). The higher the grade number, the more abnormal the cells appear and the more aggressively the tumor usually behaves.


Primary brain tumors emerge from the various cells that make up the brain and central nervous system and are named for the kind of cell in which they first form. The most common types of adult brain tumors are gliomas and astrocytic tumors. These tumors form from astrocytes and other types of glial cells, which are cells that help keep nerves healthy.

The second most common type of adult brain tumors are meningeal tumors. These form in the meninges, the thin layer of tissue that covers the brain and spinal cord.
What's the Difference Between Benign and Malignant Brain Tumors?
Benign brain tumors are noncancerous. Malignant primary brain tumors are cancers that originate in the brain, typically grow faster than benign tumors, and aggressively invade surrounding tissue. Although brain cancer rarely spreads to other organs, it will spread to other parts of the brain and central nervous system.
Types of primary brain tumors
There are many types of primary brain tumors. Primary brain tumors are named according to the type of cells or the part of the brain in which they begin. For example, most primary brain tumors begin in glial cells. This type of tumor is called a glioma.

Among adults, the most common types are:

Astrocytoma: The tumor arises from star-shaped glial cells called astrocytes. It can be any grade. In adults, an astrocytoma most often arises in the cerebrum.
Grade I or II astrocytoma: It may be called a low-grade glioma.
Grade III astrocytoma: It's sometimes called a high-grade or an anaplastic astrocytoma.
Grade IV astrocytoma: It may be called a glioblastoma or malignant astrocytic glioma.
Meningioma: The tumor arises in the meninges. It can be grade I, II, or III. It's usually benign (grade I) and grows slowly.
Oligodendroglioma: The tumor arises from cells that make the fatty substance that covers and protects nerves. It usually occurs in the cerebrum. It's most common in middle-aged adults. It can be grade II or III.
Among children, the most common types are:

Medulloblastoma: The tumor usually arises in the cerebellum. It's sometimes called a primitive neuroectodermal tumor. It is grade IV.
Grade I or II astrocytoma: In children, this lowgrade tumor occurs anywhere in the brain. The most common astrocytoma among children is juvenile pilocytic astrocytoma. It's grade I.
Ependymoma: The tumor arises from cells that line the ventricles or the central canal of the spinal cord. It's most commonly found in children and young adults. It can be grade I, II, or III.
Brain stem glioma: The tumor occurs in the lowest part of the brain. It can be a low-grade or high-grade tumor. The most common type is diffuse intrinsic pontine glioma

Brain Tumor: Symptoms and Signs

Approved by the Cancer.Net Editorial Board, 08/2015
ON THIS PAGE: You will find out more about body changes and other things that can signal a problem that may need medical care. To see other pages, use the menu on the side of your screen.

People with a brain tumor may experience the following symptoms or signs. Sometimes, people with a brain tumor do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not a brain tumor.

Symptoms of a brain tumor can be general or specific. A general symptom is caused by the pressure of the tumor on the brain or spinal cord. Specific symptoms are caused when a specific part of the brain is not working well because of the tumor. For many people with a brain tumor, they were diagnosed when they went to the doctor after experiencing a problem, such as a headache or other changes.

General symptoms include:

Headaches, which may be severe and worsen with activity or in the early morning

Seizures. Motor seizures, also called convulsions, are sudden involuntary movements of a person’s muscles. People may experience different types of seizures, including myclonic and tonic-clonic (grand mal). Certain drugs can help prevent or control them. The differences between these types of seizures are listed below:

Myclonic

Cholera is a disease caused by bacteria that produce a watery diarrhea that can rapidly lead to dehydration.
Cholera symptoms and signs include a rapid onset of copious, smelly diarrhea that resembles rice water and may lead to signs of dehydration (for example, vomiting, wrinkled skin, low blood pressure, dry mouth, rapid heart rate).
Cholera is most frequently transmitted by water sources contaminated with the causative bacterium Vibrio cholerae, although contaminated foods, especially raw shellfish, may also transmit the cholera-causing bacteria.
Cholera is presumptively diagnosed by patient history and examination of stool for rice-water appearance and presence of V. cholerae-like organisms microscopically; definitive diagnosis is done by isolation and identification of V. cholerae from stool samples.
The main treatment for cholera is fluid and electrolyte replacement, both oral and IV. Antibiotics usually are used in severe infections in which dehydration has occurred.
The prognosis of cholera ranges from excellent to poor. Rapid treatment with fluid and electrolytes result in better outcomes while people with other health problems beside cholera or those who are not rapidly replenished with fluid treatments tend to have a poorer prognosis.
It's possible to prevent cholera with appropriate measures such as safe drinking water and non-contaminated foods; some protection can be obtained from oral vaccines while avoiding areas where cholera commonly occurs or has had a recent outbreak

What is cholera?

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Cholera is an acute infectious disease caused by a bacterium, Vibrio cholerae (V. cholerae), which usually results in a painless, watery diarrhea in humans. Some affected individuals have copious amounts of diarrhea and develop dehydration so severe it can lead to death. Most people who get the disease ingest the organisms through food or water sources contaminated with V. cholerae. Although symptoms may be mild, some previously healthy people will develop a copious diarrhea within about one to five days after ingesting the bacteria. Severe disease requires prompt medical care. Hydration (usually by IV for the very ill) of the patient, and antibiotics in some individuals, is the key to surviving the severe form of the disease.

The World Health Organization (WHO) has maps of current and past areas with cholera outbreaks (see WHO reference). It is estimated that about 1.4 million to 4.3 million people are infected worldwide each year, with approximately 28,000-142,000 deaths per year. Only about one in 10 people infected with cholera develop the typical signs and symptoms. Outbreaks of cholera in 2015 include South Sudan, United Republic of Tanzania, Kenya, and most recently, 121 people diagnosed with

cholera in Iraq, their first outbreak since 2012.

The term cholera has a long history (see history section below) and has been assigned to several other diseases. For example, fowl or chicken cholera is a disease that can rapidly kill chickens and other avian species rapidly with a major symptom of diarrhea. However, the disease-causing agent in fowl is Pasteurella multocida, a gram-negative bacterium. Similarly, pig cholera (also termed hog or swine cholera) can cause rapid death (in about 15 days) in pigs with symptoms of fever, skin lesions, and seizures. This disease is caused by a pestivirus termed CSFV (classical swine fever virus). Neither one of these animal diseases are related to human cholera, but the terminology can be confusing.


What are cholera symptoms and signs?

The symptoms and signs of cholera are a watery diarrhea that often contains flecks of whitish material (mucus and some gastrointestinal lining [epithelial] cells) that are about the size of pieces of rice. The diarrhea is termed "rice-water stool" (See figure 1) and smells "fishy." The volume of diarrhea can be enormous; high levels of diarrheal fluid such as 250 cc per kg or about 10 to 18 liters over 24 hours for a 154-pound adult can occur. People may go on to develop one or more of the following symptoms and signs:

Watery diarrhea (sometimes in large volumes)
Rice-water stools (see figure 1)
Fishy odor to stools
Vomiting
Rapid heart rate
Loss of skin elasticity (washer woman hands sign; see figure 2)
Dry mucous membranes (dry mouth)
Low blood pressure
Thirst
Muscle cramps (leg cramps, for example)
Restlessness or irritability (especially in children)
Unusual sleepiness or tiredness
Other symptoms that may occur, especially with more severe disease, include the following:

Abdominal pain (cramps)
Rectal pain
Fever
Severe vomiting
Dehydration
Low or no urine output
Weight loss
Seizures
Shock
Death
Those infected require immediate hydration to prevent these symptoms from continuing because these signs and symptoms indicate that the person is becoming or is dehydrated and may go on to develop severe cholera. People with severe cholera (about 5%-10% of previously healthy people; higher if a population is compromised by poor nutrition or has a high percentage of very young or elderly people) can develop severe dehydration, leading to acute renal failure, severe electrolyte imbalances (especially potassium and sodium), and coma. If untreated, this severe dehydration can rapidly lead to shock and death. Severe dehydration can often occur four to eight hours after the first liquid stool, ending with death in about 18 hours to a few days in undertreated or untreated people. In epidemic outbreaks in underdeveloped countries where little or no treatment is available, the mortality (death) rate can be as high as 50%-60%

What causes cholera, and how is cholera transmitted?

Cholera is caused by the bacterium V. cholerae. This bacterium is Gram stain-negative, comma-shaped, and has a flagellum (a long, tapering, projecting part) for motility and pili (hairlike structures) used to attach to tissue. Although there are many V. cholerae serotypes that can produce cholera symptoms, the O groups O1 and O139, which also produce a toxin, cause the most severe symptoms of cholera. O groups consist of different lipopolysaccharides-protein structures on the surface of bacteria that are distinguished by immunological techniques.

The toxin produced by these V. cholerae serotypes is an enterotoxin composed of two subunits, A and B; the genetic information for the synthesis of these subunits is encoded on plasmids (genetic elements separate from the bacterial chromosome). In addition, another plasmid type encodes for a pilus (a hollow hairlike structure that supports bacterial attachment to human cells and facilitate the movement of toxin from V. cholerae into human cells). The enterotoxin causes human cells to extract water and electrolytes from the body (mainly the upper gastrointestinal tract) and pump it into the intestinal lumen where the fluid and electrolytes are excreted as diarrheal fluid. The enterotoxin is similar to toxin formed by bacteria that cause diphtheria in that both bacterial types secret the toxins into their surrounding environment where the

toxin then enters the human cells. The bacteria are usually transmitted by drinking contaminated water, but the bacteria can also be ingested in contaminated food, especially seafood such as raw oysters.

What is the history of cholera?

Cholera has likely been affecting humans for many centuries. Reports of cholera-like disease have been found in India as early as 1000 AD. Cholera is a term derived from Greek khole (illness from bile) and later in the 14th century to colere (French) and choler (English). In the 17th century, cholera was a term used to describe a severe gastrointestinal disorder involving diarrhea and vomiting. There were many outbreaks of cholera, and by the 16th century, some were being noted in historical writings. England had several in the 19th century, the most notable being in 1854, when Dr. John Snow did a classic study in London that showed a main source of the disease (resulting in about 500 deaths in 10 days) came from at least one of the major water sources for London residents termed the "Broad Street pump." The pump handle was removed, and the cholera deaths slowed and stopped. The pump is still present as a landmark in London. Although Dr. Snow did not discover the cause of cholera, he did show how the disease could be spread and how to stop a local outbreak. This was the beginning of modern epidemiologic studies. The last reference shows the map Dr. Snow used to identify the pump site.

V. cholerae was first isolated as the cause of cholera by Filippo Pacini in 1854, but his discovery was not widely known until Robert Koch (who also discovered the cause of tuberculosis), working independently 30 years later, publicized the

Library of Medicine houses original documents about multiple cholera outbreaks in the U.S. from the 1820s to the 1900s, with the last large outbreak in 1910-1911. Since the 1800s, there have been seven cholera pandemics (worldwide outbreaks).

Cholera riots occurred in Russia and England (1831) and in Germany (1893) when the people rebelled against strict government isolation (quarantines) and burial rules. In 2008, cholera riots broke out in Zimbabwe as police tried to disperse people who tried to withdraw funds from banks and were protesting because of the collapse of the health system that began with a cholera outbreak. Similar but less violent public protests have occurred when yellow fever, typhoid fever, and tuberculosis quarantines have been enforced by health authorities.

Multiple outbreaks worldwide continue into the 21st century with outbreaks in India, Iran, Vietnam, and several African countries occurring over the last 10 years (some recent outbreaks occurred in Haiti and Nigeria in 2010-2011). Why is cholera history repeating itself? The answer can be traced back to Dr. Snow's studies that show a source (water or occasionally food) contaminated with V. cholerae can easily and rapidly transmit the cholera-causing bacteria to many people. Until safe water and food is available to all humans, it is likely that cholera outbreaks will continue to happen.

What are risk factors for cholera, and where do cholera outbreaks occur?

Everyone who drinks or eats food that has not been treated to eliminate V. cholerae (liquids need to be chemically treated, boiled, or pasteurized, and foods need to be cleaned and cooked), especially in areas of the world where cholera is present, is at risk for cholera.

Outbreaks occur when there are disasters or other reasons for a loss of sanitary human waste disposal and the lack of safe fluids and foods for people to ingest. Haiti, a country that had not seen a cholera outbreak in over 50 years, had such circumstances develop in 2010 after a massive earthquake destroyed sanitary facilities and water and food treatment facilities for many Haitians. V. cholerae bacteria eventually contaminated primary water sources, resulting in over 530,000 people diagnosed with cholera that resulted in over 7,000 deaths. This cholera outbreak spread to Haiti's neighbor, the Dominican Republic. The Vibrio cholerae strain was closely related to a strain found in Nepal and leads some individuals to blame Nepalese troops that helped with the earthquake disaster as the source of the Haiti cholera outbreak.

In third-world countries, hunger can lead people to inadvertently eat contaminated food and/or drink contaminated water, thus raising the risk for cholera to infect malnourished populations.

There is some evidence that V. cholerae can survive in saltwater and have been isolated from shellfish; eating raw oysters is considered a risk factor for cholera, especially in underdeveloped countries and occasionally even in developed countries. A few people are diagnosed with cholera every year in the U.S. Most of the individuals diagnosed are travelers who were exposed to cholera outside the country, but occasionally, isolated cases are traced to contaminated seafood, usually from states that border the Gulf of Mexico.

Some individuals are at higher risk to become infected than others. People who are malnourished or immune-compromised are more likely to get the disease. Children ages 2-4 seem more susceptible than older children, according to some investigators. In addition, researchers have noted that patients with blood type O are twice as likely to develop cholera as others. The reason for this blood type susceptibility is not completely understood. People with achlorhydria (reduced acid secretion in the stomach) and people taking medicines to reduce stomach acid (H2 blockers and others) are also more likely to develop cholera because stomach acid kills many types of bacteria, including V. cholerae.

Is cholera contagious?

It takes about 100 million V. cholerae bacteria to infect a healthy adult. Because of this high number, significant contamination of food or water is required to transmit the disease, and direct person-to-person transmission is thought to be uncommon except in outbreaks. In outbreaks, cholera-causing bacteria become highly contagious indirectly and directly by the fecal-oral route because of widespread fecal contamination of food, water, and items like bedding and clothing.


What is the incubation period for cholera?

The incubation period (time period from exposure to the bacteria to the development of symptoms) may vary from a few hours (about six to 12 hours) to five days, with the average incubation period being about two to three days. About six to 12 hours is considered a very rapid incubation period and may suggest that rapid/immediate intervention is required for recovery.


What is the contagious period for cholera?

The contagious period for cholera begins as soon as organisms are excreted in the feces. This can occur as early as about six to 12 hours after exposure to the bacteria and can last for about seven to 14 days. Some individuals who are asymptomatic (infected but not having symptoms) will also excrete contagious organisms for about seven to 14 days.


How do health-care professionals diagnose cholera?

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Preliminary diagnosis is usually done by a caregiver who takes a history from the patient and observes the characteristic rice-water diarrhea, especially if a local outbreak of cholera has identified. The diarrhea fluid is often teeming with motile, comma-shaped bacteria (presumptively V. cholerae) that can be seen with a microscope. The definitive diagnosis is made by isolation of the bacteria from diarrhea fluid. All state health department laboratories in the U.S. are able to perform tests for Vibrio cholerae. Readers may see terms like serotypes Inaba, Ogawa, and Hikojima to describe V. cholerae; they simply indicate which O antigens (O antigens designated A, B, or C) are found on these strains of V. cholerae. PCR tests have also been developed to detect the genetic material of cholera, but currently they are not as widely used as the immunologic tests based on type-specific antiserum.

Definitive diagnosis helps to distinguish cholera from other diseases caused by other bacterial, protozoal, or viral pathogens that cause dysentery (gastrointestinal inflammation with diarrhea).


What is the treatment for cholera?

The CDC (and almost every medical agency) recommends rehydration with ORS (oral rehydration salts) fluids as the primary treatment for cholera. ORS fluids are available in prepackaged containers, commercially available worldwide, and contain glucose and electrolytes. The CDC follows the guidelines developed by the WHO (World Health Organization) as follows:

Reassess the patient every one to two hours and continue hydrating. If hydration is not improving, give the IV drip more rapidly. 200 mL/kg or more may be needed during the first 24 hours of treatment.
After six hours (infants) or three hours (older patients), perform a full reassessment. Switch to ORS solution if hydration is improved and the patient can drink.
In general, antibiotics are reserved for more severe cholera infections; they function to reduce fluid rehydration volumes and may speed recovery. Although good microbiological principles dictate it is best to treat a patient with antibiotics that are known to be effective against the infecting bacteria, this may take too long a time to accomplish during an initial outbreak (but it still should be attempted); meanwhile, severe infections have been effectively treated with tetracycline (Sumycin), doxycycline (Vibramycin, Oracea, Adoxa, Atridox, and others), furazolidone (Furoxone), erythromycin (E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone), or ciprofloxacin (Cipro, Cipro XR, ProQuin XR) in conjunction with the following antibiotics in conjunction with IV hydration and electrolytes:

Tetracycline (Sumycin)
Doxycycline (Vibramycin, Oracea, Adoxa, Atridox, and others)
Furazolidone (Furoxone)
Erythromycin (E-Mycin, Eryc, Ery-Tab, PCE, Pediazole, Ilosone)
Azithromycin (Zithromax)
Sulfamethoxazole/trimethoprim (Bactrim, Septra)
Ampicillin
Ciprofloxacin (Cipro, Cipro XR, ProQuin XR)
Norfloxacin (Noroxin)
Many antibiotics are listed; however, because of widespread antibiotic resistance, including multi-resistant Vibrio strains, antibiotic susceptibility testing is advised so the appropriate antibiotic is chosen. In addition, quinolones (for example, ciprofloxacin, norfloxacin) should not be used in children if other antibiotics can be effective because of possible musculoskeletal adverse effects.


What physicians usually treat cholera?

Because most individuals have either mild or no symptoms, these people are either not treated or treated by their primary-care physician. However, in some children and in individuals who have more severe disease, besides the primary-care physician or pediatrician, an infectious-disease specialist, a critical-care specialist, a gastroenterologist, and/or an internist may be needed to help the team manage and treat the patient.

In addition, specialists in travel medicine and/or epidemiology can help individuals avoid cholera and/or can give advice about prevention, treatment, and prognosis to those individuals traveling to or living in endemic areas

What is the prognosis of cholera?

The prognosis (outcome) of cholera can range from excellent to poor, depending on the severity of the dehydration and how quickly the patient is given and responds to treatments. Death (mortality) rates in untreated cholera can be as high as 50%-60% during large outbreaks but can be reduced to about 1% if treatment protocols (see above treatment section) are rapidly put into action. In general, the less severe the symptoms and the less time people have dehydration symptoms, the better the prognosis; in many people, if dehydration is quickly reversed, the prognosis is often excellent.


Is it possible to prevent cholera? Are cholera vaccines available?

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Yes, cholera can be prevented by several methods. Developed countries have an almost zero incidence of cholera because they have widespread water-treatment plants, food-preparation facilities that usually practice sanitary protocols, and most people have access to toilets and hand-washing facilities. Although these countries may have occasional lapses or gaps in these methods, they have prevented many disease outbreaks, including cholera.

Individuals can prevent or reduce the chance they may get cholera by thorough hand washing, avoiding areas and people with cholera, drinking treated water or similar safe fluids, and eating cleaned and well-cooked food. In addition, there are vaccines available that can help prevent cholera, although they are not available in the U.S., and their effectiveness ranges from 50%-90%, depending on the studies reported. The vaccines are oral preparations, because injected vaccines have not proved to be very effective. Two vaccines (Shanchol and Dukoral) are composed of killed V. cholerae bacteria and don't contain the enterotoxin B subunit. Unfortunately, both offer protection for only about two years, although one report suggests that Shanchol is about 65% effective over five years. Both vaccines are usually given in two doses, about one to six weeks apart. Unfortunately, the vaccines have limited availability; their recommended use is for people going to areas of known outbreaks with the likely possibility the person may be exposed to cholera. Some researchers suggest this limited oral vaccine availability should be changed and cite data that oral vaccine may help limit outbreaks, even after they have begun.

Research is ongoing; a research study in Haiti will try to determine if a two-dose vaccine in people will suffice to protect a difficult to treat (rural poor) population from cholera and thus save many lives. There are over 30 universities researching this disease (cholera's epidemiology, pathology, immunology, vaccine production, and other problems) currently worldwide.

In 2015, about 2 million doses of oral cholera vaccine were shipped to various outbreak areas, and currently available information suggests that there was a significant reduction in transmission of cholera; the study will be concluded in 2018