Cholera

What is Cholera

             

Cholera is an acute diarrheal illness caused by infection of the intestine with vibrio cholerae bacteria People can get sick when they swallow food or water contaminated with cholera bacteria. The infection is often mild or without symptoms, but can sometimes be severe and life-threatening.

Causes

1.  Surface or well water. Contaminated public wells are frequent sources of large-scale cholera outbreaks. ...

2.  Seafood. Eating raw or undercooked seafood, especially shellfish, that comes from certain places can expose you to cholera bacteria. ...

3.  Raw fruits and vegetables. ...

4.  Grains.

A bacterium called Vibrio cholerae causes cholera infection. The deadly effects of the disease are the result of a toxin the bacteria produces in the small intestine. The toxin causes the body to secrete enormous amounts of water, leading to diarrhea and a rapid loss of fluids and salts (electrolytes).

Cholera bacteria might not cause illness in all people who are exposed to them, but they still pass the bacteria in their stool, which can contaminate food and water supplies.

Contaminated water supplies are the main source of cholera infection. The bacterium can be found in:

Surface or well water. Contaminated public wells are frequent sources of large-scale cholera outbreaks. People living in crowded conditions without adequate sanitation are especially at risk.

Seafood. Eating raw or undercooked seafood, especially shellfish, that comes from certain places can expose you to cholera bacteria. Most recent cases of cholera in the United States have been traced to seafood from the Gulf of Mexico.

Raw fruits and vegetables. Raw, unpeeled fruits and vegetables are a frequent source of cholera infection in areas where there's cholera. In developing countries,  uncomposted manure fertilizers or irrigation water containing raw sewage can contaminate produce in the field.

Grains. In regions where cholera is widespread, grains such as rice and millet that are contaminated after cooking and kept at room temperature for several hours can grow cholera bacteria.

Symptoms of cholera

Most people exposed to the cholera bacterium (Vibrio cholerae) don't become ill and don't know they've been infected. But because they shed cholera bacteria in their stool for seven to 14 days, they can still infect others through contaminated water.

Most cases of cholera that cause symptoms cause mild or moderate diarrhea that's often hard to tell apart from diarrhea caused by other problems. Others develop more-serious signs and symptoms of cholera, usually within a few days of infection.

Symptoms of cholera infection can include:

1.  Diarrhea. Cholera-related diarrhea comes on suddenly and can quickly cause dangerous fluid loss — as much as a quart (about 1 liter) an hour. Diarrhea due to cholera often has a pale, milky appearance that resembles water in which rice has been rinsed.

2.  Nausea and vomiting. Vomiting occurs especially in the early stages of cholera and can last for hours.

3.  Dehydration. Dehydration can develop within hours after cholera symptoms start and range from mild to severe. A loss of 10% or more of body weight indicates severe dehydration.

Signs and symptoms of cholera dehydration include irritability, fatigue, sunken eyes, a dry mouth, extreme thirst, dry and shriveled skin that's slow to bounce back when pinched into a fold, little or no urinating, low blood pressure, and an irregular heartbeat.

Dehydration can lead to a rapid loss of minerals in your blood that maintain the balance of fluids in your body. This is called an electrolyte imbalance.

Diagnosis and Detection

It is almost impossible to distinguish a single patient with cholera from a patient infected by another pathogen that causes acute watery diarrhea without testing a stool sample. A review of clinical features of multiple patients who are part of a suspected outbreak of acute watery diarrhea can be helpful in identifying cholera because of the rapid spread of the disease.

While management of patients with acute watery diarrhea is similar regardless of the illness, it is important to identify cholera because of the potential for a widespread outbreak.

Suspected cholera case

In areas where a cholera outbreak has not been declared: Any patient 2 years old or older presenting with acute watery diarrhea and severe dehydration or dying from acute watery diarrhea.

In areas where a cholera outbreak is declared: any person presenting with or dying from acute watery diarrhea.

WHO also recommends the following definition for confirmed cholera cases.

Confirmed cholera case

A suspected case with Vibrio cholerae O1 or O139 confirmed by culture or PCR and, in countries where cholera is not present or has been eliminated, the Vibrio cholerae O1 or O139 strain is demonstrated to be toxigenic.

Treatment

Most persons infected with the cholera bacterium have mild diarrhea or no symptoms at all. Only a small proportion, about 10%, of persons infected with Vibrio cholerae O1 may have illness requiring treatment at a health center. Cholera patients should be evaluated and treated quickly. With proper treatment, even severely ill patients can be saved.

Rehydration treatment primary treatment for cholera patients, refers to the prompt restoration of lost fluids and salts.

Antibiotic treatment reduces fluid requirements and duration of illness, and is indicated for severe cases of cholera.

 Zinc treatment as also been shown to help improve cholera symptoms in children.