Photo from indianexpress.com
Cholera is a bacterial disease that is typically transmitted through contaminated water. Cholera is characterized by severe diarrhea and dehydration. Cholera, if left untreated, can be fatal within hours, even in previously healthy people.
In industrialized countries, modern sewage and water treatment have virtually eliminated cholera. However, cholera persists in Africa, Southeast Asia, and Haiti. When poverty, war, or natural disasters force people to live in overcrowded conditions with inadequate sanitation, the risk of a cholera epidemic rises.
Cholera is easily treatable. A simple and inexpensive rehydration solution can prevent death from severe dehydration.
WHAT ARE THE SYMPTOMS OF CHOLERA?
Most people who are exposed to the cholera bacterium (Vibrio cholerae) do not become ill and are unaware that they have been infected. They can still infect others through contaminated water, however, because they shed cholera bacteria in their stool for seven to fourteen days.
Most cases of cholera that cause symptoms cause mild to moderate diarrhea, which can be difficult to distinguish from diarrhea caused by other problems. Others develop more serious cholera signs and symptoms, usually within a few days of infection.
The following are some of the symptoms of cholera infection:
- Diarrhea: Cholera-related diarrhea appears suddenly and can result in dangerous fluid loss — up to a quart (about 1 liter) per hour. Cholera diarrhea has a pale, milky appearance that resembles water that has been rinsed with rice.
- Vomiting and nausea: Vomiting is common in the early stages of cholera and can last for several hours.
- Dehydration: Dehydration can occur within hours of the onset of cholera symptoms and can range from mild to severe. A 10% or greater loss of body weight indicates severe dehydration.
Irritability, fatigue, sunken eyes, a dry mouth, extreme thirst, dry and shriveled skin that is slow to bounce back when pinched into a fold, little or no urinating, low blood pressure, and an irregular heartbeat are all signs and symptoms of cholera dehydration.
Dehydration can cause a rapid loss of minerals in your blood, which help maintain fluid balance in your body. This is referred to as an electrolyte imbalance.
Electrolyte imbalance
An electrolyte imbalance can cause serious symptoms such as:
- Muscle cramps: These are caused by the rapid loss of salts like sodium, chloride, and potassium.
- Shock: One of the most serious consequences of dehydration is this. It occurs when a decrease in blood volume causes a decrease in blood pressure and a decrease in the amount of oxygen in your body. Severe hypovolemic shock can kill in minutes if left untreated.
WHAT ARE THE CAUSES OF CHOLERA?
Cholera is caused by the bacterium Vibrio cholerae. The disease's lethal effects are caused by a toxin produced by bacteria in the small intestine. The toxin causes the body to secrete massive amounts of water, resulting in diarrhea and rapid fluid and salt loss (electrolytes).
Although not all people who are exposed to cholera bacteria become ill, they do pass the bacteria in their stool, which can contaminate food and water supplies.
The main source of cholera infection is contaminated water supplies. The bacterium can be found in the following places:
- Raw fruits and vegetables: Raw, unpeeled fruits and vegetables are a common source of cholera infection in cholera-infected areas. Uncomposted manure fertilizers or irrigation water containing raw sewage can contaminate produce in developing countries.
- Grains: In cholera-endemic areas, grains such as rice and millet that have been contaminated after cooking and left at room temperature for several hours can support the growth of cholera bacteria.
- Surface or well water: Large-scale cholera outbreaks are frequently caused by contaminated public wells. People who live in overcrowded conditions without adequate sanitation are especially vulnerable.
- Seafood: Consuming raw or undercooked seafood, particularly shellfish, from certain areas can expose you to cholera bacteria. The most recent cholera outbreaks in the United States have been linked to seafood from the Gulf of Mexico.
WHAT ARE THE RISK FACTORS OF CHOLERA?
Except for infants who receive immunity from nursing mothers who have previously had cholera, everyone is susceptible to cholera. Nonetheless, certain factors can make you more susceptible to the disease or make you more likely to experience severe signs and symptoms.
Cholera risk factors include:
Inadequate sanitation: Cholera is more likely to thrive in situations where maintaining a sanitary environment, including a safe water supply, is difficult. Such circumstances are common in refugee camps, impoverished countries, and areas affected by famine, war, or natural disasters.
Type O blood: People with type O blood are twice as likely as people with other blood types to develop cholera for unknown reasons.
Shellfish that is raw or undercooked: Although large-scale cholera outbreaks are no longer common in developed countries, eating shellfish from waters known to harbor the bacteria greatly increases your risk.
Stomach acid deficiency or absence: Cholera bacteria cannot survive in an acidic environment, so stomach acid is frequently used as a defense against infection. People with low stomach acid levels, such as children, the elderly, and those who take antacids, H-2 blockers, or proton pump inhibitors, lack this protection, putting them at greater risk of cholera.
Exposure at home: If you live with someone who has cholera, you are at a higher risk of contracting the disease.
WHAT ARE THE COMPLICATIONS OF CHOLERA?
Cholera can be fatal in a matter of hours. Rapid loss of large amounts of fluids and electrolytes can result in death within hours in the most severe cases. People who do not receive treatment in less severe cases can die from dehydration and shock hours to days after cholera symptoms first appear.
Although shock and severe dehydration are the most serious complications of cholera, other issues can arise, including:
Hypoglycemia (low blood sugar): When people become unable to eat, dangerously low levels of blood sugar (glucose) — the body's main energy source — can occur. Children are most vulnerable to this complication, which can result in seizures, unconsciousness, and even death.
Potassium deficiency: People suffering from cholera lose a lot of minerals in their stools, including potassium. Extremely low potassium levels impair heart and nerve function and are potentially fatal.
Kidney failure: Excess fluids, some electrolytes, and wastes build up in the body when the kidneys lose their filtering ability, posing a potentially life-threatening condition. Kidney failure is frequently associated with shock in cholera patients.
HOW IS CHOLERA DIAGNOSED?
Although severe cholera symptoms are unmistakable in areas where it is common, the only way to confirm a diagnosis is to identify the bacteria in a stool sample.
Rapid cholera dipstick tests allow doctors in remote areas to confirm a cholera diagnosis quickly. Rapid confirmation reduces the number of deaths at the start of cholera outbreaks and allows for earlier public health interventions to control the outbreak.
HOW IS CHOLERA TREATED?
Cholera necessitates immediate treatment because the disease can kill within hours.
- Rehydration: The goal is to replace lost fluids and electrolytes through the use of a simple rehydration solution and oral rehydration salts (ORS). The ORS solution is sold as a powder that can be mixed with either boiled or bottled water.
Approximately half of those infected with cholera die if they are not rehydrated. With treatment, fatalities are reduced to less than 1%.
- Intravenous fluids: Most people with cholera can be treated with oral rehydration alone, but severely dehydrated people may require intravenous fluids as well.
- Antibiotics: While not a required part of cholera treatment, some antibiotics can reduce cholera-related diarrhea and shorten its duration in critically ill patients.
- Zinc supplements: Zinc has been shown in studies to reduce diarrhea and shorten its duration in children with cholera.
HOW CAN CHOLERA BE PREVENTED?
Cholera is uncommon in the United States, with the few cases being linked to international travel or contaminated and improperly cooked seafood from Gulf Coast waters.
If you travel to cholera-infected areas, the risk of contracting the disease is extremely low if you take the following precautions:
- Wash your hands frequently with soap and water, especially after using the restroom and before handling food. Before rinsing, rub soapy, wet hands together for at least 15 seconds. If soap and water are not available, an alcohol-based hand sanitizer should be used.
- Eat fully cooked and hot food and, if possible, avoid street vendor food. If you do purchase a meal from a street vendor, make sure it is cooked in front of you and served hot.
- Stick to easy-to-peel fruits and vegetables like bananas, oranges, and avocados. Salads and fruits that cannot be peeled, such as grapes and berries, should be avoided.
- Drink only safe water, such as bottled water or water that has been boiled or disinfected by you. Even brush your teeth with bottled water.
- Hot beverages, as well as canned or bottled drinks, are generally safe, but wipe the outside before opening. If you don't make your own ice with safe water, don't put it in your drinks.
- Avoid raw or undercooked fish and seafood of any kind, as well as sushi.
CHOLERA VACCINE
A vaccine called Vaxchora is available in the United States for adults traveling from the United States to cholera-affected areas. It is a liquid dose that must be taken orally at least 10 days before travel.
Oral vaccines are also available in a number of other countries. For more information on these vaccines, speak with your doctor or your local public health office. Even if you have the vaccine, you should still take the precautions listed above to avoid cholera.