Amebiasis

What is Amebiasis?

Amebiasis is an infection that is normally caused by protozon or amebas, particularly Entamoeba histolytica. This infection is also denoted as amebiosis, amebic dysentery and amebism. Amebic dysentery is the name that is most frequently used and it refers to a chronic or acute protozoal infection. These infections cause many grades of sickness, from having no symptoms or diarrhea that is mild to dysentery that is fulminant.

This infection is normally contracted by ingesting food or water that is contaminated with amoebic cysts.

While very rare, amebiasis may cause abscesses in the lungs, brain and liver or even other areas of the body. Symptoms take a few days to a few weeks to manifest themselves but normally it is between 2 to 4 weeks. The blood that is sometimes found in stools from this infection comes from amoebae invading the intestinal lining.

Even rarer, amebiasis may cause an abscess to develop in the liver. After infection, it might take a few days to several months or even years before the individual can become ill but it is usually about 2 to 4 weeks. In order to trace the reason for the illness, it is essential to know what the individual has eaten and drank as well as travelled in the weeks before becoming ill.

These parasites can cause the formation of ulcers in the intestine resulting in amoebic dysentery. When this occurs the diarrhea will often become bloody and watery, the abdominal pains become more serious and fever will develop.

Amebiasis Symptoms

Normally this illness lasts about 2 weeks but it can return if treatment is not given.

Emaciation as well as anemia can happen in individuals with long-lasting infection. Often a large bulge or ameboma can form and block the intestine. Sometimes, the trophozoites puncture the walls of the intestines and can come into the cavity of the abdomen. This causes abdominal pain that is severe as well as an abdominal contamination known as peritonitis which needs speedy medical treatment.

Symptoms that are mild:

• Abdominal cramps
• Diarrhea
• Passing of 3 -8 semi-formed stools each day
• Passing of stools that are soft together with mucus and occasionally blood
• Gas in the intestines
• Fatigue
• Rectal pain with bowel movement
• Weight loss without trying

Severe symptoms:

• Abdominal tenderness
• Stools that are bloody
• Passing of liquid stools with blood streaks
• Passing of 10-20- stools each day
• Vomiting
• Fever

Note: In 90% of individuals with amebiasis there are no symptoms

Amebiasis Causes

Amoebiasis is caused by a protozoa and is usually spread by contaminated water or from food served by hands that are contaminated. It can also be spread to additional organs like the brain or the liver by invading the blood system of the intestines. Carriers who are asymptomatic can pass cysts in feces. Contaminated drinking water can also spread this infection. This infection can also spread by oral-anal contact.

Common causes as well as risk factors for amebiasis consist of:

• Consuming food that is contaminated
• Anal or direct contact from person to person
• Unhygienic conditions
• Poor sanitation areas
• Eating vegetable and fruits which have been contaminated

Entamoeba histolytica can live in the colon minus any symptoms. But, often, it invades the wall of the colon triggering acute dysentery, colitis, or long-term diarrhea. This infection also spreads thru the blood system to the liver and very rarely to the brain, lungs or other organs.

This condition is often seen almost anywhere in the world but is most common in tropical regions with living conditions that are crowded and have poor sanitation. Mexico, Africa, regions of South America and India has substantial health problems linked with this disease.

Entamoeba histolytica is spread by water or food that is contaminated. This is very common in areas where human waste is recycled as fertilizer.

Risk factors for severe amebiasis include:

• Alcoholism
• Malnutrition
• Cancer
• Pregnancy
• Old age
• Recent travel to a tropical region
• Use of corticosteroid drugs for suppression of the immune system
• In the United States, amebiasis occurs among those individuals living in institutions as well as individuals who have anal intercourse.

Amebiasis Prevention

There is no vaccine to prevent amebiasis.

When traveling to tropical regions where sanitation that is poor exists, drink only purified water or water that is boiled and do not eat vegetables that are uncooked or fruit that is unpeeled. A good rule in these areas regarding food is to cook it, boil it, peel it, or forget it.

Safe sex procedures should always be used, for instance using dental dams and condoms for oral as well as anal contact. This can be an aid in preventing infection.

The prevention and control of amebic infections, for instance programs to control other water or food borne diseases, can also be very effective using a multi-layered methodology that needs both individual as well as corporate participation. Operational deterrence could be successful using the following measures:

• Providing potable water which is free of fecal contamination
• Chemoprophylaxis should be given as treatment for those who are chronic cyst carriers
• Education of groups that are high-risk for sexual and other habitual practices that may promote fecal-oral transmission
• Thorough rinsing of vegetables and fruits using disinfectants that are effective before consumption

Amebiasis Diagnosis

Making a diagnosis can be problematic due to the fact that other parasites may resemble E. histolytica when examined under the microscope. Individuals who are infected do not always have symptoms. If your physician believe that you are infected and should be treated, medication is available.

Examination of the abdomen can show enlargement of the liver or abdominal tenderness.

Tests include:

• Blood test for amebiasis
• Examination of the inside of the lower colon
• Microscope exam of 3 stool specimens a couple of days apart

Amebiasis Treatment

Usually oral antiparasitic drugs are the standard treatment for amebiasis. The choice of drug usually depends on the how severe is the infection. Normally oral metronidazole is used for 10 days

If the individual is vomiting, it may be necessary to treat with an intravenous medication until the individual can tolerate anything by mouth. Antidiarrheal medications are not normally prescribed since they can often make the condition worse.

After treatment, stools should be re-checked to make certain that the infection has been cleared.

Treatment includes:

• Treated with antimicrobial medications
• Severe cases such as amebic liver abscess may require hospitalization and surgery is needed

Asymptomatic intestinal infection can be treated with:

• Metronidazol
• Iodoquinol
• Paromomycin
• Diloxanide furoate

More severe cases of amebic dysentery need:

• Replacement of any lost blood or fluid
• With individual who have hepatic abscess treatment can be metronidazole and tinidazole
• For individuals who are vomiting, intravenous therapy can be used
• Oral antiparasitic medication is useful treatment for amebiasis

There are two drugs for amebiasis:

• Luminal amebicides
• Tissue amebicides