Amoebiasis is a parasitic disease caused by an amoeba called Entamoeba histolytica . This parasitic disease is rife with cosmopolitan choice and is endemic (throughout the year) in hot and humid. In other regions, it may be in the form of small outbreaks or isolated cases. Amoebiasis is one of the diseases known as “the faeces.”
Amoebiasis can be severe, especially among those most vulnerable such as young children, pregnant women, elderly or living with a chronic illness (eg diabetes) and those whose immune systems are deficient (immunocompromised ). Each year about 100,000 people worldwide die as a result of amebiasis.
The healthy carriers of the parasite or sick are the only source of contamination. Transmission of amoebiasis is through fecal-oral route, either directly by contact from person to person (dirty hands) or indirectly through food or water contaminated with feces containing cysts amoeba.
Amoebae belong to the family of protozoa which are organisms formed from a single cell. They are spread by the feces in the environment in the form of highly resistant cysts, can survive for several months. After being ingested, the cysts lost their shells under the effect of digestive juices and release small amoeba or amœbules earning the colon (large intestine). Unlike cysts, these forms of the parasite are very fragile and are quickly destroyed when they are eliminated with feces. When the parasite remains strictly in the form of cyst, it proliferates in the colon without causing damage to the gastrointestinal mucosa. This is amoebiasis-infection (without disease). In contrast, amœbules can invade the colonic mucosa and even the cross and then migrate to other organs, mainly the liver, but also the lungs, the pleura (membrane surrounding the lungs), heart or skin where they cause the formation abscess .. They are also able to borrow the bloodstream to the brain.
Amoebiasis can be silent (asymptomatic). In other cases, the symptoms of the infection appear several days to several weeks after infection. We distinguish the primary amoebic invasion, which corresponds to the initial infection of the intestine with amoebae and amoebiasis late that occurs when the previous is not treated and that most often affects the liver.
The intestinal disease or colic is characterized by diarrhea with stools containing blood and mucus (mucoid diarrhea, bloody), referred to as amoebic dysentery. Diarrhea can be prolonged and associated with other signs: fatigue, weight loss and sometimes fever. In some cases, intestinal amebiasis resulting in a severe form: malignant colonic amebiasis.
Hepatic Amoebiasis occurs typically by pain in the region where the liver (right upper quadrant), a volume increase of the latter (hepatomegaly), a fever of about 38-39 ° C without sweat . Without treatment, the disease continues to evolve and the patient’s general condition deteriorates.
Extraintestinal amoebiasis are complications of hepatic amoebiasis and can take different forms:
Amoebae can be found in the stool provided it is sought quickly, because once outside the body of the individual noisy, they die quickly. For the diagnosis of intestinal amebiasis, the parasitological examination should be done on fresh stool. Amoebae are rarely found in the liquid content of the abscess which is collected by a puncture. During cutaneous amoebiasis, they can be found in biopsies of ulcer edges. Directly visualizing lesions, endoscopy helps to make the diagnosis of colonic amoebiasis.
The search for anti-amoebic in the blood (serology) is part of examinations designed to confirm the diagnosis of hepatic amoebiasis. It is also interesting for the diagnosis of amebiasis other, with the exception of intestinal amoebiasis.
Abdominal ultrasound revealed the presence of abscesses in the liver and chest radiograph reveals amoebic lesions in the lungs and / or pleura.
There are two types of antiamoebic drugs or amoebicides: the so-called contact amoebicides that destroy the amoebas in the bowel and amoebicides called diffusible or tissue that act against amoebas present in tissues. Some of them may be administered in treatment “minute”. It is important to verify that the amoebae have been eradicated by parasitological controls that will be made two weeks after the end of treatment.
In acute intestinal amebiasis simple, effective treatment is rapid, with disappearance of symptoms within days. In severe forms of amoebiasis, patients may need to be hospitalized in an intensive care unit. The amoebic abscess should be drained. This drainage is most often by puncture through the skin and, in case of failure or rupture of the abscess by surgery.
Although treating intestinal amebiasis avoids the occurrence of extraintestinal forms. Finally, asymptomatic individuals (healthy carriers) should be treated in order to fight against the transmission of the disease.
There is no vaccine or effective prophylaxis against amoebiasis. Prevention of this infection is therefore based primarily on simple measures of general hygiene and food. As recommended by the Committee of diseases related to travel and import and the High Council of Public Health (HCSP-CMVi), travelers who have to stay in countries where sanitation is precarious must strictly a number of rules lifestyle modifications (French recommendations 2011) essentially:
Infectious and Tropical Diseases
Exercised most often in the hospital, and that specialty studies supports the diseases caused by microbes: bacteria (tuberculosis, skin infections), virus (AIDS, hepatitis), mushrooms (fungi), parasites (malaria). They are still present in the tropics.
Today, with increased travel and because of climate change, tropical diseases are increasingly common in hospitals.