What is amebiasis?

Amebiasis is a disease caused by infection. In current clinical practice, this disease is prone to occur in subtropical temperate regions and autumn seasons. Both men and women are susceptible to infection, so we must pay attention to prevention.

1. Amoebic infection is caused by various amoebas under the class Rhizopoda, order Amoebina, family Ent-amoebidae, and genus Entamoeba, which are clinically referred to as amoebas. Among them, although there are many types of intestinal amoeba, most of them parasitize in the human body as commensal organisms and have no pathogenic ability. Only Entamoeba histolytica can cause disease under certain conditions after parasitizing the human body, and is considered to be a pathogenic amoeba.

2. Causes

After the cyst is swallowed, it enters the lower small intestine, where the trophozoite escapes from the cyst and descends with the feces. It then lives in the cecum, colon, rectum and other parts of the body, where it feeds on bacteria in the intestinal cavity and superficial epithelial cells. Under suitable conditions, trophozoites invade the intestinal mucosa, causing ulcers, and when they reach a certain range and degree, they lead to dysentery.

3. Epidemiology

1. Source of infection: Chronic patients, patients in recovery and healthy "cyst excretors" are the sources of infection of this disease. Acutely ill patients, when only trophozoites are excreted in their feces, are not a source of infection.

2. Transmission route: Cysts can survive in the soil for more than 8 days; in a humid and cool environment, such as feces, they can survive for several weeks. The cysts can enter the human body through contaminated drinking water, food, vegetables, etc. In areas with poor sanitary conditions, water sources or food are easily contaminated by feces. In areas where feces is used as fertilizer, unwashed and undercooked vegetables are an important factor of transmission. Flies and cockroaches can come into contact with feces, carry the cysts on their body surfaces and vomit or defecate, thus contaminating food and becoming important vectors of transmission.

3. Epidemic characteristics: Entamoeba histolytica occurs more frequently in tropical, subtropical and temperate regions, with the highest incidence in autumn, followed by summer. The incidence rate in rural areas is higher than in urban areas, in men more than in women, and in adults more than in children. There are very few young children, which may be related to the number of opportunities to swallow food containing cysts.