DYSENTERY?-Causes. The Negative Effects. Prevention.


Dysentery is an infection of intestinal tract caused by protozoa or bacteria which contaminate the foods or drinks taken orally, resulting to severe diarrhoea (passing of three or more watery stools a day) mixed with blood and mucus. It is one of the ancient environmental diseases with high incidence of deaths among different ages, races and genders. Dysentery is more frequent in countries where there is poor sanitation, water supplies and sewage disposal; and where human feces are used as fertilizer. Severe dysentery is more common in developing countries and may vary by region and medical specialty.   Most cases of dysentery are spread within families and in places where people are in close contact such as schools, nurseries, barracks and daycare centres. Proper control and treatment of the underlying infections of amoebic dysentery and bacillary dysentery are important.  Insufficiently treated amoebiasis and shigellosis can lie dormant for years; and later lead to severe and potentially fatal complications.

Amoebiasis  (amoebic dysentery) and shigellosis (bacillary dysentery) are most common forms of dysentery, found mainly in tropical areas. Conservative global estimates from the World Health Organization (WHO) suggest that Amoebiasis infects over 50 million people each year, killing about 50,000 while 90 million cases of Shigellosis are contracted annually, with at least 100,000 of these resulting in death.   It’s important you know and promptly report the case(s) of dysentery for easy treatment and interruption of the spread.


Dysentery  is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing blood and mucus. Dysentery results from protozoa, viral or bacterial infections acquired primarily from unhygienic environment. These pathogens typically reach the large intestine after oral contact with contaminated objects or hands or through ingestion of contaminated food or water. Dysentery-causing pathogens also spread through cold and uncooked food such as salad that has been contaminated with infected human stools. The pathogens can live and spread for up to four weeks after a person has become infected.

There are two main types of dysentery which are dysentery caused by bacteria called shigella (bacillary dysentery or shigellosis), which is the most common type of dysentery globally and dysentery caused by protozoa called amoeba (amoebic dysentery or amoebiasis). Both types of dysentery are commonly spread through oral contact with contaminated foods and drinks sequel to poor hygiene.


Dysentery may be caused by amoebiasis (amoebic dysentery).  When the amoebas inside the bowel of an infected person are ready to leave the body, they group together and form a shell (cyst) that surrounds and protects them against attacks. The cyst, housing the amoebas, passes out of the person’s body through the feces. If the person does not dispose of the feces hygienically, it can contaminate food and water. If another person mistakenly eats food or drinks water contaminated with feces containing the encysted protozoa, the person will also become infected with the amoebas. After entering the person’s body through the mouth, the cyst will travel down into the stomach. It should be noted that the amoebas inside the cyst are protected from the stomach’s digestive acid. From the stomach, the cyst will travel to the intestines where it breaks and releases the amoebas that cause the dysentery. Also the amoebas can burrow into the walls of the intestines, causing small abscesses and ulcers. The amoebas that cause dysentery can also be sexually transmitted during mouth-to-anus contact.

Severe dysentery may also be caused by shigellosis (bacillary dysentery). The shigella bacteria can be found in surfaces with contaminated feces and are equally spread through poor hygiene. The bacteria can infect someone who touch the surface and transfer the bacteria to the mouth. The bacteria will travel from the mouth to the bowel, invading the cells that line the large bowel. The bacteria will multiply, killing the cells and producing symptoms of dysentery.

With correct treatment, most cases of amoebic and bacterial dysentery subside within ten days and most people can fully recover within two to four weeks of proper treatment. If the infection is left untreated, the prognosis varies with the immune status of the individual patient and the severity of the infection. Amoebic and bacillary dysentery can be fatal if left untreated.


Each specific pathogen has its own mechanism or pathogenesis, but generally there may be damage to the intestinal lining and inflammatory immune response system. The outcome of the damage can result to impaired nutrient absorption; and excessive water and essential minerals loss through the feces due to breakdown of the control mechanisms in the intestinal tissues that usually remove water from the stools. And in severe cases, pathogenic organisms can enter into the bloodstream causing different health problems. Bacteria dysentery is most severe and spreads faster in a community.


Signs and symptoms of dysentery usually start one to ten days after infection. These signs and symptoms last for three days to several weeks. Exposed people may experience either mild, severe or even no symptoms at all. However, the general signs and symptoms include mild stomach pains, rectal tenesmus (a feeling of incomplete defecation with cramping rectal discomfort), frequent watery, painful and usually foul-smelling diarrhea (sometimes over a litre of fluid per hour) containing blood and/or mucus, nausea (feeling sick) and vomiting (being sick).  Severe abdominal painful spasms and cramps, high temperature (fever) of above 38oC (100.4oF), edema, cell death, bleeding from the rectum are commonly observed. Loss of appetite, rapid weight loss, liver abscess, generalized muscle aches; and dry mouth, skin and lips due to dehydration, are common signs and symptoms of dysentery. There are presentations of lower abdominal tenderness, temporary lactose intolerance, shock and delirium.


It is important to avoid using public facilities without washing your hands (preferably with antiseptic soap), careless contact with someone known to have dysentery and sharing items such as towels and handkerchiefs. Eating fresh fruits or vegetables that cannot be hygienically peeled or washed before eating should be avoided. People should avoid eating food or drink bought from street vendors (except drinks from standard sealed cans or bottles). At home, wash hands with soap and water after using the toilet and an unsafe contact with an infected person. Routinely, wash hands regularly throughout the day especially when back home from each day’s activities that expose you to germs. Wash hands with soap and water before handling babies, cooking and eating food; and feeding young or elderly people.


People should not permit delays in prompt reporting of the signs and symptoms of dysentery above so as to prevent the spread of dysentery-causing pathogens to other organs such as the brain, lungs and the liver where it can cause untoward complications. Dehydration in babies and young children with dysentery should be avoided to prevent health fatality.

See the doctor if you have diarrhoea that contains blood and/or mucus especially if you just returned from a country with poor sanitation. Drink plenty of fluids that are hygienically secured to replace fluids and electrolytes that have been lost through diarrhoea. As much as possible, wash laundry of an infected person inside the hottest setting.

The aim of this document is to remind you to be more conscious of your personal and environmental hygiene. Dysentery is preventable and treatable; therefore seek early medical intervention as soon as the infection is contracted.

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