amoebic dysentery (amoebiasis)

Amoebic dysentery, also known as amoebiasis, is a tropical disease that primarily leads to disorders of the large intestine. The infection is caused by a pathogen called Entamoeba histolytica.

Distribution of amoebiasis

Worldwide, amoebic dysentery is one of the most common human diseases caused by parasites. Each year, approximately 50 million people contract amoebic dysentery. Every tenth person is a carrier of the parasite, even if they are not affected by the disease themselves.

In our country it is mainly known as a travel disease, which one has to be careful of when travelling to the tropics or subtropics.

In addition to the usual intestinal form, which affects the intestinal tract, there is also an extraintestinal form, which occurs more frequently in men. Why this is so, still could not be clarified.

The infection is caused by a pathogen called Entamoeba histolytica. This is transmitted orally via contaminated food or drinking water. It is not the parasite itself but its cysts that are excreted in the faeces and then reabsorbed. These parasites then settle in the colon and develop back into infectious parasites within one to four weeks.

A particularly high risk of becoming infected with amoebiasis exists for people with a weakened immune system, as they are naturally unable to defend themselves against the parasite at all.

When travelling to such areas, it is very likely that one ingests Entamoeba histolytica and that it also settles in the colon. Most of the time, however, the infection runs its course without any symptoms. Nevertheless, cysts are excreted with the stool, which means that the germ is often passed on unnoticed.

Only in about 5 to 20% of cases do symptoms develop. A distinction is made between the intestinal and the extraintestinal type.

Amoebic dysentery of the intestinal type

If the parasite remains in the intestine and only damages it, a raspberry jelly-like diarrhoea occurs acutely. This is because the intestine tries to get rid of the pathogen as quickly as possible, which is why a lot of secretion and mucus is produced. The infection causes slight bleeding of the colon walls, which explains the typical colouring and consistency.

In addition to diarrhea, cramps and sometimes fever also occur. If the germ is not combated and the infection becomes chronic, such unpleasant intestinal inflammations sometimes recur over many years.

Amoebic dysentery of the extraintestinal type

If the germ cannot be kept in the large intestine, it migrates via the blood system to the liver and usually settles there. Several months or even years can pass before symptoms appear here. Then there are acute abscesses (encapsulated collections of pus) with a feeling of pressure and pain in the right upper abdomen. Sometimes the body temperature may rise slightly, but fever rarely occurs.

In very large abscesses of the liver, the thorax may also become constricted, which can lead mainly to pain and also breathing difficulties. In very rare cases, the parasite also settles in other organs, such as the brain, spleen or lungs.

The diagnosis must be made differently depending on the form and manifestation. As with any infection, you soon find altered parameters in the blood, but they do not indicate anything specific. These include, for example, that the white blood cells, our defence system, are elevated.

Stool samples and imaging techniques

In the intestinal form, if the pathogen is suspected, it can be detected directly from a fresh stool sample to confirm the diagnosis. In the extraintestinal form, abscesses, effusions and changes in the liver are detected by various imaging techniques such as X-rays, computed tomography, ultrasound and magnetic resonance therapy. Blood samples can be used to detect antibodies formed against the pathogen. In this form, the pathogen itself is present neither in the blood nor in the stool.

Do not forget the conversation

Of course, it is important to speak openly and honestly with the doctor. Because especially the conversation with the doctor can give a good indication of what disease is really present. In the case of amoebic dysentery, it is therefore essential to talk about what trips have been made in recent months.

In the treatment of amoebic dysentery, care must be taken on the one hand to ensure that the symptoms of the disease disappear, and on the other hand, the transmission of the pathogen should also be stopped quickly. For this purpose, a so-called contact amoebicide is prescribed, which should also be used if there are no symptoms, but only evidence of the pathogen.

Fighting the symptoms

The main thing is to fight the symptoms. That is why everything is initially done to eliminate diarrhea, abdominal cramps and all other possible complaints. But of course it must not stop at this treatment, at least not if there are signs that the body's own immune system cannot cope with the parasite. Then antibiotic therapy must be started.

Therapy of the intestinal form

Any form of amoebiasis is treated with an imidazole derivative given by infusion over ten days. This is an antibiotic that directly attacks the parasite. In order to prevent the transmission of the infectious cysts, the patient is treated orally with paromomycin for the same length of time after the antibiotic therapy. Finally, a stool examination confirms that no more parasites are being excreted. This must be done mainly because the disease is subject to compulsory notification.

Therapy of the extraintestinal form

This is treated in exactly the same way as the intestinal form, except that abscesses are also punctured and cleared out if there is a risk of them spreading to organs or other body cavities.

Hygienic measures

In addition, of course, strict hygienic guidelines must be followed to prevent the parasite from being passed on. Otherwise, an epidemic of disease would quickly develop, which would then be difficult to control.

If treatment is carried out, the prognosis is very good. In most cases, the pathogen is completely eliminated within a few weeks and only the memory of the infection remains.

If no therapy is started, or it is not carried out consistently, the chronic form of amoebiasis can also develop, which is more than just unpleasant. In some cases it can even lead to death.

Prophylaxis consists mainly of avoiding the areas where Entamoeba histolytica is found. These include, above all, Central and South America, South Asia and Africa.

If one does not want to do this, then it is important to maintain strict hygiene when traveling. To do this, one can follow these tips:

• Peel uncooked fruits and vegetables before eating them.
• It is best to boil vegetables
• Do not eat raw meat or raw seafood
• Do not drink water from the tap or from unsealed water bottles.
• Boil water before brushing your teeth
• Do not eat ice cubes, homemade water ice or sorbet.

If you follow these tips, you're fairly well protected from amoebic dysentery. If you still get it, it's important to go to the doctor, get diagnosed, and start treatment as soon as possible.