What is the Parasite Screen?
A parasite is an organism, which expoits any other live animal for nutrition. In most cases the parasitic process causes harm to the host through the actual removal of the nutrients, or by carrying other diseases into the body.
Parasites are often thought of as atropical disease, but this is a huge misconception. It is estimated that as many as 10% of people in the UK have parasites. Many people will carry parasitic infections at a subclinical level for years, with the parasite feeding, reproducing and affecting the health of the host. Contaminated foood water, raw or inadequately cooked meat or fish and physical contact are the most widespread source of intestinal parasites.
The effect of parasites living in the gut depends on the species of parasite identified.
There are two main types of intestinal parasite; Helminths and Protozoa.
The Helminths are a group of parasites often referred to as worms. There are many species that infect humans, but they generally have similar life cycles. The adult inhabits the gut often fixing themselves with hooks to the gut wall, laying thousands of eggs a day. the eggs will often penetrate the gut wall, and grow into larvae, which ten circulates in the blood system, passing through the liver and lungs before re-entering the gut.
Diagnosis of helminth infection is normally through the detection of the eggs in the stool. These eggs are highly infectious and very robust – they can often survive outside the body for many years.
The Protozoa are single celled organisms. These organisms combine all organs needed for feeding, reproducing and mobility in one single cell, typically about a fiftieth of a milimetre in diameter.
The ability to rapidly reproduce and the excretion of toxic waste materials, means that when these animals do infect the gut, there is the potential for serious acute disease. There are many protozoa that are recognised as pathogenic, that is ‘disease causing’.
Common symptoms of intestinal parasites.
- Diarrhoea
- Nausea or vomiting
- Gas or bloating
- Dysentery (loose stiils sontaining blood and mucus)
- Rash or itching around the rectum or vulva
- stomach pain or tenderness
- Feeling tired
- Weight loss
- Passing a worm, or secrion of a worm in your stool.
The likelihood of a parasitic infection i greatly incresed if a patient experiences any of the above symptoms following foreign travel.
Some of the above symptoms are typical of Irritable Bowel Syndrome (IBS) and while food intolerance is strongly associated with IBS, there is also evidence that parasites may be the cause for some IBS sufferers. Single celled orgamisms living in the gut cause irritation and can lead to colon contractions, resulting in reduced gut flow and spasm of the colonic muscle causing cramp. The two main culprits are Blastocystis and Dientamoeba.
Testing
A total of 12 investigations are carried out on samples proided by the patient. Samples need to be taken on 3 different days, and put into the pots provided containing a preservative. On the final say a sample is also placed into a pot without preservative, to enable the lab to examine the live gut fauna.
Samples are subjected to a microscopic examination specific stains to highlight any parasite species. The lab uses state of the art microscopes photography to record the presence of any species detected. It is key that the parasite is correctly determined, as this will have an important implication for any therapy.