Medical laboratory workshop Episode 2 (A rare occurrence - Live view of Miracidium of Shistosoma haematobium after hatching from egg

In the last episode that birthed this workshop series, we critically explained the life cycle of Shistosoma species and with more emphasis on Shistosoma haematobium which we found in the urine sample of a male patient.

We were also able to establish the various unique features that are associated with the parasite and also we explained the significance of this parasite when they are found in urine or faeces. From the discussion as well, we can conclusively say that, there are only two motile forms of the parasite - Miracidium and Cercariae (the infective form of the parasite).

_{3D Image of Schistosoma Mansoni Miracidium}

Fortunately for us, we were able to see the eggs of this parasite and judging from the flow of the life cycle, the next stage it would form would be the Miracidium. Well, we actually discovered something that has been observed to happen on rare occasion - the presence of a live motile Miracidium within a freshly voided urine sample. Read on, you have one or two things to learn.

This post will be the continuation of the last episode. If you are just joining the series, it would be awesome if you read the previous episode so as to get a good grasps of what we will be discussing. Since the parasite is motile, the best possible way to observe it is through video.

Our pattern of discussion today will slightly be different from last episode. As we discuss, We will as well incorporate our result and findings. Let's briefly learn more about the stage of this parasite called Miracidium.

General overview

Miracidium is the first motile stage of the parasite Schistosoma species and narrowing it down to the specie we saw - Schistosoma haematobium. The Miracidium is released from the egg of the parasite once they come in contact with water. This particular form of the parasite is highly motile.

_{Miracidium of Shistosoma haematobium within an unhatched egg.}

Note at this point that, the presence of the egg of schistosoma is a good indication of infection with the parasite, but another question that needs to be addressed is, the viability of the eggs. Not all eggs are viable and the easy way to do this, is to carry out manual hatching of the eggs.

How to hatch the eggs of Schistosoma for viability testing

When you hatch the egg of schistosoma and you observe a actively motile Miracidium, then it means the egg is viable. A more direct way to determine the viability of Shistosoma egg, is to do a wet preparation of either the stool sample or urine. The major thing you look out for is, if there is an active moving flame cell in the Miracidium.

First thing first, you need to hatch the egg first before you can do the above viability testing, and to do this, you will need only two things - Normal saline and dechlorinated water (water with no chlorine content). Using water with no chlorine content is necessary because, chlorine has the capacity of killing Miracidia. Hence, if used, it would likely give a false negative result.

The first thing you do is to mix the stool sample or urine sample with normal saline in a glass jar or flask that has a side arm. Allow it to settle for 2 hours or you can spin. For stool sample, you will need to filter the mixture to remove debris. After spinning or allowing to settle for 2hours, you then decant the supernatant fluid.

You then pour the dechlorinated water into the jar and cover the jar with black paper or aluminum foil leaving out only the handle. Keep it near source of illumination over night. After 24hours, use a hand lens to observe the jar, if the eggs are viable, you will see that some have hatched with an active swimming Miracidium inside the water.

Any striking feature of Miracidium?

One remarkable thing about the stage of this parasite is that, it does not feed nor require any source of feeding. Its main focus is on locating any suitable intermediate host so that it can undergo asexual reproduction to produce the infective form, the Cercariae. This asexual reproduction mostly occurs in water snails.

You might want to ask how are they able to locate their host. They do this using light gravity, random motion and chemo sensitivity. Once they find their suitable intermediate host, they penetrate and undergo asexual reproduction as we have explained about and consequently produce the sporocyst form. If they do not find their intermediate host, the chances of survival will be in jeopardy.

Almost all their entire body is covered with cilia of which they use for movement in search of suitable intermediate host. Since they do not feed, they use the store of food within them and if they do not find any suitable host soon enough, they die off. In essence, the availability of intermediate host is very important.

The cilia of the Miracidium are not clearly visible whilst they are within the egg until after hatching. The live image of the captured Miracidium as it moved within blood cells found in the urine of the patient is seen below.

_{Image of live Motile Miracidium of Shistosoma haematobium after hatching from the egg. It also reveals the cilia covering almost the entire body of the parasite}

All things being equal, one would expect that this parasite form be found in water or snail only after the egg has been expelled from the body of the infected person through stooling. The case is quite different here. On further critical view of the urine specimen, we were able to discover some hatched motile Miracidium. A nice discovery of which is backed by other report confirming the possibility.

The report of GW Procop and colleagues has shown that their possibility of having miracidium in a freshly voided urine and this has some clinical and diagnostic importance. Though the occurrence has been reported to be rare. Well, we have been able to detect it in our time.

Since this is rare, what then could be the clinical significance of this. Judging from the nature of the boy's urine sample, it had numerous amount of blood, which could be an indication of a chronic infection with this parasite.

_{Presence of numerous blood cells in chronic stage of schistosomiasis}

Let's briefly discuss look at the significance of the presence of Miracidium in urine sample.

The video below was recorded through the ocular lens of the microscope using an android phone since a digital microscope is currently not available. We had to improvise and I believe it's relatively clear and close enough for visualization of the Miracidium.