Table of Contents
What is Schistosoma haematobium?
Schistosoma haematobium is a parasitic flatworm that causes a disease called urinary schistosomiasis, or bilharzia. This infection is common in parts of Africa and the Middle East, especially in areas with freshwater bodies like lakes, rivers, and ponds.
The parasite is found more in these environments, making people who rely on these water sources for bathing, washing, or fishing vulnerable to infection.
When do you suspect you might have Schistosoma haematobium?
- When you notice an intense irritation and skin rash, referred to as “swimmer’s itch”. This may occur at the site of cercarial penetration and usually starts within 24 hours of infection by Schistosoma haematobium
- When you experience blood in your urine – Haematuria.
- When you are having Painful Urination, this could be due to Inflammation or irritation of the bladder by the ova.
- When you are urinating more frequently than normal.
How do we detect it in the lab?
In diagnosing parasitic infections like schistosomiasis, particularly Schistosoma haematobium, the ability to pay attention to details, becomes a laboratory scientist’s greatest tool.
In the world of microscopes, the smallest details can be the most important clue in the puzzle of diagnosis.
The ability to spot, recognize and identify the morphology of Schistosoma haematobium Ova —eggs that may be overlooked or tagged insignificant at first glance—can be the difference between a correct diagnosis and a missed one.
Today, we explore the world of Schistosoma haematobium ova and the role it plays in the detection of urinary schistosomiasis.
The Microscope side of the story
- Sample Collection: Mid-day urine samples are usually collected, as this is the time when egg excretion tends to be highest. Patients are also instructed to provide the last portion of the voided urine, as ova are often concentrated there.
- Transport: Urine samples should be transported to the laboratory at room temperature and as soon as possible to keep the eggs viable.
- Centrifugation: Once the sample arrives in the laboratory, it is centrifuged to allow the eggs to settle at the bottom.
- Sediment Preparation: After centrifugation, carefully decant the supernatant without disturbing the sediment.
- Wet Mount Preparation: Resuspend the sediment by gently agitating the tube to mix with the remaining urine. Place a drop of this resuspended sediment on a clean glass slide, cover it with a coverslip, and prepare a wet mount for examination.
- Microscopy: On a light microscope, focus the wet mount using x10 objective, then examine with x40 objectives.
Findings
- Ova of Schistosoma haematobium
- Sometimes the miracidia of Schistosoma haematobium (hatched egg).
- Red blood cells in urine
The characteristic ova of Schistosoma haematobium
At the heart of every Schistosoma haematobium diagnosis is the ova, or egg, released by adult female schistosomes living within human hosts. That means for an egg to be seen in the urine, there are usually adult worms present in the patient’s body. We will discuss how they got there and the life cycle of Schistosoma in another article.
But the ova find their way into the urinary system, eventually making their presence known in urine samples.
Yet, for the untrained eye, an ova may appear as nothing more than an oval shaped artifact.
For laboratory scientists, however, each ova is like a fingerprint—distinct and incriminating.
The most distinguishing feature of Schistosoma haematobium Ova is its terminal spine (a small spine at one end).
The eggs are typically pale yellow, large and elongated, with a clear terminal spine. measuring approximately 110-170 µm in length and 45-70 µm in width.
While this might seem like too much details, the position and appearance of this spine set Schistosoma haematobium Ova apart from its close relatives, such as Schistosoma mansoni ova, which has a lateral spine and Schistosoma japanicum ova which has no spine at all but rather possess a lateral knob.
The presence of a single terminal spine gives scientists an unmistakable clue. It’s this sharp feature that often marks the definitive diagnosis, leading to prompt and appropriate treatment.
Proper training and experience are needed to distinguish these eggs from other objects or potential contaminants in the sample.
Take home
In the world of parasitology, the smallest structures can tell the biggest stories. Schistosoma haematobium ova, with their distinctive terminal spine, may appear unsuspicious, but they hold the key to diagnosing a disease that affects millions of people globally.
Every time a laboratory scientist identifies one of these eggs, they’re unlocking a piece of information that leads directly to better health outcomes.
So, next time you think of medical breakthroughs, remember that some of the most important advances happen on the smallest of scales—right there under the lens of a microscope.
