How Common is Microsporidium?

Microsporidium is common in certain groups like blood donors, pregnant women, slaughterhouse workers, and people with unexplained diarrhea, with infection rates ranging from 1.3% to 22%.

How do you get Microsporidium?

Microsporidia can enter the host through ingestion or inhalation.

What else can Microsporidium be?

Bacterial gastroenteritis, Cryptosporidiosis, Cystoisosporiasis, Cytomegalovirus, Giardiasis, Inflammatory bowel disease, Tropical sprue, Viral gastroenteritis.

What kinds of test are needed for Microsporidium?

The types of tests needed for Microsporidium include: - Microscopic observation of stool samples using staining methods such as trichrome stain, fluorescence staining, Gram stain, carbol-fuchsin stain, and silver stains. - Serological assays, such as immunoblot, ELISA, and IFA, which involve using special antibodies in blood tests. - Genetic analysis techniques like PCR and nucleotide sequencing to identify microsporidia species with high accuracy. - Cultivating microsporidia in lab environments using insect cells, tissues, living hosts, or certain types of cell cultures. - Treatment with drugs like albendazole and fumagillin, which have shown effectiveness against certain microsporidia species.

Are there long term effects of Microsporidium?

The prognosis for Microsporidium varies depending on the host and the severity of the infection. In animals, Microsporidium can lead to high mortality rates, particularly in honeybees. In humans, Microsporidium is considered an opportunistic infection and primarily affects individuals with weakened immune systems. The prevalence rates of Microsporidium infection among HIV-positive individuals can range from 2% to 78%, depending on the level of immunosuppression and medical treatment.

Microsporidium

What is Microsporidium?

Microsporidia are a large and special group of organisms that live inside other cells and can’t survive on their own. Biologists have been studying these microscopic parasites for over a century and a half. They are extremely good at infecting their hosts and are significant parasites in the farming sector. For instance, they can affect honeybees, silkworms and various insects.

This organism can also infect fish, rodents, rabbits, primates, and even humans. The rest of this article will focus on providing more information about Microsporidia, taking into consideration the latest scientific findings.

What Causes Microsporidium?

Microsporidia are a group of organisms that scientists have been studying for over 150 years. They comprise of about 187 types with around 1500 different species. These tiny organisms are found everywhere in the environment and have evolved in a unique way that not only allows them to thrive in the world around them, but also inside other cells.

The way scientists categorize Microsporidia is based on what they look like under a microscope and the properties of their spores, which are a part of their structure that’s essential to their survival and reproduction. It’s important to note that sometimes, the types of hosts these organisms can live in don’t always align with their evolutionary relationships. These relationships are generally discovered by studying the organisms’ molecules – more specifically, using methods like rRNA genetic sequencing, which is currently the main technique used to categorize them.

Risk Factors and Frequency for Microsporidium

Microsporidiosis is an infection caused by parasites known as Microsporidia. This condition affects animals and humans worldwide, though the severity and impact can vary.

For animals, microsporidiosis is primarily a problem in agriculture. For instance, it can significantly affect honeybee populations, with certain strains like Nosema apis and Nosema ceranae leading to high mortality rates. One study found that about 94% of honeybees infected with N. ceranae died within 8 days of infection. Microsporidia not only invade and proliferate within the epithelial cells of the bees, but their lifecycle completes in just three days.
Other species of the same parasite can infect different kinds of aquatic life – for example, Loma salmonae can induce systemic symptoms in salmon, including significant changes in the gills, and even infects organs like heart, spleen and kidneys. Shrimps can also be infected by Thelohania species.

The effects of Microsporidia on humans weren’t fully recognized until the late 20th century. Since then, it has been widely acknowledged as an opportunistic infection – meaning, it primarily affects those with weakened immune systems. These include children, the elderly, transplant recipients, people living with HIV/AIDS, and even travelers.

Out of the around 1500 species of Microsporidia, only 17 are harmful to humans. Among these, Enterocytozoon bieneusi and Encephalitozoon intestinalis are most commonly found in infected individuals.
In developed countries, prevalence rates of Microsporidia infection among HIV-positive individuals with diarrhea range from 2% to 78%, with rates varying depending on the level of immunosuppression and medical treatment. In HIV-positive individuals without diarrhea, rates of infection range from 1.4% to 4.3%.
In people not infected with HIV, the rates of infection range between 1.3% and 22% among certain groups like blood donors, pregnant women, slaughterhouse workers, and people with unexplained diarrhea.

While Microsporidia infection has decreased in HIV patients in developed countries due to improved therapies and hygiene standards, it remains a health concern in many parts of the world.

Signs and Symptoms of Microsporidium

The discovery of microsporidia, a type of microscopic parasite, dates back to 1838 when Gluge found this parasite infecting fish. The parasite was later named Glugea anomala. Since then, several types of microsporidia have been found, with N. bombycis being the first one identified in 1857. This parasite is known to infect Lepidoptera and Hymenoptera, leading to the pepper disease.

The disease had severe consequences for the European silk industry, causing heavy losses in countries like France, Italy, and Germany. During these challenging times, scientist Louis Pasteur came up with disease prevention measures, saving the silk industry from rapid downfall.

Identifying and classifying microsporidia was not an easy task. Scientists had several theories regarding their nature, proposing them as algae, yeast spores, fungi-related organisms, and even tumor cells or degraded erythrocytes.

After continuous research, in 1882, a scientist named Balbiani suggested a separate category for N. bombycis, calling it Microsporidia. This term was later updated in 1977, defining the phylum as Microspora. Today, after many studies and advances, Microsporidia are seen as degenerate organisms, not primitive types.

In 2008, scientists identified a connection between Microsporidia and fungi. They discovered similar microsporidia parasites distributed among various kinds of animals, including invertebrates, fish, and humans.

Recent studies in 2012, proposed that Microsporidia are single-cell parasites belonging to the SAR-inclusive class which includes Stramenopila, Alveolata, Foraminifera, Cercozoa, and Polycystinea.

Now, let’s talk a bit about these organisms’ characteristics and life cycle. Microsporidia are eukaryotic creatures, meaning they have well-defined nuclei. They are oval-shaped and have an internal membrane system, but lack peroxisomes. They contain special structures known as mitosomes, which are like the cell’s powerhouse.

Microsporidia are known for creating environmentally resistant spores due to their unique structures and their ability to extend their internal polar tube to inject its content into the host, making them immune to extreme temperatures and harsh conditions such as dehydration and chemical exposure.

Spores enter the host through ingestion or inhalation. Once inside, they germinate and extend their polar tube to inject into the host cell. This process of injection and transfer is what feeds the microsporidia.
Later, these cells develop into meronts, which are the reproductive stage and form sporonts.

The sporonts then divide and mature into sporoblasts equipped with an injection apparatus. This feature significantly helps identify microsporidia. As the host cells burst open, these mature spores are released and can infect nearby cells. This way, one single infection can lead to numerous spores, making them highly pathogenic and capable of causing infection.

Testing for Microsporidium

Microsporidia are tiny organisms that can be hard to spot as they infect slowly and sometimes without causing noticeable symptoms. This is why they’re often missed as a cause of diarrhea globally. To identify these organisms, special techniques are used in labs by trained staff.

When it comes to detecting Microsporidia, doctors often use microscopic observation of stool samples. New staining methods have been developed to help with the process, such as trichrome stain and fluorescence staining using substances called optical brighteners. They can also be identified using traditional stains like Gram stain, carbol-fuchsin stain, and silver stains.

There are also some helpful blood tests, known as serological assays, such as the immunoblot, Enzyme-Linked Immunosorbent Assay (ELISA) and Immunofluorescence Assay (IFA) which involve using special antibodies. However, these tests may not work as well in people with HIV as their immune system isn’t functioning properly.

More sophisticated techniques involving genetic analysis are turning out to be very promising. These methods, including polymerase chain reaction (PCR) and nucleotide sequencing, can identify microsporidia in the infected person with high accuracy. By isolating the microsporidia’s genetic material and amplifying specific sequences, doctors can quickly identify the microsporidia species.

There are also ways to make microsporidia grow in a lab, either in insect cells or tissues or by injecting them into living hosts – for instance, N. bombycis in the ovarian tissue of the silk moth and N. ceranae in honeybees. Other types of samples, like urine, mucus, lung fluid, feces, intestinal fluid, eye scrapings, corneal biopsies, spinal fluid, muscle biopsies, and brain tissue, have shown that Microsporidia can grow in certain types of cell cultures.

One specific parasite, Nosema algerae (which infects mosquitoes), has been successfully grown in pig kidney cells in the lab. A type of mosquito’s cells has also been used to cultivate Microsporidia from fish. While both of these methods are very helpful, they need to be done by trained personnel with the proper equipment in a suitable lab environment.

Treatment Options for Microsporidium

Microsporidia infection in animals and humans is often treated with drugs like albendazole and fumagillin. Previously, substances like Nosemack (an organic mercury compound) were used. However, this was found to be less effective against the parasites and more harmful to farm bees than the medication fumagillin. Fumagillin shows a strong ability to kill amoebas and research has demonstrated that it can stop the growth of Nosema apis (a type of microsporidia) in honeybees.

On the other hand, albendazole is a reliable medication for treating infections caused by Encephalitozoon species in both humans and animals. However, it is not always as effective against a microsporidium called Enterocytozoon bieneusi. Albendazole works by preventing tubulin, a protein necessary for the survival of these parasites, from forming properly. This medication is also commonly used to treat worm infections (anthelmintic) and fungal infections.

Here are some conditions that can cause similar symptoms and could be confused with each other: