Protozoan Diseases - An Overview of Protozoal Infections

Protozoan infections bring various chemotherapeutic control challenges. Several advances have been made to treat the diseases caused by protozoa. However, the high volumes of drug resistance make them life-threatening. Protozoal infections are life-threatening for patients. The ones suffering from secondary infections like HIV should be more careful.
 

Protozoan parasites cause infection. They could be acutely lethal, chronically lethal, or acutely debilitating. Some of them could be asymptomatic. Highly effective treatments are available for some protozoan diseases. 
 

Read on to learn more about Protozoa illnesses, symptoms, risk factors, and diagnosis.

Common Diseases Caused By Protozoa

Protozoans cause many important human and animal diseases. In addition to being known as parasites, some protozoa are considered opportunistic pathogens that primarily affect immunocompromised individuals.
 

Human Diseases – African sleeping sickness, malaria, amoebic dysentery, etc.

Animal Diseases – Leishmaniasis (dogs, humans and rodents), Babesiosis, etc.

Diseases Caused By Protozoa

There are various complexities in the life cycles of parasitic protozoans. It has multiple morphological forms, including multiple vectors and hosts. Most of them survive on dynamic feeding. They may grow into a huge form termed the trophozoite. 
 

If the conditions are unfavourable, the trophozoite turns into a cyst. These protozoans infect the tissues or blood of an individual. And this eventually leads to diseases caused by protozoa.

What Kind Of Diseases Can Humans Suffer Due To Protozoa?

Listed below are common diseases caused by air pollution and protozoa –
 

Malaria 

Mosquitoes cause this protozoan infection. It affects humans as well as animals. Plasmodium falciparum is the species that causes this disease. Anopheles mosquitoes are known to spread this disease. The common symptoms of malaria are headaches, vomiting, tiredness, and fever. 
 

Trypanosomiasis 

The protozoan trypanosoma causes several protozoan diseases in humans. It causes African Trypanosomiasis and American Trypanosomiasis in humans. The common symptoms of Trypanosomiasis are aching muscles and swollen lymph glands. Other symptoms are joint pain and fever.
 

Amoebiasis 

Entamoeba histolytica protozoa causes it. Amoebiasis results in extreme weight loss and diarrhoea. Other symptoms include bloody diarrhoea, abdominal pain, and colonic ulcerations. It is one of those protozoan diseases which cause anaemia. 
 

Leishmaniasis 

Over twenty species of Leishmania cause infection. It is one of the most severe protozoan diseases in humans. The transmission takes place by the sandflies' protozoa. Individuals suffering from this infection may have fever and skin ulcers. Additional symptoms include low red blood cells and enlarged liver.

Protozoa Symptoms and Signs

There are various symptoms of the diseases caused by protozoa and their symptoms. They may vary according to the parasites that cause infections. The common protozoa symptoms are high fever, body shivering, and vomiting. The individual may also suffer from Muscular spasms. 
 

Additional symptoms of protozoan diseases are:
 

• Weakness
• Weight loss 
• Seizures
• Spleen enlargement
• Enlarged liver
• Jaundice 
• Eye infections 
• Stomach cramps 
• Nausea 
• Swollen lymph nodes
• Pain in muscles 
• Skin rash
   

Besides, the individuals may also suffer from intense weariness and irritability. The infection also affects the central nervous system. It may result in neurologic disorders. The person may develop progressive disorientation and personality changes.

Problems Caused By Protozoan Diseases in Humans

Protozoan diseases cause tissue damage. Generally, it is due to the immune system's response to the host antigens. The cytokine profiles also impact the body. It could also be because of toxic protozoal products.

How Do Diseases Caused By Protozoa Spread?
 

There are several risk factors associated with the diseases caused by protozoa. The major ones are mentioned below – 
 

• Consuming undercooked meat 
• Consuming contaminated shellfish
• Eating meat handled with contaminated hands
• Intake of food which was treated or cooked using contaminated knives and utensils
• Consuming unpasteurised milk from goat
• Ingesting oocysts accidentally after clearing the litter box of the cat
• Consuming anything that could have possibly come in contact with the faeces of the cat
• Ingesting contaminated soil
• Intake of contaminated water 
   

Diagnosis of Protozoa Diseases
 

Protozoa cannot be seen with the naked eye. They are microscopic organisms. The individuals who suffer from infection have Protozoa in their stool or red blood cells.
 

Diseases caused by protozoa and their symptoms can be diagnosed with blood tests. Plus, PCR tests are also recommended. 
 

Other diagnostic procedures include:
 

• Direct pathogen Isolation 
• Samples of multiple stools 
• lymph node Biopsy
• Colonoscopy or Endoscopy 
   

Different Methods of Treatment 
 

The treatment adopted by healthcare professionals depends on the results of the diagnosis. 
 

There are various medicines recommended for treating protozoa infections. The doctor identifies the protozoa. And then, they choose the right antiprotozoal for protozoan diseases in humans accordingly. 
 

• Diloxanide
• Flagyl tablets 
• Daraprim 
• Fasigyn 
• Metronidazole tablets 
• Mepacrine
• Pentacarinat injection 
• Norzol suspension 
• Wellvone 
• Pentostam 
   

The patient may recover from protozoan diseases depending on their condition. The individual’s immunity also plays a crucial role here. Generally, it takes two weeks for complete recovery.
 

Individuals should take preventive measures to protect themselves from protozoa.

Preventive Measures for Controlling Diseases Caused By Protozoa

Protozoan parasites are comparatively larger. They have a complex structure of pathogens. They evade the immune system of the host using different mechanisms. Hence, it is difficult to find the right vaccines for protozoa symptoms. 
 

Hence, prevention is the best option to treat protozoan infection. Follow the preventative measures listed below – 
 

• Generally, protozoan infection is caused through faecal or oral routes. Hence, it is recommended to ensure personal hygiene. 
• Take proper sanitation measures to reduce protozoal infections.
• Use antiprotozoal drugs for treating protozoan diseases. The most prescribed drugs are - benznidazole, Metronidazole, dehydroemetine, and hydroxychloroquine.

Conclusion

Diseases caused by protozoa have huge economic, health, and social impacts. They are common in tropical areas. Protozoans cause around 1.1 million parasite-related fatalities every year. 
 

The lack of proper vaccines and medicines adds to the burden. It is imperative to maintain proper hygiene practices, avoid cleaning cat litter and drink boiled water to eliminate any causes for worry. However, prevention is the best option.