We all have heard about bacterial infections, viral infections and fungal infections. We hear of recalls on green leafy veggies that have E.coli. Influenza and coronavirus are well-known viruses that can lead to devastating effects in humans. Fungal infections can manifest on toe nails and other areas of the skin. People can get thrush, vaginal yeast infections and people can also harbor excessive Candida in the gut. But there is another class of organisms that can inflict deleterious consequences in humans, and those are parasites. Some people think parasites are mostly found in countries where sanitary measures are perhaps lacking a bit. They are there, however parasites are present in the U.S. and more developed countries as well. So the thought that you only get a parasite from traveling to a certain country is not entirely accurate.
A parasite is an organism that depends on a host for food and thus for its survival. A parasite is dependent on a host; it cannot live without a host and the host's food supply. A parasite is transmitted in a number of different ways. A fecal-oral route is common where there are unsanitary measures in place with humans or this can manifest from the fecal material of livestock affecting crops. This can lead to contaminated food and water that is consumed. Person to person contact is a mode of transmission as well as insects being vectors for the parasite. For instance, in the case of malaria, the Plasmodium parasite is carried by the mosquito that can enter a person's bloodstream when the mosquito bites them.
There are three main classes of parasites. There are protozoa, helminths and ectoparasites.
A few examples of protozoa include giardia, toxoplasmosis and malaria.
Heminths are the worm parasites. Things like roundworms, tapeworms, hookworms, pinworms, etc. They oftentimes burrow in the colon of the host. However there are times they can become extra-intestinal and lodge in various other areas of the body. They can also travel to the brain as well as lodge in the skin. They can form cysts there and reproduce causing greater infections.
The ectoparasites are things like mites, lice, flees and ticks. They reside on the skin or burrow into the skin. Mites for instance cause scabies, which is a contagious and super itchy dermatitis.
There are some key symptoms to look for when it comes to parasitic infections. People oftentimes explain a feeling of generalized abdominal pain with vomiting and diarrhea. There can be weight loss and increased appetite. Think about it this way - the parasite is consuming the food that you're ingesting and therefore the nutrients are not keeping you satiated for long. There can be symptoms like skin rashes, anemia, allergies, malaise, fatigue and apathy. In the case of pinworms, there can also be a perianal itching usually at nighttime. This is due to the fact that the pinworms make their way out of the colon to the perianal area at night for breeding.