Parasites are organisms that live off other organisms (the host). These low life forms of nature steal nutrients from the host, without doing anything to produce something on their own. Now while many types of microbes (bacteria, fungi, and viruses) can also fit a similar description, medical professionals use the term “parasites” to point to protozoa (in the likes of amebas – organisms that consist of only one cell) and worms (helminths – larger, consisting of many cells and having developed internal organs.
Protozoa reproduce in the simplest of ways – by cell division. This group consists of a wide range of single-cell organisms. As opposed to them, the majority of worms reproduce by laying eggs/larvae who need to spend some time in incubation before being able to infect hosts. This group includes roundworms (hookworms) and flatworms (tapeworms and flukes).
It is common knowledge that parasitic infections occur more often in rural or developing areas.
In developed areas, these infections may show in people with a weakened immune system. These infections are diagnosed by the doctor taking samples of blood, stool, urine, and phlegm. Sometimes, they can take a sample from other infected tissues. Luckily, there are effective drugs for treating most parasitic infections.
These infections may also occur in places where there’s poor sanitation and unhygienic practices.
Parasites generally enter the body through the mouth or skin of the person they have chosen as a host.
In order to enter through the mouth, they need to be swallowed. In this case, they will remain in the intestine or burrow through the intestinal wall. The latter is dangerous as they can then invade other organs.
Parasites can also enter their host directly through the skin. Some can be transmitted by insect bites.
In rare and isolated cases, these harmful organisms can be spread through blood transfusions, transplanted organs, needle injections or from a pregnant mom to her fetus.
Fecal-oral Type of Transmission
The fecal type of transmission has to do with feces or stool, whereas the oral type has to do with the mouth, meaning things that are taken into the mouth.
The first type of transmission occurs when a person somehow ingests something contaminated by feces. This can mean contamination by an infected animal or person. Dogs and cats are not the most common carriers, but they are the animals we are in contact the most, therefore, yes – the contamination can occur through them if the animal roams freely in unclean areas. Since the majority of parasites like to live in people’s digestive tract, pieces of the main parasite or its eggs can often be found in people’s feces.
Infected people can spread the infection onto others if they don’t wash their hands adequately. The chances for this to occur are huge if people don’t wash their hands after using the toilet. Once the hands are contaminated, anything they touch afterward will become contaminated with parasites as well – for instance food. However, ingestion does not have to mean the contamination had to do with food. For instance, if someone who is contaminated and hasn’t washed their hands touches an object, the object itself becomes contaminated, thus the next person who touches it may get infected as well.