How Are Lamblia Transmitted From Person To Person? All Transmission Paths

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How Are Lamblia Transmitted From Person To Person? All Transmission Paths
How Are Lamblia Transmitted From Person To Person? All Transmission Paths

Video: How Are Lamblia Transmitted From Person To Person? All Transmission Paths

Video: How Are Lamblia Transmitted From Person To Person? All Transmission Paths
Video: How are pathogens spread and controlled | Health | Biology | FuseSchool 2023, December

Ways of human infection with lamblia


  • 1 Life cycle of lamblia
  • 2 Symptoms of Giardia infection
  • 3 Source of infection with giardiasis
  • 4 Ways of infection
  • 5 In what situations does infection with giardiasis occur?

Giardiasis is a fairly widespread parasitic disease caused by the simplest unicellular parasites - lamblia. This disease does not belong to a number of serious ones, but if you do not start treating it in a timely manner, it can cause a number of serious complications - allergies, gastrointestinal tract disorders, nervous disorders, etc. Absolutely everyone can get giardiasis, but most often children are exposed to it … The main cause of infection is neglect of basic personal hygiene standards.

Life cycle of lamblia


Life cycle of lamblia

To understand exactly how and for what reasons the infection with lamblia occurs, it is necessary to consider the stages of development of this parasite. Giardia exists in two forms:

  • Vegetative (trophozoites);
  • Cyst.

In its vegetative form, lamblia has the ability to develop and reproduce. With the help of suction cups, they are attached to the intestinal walls, actively absorbing nutrients. Giardia does not require oxygen to function normally. In this form, they are able to exist only within a person. In an open environment, trophozoites die within twenty minutes.

Cysts are smaller than trophozoites. This is a static form, in this form, lamblia are able to survive even in an alkaline environment. In the form of cysts in an open environment, lamblia can exist for two months. If the weather conditions are comfortable enough for them, and the soil is moist, cysts can live in it for up to four months.


Giardia enters the human body just in the form of cysts. Here the membrane dissolves and the cyst takes on a vegetative form. Further, the trophozoite enters the intestines, into a favorable habitat for itself, where it begins to lead an active life.

Giardia reproduces very quickly, but one or two individuals of the parasite will not be enough for the occurrence of giardiasis. For this, at least 10 cysts must enter the body. One adult individual takes 5-6 hours to reproduce a similar lamblia. In 10 hours, a colony of parasites is able to double its number.

Most often, giardia live in the small intestine, where all the nutrients are absorbed by humans. The parasite also feels good in the large intestine, where individual individuals who do not have time to gain a foothold on the walls of the epithelium enter.

In the lower part of the intestine, the vegetative form of lamblia is unable to survive. Here they either die or transform, transforming into the form of cysts.

Symptoms of lamblia infection

Signs of infection do not appear immediately. After the invasion, it can take at least a week before the disease makes itself felt. This is due to the fact that lamblia takes some time to begin active reproduction. Only when their number begins to increase rapidly, the human body begins to actively respond to the invasion of parasites. If a person's immunity is strong enough, or too few individuals have entered the body, giardiasis may not manifest itself at all.

It is easier for an adult to resist the penetration of parasites, the symptoms of infection with lamblia in humans may be subtle, while in children they are much more pronounced.

In the early stages of the disease, reactions such as:

  • Allergy. It manifests itself as a result of the ingress of toxins into the skin, it is expressed in the form of a runny nose, tearing, skin rashes and other things.
  • Enlargement of the liver and spleen in size, this is possible with hepatic giardiasis.
  • Stool disorder. This symptom manifests itself more often than others, frothy diarrhea is most often noted. Giardia settle in the intestines and their active reproduction cannot but affect its work
  • Unstable stools. Diarrhea is abruptly replaced by constipation and vice versa.
  • Pain in the lower abdomen is common. At the same time, it is very difficult to determine exactly where the source of pain is.
  • In the corners of the lips "sticks" appear. This occurs as a result of dry skin.
  • Gas formation is common after eating.
  • "Marble" skin tone, with the hepatic form of giardiasis, it acquires an icteric color.
  • Dry skin is common. This is due to a lack of vitamins, which Giardia "intercept" before the owner.
  • Abrupt mood swings, overexcitation.
  • Bad sleep.

If you do not start timely treatment, giardiasis from the acute stage becomes chronic. This condition is characterized by the following symptoms:

  • Weight loss. As a result of a lack of nutrients for a long time, a person begins to actively lose weight. This process is gradual but stable.
  • As a result of constant lack of sleep, lack of micronutrients in the required amount, a person begins to get tired faster and lose efficiency. As a result, irritability and even depression.
  • Intestinal disorders in the chronic stage become permanent and uncontrollable.

Due to the fact that at this stage of the course of the disease, the amount of toxins in the body increases, more serious health problems can begin.

  • Enlargement of the adenoids, this symptom appears more often than others
  • The lymph nodes also increase in size.
  • Often the patient develops a low-grade fever. The thermometer reading does not rise above 37.5, but it does not fall below 37.1.
  • Against the background of reduced immunity, all kinds of infections often occur, especially often a person suffers from diseases of the common cold.
  • All infections that a person gets at this stage are much more difficult to treat and require a longer recovery time than usual.

Source of infection with giardiasis

The only source of infection is humans. It is he who is the host for lamblia. Parasites live in the human body, multiply and are excreted in the feces, falling into an open environment. Through the soil, water, Giardia is actively distributed, getting into the body of other people.

It has been established that animals can also be a source of infection. Parasites can be found on their fur, on the face.

Infection routes


Methods of penetration of lamblia

To minimize the risk of infection, you should know how Giardia is transmitted. A person can become infected in three main ways:

  • Water;
  • Contact and household;
  • Food.

The waterway is not the most common, but it presents a very real danger. How can you get Giardia this way? For example, drinking unboiled water, in which there are giardia. They can get into it as a result of poor-quality cleaning. Often outbreaks of giardiasis occur after major accidents in sewer and water supply networks. With a large discharge into water bodies, from which water is taken for drinking needs of the population, wastewater from livestock farms, industries.

In almost all fresh water bodies, since Giardia does not live in salt water, there are up to 30 cysts per one cubic meter of water. If such water is insufficiently treated, contamination is inevitable. In wastewater, there can be up to 1100 representatives of this type of parasite per cubic meter.

To reduce the risk of contracting giardiasis through water, you should not drink it directly from the tap. For prophylaxis, the water should be filtered, or even better, boiled. Also, for the sake of your own safety, you should not swim in water bodies that do not meet the required standards. Even in the pool, there can be large numbers of cysts in the water, so even active chlorine, which is often used to disinfect water, is not able to kill the parasites living in it.

In order to become infected by water, it is not at all necessary to swallow dirty water while swimming. Dirty water remains on the body and hands, it is not difficult for parasites to get into the mouth from dirty hands.

The household contact route is the most common way. It is in this way that giardia is transmitted from person to person, and not only they, but all intestinal infections.


Source of infection

How exactly are Giardia transmitted from person to person? Dirty hands, unwashed household items become a source of infection. 35% of cases are children of preschool age attending child care facilities. This is because children still do not follow the rules of personal hygiene and do not wash their hands with soap and water after using the toilet. As a result, bacteria can spread to toys, doorknobs, pencils and other common items. Giardia feel great in the sandpit, especially in the warm season.

To prevent the possibility of infection in this way, children should be taught to wash their hands with soap and water after using the toilet, after returning from the street. You should not be allowed to bite your nails, pick up objects from the floor and put them in your mouth, lick your fingers. For prophylaxis, kindergartens carry out regular general cleaning with thorough washing of all toys and surfaces.


Cat infection

Please note that pets can also become a source of Giardia infestation. Cats and dogs do not get sick with giardiasis, but they can carry them on their fur along with the ground. Therefore, you should teach your child to wash their hands every time after contact with animals.

Human hands can become a source of infection. If a person is sick with giardiasis and does not have the habit of washing his hands after using the toilet with soap, cysts of parasites may be on the skin of his hands. Moreover, their number can be significant, if we take into account that one gram of feces of an adult can contain up to 12 million cysts. For one gram of a child's feces, their number is fifty times less, but the risk is quite high.

That is why, if giardiasis is found in one of the family members or children's collective, the whole family and all children from a close circle of friends are checked for the disease. All furniture, dishes and other household items should be thoroughly wiped out with disinfectants, otherwise others may become infected. The patient himself can also get sick again, especially when you consider that after the illness, his immunity is not yet too strong.

The food route of infection is not as common as the two previous ones, but still the probability of infection in this way is quite high. Infection with giardiasis occurs through unwashed vegetables and fruits. Especially if the vegetables were harvested from a garden bed, on which manure or human feces were used to feed the soil. Together with feces, cysts could get into the soil, which can live in the ground for more than two months.

Giardia cysts can get on vegetables through the dirty hands of the seller or anyone else who touched them. Giardia can carry flies on their paws. As a result, these vegetables also become a source of infection.

To avoid contracting giardiasis in this way, you need to thoroughly wash vegetables and fruits before eating. It will not be superfluous to process fruits, even bananas, with special detergents for washing food.

In what situations does infection with giardiasis not occur?

Not everyone can get giardiasis even when cysts have entered their body. For the development of this disease, certain conditions are necessary, if they are not there, Giardia cannot lead to infection.

  • The number of parasites is not large enough. For the development of the disease, there must be at least 10 individuals. However, in this case, the body must have a weakened immune system. In order for giardiasis to manifest itself in an adult organism, there must be about 100 individuals.
  • If a person's immunity is strong enough, then Giardia, once in the digestive system, will not be able to actively multiply. The body will actively respond to them by producing the required amount of antibodies. In a few months, the body will cope with the infection on its own, and the person may never know that he had a parasitic disease.