There are parasites in the body

Human parasites are organisms that live on or in the human body, obtaining nutrients and shelter at the expense of the host. These organisms range from microscopic protozoa and worms (worms) to larger arthropods. Parasites have different life cycles and modes of transmission, and they can affect different organs and systems in the body.Unicellular parasites (protozoa) and multicellular parasites (helminths, arthropods) are antigenically and biochemically complex, as are their life histories and the pathogenesis of the diseases they cause. During their lifetime, parasites typically pass through several developmental stages, accompanied not only by changes in structure but also in biochemical and antigenic composition. Some larval stages of worms bear little resemblance to the adult stages (such as tapeworms and flukes). Some protozoan parasites also undergo significant changes during their lifetime. For example, Toxoplasma gondii is an intestinal coccidia in cats, but in humans it has a different form and is found in deeper tissues.Some of these infections may progress from a well-tolerated or asymptomatic state to life-threatening disease. Many parasitic infections are transmitted from animals to humans (zoonotic infections).

protozoan parasites

Protozoa are microscopic, single-celled organisms that can be free-living or parasitic. Protozoa that live in the human intestine are usually transmitted to another person through the fecal-oral route (for example, through contaminated food or water or person-to-person contact). Protozoa that live in human blood or tissues are transmitted to other humans via arthropod vectors (e. g. , through mosquito or midge bites).Human protozoan parasites can be divided into four categories based on their mode of movement.

1. Sarcopodia: uses pseudopods for locomotion. These include the amoeba (dysenteric liver abscess), amoeba (colitis), and Acanthamoeba (can cause a serious and often fatal infection of the brain and spinal cord called granulomatous encephalitis).
2. Flagellates (sarcomastigotes): Use flagella for movement. These include giardiasis (diarrhoea), trypanosomiasis (sleeping sickness and Chagas disease), leishmaniasis (visceral, cutaneous and mucocutaneous leishmaniasis) and trichomoniasis (a sexualtransmitted infections (STI)).
3. Apical Complex: The apical complex is used for movement. Includes Plasmodium (malaria), Toxoplasma gondii (zoonotic infection caused by the parasite Toxoplasma gondii, with a variety of clinical symptoms in humans).
4. Ciliates: These ciliates move by cilia and include a large protozoan, Barania, which is the only ciliate known to infect humans (dysentery). Approximately 1% of the world's population is infected with cysticercosis.

worm

Worms are large multicellular organisms that are usually visible to the naked eye in their adult stages. Worms can be free-living or parasitic. After reaching adulthood, the worms cannot reproduce in the human body. Human parasites are divided into three main types of worms:

• Flukes: Fasciola hepatica – a liver fluke; Fasciola buschii – an intestinal fluke; Paragonimus westermani – a lung fluke; Schistosoma is a blood fluke.
• Cestodes: Diphyllobothrium Latum – broad tapeworm; Hymenolepis Nana – dwarf tapeworm; Taenia Saginata – cattle tapeworm; Taenia solium – pork tapeworm.
• Nematodes (roundworms) cause a variety of diseases in humans, which may be intestinal or may directly affect certain tissues. roundworms
• Lumbricoides - giant roundworms; pinworms - pinworms, etc.

ectoparasites

These are organisms that live on the outside of the host's skin. Skin parasites feed on the blood and epidermis. They are often so small that they cannot be seen. Some species burrow into the skin, others live on the surface. Some parasites can spend their entire life cycle inside the body, but many live outside the body and only feed occasionally.

• Bed bugs are a common parasite called bed bugs.
• Dermatobia hominis are the larvae of the human gadfly.
• Sarcoptes scabiei is a mite that causes scabies.

Human parasites affect millions of people around the world, especially in areas with limited access to clean water, sanitation and healthcare.

Pathological causes

• Food and water are contaminated. Improperly treated or contaminated water sources may contain parasites such as Giardia lamblia and Cryptosporidium parvum, which can cause gastrointestinal infections. Eating undercooked or contaminated food, especially raw or undercooked meat and seafood, can lead to the spread of parasites such as Toxoplasma gondii and Trichinella spiralis.
• Poor hygiene and sanitation. Many parasitic infections, especially those caused by helminths (e. g. , roundworms, hookworms), are spread through contact with fecal-contaminated soil, food, or water.
• Vector transmission via insect vectors. Parasites such as Plasmodium (malaria), trypanosomes (Chagas disease, African sleeping sickness), and filarial worms (causing lymphatic filariasis) are transmitted through the bites of infected insects (mosquitoes, bed bugs, and midges).
• Animal-to-human transmission: Some parasites are hosts in animals, and humans can become infected through direct contact with an infected animal or its excrement. For example, Toxoplasma gondii can be spread through contact with cat feces.
• Imported infection. Individuals who travel to areas where certain parasites are endemic may be at risk of contracting infections not commonly seen in their home country.
• Transmission from person to person. Some parasites in the body, especially intestinal parasites such as pinworms (pinworms) and Giardia lamblia, can be spread through direct contact between people, usually in crowded or communal living conditions.
• Contaminated soil: Certain types of worms, including nematodes, can infect humans through contact with contaminated soil containing parasite eggs or larvae.

disease symptoms

Helminthiasis can present with a variety of symptoms, depending on the type of parasite in the person, the site of infection and the severity of the invasion:

• Abdominal pain, cramping, and discomfort.
• Nausea and vomiting.
• Diarrhea or constipation.
• Weight loss and malnutrition.
• Anemia occurs due to loss of blood and nutrients.
• There are visible insects in the feces.
• Perianal itching (Pinworm (pinworm) infection can cause perianal itching in children, especially at night).
• Respiratory symptoms: Some worms, such as roundworms, can migrate into the respiratory tract and cause symptoms such as coughing and wheezing.
• High temperature: In some cases, worm infection can cause a low-grade fever.
• Certain liver fluke or tapeworm infections can cause enlargement of the liver (hepatomegaly) or spleen (splenomegaly).

Protozoa (protozoan parasites) most commonly cause diarrhea. Excessive diarrhea can lead to dehydration, which is especially common in children under 5 years old. Toxins released by pathogens and entering the bloodstream can cause weakness and pain in the abdomen and muscles. When the infection becomes chronic, weight loss and rashes may occur.

Diagnosis of disease

Diagnosis of parasitic infections requires a combination of clinical evaluation, laboratory testing for parasites, and sometimes imaging studies.A detailed medical history, including information about travel to other countries, exposure to contaminated water or food, and symptoms, can help health care providers narrow down potential parasitic infections. A physical exam may reveal signs and symptoms associated with infection, such as rash, abdominal tenderness, or organ enlargement.Microscopic examination of stool samples is a common method of identifying intestinal parasites, including helminths and protozoa. If pinworm disease is suspected, a smear test of the perianal area should be performed and then examined under a microscope. Parasite blood tests can be used to detect antibodies, antigens, or DNA from parasites.

• To diagnose hydatid disease, serology and sometimes liver ultrasound are required.
• Metatesticular disease can be diagnosed by stool examination, serological testing, and sometimes DNA testing.
• Toxocariasis can be detected by a Toxocara antibody test, a parasite DNA test, and a general blood test that shows eosinophilia.
• Giardiasis is diagnosed by stool analysis and serological testing.
• To diagnose ascariasis, stool microscopy and a roundworm antibody test are used.
• Trichinellosis: Serological testing and DNA analysis of Trichinella spiralis.

Urine samples can detect the presence of parasite eggs, larvae or antigens, especially in infections such as schistosomiasis. Radiological imaging, such as ultrasound, computed tomography, or MRI, can be used to visualize and assess the extent of tissue damage caused by certain parasites, particularly in the case of cystic or tissue-infiltrating parasites.

treat

Treatment of parasitic infections usually involves the use of antiparasitic drugs. The specific medications and duration of treatment depend on the type of infection causing the infection, its severity and the organs affected. Metronidazole and tinidazole are effective against a variety of protozoa, including Entamoeba histolytica and Giardia. Atovaquone-Proguanil: Used to treat and prevent malaria and some protozoal infections. Anthelmintics include albendazole, praziquantel, ivermectin, pyrantel pamoate, sulfadiazine, and suramin.

Disease prediction and prevention

The prognosis for treating internal parasites varies widely and depends on a variety of factors, including the type of parasite, the severity of the infection, the organ systems affected, and the person's overall health. In many cases, prompt and appropriate treatment can lead to good results, while lack of treatment or severe infection can lead to complications and long-term health consequences.The human immune system plays an important role in determining the outcome of parasitic infections. Immunocompetent people may have a better prognosis than those with weakened immune systems.The occurrence of complications such as organ damage, chronic inflammation, or secondary infection can significantly affect the prognosis. Long-term or untreated infection may cause complications.Some parasitic infections may become chronic and last for a long time. Chronic infections can cause ongoing health problems and be difficult to manage.Involvement of key organ systems such as neurological, cardiovascular, or respiratory systems may have a significant impact on prognosis. Parasites that attack vital organs can cause more serious and life-threatening complications.Preventing parasitic infections involves taking various steps to reduce the risk of infection and transmission. General recommendations for preventing parasitic infections are:

• Wash your hands thoroughly with soap and water after using the toilet, before eating, and after touching pets or soil.
• Keep your nails short and clean to minimize the risk of parasite eggs or cysts developing under your nails.
• Cook meat, fish and poultry thoroughly to kill parasites. Wash fruits and vegetables thoroughly, especially those eaten raw.
• Drink purified or boiled safe drinking water, especially when traveling to areas with a high risk of waterborne parasites.
• Use insect repellent to prevent bites from mosquitoes, ticks, and other vectors that can transmit parasitic diseases.
• Make sure your pet receives regular veterinary check-ups and deworming medication.
• Dispose of pet waste properly to minimize the risk of pest infestation.