How does the immune system fight toxoplasmosis?
Humoral immunity is essential for resistance to toxoplasmosis. It has long been recognized that infection with T. gondii promotes antibody responses, and that these antibodies can kill the parasite [112].
Does toxoplasmosis weaken your immune system?
Persons with compromised immune systems may experience severe symptoms if they are infected with Toxoplasma while immune suppressed. Persons who acquire HIV infection and were not infected previously with Toxoplasma are more likely to develop a severe primary infection.
How does the immune system response to parasite?
An immune response to parasites, specifically worms, triggers an IgE response. IgE elicits an immune response by binding to Fc receptors on mast cells, eosinophils, and basophils, causing degranulation and cytokine release. In atopic individuals, IgE is also made to allergens. IgE is at low levels in the blood.
What is the treatment for toxoplasmosis in humans?
Most healthy people recover from toxoplasmosis without treatment. Persons who are ill can be treated with a combination of drugs such as pyrimethamine and sulfadiazine, plus folinic acid.
Can toxoplasmosis cause autoimmune disease?
T. gondii tachyzoites infect almost all nucleated cells and their intracellular multiplication and lifelong persistence in the host cells play an important role in triggering and development of autoimmune diseases (ADs).
Is toxoplasmosis curable in humans?
Many congenital toxoplasmosis cases can be cured with medications. Even children who had severe infections at birth may never show signs of severe long-term damage if they are diagnosed and treated early. Delays in diagnosis and treatment can contribute to a poor prognosis.
What happens in the immune response?
In an immune response, the immune system recognizes the antigens (usually proteins) on the surface of substances or microorganisms, such as bacteria or viruses, and attacks and destroys, or tries to destroy, them. Cancer cells also have antigens on their surface.
How do parasites escape the immune system?
For example, (i) parasites can hide away from the immune system by invading immune-privileged tissue such as the central nervous system or the eye (Bhopale 2003). Also some parasitoids place their eggs inside tissue such as the fat body that is not well patrolled by the host's immune system.
Which immune cells are involved in the killing of extracellular parasites?
In their studies, complement, neutrophils and macrophages are all involved. Although either neutrophils or macrophages need to be in contact with the worm, the cell types can be separated from each other. So soluble communication between the cells is needed but either one can kill.
Can you vaccinate against toxoplasmosis?
Congenital toxoplasmosis has a high impact on human disease worldwide, inducing serious consequences from fetus to adulthood. Despite this, there are currently no human vaccines available to prevent this infection.
Why is Toxoplasma gondii not treatable by antibiotics?
Antibiotic treatment is thought to eradicate the tachyzoite form of the parasite during the acute inflammatory phase. Antibiotics are not effective against the latent bradyzoite cyst form of the parasite.
How long does it take to treat toxoplasmosis?
Toxoplasmosis is treated primarily with antibacterial and anti-parasitic drugs for about four weeks. Laboratories can perform blood and tissue tests to confirm infection with Toxoplasma gondii.
Overview
- Toxoplasmosis is a disease caused by the parasite Toxoplasma gondii, which can be found in garden soil and raw meat. Cats can get toxoplasma infection by killing and eating infected prey. The disease can also be passed on from cats to humans.
- Toxoplasma is first and foremost a parasite of cats that is found worldwide. Infection is most common in free-roaming cats who usually pick it up by eating rodents or other critters that have Toxoplasma organisms encysted in their tissues. Once liberated into the intestines of a cat, the parasites multiply within the digestive tract. Toxoplasma eggs, known as oocysts, are shed in ca…
Treatment
- Most healthy people don't require toxoplasmosis treatment. But if you're otherwise healthy and have signs and symptoms of acute toxoplasmosis, your doctor may prescribe the following drugs: 1. Pyrimethamine (Daraprim). This medication, typically used for malaria, is a folic acid antagonist. It may prevent your body from absorbing the B vitamin folate (folic acid, vitamin B-9)…
- In most cases, if you are a generally healthy person, no treatment is necessary unless your symptoms are severe or unusually persistent. If toxoplasmosis affects your eyes, your doctor may treat you with pyrimethamine (Daraprim) combined with either sulfadiazine (Microsulfon) or clindamycin (Cleocin).If you have a weakened immune system, your doctor will treat you with a …
- Antibiotics are available that can clear up most of the symptoms of toxoplasmosis. Although they do not kill the parasite, they can provide an effective treatment.
- Older children and teenagers with a normal immune system do not require specific medical treatment for toxoplasmosis unless they are pregnant. All infected newborns should be treated to avoid eye problems and inflammation of the brain. Patients with a weakened immune system usually require treatment. Your pediatrician will often call in a specialist in infectious diseases t…
Prevention
- You can help prevent toxoplasmosis by taking the following precautions: 1. Do not eat meat that is raw or rare. If you have a meat thermometer, cook meat to an internal temperature of at least 140° Fahrenheit. 2. Wash your hands thoroughly after you handle raw meat, after you work in your garden, and after you change a cat's litter box. 3. If you are pregnant or have a weakened immun…
- Cats who are capable of shedding eggs should be isolated from children and other pets, pregnant moms and any immunocompromised people in the household. Also, be sure to clean his litter box and bedding twice each day while wearing disposable gloves.
- People with healthy immune systems usually do not need treatment for toxoplasmosis. For people with symptoms, the treatment most frequently used is a combination of pyrimethamine* and sulfadiazine or clindamycin. There are a few minor variations, but treatment is basically similar for babies, healthy adults, and people with AIDS. People taking pyrimethamine are usuall…
- Hygiene measures, particularly for pregnant women and seronegative immunocompromised patients: 1. Wash hands before handling food. 2. Thoroughly wash all fruit and vegetables, including ready-prepared salads, before eating. 3. Thoroughly cook raw meats and ready-prepared chilled meals. 4. Wear gloves and thoroughly wash hands after handling soil and gardening. 5. A…
Diagnosis
- Most pregnant women in the United States aren't routinely screened for toxoplasmosis, and most states don't screen infants for the infection. Without specific screening, toxoplasmosis is often difficult to diagnose because signs and symptoms, when they occur, are similar to those of more common illnesses, such as the flu and mononucleosis.
- Your doctor will ask about your medical history to find out whether you have any medical problem that would weaken your body's immune defenses against toxoplasmosis, including HIV or AIDS, cancer, an inherited immune deficiency or an organ transplant. In addition, your doctor will review your current medications to check for any drug that may suppress or damage your immune defe…
- If you suspect your cat is carrying the parasite that causes toxoplasmosis, its time to get him tested by your veterinarian. If he tests positive, it means he has been exposed to the disease but is unlikely to be shedding oocysts after an initial two-week period. If he tests negative, it means he has not been exposed and could still become infected and shed oocysts-but again only for two …
- You will need to give a detailed history of your cat's health, onset and nature of symptoms, and possible incidents that might have precipitated this condition, such as contact with other cats. Your veterinarian will perform a thorough physical exam to evaluate your cat's body systems and to evaluate the overall health of your cat. Routine laboratory tests -- such as a complete blood co…
Symptoms
- In people with normal immune defenses, up to 90% of cases of toxoplasmosis do not cause any symptoms, so the infection often is not recognized. In the relatively few cases in which symptoms do develop, the most common symptoms are: 1. Painless swelling of the lymph nodes 2. Headache 3. Malaise (a general sick feeling) 4. Fatigue 5. Low-grade fever In rare cases, patient…
- Most cats become immune to the disease through exposure to the parasite. However, those who arent already immune may have mild diarrhea and a loss of appetite; the disease can also affect a felines lungs, liver and nervous system. Kittens exposed to the parasite while still in the womb are most vulnerable-and are more likely than adult cats to show symptoms.
- In healthy cats, Toxoplasma generally causes few signs of illness. In cats with a suppressed immune system, a wide variety of illnesses can occur, including problems with the eyes, respiratory system, liver, and brain. In these cases, it’s tough to pin down the cause because of the wide range of signs that may show up, running the gamut from cough to seizures. As part of the …
Causes
- Toxoplasmosis is an infection caused by Toxoplasma gondii, a single-celled parasite that spends most of its life cycle inside cats. Because an infected cat can pass millions of Toxoplasma parasites daily in its feces, toxoplasmosis can spread easily to almost any other animal that shares the environment with cats. In humans, Toxoplasma parasites usually enter the body by b…
- Cats most often become carriers of toxoplasmosis by killing and eating wild animals who have been infected-a good reason not to let your cat outside to hunt! A cat may also contract the disease should he come into contact with an infected cats feces. Once a cat is infected, the parasite multiplies in his intestines until immature eggs called oocysts are shed in his feces. Inf…
- Cats become infected through contact with the T. gondii parasite, which may be acquired from rooting in infected soil or from ingesting cat feces.
- The most common way people get toxoplasmosis is by ingesting toxoplasma eggs (oocysts). Cats are the primary source of these eggs. While Toxoplasma gondii can reproduce asexually in a variety of animals, only in the intestines of cats does it undergo sexual reproduction to generate eggs, which are then passed out in the cat's feces. The eggs that are passed by the cat can rem…
Prognosis
- People with AIDS who have recovered from acute toxoplasmosis are at high risk of future episodes, because the dormant parasite may be reactivated. To prevent this, an AIDS patient must begin a regimen of preventive drugs and continue to take the medications as long as his or her immune system remains weakened. One popular prophylactic drug combination — trimethopri…
- 1. Most cases in immunocompetent healthy individuals remain subclinical or resolve spontaneously. 2. The prognosis in AIDS patients was poor but has improved considerably since the advent of ART (also called HAART). 3. The overall prognosis with maternal infection is fairly good: 1. The overall risk of vertical transmission with maternal seroconversion is 26%. 2. Amon…
- The prognosis is poor when congenital toxoplasmosis is acquired during the first three months of pregnancy. Afflicted children die in infancy or suffer damage to their central nervous systems that can result in physical and mental retardation. Infection later in pregnancy often results in only mild symptoms, if any. The prognosis for acquired toxoplasmosis in adults with strong immune syste…
Definition
- Toxoplasmosis is an infectious disease caused by the one-celled parasitic organism Toxoplasma gondii. Although most individuals do not experience any symptoms, the disease can be very serious and even fatal in fetuses, newborns, and individuals with weakened immune systems.
Epidemiology
- Toxoplasmosis is a parasitic infection that infects a large proportion of the world's population, but rarely causes disease. Certain people, however, are at high risk of severe or life-threatening disease from this parasite. They include infants who are infected at birth, people with AIDS, people with cancer, and people who have had bone marrow or organ transplantation.
- T. gondii is worldwide in distribution but the disease occurs less frequently in areas where the environment is unfavourable for the oocysts, such as colder or drier regions and high altitudes. The seroprevalence of populations varies widely - for example: 1. A systematic review found that in the USA 16-40% of the population were infected compared to 50-80% in South America. 2. On…
- Serologic prevalence data indicate that toxoplasmosis is one of the most common infections of humans throughout the world, and prevalence increases with age . Due to environmental factors impacting the survival of the oocysts, infection is more common in warm climates and at lower altitudes than in cold climates and mountainous regions. Variations in mode of exposure also le…
Further Information
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- This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com). 1. AIDSinfo. http://aidsinfo.nih.gov. Accessed May 19, 2009. 2. Centers for Disease Control and Prevention (CDC). www.cdc.gov. Accessed May 19, 2009. 3. HIV InSite. http://hivinsite.ucsf.edu. Accessed May 19, 2009. 4. Natio…