TOXOPLASMOSIS

1. TOXOPLASMOSIS Developed by Pam Holmes, Christy Stalcup, and Pam Yarborough

2. WHAT IS TOXOPLASMOSIS? Toxoplasmosis is an infection caused by a parasite most often found in cats and farm animals. Humans can catch this disease from: coming into contact with infected cat feces eating raw or undercooked meat that’s infected eating contaminated vegetables or fruits being born with it Note: Once a person is infected, the infection remains in the body for life, usually in an inactive form. It can reactivate when that person’s immune system is weak.

3. About 98% of cases of Toxoplasmosis are acquired through Congenital Toxoplasmosis. One study showed that 76% of infants infected with congenital toxoplasmosis had ocular lesions, 51% had neurological involvement, and 26% had either hydrocephalus (increased intracranial pressure) or michrocephaly (small brain). It is evident that vision problems are very common with Congenital Toxoplasmosis. Once the mother develops immunity to the organism, all future pregnancies are protected from transmission of the organism.

4. Signs and Symptoms 1. Toxoplasmosis in an otherwise healthy person may have no symptoms or only a few swollen glands usually in the patient’s neck. 2. Toxoplasmosis in a person with a weakenedimmune system may only have symptoms of swollen glands, or in the case of an infection that attacks the brain and nervous system, the symptoms may include fever, seizures, headache, psychosis, and problems with vision, speech, movement, or thinking.

5. 3. Children born with Toxoplasmosis, which accounts for about 98% of cases, may show symptoms including: • Fever • Swollen glands • Jaundice • An unusually large or small head • Rash • Bruises or bleeding under the skin • Anemia • Enlarged liver or spleen • Seizures • Limp muscle tone • Mental retardation • Hearing loss • Vision problems (toxoplasmosis of the eye)

6. Toxoplasmosis of the Eye Congenital Toxoplasmosis is the most common form. If the mother acquires the infection during the first trimester, 17% of these babies develop congenital toxoplasmosis and the effects are severe. However, if the infection occurs during the third trimester, 65% of the babies develop the disease. Yet, the infant usually has no symptoms.

7. DAMAGE TO THE EYE The parasite usually invades the retina and the choroid tissue. Depending upon the area and severity of the infection, visual acuity can be unaffected to severely affected. The retina is inflamed by the infection and sometimes when the inflammation settles, scars are left on the retina. Symptoms include floaters and blurred vision. If the scarring is on the central macula, detailed vision will be affected. Approximately 35% of all retinachoroiditis cases can be attributed to toxoplasmosis. Active Toxoplasmosis Inactive Toxoplasmosis Scar

8. Common Effects: Inflammation of retina Blurred vision Floaters Nystagmus Amblyopia Squint Occasional Effects: Cataracts The eye can be small Optic atrophy Cerebral visual impairment Effects of Ocular Toxoplasmosis

9. Functional Implications Functional implications vary depending on severity of infection and/or scaring and how successful the treatment. Those affected often describe vision as “hazy” with floaters. Some implications are more serious such as total blindness in one or both eyes. Those affected early during pregnancy often suffer other implications such as mild to severe mental retardation, cerebral palsy, seizures and other problems. Appropriate accommodations and modifications should be determined by the FVE.

10. Treatment Treatment will not result in the elimination of the organism from the eye. Since new lesions can form if the organism reactivates, especially during adolescence, patients should be closely monitored. Medications: • Spiramycin during pregnancy • Antibiotics and steroid tablets during an infection • Pyrimethamine/sulphadoxine for 6-12 months as follow-up procedure

11. Sam History Sam is a third grader that was diagnosed with Toxoplasmosis (visual impairment), mental retardation, and other health impairment. He suffered acute retino-choroidal inflammation which produced dense scaring in both eyes. He has suffered reactivations which caused adjacent scars creating satellite lesions to the macula in the right eye. His eye report states that there is significant scar tissue stretching from the nasal passage to the optic nerve. There is little medical information other than eye examination reports. It was determined in ARD meeting that there was little (if any) pre-natal care and treatment of the toxoplasmosis after birth. It is a continuing problem to get consent signed to obtain medical records from the parents. Environment Sam is attending third grade in an inclusive classroom environment. He functions about 2 ½ years below grade level. It is difficult to determine if it is visual deficits or cognitive ability that hinders learning. Some modifications in the classroom are 36 pt font, one step directions, peer tutoring, slant board, frequent breaks, well lit environment, auditory instruction coupled with visual input, clear/uncluttered copies, contrast, allow positioning for materials as needed, do not ask questions like “can you see this” have him tell you what he sees, do not place him beyond 6-8 feet from board, make sure he is wearing glasses at all times and watch for signs such at fatigue and headaches.

12. Sources http://www.nlm.nih.gov/medlineplus/ency/imagepages/17186.htm http://www.eyemdlink.com/Condition.asp?ConditionID=444 http://www.patient.co.uk/showdoc/40000376/ www.viscotland.org.uk http://www.kidshealth.org/PagManager.jsp?dn=KidsHealth&lic=1&ps-107&cat_id=20045&art...... http://www.revoptom.com/handbook/sect5i.htm Program in Low Vision Therapy, Region 4 Education Service Center, McKinney, Bill, Ph.D. Executive Director, 2004. Houston, Tx pg 25