|Herpes Varicella-Zoster (Shingles) Infection
|Chickenpox Varicella Infection
|Varicella Cerebral Vasculopathy
|Herpes Zoster Ophthalmicus (HZO) Shingles
|Rubella (German Measles)
|Epstein-Barr Virus infection
| Cytomegalovirus (CMV) infections
| CMV retinitis infections
Causes focal CNS lesions and encephalopathy best seen on MRI which improve with treatment
- Toxoplasmosis is a Intracellular protozoan (toxoplasma gondii) infection
- 22% of the UK population are seropositive for previous exposure
- Over 90% of French population are seropositive
- T. gondii was discovered by Charles Nicolle and L. Manceaux in 1908 in a North African rodent,
- Foodborne: Raw or undercooked meat
- Zoonotic: Cats, birds, and other animals or soil contaminated by cat faeces
- Congenital: From infected mother to fetus
- Blood tranfusion
- Pregnancy - harmful to fetus
- Seen in 10 percent of untreated AIDS patients
- Immunocompromised e.g. HIV when CD4 < 100/mm3
- Immunosuppressant therapy
Clinical - worse the earlier in gestation
- Lymphadenopathy: can involve cervical glands. Similar to glandular fever. Seen in immunocompetent individuals. Glands can be up to 3 cm.
- Toxoplasmic encephalitis: fever, severe headache, seizures, coma, seizures, neurology usually in immunocompromised e.g. HIV
- Congenital Toxoplasmosis: Infection before or during pregnancy. Microcephaly and Hydrocephalus, Chorioretinitis, Mental retardation
- Systemic Toxoplasmosis - dry cough, fever, SOB, CXR changes. Causes myocarditis, pneumonia, pleuritis, hepatitis with hepatomegaly, splenomegaly, bone marrow infiltration and CNS infection. Rare if normal immune system.
- Ocular toxoplasmosis: progressive retinochoroiditis - multiple, yellow-white, cotton-like patches with indistinct margins located in small clusters in the posterior pole. Pain and visual loss
- Immunocompetent adults: Almost always asymptomatic
- Sabin–Feldman indirect fluorescent antibody test is used in
immunocompetent patients. A x 4 ↑ IgG or the presence
of IgM indicates acute infection. The presence of high-avidity IgG
excludes infection in the past 3–4 mths, which is important in pregnancy.
- May cause a heterophile antibody-negative glandular fever-like illness
- HIV test, CD4 < 200, Test for Lymphoma
- Pulmonary : fungal pneumonia, pneumonitis can resemble PCP, Effusions. Get CXR/CT chest
- CT/MRI - multiple ring contrast-enhancing lesions (Primary brain lymphoma also seen with AIDs causes a single lesion). Toxoplasmosis is unlikely if a single and solitary disease.
- Specific IgG seroconversion; or
- Clinical features typical for toxoplasmosis, detection of specific serum IgA/IgM, and high levels of low-avidity specific IgG (<20%); or
- Epithelioid cells and lymphoid follicular hyperplasia found on histologic examination of an enlarged lymph node, presence of specific IgM, and increasing or elevated levels of specific IgG; or
- Isolation of the parasite in cultures or detection of its genetic material in blood, body fluids, or tissues.
- Lymph node tissue may be used as a source of T. gondii DNA
to be amplified by PCR, or be stained with T. gondii antisera to
demonstrate treponemes histochemically.
- Immunocompetent, nonpregnant patients typically do not require treatment
- HIV/CNS/Systemic disease consider a trial of Sulfadiazine and Pyrimethamine for 6 weeks and rescan and clinically reassess. Consider HAART as soon as stable. Risk of IRIS.
- It should result in improvement in 3 weeks. If not consider Primary CNS lymphoma, Tuberculoma, Focal cryptococcal infection