**7. Preventive measures**

Prevention of *Toxoplasma* infection comprise two important measures i.e. infected-meats and contamination by oocyst from cat excreta. HIV-infected persons with negative *T. gondii* antibody should be recommended to consume only well-cooked meats or those frozen for at least 24 hours. Properly cooked until the internal temperature is over 60C, correctly smoked or cured in the brine are safe, but microwave cooking is not (Mariuz & Steigbigel, 2001). Noteworthy, increasing animal-friendly production systems might increase *T. gondii* prevalence if cooking practice is not proper. Chumpolbanchorn et al (2009) demonstrated 64.03% *T. gondii* antibody in Thai free-range chickens, while low prevalence (2.3%) was found in animal-friendly pig production systems in the Netherlands (Kijlstra et al, 2004).

Limiting exposure to cats, their litter and soil contamination with cat fecaes are things to be practised as well as avoiding infective oocysts by daily disposal cat litter and thorough hand washing, keeping cats indoor and feeding with canned or well-cooked food.

Toxoplasmic Encephalitis 301

Cabral, R.F., Valle Bahia, P.R., Gasparetto, E.L., et al. (2010). Immune reconstitution

Carr, A., Tindall, B., Brew, B.J. et al. (1992). Low-dose trimethoprim-sulfamethoxazole

Cavalcante, G.T., Aguilar, D.M., & Camargo, .LM. (2006). Seroprevalence of Toxoplasma

CDC Recommendations and Reports. (2009). Guidelines for Prevention and Treatment of

Chang, L., Cornford, M.E., Chiang, F.L., et al. (1995). Radiologic-pathologic correlation.

Chankrachang, S. (2004). CNS Infection in HIV-Infected Patients, In: *Infection: Molecular,* 

Chumpolbanchorn, K., Anankeatikul, P., Ratanasak, W., et al. (2004). Prevalence of

Collazos, J. (2003). Opportunistic infections of the CNS in patients with AIDS: diagnosis and

Contini, C., Cultrera, R., Seraceni, S., et al. (2002). The role of stage-specific oligonucleotide

Cultrera, R., Seraceni, S., Contini, C. Efficacy of a novel reverse transcriptase-polymerase

expression in human clinical specimens. *Mol Cell Probes.* Vol. 16, pp.31-39. Dedicoat, M. & Livesley, N. (2008). Management of toxoplasmic encephalitis in HIV-infected

Dubey, J. P. (2007). The history and life cycle of *Toxoplasma gondii*. In: *Toxoplasma gondii. The* 

Dubey, J.P.; Miller, N.L.; Frenkel J.K. (1970). The *Toxoplasma gondii* oocyst from cat fecaes. *J* 

Ferguson, D.J. (2009a). *Toxoplasma gondii*: 1908-2008, homage to Nicolle, Manceaux and

Splendore. *Mem Inst Oswaldo Cruz*. Vol. 104, No. 2, pp.133-148.

immunodeficiency syndrome. *Am J Med*. Vol.86, pp.521-527.

Cooper, D.A. et al. (1996). Clinical treatment. *AIDS*. Vol. 10, (suppl A), pp. S133-4.

management. *CNS Drugs*. Vol.17, pp.869-887.

adults-a review. *S Afr Med J*. Vol. 98, pp.31-32.

pp.E65-66.

pp.:647-649.

Vol. 15;117, pp.106-111.

2009/58(RR04);1-198

Bangkok, Thailand.

Vol.51,pp.879-890.

Academic Press, New York.

*Exp Med,* Vol. 132 pp. 636-662.

pp.1653-1663.

inflammatory syndrome and cerebral toxoplasmosis. *Am J Neuroradiol*. Vol.31,

prophylaxis for toxoplasmic encephalitis in patients with AIDS. *Ann Intern Med*.

*gondii* antibodies in humans from rural Western Amazon, Brazil. *J Parasitol*. Vol. 92,

Opportunistic Infections in HIV-Infected Adults and Adolescents, Recommendations from CDC, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America, April 10,

Cerebral toxoplasmosis and lymphoma in AIDS. *AJNR Am J Neuroradiol*. Vol.16,

*Cellular and Clinical Basis,* Wattanasirichaikul, S., Aussadamongkol, K., Rigunti, M., Santiwattanakul, S. eds., pp.1703-13, Medsai Printing, ISBN: 974-92320-7-0,

*Toxoplasma gondii* indirect fluorescent antibodies in naturally- and experimentallyinfected chickens (*Gallus domesticus*) in Thailand. *Acta Parasitol*.Vol.54, pp.194-196. Cohn, J.A., McMeeking, A., Cohen, W., et al. (1989). Evaluation of the policy of empiric

treatment of suspected Toxoplasma encephalitis in patients with the acquired

primers in providing effective laboratory support for the molecular diagnosis of reactivated Toxoplasma gondii encephalitis in patients with AIDS. *J Med Microbiol*.

chain reaction (RT-PCR) for detecting Toxoplasma gondii bradyzoite gene

*Model Apicomplexan: Perspectives and Methods.* L. M. Weiss, & K. Kim, (Eds.), 1–17,

### **8. Conclusion**

Toxoplasmic encephalitis is the most common cause of focal CNS infections in people with AIDS. Its incidence has been reduced after prophylaxis was widely advocated, but the dramatic reduction occurred since HAART introduction. Although HAART restores immune status and improves the quality of life, some patients were complicated by immune reconstitution inflammatory syndrome (IRIS) with clinical and radiological deterioration. However, TE-IRIS rarely occurs. Clinical features of TE comprise focal and generalized CNS dysfunctions or with psychiatric abnormalities. Its insidious onset and clinical presentations depend on the location, size and number of focal lesions, which is usually multiple. The majority of cases were diagnosed presumptively including clinical relevance to CNS abnormalities, suggestive brain imaging and serological showing past *T. gondii* infection or response to anti-toxoplasmic therapy. Standard treatment is a combination of pyrimethamine and sulfadiazine for 3-6 weeks followed by either life-long maintenance prophylaxis or HAART to prevent TE relapse. Despite the efficacy of currently available drug regimens, the mortality and adverse effects continue to be problems for the responsible physician. Primary prophylaxis should be given to HIV-infected persons whose CD4 count is <200 cell/mm3 to prevent TE reactivation. HIV-infected individuals with negative *T. gondii* antibody should be instructed on preventing *Toxoplasma* transmission by avoiding either consuming infected meat or ingesting contaminated food and water by oocysts from cat excreta.

#### **9. References**


Toxoplasmic encephalitis is the most common cause of focal CNS infections in people with AIDS. Its incidence has been reduced after prophylaxis was widely advocated, but the dramatic reduction occurred since HAART introduction. Although HAART restores immune status and improves the quality of life, some patients were complicated by immune reconstitution inflammatory syndrome (IRIS) with clinical and radiological deterioration. However, TE-IRIS rarely occurs. Clinical features of TE comprise focal and generalized CNS dysfunctions or with psychiatric abnormalities. Its insidious onset and clinical presentations depend on the location, size and number of focal lesions, which is usually multiple. The majority of cases were diagnosed presumptively including clinical relevance to CNS abnormalities, suggestive brain imaging and serological showing past *T. gondii* infection or response to anti-toxoplasmic therapy. Standard treatment is a combination of pyrimethamine and sulfadiazine for 3-6 weeks followed by either life-long maintenance prophylaxis or HAART to prevent TE relapse. Despite the efficacy of currently available drug regimens, the mortality and adverse effects continue to be problems for the responsible physician. Primary prophylaxis should be given to HIV-infected persons whose CD4 count is <200 cell/mm3 to prevent TE reactivation. HIV-infected individuals with negative *T. gondii* antibody should be instructed on preventing *Toxoplasma* transmission by avoiding either consuming infected meat or ingesting contaminated food and water by oocysts from

Abgrall, S., Rabaud, C., Costagliola, D*.* (2001). Incidence and risk factors for toxoplasmic

Antinori, A., Murri, R., Ammassari, A., et al. (1995). Aerosolized pentamidine,

Béraud, G., Pierre-François, S., Foltzer, A., et al. (2009). Cotrimoxazole for Treatment of

Berger, J.R., Moskowitz, L., Fischl, M., Kelley, R.E. (1987). Neurologic disease as the

Bossi, P., Caumes, E., & Astagneau, P. (1998). Epidemiologic characteristics of cerebral

encephalitis in human immunodeficiency virus-infected patients before and during the highly active antiretroviral therapy era. *Clin Infect Dis* Vol. 33, pp.1747-1755. Ajzenberg, D., Yera, H., Marty, P., et al (2009). Genotype of 88 *Toxoplasma gondii* Isolates

Associated with Toxoplasmosis in Immunocompromised Patients and Correlation with Clinical Findings. *The Journal of Infectious Diseases*, Vol. 199,pp.1155–1167. Antinori, A., Larussa, D., Cingolani, A. et al. (2004). Prevalence, associated factors, and

prognostic determinants of AIDS-related toxoplasmic encephalitis in the era of advanced highly active antiretroviral therapy. *Clin Infect Dis*. Vol. 39, pp.1681-1691.

cotrimoxazole and dapsone-pyrimethamine for primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmic encephalitis. *AIDS*. Vol.;9,

Cerebral Toxoplasmosis: An Observational Cohort Study during 1994–2006.*Am J* 

presenting manifestation of acquired immunodeficiency syndrome. *South Med J.*

toxoplasmosis in 399 HIV-infected patients followed between 1983 and 1994. *Rev* 

**8. Conclusion** 

cat excreta.

**9. References** 

pp.1343-1350.

Vol. 80, pp.683-686.

*Trop Med Hyg.* Vol. 80, pp. 583–587.

*Med Interne*.Vol. 19, pp.313-317.


Toxoplasmic Encephalitis 303

Katlama, C., Mouthon, B., Gourdon, D., et al. (1996). Atovaquone as long-term suppressive

Khetsuriani, N., Holman, R.C., & Anderson, L.J. (2002). Burden of Encephalitis-Associated Hospitalizations in the United States, 1988–1997.*CID*. Vol.35, pp. 175-182. Kijlstra, A., Eissen, O.A., Cornelissen, J., et al. (2004). *Toxoplasma gondii* infection in animalfriendly pig production systems. *Invest Ophthalmol Vis Sci*. Vol. 45, pp.3165-3169. Konishi, H.Y. *et al.* (2000). High prevalence of antibody to *Toxoplasma gondii* among humans

Köppen, S., Grünewald, T., Jautzke, G. et al. (1992). Prevention of *Pneumocystis carinii*

Kung, D.H., Hubenthal, E.A., Kwan, J.Y., et al. (2011). Toxoplasmosis myelopathy and

Lee, G.T., Antelo, F. & Mlikotic, A.A. (2009). Best cases from the AFIP: cerebral

Lejeune, M., Miró, J.M., De Lazzari, E., et al. (2011). Restoration of T cell responses to

Leport, C., Chêne, G., Morlat, P. et al. (1996) Pyrimethamine for primary prophylaxis of

Levy, R.M., Bredesen, D.E., Rosenblum, M.L.(1985). Neurological manifestations of the

López, R., Contreras, R., & Font, L. (1992). Presence of antibodies against *Toxoplasma gondii*

Luft, B.J. & Castro, K.G.(1991) An overview of the problem of toxoplasmosis and

Luft, B.J. & Remington, J.S. (1988). AIDS commentary. Toxoplasmic encephalitis. *J Infect Dis*.

Luft, B.J. & Remington, J.S. (1992). Toxoplasmic Encephalitis in AIDS. *Clin Infect Dis.* 

Luft, B.J., Conley, F. & Remington, J.S. (1983). Outbreak of Central Nervous System Toxoplasmosis in Western Europe and North America. *Lancet*. Vol. 9, pp. 781-784. Luft, B.J., Hafner, R., Korzun, A,H., et al. (1993). Toxoplasmic encephalitis in patients with the acquired immunodeficiency syndrome. *N Engl J Med*. Vol. 329, pp.995-1000. Mahittikorn, A., Wickert, H. & Sukthana, Y.(2010). *Toxoplasma gondii*: Simple duplex RT-PCR

immunosuppressed mice. *Exp Parasitol.* Vol.124,pp. 225-231.

a double-blind, randomized trial. *J Infect Dis.* Vol. 173, pp.91-97.

pyrimethamine/sulfadoxine. *Clin Investig*. Vol. 70, pp.508-512.

intolerance. *AIDS*. Vol.10, pp.1107-1112.

in Surabaya. *J Infect Dis.* Vol. 53, pp.238-241.

syndrome? *Neurologist*. Vol. 17, pp.49-51.

24,[Epub ahead of print]

Vol. 157, pp.1-6.

Vol.15,pp.211-222.

toxoplasmosis. *Radiographics*. Vol.29, pp.1200-1205.

the literature. *J Neurosurg.* Vol.62, pp.475-495.

*Clin Microbiol Infect Dis*. Vol.10, pp.178-181.

therapy for toxoplasmic encephalitis in patients with AIDS and multiple drug

pneumonia and toxoplasmic encephalitis in human immunodeficiency virus infected patients: a clinical approach comparing aerosolized pentamidine and

myopathy in an AIDS patient: a case of immune reconstitution inflammatory

toxoplasma gondii after successful combined antiretroviral therapy in patients with AIDS with previous Toxoplasmic encephalitis. *Clin Infect Dis*. Vol. 52, pp. 662-670. Legrand, L., Catherine, L., Brivet, F. et al. (2010). Solitary Hypothalamopituitary

Toxoplasmosis Abscess in a Patient with AIDS. *AJNR Am J Neuroradiol*. Vol.

toxoplasmic encephalitis in patients with human immunodeficiency virus infection:

acquired immunodeficiency syndrome (AIDS): experience at UCSF and review of

in adolescents from the African continent. *Rev Latinoam Microbiol*. Vol. 34, pp. 49-52.

pneumocystosis in AIDS in the USA: implication for future therapeutic trials. *Eur J* 

assay for detecting SAG1 and BAG1 genes during stage conversion in


Ferguson, D.J. (2009b). Identification of faecal transmission of *Toxoplasma gondii*: Small

Frenkel, J.K. & Fishback J.L. (2000) Toxoplasmosis. In: *Hunter's Tropical Medicine and* 

Furrer, H., Egger, M., & Opravil, M. (1999). Discontinuation of primary prophylaxis against

Furrer, H., Opravil, M., Bernasconi, E., et al. (2000). Stopping primary prophylaxis in HIV-1-

Gapen, P. (1982). Neurological complications now characterizing many AIDS victims.

Ghosn, J., Paris, L., Ajzenberg, D., et al. (2003). Atypical toxoplasmic manifestation after

1-infected patient with immune recovery. *Clin Infect Dis*. Vol.37, pp.112-114. Girard, P.M., Landman, R., Gaudebout, C. et al. (1993). Dapsone-pyrimethamine compared

Ho, Y.C., Sun, H.Y., Chen, M.Y., et al. (2008). Clinical presentation and outcome of

Hoffmann, C., Ernst, M., Meyer, P., et al. (2007). Evolving characteristics of toxoplasmosis in

Howard, R. & Manji, H. (2009). Infection in the nervous system, In: *Neurology: A Queen* 

Jacobson, M.A., Besch, C.L., Child, C., et al. (1995). Primary prophylaxis with

Jones, J.L., Hanson, D.L., Chu, S.Y.et al. (1996). Toxoplasmic encephalitis in HIV-infected

Katlama C. (1992), New perspectives on the treatment and prophylaxis of *Toxoplasma gondii* 

Katlama, C. (1995). The impact of the prevention of cerebral toxoplasmosis. *J Neuroradiol*.

persons: risk factors and trends. *AIDS.* Vol.10, pp.1393-13939.

infection. *Cur Opinion Infect Dis.* Vol. 5,pp. 833-839.

pp. 289-335, Willy Blackwell, ISBN 978-1-4051-3443-3449, Oxford, UK Hutchison, W.M.; Dunachie J.F.; Siim J. C.; Work, K. (1969). The life cycle of *Toxoplasma* 

infection. *J Microbiol Immunol Infect*. Vol. 41, pp.386-932.

*Emerging Infectious Diseases*, G.T. Strickland, (Ed.), 691-701, W.B. Saunders, London Furco, A., Carmagnat, M., Chevret, S., et al. (2008). Restoration of *Toxoplasma gondii*-specific

immune responses in patients with AIDS starting HAART. *AIDS*. Vol. 18,pp.2087-

*Pneumocystis carinii* pneumonia in HIV-1-infected adults treated with combination antiretroviral therapy. Swiss HIV Cohort Study. *N Engl J Med*. Vol. 29, pp.1301-

infected patients at high risk of toxoplasma encephalitis. Swiss HIV Cohort Study.

discontinuation of maintenance therapy in a human immunodeficiency virus type

with aerosolized pentamidine as primary prophylaxis against *Pneumocystis carinii* pneumonia and toxoplasmosis in HIV infection. *N Engl J Med*. Vol.27;328, pp.1514-

toxoplasmic encephalitis in patients with human immunodeficiency virus type 1

patients infected with human immunodeficiency virus-1: clinical course and *Toxoplasma gondii*-specific immune responses. *Clin Microbiol Infect*. Vol.13, pp.510-

*Square Textbook,* Charles Clarke, Robin Howard, Martin Rossor, Simon Sharvon eds,

pyrimethamine for toxoplasmic encephalitis in patients with advanced human immunodeficiency virus disease: results of a randomized trial. *J Infect Dis*. Vol.

science, large characters. *Int J Parasitol.* Vol.39, No.8, pp. 871-875.

2096.

1306.

1520.

515.

*Lancet*. Vol. 24;355, pp.2217-2218.

*gondii*. *Brit Med J,* Vol. 4, pp. 806.

169,pp.384-394.

Vol. 22, pp.193-195.

*JAMA.* Vol.248, pp.2941-2942.


Toxoplasmic Encephalitis 305

Richards, F.O. Jr, Kovacs, J.A, & Luft, B.J. (1995). Preventing toxoplasmic encephalitis in

Sacktor, N., Lyles, R.H., Skolasky R, et al*.* (1990). HIV-associated neurologic disease

Shelburne, S.A., Montes, M., & Hamill, R.J. (2006). Immune reconstitution inflammatory

Soriano, V., Dona, C., Rodríguez-Rosado, R., et al. (2000). Discontinuation of secondary

Subsai, K., Kanoksri, S., Siwaporn, C., et al. (2006). Neurological complications in AIDS

Sukthana, Y. (2006). Toxoplasmosis: beyond animals to humans. *Trends Parasitol*, Vol. 22, pp.

Sukthana, Y., Chintana, T., Lekkla, A. (2000). *Toxoplasma gondii* antibody in HIV-infected

Sungkanuparpha, S., Vibhagoola, A., Mootsikapunb, P., et al, (2002). Opportunistic

Torres, R.A., Barr, M., Thorn, M., et al. (1993). Randomized trial of dapsone and aerosolized

Torres, R.A., Weinberg, W., Stansell, J., et al. (1997). Atovaquone for Salvage Treatment and

Tremont-Lukats, I.W., Garciarena, P., Juarbe, R., et al. (2009). The immune inflammatory

Tsambiras, P.E., Larkin, J.A., Houston, S.H. (2001). Case report. Toxoplasma encephalitis

Venkataramana, A., Pardo, C.A., McArthur, J.C., et al. (2006). Immune reconstitution

Vyas, R. & Ebright, J.R. (1996). Toxoplasmosis of the spinal cord in a patient with AIDS:

Wainstein, M.V., *et al*. (1993). The sensitivity and specificity of the clinical, serological and

*Conference on Antimicrobial Agents and Chemotherapy,* San Diego, 2002. Torre, D., Casari, S., Speranza, F., et al. (1998). Randomized trial of trimethoprim-

toxoplasmic encephalitis. *Am J Med*. Vol.95, pp. 573-583.

after initiation of HAART. *AIDS Read*. Vol.11, pp. 608-610.

case report and review. *Clin Inf Dis.* Vol.23, pp.1061–1065.

active antiretroviral therapy. *AIDS*. Vol. 10, pp.383-386.

persons. *J Med Assoc Thai*. Vol. 83, pp. 681-684.

1, pp.S49-56.

pp.257-260.

pp.233-239.

137-142.

1349.

pp.422-429.

383-388.

*Med.* Vol. 150, pp. 656–657.

170.

persons infected with human immunodeficiency virus. *Clin Infect Dis*. Vol. 21 Suppl

incidence changes: Multicenter AIDS Cohort Study, 1990–1998. *Neurology* Vol. 56,

syndrome: more answers, more questions. *J Antimicrob Chemother*. Vol. 57, pp. 167-

prophylaxis for opportunistic infections in HIV-infected patients receiving highly

patients receiving HAART: a 2-year retrospective study. *Eur J Neurol*. Vol. 13,

infections after the initiation of highly active antiretroviral therapy in advanced AIDS patients in an area with a high prevalence of tuberculosis. *The 42nd Interscience* 

sulfamethoxazole versus pyrimethamine-sulfadiazine for therapy of Toxoplasmic encephalitis in patients with AIDS. *Antimicrob Agents Chemother* Vol. 42, pp.1346–

pentamidine for the prophylaxis of *Pneumocystis carinii* pneumonia and

Suppression of Toxoplasmic Encephalitis in Patients with AIDS. *CID*. Vol. 24,

reconstitution syndrome and central nervous system toxoplasmosis. *Ann Intern*

inflammatory syndrome in the CNS of HIV-infected patients. *Neurology.*Vol.67, pp.

tomographic diagnosis of *Toxoplasma gondii* encephalitis in the acquired immunodeficiency syndrome (AIDS). *Rev Soc Bras Med Trop*. Vol.26, pp. 71-75.


Mariuz, P. & Steigbigel, R.T. (2001). *Toxoplasma* infection in HIV-infected patients,

Miro, J,M,, Lopez, J.C., Podzamczer, D., et al. (2006). Discontinuation of primary and

Murdoch, D.M., Venter, W.D., Van Rie, A., et al. (2007). Immune reconstitution

Nissapatorn, V. & Abdullah, K.A. *et al.* (2004). Review on human toxoplasmosis in Malaysia:

Nissapatorn, V. (2009). Toxoplasmosis in HIV/AIDS: a living legacy. *Southeast Asian J Trop* 

Nissapatorn, V., Lee, C., Quek, K.F., et al. (2004). Toxoplasmosis in HIV/AIDS patients: a

Oksenhendler, E, et al. (1994). *Toxoplasma gondii* infection in advanced HIV infection. *AIDS*.

Opravil, M., Hirschel, B., Lazzarin, A. et al. (1995). Once-weekly administration of

Petersen, E. & Liesenfeld, O. (2007). Clinical Disease and Diagnostics, In: *Toxoplasma gondii:* 

Pfeffer, G., Prout, A., Hooge, J., et al. (2009). Biopsy-proven immune reconstitution

Ragnaud, J.M., Morlat, P., Dupon, M., et al. (1993). Cerebral toxoplasmosis in AIDS. 73 cases.

Ribera, E., Fernandez-Sola, A., Juste, C.et al. (1999). Comparison of high and low doses of

dapsone/pyrimethamine vs. aerosolized pentamidine as combined prophylaxis for Pneumocystis carinii pneumonia and toxoplasmic encephalitis in human immunodeficiency virus-infected patients. *Clin Infect Dis*. Vol. 20, pp.531-541. Palm, C., Tumani, H., Pietzcker, T., et al. (2008). Diagnosis of cerebral toxoplasmosis by

detection of Toxoplasma gondii tachyzoites in cerebrospinal fluid. *J Neurol.* Vol.255,

*the Model Apicomplexan: Perspective and Methods,* Wiss, L.M. & Kim, K. eds, pp.81-

syndrome in a patient with AIDS and cerebral toxoplasmosis. *Neurology*. Vol.

Clinical Epidemiology Group on AIDS in Aquitania. *Presse Med*. Vol.22, pp.903-908.

trimethoprim-sulfamethoxazole for primary prevention of toxoplasmic encephalitis in human immunodeficiency virus-infected patients. *Clin Infect Dis.* Vol. 29,

eds., pp.147-177,Cambridge University Press, ISBN,0521 44328 8, UK. Martin-Blondel, G., Alvarez, M., Delobel, P., et al,. (2010). Toxoplasmic encephalitis IRIS in

*Psychiatry*. Vol.26, doi: 10.1136/jnnp.2009.199919

*AIDS*, Bangkok, Thailand, June 2004.

Vol. 35, pp.24-30.

Vol. 8, pp.483-487.

pp. 939-941.

73,pp.321–322.

pp.1461-1466.

treatment options. *AIDS Res Ther* Vol. 4, pp.9.

*Med Public Health*. Vol. 40, pp.1158-1178.

current situation. *Jpn J Infect Dis*. Vol.57, pp,160-165.

100, Elsevier, ISBN,13:978-0-12-369542-0, London

In:*Toxoplasmosis A comprehensive clinical guide,* Joynson, D.H.M. & Wreghitt, T.G.

HIV-infected patients: a case series and review of the literature. *J Neurol Neurosurg* 

secondary *Toxoplasma gondii* prophylaxis is safe in HIV-infected patients after immunological restoration with highly active antiretroviral therapy: results of an open, randomized, multicenter clinical trial. *Clin Infect Dis*. Vol.1;43,pp.79-89. Mootsikapun, P., Chetchotisakd, P.,& Anunnatsiri, S. (2004). Toxoplasmic encephalitis in 110

adult Thai AIDS patients: a retrospective review, *15th International Conference on* 

inflammatory syndrome (IRIS): review of common infectious manifestations and

the past, present and prospective future. *Southeast Asian J Trop Med Public Health.* 


**13** 

*USA* 

**Autoimmunity in the Mediation of** 

Chandirasegaran Massilamany and Jay Reddy

*School of Veterinary Medicine and Biomedical Sciences* 

**Implications for Therapy** 

*University of Nebraska-Lincoln* 

**Granulomatous Amoebic Encephalitis:** 

*Acanthamoeba* spp. are free-living amoebae that are ubiquitous in the environment. Most healthy individuals carry *Acanthamoeba*-reactive antibodies, suggesting constant exposure to amoebae. In spite of the high prevalence of the amoebae, the incidence of diseases caused by *Acanthamoeba* is very low. Non-opportunistically, Acanthamoebae can induce keratitis in healthy humans, but as an opportunistic pathogen, the amoebae can cause fatal encephalitis

Amoebic encephalitis is a life-threatening disease of the central nervous system (CNS) caused by free-living amoebae belonging to the genera *Acanthamoeba*, *Balamuthia* and *Naegleria*. Because they lack host-specificity, the ubiquitous amoebae can infect a wide range of species (Marciano-Cabral & Cabral, 2003, Schuster & Visvesvara, 2004). The diseases caused by *Acanthamoeba* spp. and *Balamuthia* spp. are generally termed "granulomatous amoebic encephalitis" (GAE), whereas those caused by *Naegleria* spp. are called 'primary amoebic meningioencephalitis (PAM)'(Marciano-Cabral & Cabral, 2003, Schuster & Visvesvara, 2004, Khan, 2006, da Rocha-Azevedo*, et al.*, 2009). While Acanthamoebae induce illness mostly in immunocompromised individuals, *Balamuthia* spp. and *Naegleria* spp. can cause diseases in both immune-sufficient and immune-deficient individuals (Martinez & Visvesvara, 2001, Marciano-Cabral & Cabral, 2003, Schuster & Visvesvara, 2004, Khan, 2006, da Rocha-Azevedo*, et al.*, 2009). Nevertheless, all of them can induce keratitis in healthy individuals, often in contact lens-wearers (Jones*, et al.*, 1975, Martinez & Visvesvara, 1997, Marciano-Cabral & Cabral, 2003, da Rocha-Azevedo*, et al.*, 2009). We recently discovered that *A. castellanii* contains mimicry sequence for immunodominant epitope of CNS myelin proteolipid protein (PLP), suggesting that exposure to *A. castellanii* can lead to the generation of autoimmune responses by antigenic mimicry. In this review, we discuss our understanding of the pathophysiology of *Acanthamoeba*-induced encephalitis, with a special

especially in immunocompromised individuals and treatments are often ineffective.

emphasis on autoimmunity in mediation of the disease, and implications for therapy.

Based on morphological characteristics, such as shape and size of amoebic cysts, and growth conditions, the genus *Acanthamoeba* was initially classified into groups I, II, and III,

**2. Characteristics of** *Acanthamoeba* **infections** 

**1. Introduction** 

