Toxoplasmosis
د. هديل فاضل فرهود
I. Identification : Asystemic protozoan disease, infections are frequently asymptomatics or present as an acute disease with only lymphadenopathy , or one resembling infectious mononucleosis , with fever ,lymadenopathy and lymphocytosis persisting for days or weeks .
A primary infection during early pregnancy may lead fetal infection with death of the fetus or chorioretenitis , brain damage with intracerebral calcification , hydrocephaly , microcephaly , fever, jaundice , rash , hepatosplenomegaly , xanthochromic CSF & convulsion at birth or shortly thereafter .
Later in pregnancy , maternal infection results in mild or subclinical fetal disease with delay manifestation , such as recurrent or chronic chorioretinitis .
2- Infectious agent : Toxoplasma gondii .
3- Occurrence : world wide in mammals and birds , infection in human is common.
4- Reservoir: the definitive hosts of T.gondii are cats which acquire infection mainly from eating infected mammals ( especially rodents ) or bird .
The intermediate hosts of T. gondii include sheep, goat, rodents , cattle, chickens & birds .
5- Mode of transmission :
*transplacental infection in human ,
*contact with infected cat ( children may become infected by ingesting infective oocyts by playing with cats have defecated )
* eating raw meat from infected cattle & drink milk from infected cattle or goats or by ingestion of infective oocytes in food or water contaminated with cats feces .
* rarely be acquired by blood transfusion or organ transplantation from an infected donor .
6- Incubation period : from 10-23 days in one common source outbreak from ingestion of undercooked meat , 5-20 days in an outbreak associated with cats .
7- Period of communicability : not directly transmitted from person to person except in utero . Oocyte shed by cats feces and become infective 1-5 days later and may remain infective in water and soil for over a year.
8- Susceptibility and resistance : susceptibility to infection is general , but immunity is readily acquired and most infections are asymptomatic . duration and degree of immunity are unknown but assumed to be long lasting or permanent , antibodies persist for years, probably for life .
Methods of control
A. Preventive measures :
1- Educate pregnant women about these preventive measures :
a- use irradiated meats or cook them to 150 F( 66 C ) before eating freezing meat reduces infectivity but does not eliminate it .
b- should avoid cleaning litter pans and contact with cats of unknown feeding history . Wear gloves during gardening and wash hand thoroughly after work and before eating .
2- feed cats dry, canned or boiled food and discourage hunting .
3- disposal cat feces and litter daily
4- wash hands thoroughly before eating and after handling raw meat or having contact with soil possibly contaminated with cat feces .
5- control stray cats and prevent them from gaining access to areas used by children for play .
B- Control of patient, contact and the immediate environment :
1- report to local health authority : not ordinary required .
2- Isolation : none 3- concurrent disinfection : none
4- Quarantine : none 5- Immunization of contacts : none
6- Investigation of contacts and source of infection : in congenital cases , determine antibody titers in mother , in acquired cases , determine antibody titers in members of the household and common exposure to cat feces , soil , raw meat or infected animals .
7- specific treatment :
Treatment is not routinely indicated for healthy immunocompetent host , except in an initial infection during pregnancy or the presence of active chorioretinitis , myocarditis , or other organ involvement .
Pyrimethamine combined with sulfadiazine and folinic acid ( to avoid bone marrow depression ) for 4 weeks is a preferred treatment for those with sever symptomatic disease .
Clindamycine , in addition to these agents , has been used to treat ocular toxoplasmosis .
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .