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===Laboratory Findings=== | ===Laboratory Findings=== | ||
Principles and methods used for the diagnosis of congenital toxoplasmosis: | |||
{| class="wikitable" | |||
!Principle | |||
!Detection | |||
!Method | |||
!Findings supporting the diagnosis of | |||
Toxoplasmosis | |||
|- | |||
|Toxoplasma specific | |||
humoral responses | |||
|IgG, IgM, IgA | |||
|Dye test, ELISA, and ELISA-like assays, | |||
ISAGA, immunofluorescence, | |||
agglutination | |||
|Positive IgM after 5 days of life and in the absence | |||
of blood transfusions. Positive IgA after 10 days | |||
of life. Persistence of Toxoplasma IgG beyond 1 year of age | |||
|- | |||
| | |||
|IgG, IgM, and IgA to specific | |||
Toxoplasma antigen | |||
|Western blot | |||
|Presence of specific bands only seen in the | |||
newborn or bands with higher intensity than | |||
maternal ones for IgG and/or IgM and/or IgA | |||
in a reference laboratory | |||
|- | |||
|Toxoplasma | |||
nucleic acid | |||
amplification | |||
|DNA | |||
|PCR | |||
|Positive result in any body fluid (e.g., amniotic | |||
fluid, cerebrospinal fluid, peripheral blood, urine | |||
|- | |||
|Immunohistochemistry of | |||
Toxoplasma specific antigens in tissue | |||
|Antigens | |||
|Immunoperoxidase | |||
|Positive result in any tissue (e.g., brain or other | |||
fetal tissue | |||
|- | |||
|Visualization by microscopy | |||
|Visual identification of tachyzoites | |||
and/or cysts | |||
|Stains such as hematoxylin/eosin, | |||
Giemsa | |||
|Positive identification in a reference laboratory | |||
|- | |||
|Isolation of Toxoplasma | |||
|Whole live parasite | |||
|Inoculation in peritoneal cavity of | |||
mice | |||
|Detection of live cysts from any body fluid or | |||
tissue that has been inoculated in mice in a | |||
reference laboratory | |||
|- | |||
|Brain imaging | |||
|Brain calcifications, hydrocephaly, | |||
microcephaly | |||
|Ultrasound, computed tomography, | |||
brain magnetic resonance imaging | |||
|Findings can be suggestive but are not diagnostic | |||
of CT since other etiologies may result in | |||
similar findings | |||
|- | |||
|Retinal exam | |||
|Inflammation in choroidal and | |||
retinal layers | |||
|Ophthalmological exam | |||
|Retinochoroidal lesions can be highly suggestive | |||
or, at times, diagnostic of congenital Toxoplasmosis | |||
|} | |||
==Treatment== | ==Treatment== |
Revision as of 21:21, 17 January 2017
Congenital Toxoplasmosis
Overview
Historical Perspective
- In 1908, Nicolle and Manceaux described the parasite in the blood, spleen and liver of a North African rodent–gundi (Ctenodactylus gundi), due to its similar appearance as leishmania they named it Leishmania gondii.[1]
- In 1909, Nicolle and Manceaux renamed the parasite as T. gondii.[2]
- In 1937, Sabin & Olitsky described that Toxoplasma was an obligate intracellular parasite and could be passed onto laboratory animals by intracranial, subcutaneous, intraperitoneal inoculation of brain homogenates (The slurry of tissues and cells which results when cell structure has been mechanically disrupted). They have also suggested that ingestion of Toxoplasma contaminated tissue can result in Toxoplasmosis.[3]
- In 1937 to 1940, Wolf and Cowen have described necrotic and granulomatous lesions on autopsy of a 3 day old infant's brain infected with Toxoplasma. They have also reported that the mothers were asymptomatic but carried antibodies against Toxoplasma and the possibility of congenital transmission was expressed.[4][5]
- In 1940, Pinkerton and Weinman reported the first fatal case of Toxoplasmosis in an adult.[6]
- In 1948, Sabin and Feldman developed a serological test to identify infected individuals by using antibodies specific to Toxoplasma, called the Sabin Feldman Dye test. The serological test when used in large population studies showed a high proportion of humans and domestic animals carried antibodies against Toxoplasma.[7]
- In 1965, Desmonts described that ingestion of under-cooked and uncooked meat plays a role in the pathogenesis of Toxoplasmosis.[8]
- In 1970, Dubley described the life cycle of the parasite and established that the cats are the definitive hosts and any warm blooded animal can be an intermediate host.[9][10][11]
Causes
Risk Factors
Screening
Epidemiology, Demographics
Natural History, Complications, Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Principles and methods used for the diagnosis of congenital toxoplasmosis:
Principle | Detection | Method | Findings supporting the diagnosis of
Toxoplasmosis |
---|---|---|---|
Toxoplasma specific
humoral responses |
IgG, IgM, IgA | Dye test, ELISA, and ELISA-like assays,
ISAGA, immunofluorescence, agglutination |
Positive IgM after 5 days of life and in the absence
of blood transfusions. Positive IgA after 10 days of life. Persistence of Toxoplasma IgG beyond 1 year of age |
IgG, IgM, and IgA to specific
Toxoplasma antigen |
Western blot | Presence of specific bands only seen in the
newborn or bands with higher intensity than maternal ones for IgG and/or IgM and/or IgA in a reference laboratory | |
Toxoplasma
nucleic acid amplification |
DNA | PCR | Positive result in any body fluid (e.g., amniotic
fluid, cerebrospinal fluid, peripheral blood, urine |
Immunohistochemistry of
Toxoplasma specific antigens in tissue |
Antigens | Immunoperoxidase | Positive result in any tissue (e.g., brain or other
fetal tissue |
Visualization by microscopy | Visual identification of tachyzoites
and/or cysts |
Stains such as hematoxylin/eosin,
Giemsa |
Positive identification in a reference laboratory |
Isolation of Toxoplasma | Whole live parasite | Inoculation in peritoneal cavity of
mice |
Detection of live cysts from any body fluid or
tissue that has been inoculated in mice in a reference laboratory |
Brain imaging | Brain calcifications, hydrocephaly,
microcephaly |
Ultrasound, computed tomography,
brain magnetic resonance imaging |
Findings can be suggestive but are not diagnostic
of CT since other etiologies may result in similar findings |
Retinal exam | Inflammation in choroidal and
retinal layers |
Ophthalmological exam | Retinochoroidal lesions can be highly suggestive
or, at times, diagnostic of congenital Toxoplasmosis |
Treatment
Medical Therapy
Surgical Therapy
Prevention
Primary Prevention
Secondary Prevention
References
- ↑ Weiss LM, Dubey JP (2009). "Toxoplasmosis: A history of clinical observations". Int J Parasitol. 39 (8): 895–901. doi:10.1016/j.ijpara.2009.02.004. PMC 2704023. PMID 19217908.
- ↑ Weiss LM, Dubey JP (2009). "Toxoplasmosis: A history of clinical observations". Int J Parasitol. 39 (8): 895–901. doi:10.1016/j.ijpara.2009.02.004. PMC 2704023. PMID 19217908.
- ↑ Heath, Parker (1945). "TOXOPLASMOSIS". Archives of Ophthalmology. 33 (3): 184. doi:10.1001/archopht.1945.00890150028003. ISSN 0093-0326.
- ↑ Paige, Beryl H. (1942). "TOXOPLASMIC ENCEPHALOMYELITIS". American Journal of Diseases of Children. 63 (3): 474. doi:10.1001/archpedi.1942.02010030044004. ISSN 0096-8994.
- ↑ Wolf A, Cowen D, Paige BH (1940). "TOXOPLASMIC ENCEPHALOMYELITIS : IV. EXPERIMENTAL TRANSMISSION OF THE INFECTION TO ANIMALS FROM A HUMAN INFANT". J Exp Med. 71 (2): 187–214. PMC 2135077. PMID 19870956.
- ↑ Weiss LM, Dubey JP (2009). "Toxoplasmosis: A history of clinical observations". Int J Parasitol. 39 (8): 895–901. doi:10.1016/j.ijpara.2009.02.004. PMC 2704023. PMID 19217908.
- ↑ Sabin AB, Feldman HA (1948). "Dyes as Microchemical Indicators of a New Immunity Phenomenon Affecting a Protozoon Parasite (Toxoplasma)". Science. 108 (2815): 660–3. doi:10.1126/science.108.2815.660. PMID 17744024.
- ↑ Desmonts G, Couvreur J, Alison F, Baudelot J, Gerbeaux J, Lelong M (1965). "[Epidemiological study on toxoplasmosis: the influence of cooking slaughter-animal meat on the incidence of human infection]". Rev Fr Etud Clin Biol (in French). 10 (9): 952–8. PMID 5853186.
- ↑ Dubey JP, Miller NL, Frenkel JK (1970). "Characterization of the new fecal form of Toxoplasma gondii". J Parasitol. 56 (3): 447–56. PMID 5467864.
- ↑ Dubey JP, Miller NL, Frenkel JK (1970). "The Toxoplasma gondii oocyst from cat feces". J Exp Med. 132 (4): 636–62. PMC 2138867. PMID 4927658.
- ↑ Hutchison WM, Dunachie JF, Siim JC, Work K (1969). "Life cycle of toxoplasma gondii". Br Med J. 4 (5686): 806. PMC 1630290. PMID 5359949.