Editing Toxoplasmosis (section)

== Signs and symptoms ==
Infection has three stages:

=== Acute ===
Acute toxoplasmosis is often asymptomatic in healthy adults.<ref name="Dupont_2012">{{cite journal |vauthors=Dupont CD, Christian DA, Hunter CA | title = Immune response and immunopathology during toxoplasmosis | journal = Seminars in Immunopathology | volume = 34 | issue = 6 | pages = 793–813 | year = 2012 | pmid = 22955326 | pmc = 3498595 | doi = 10.1007/s00281-012-0339-3 }}</ref><ref name=Dubey2008/> However, symptoms may manifest and are often [[influenza]]-like: swollen [[lymph node]]s, headaches, fever, and fatigue,<ref name="The Mayo Clinic_2015">{{cite web | title = toxoplasmosis | website = [[Mayo Clinic]] | url = http://www.mayoclinic.org/diseases-conditions/toxoplasmosis/basics/symptoms/con-20025859 | url-status = live | archive-url = https://web.archive.org/web/20150908012728/http://www.mayoclinic.org/diseases-conditions/toxoplasmosis/basics/symptoms/con-20025859 | archive-date = 2015-09-08 }}</ref> or [[myalgia|muscle aches]] and pains that last for a month or more. It is rare for a human with a fully functioning [[immune system]] to develop severe symptoms following infection. People with weakened immune systems are likely to experience headache, confusion, poor coordination, seizures, lung problems that may resemble tuberculosis or ''Pneumocystis jirovecii'' pneumonia (a common opportunistic infection that occurs in people with AIDS), or chorioretinitis caused by severe inflammation of the retina (ocular toxoplasmosis).<ref name="The Mayo Clinic_2015"/> Young children and [[Immunodeficiency|immunocompromised]] people, such as those with HIV/AIDS, those taking certain types of [[chemotherapy]], or those who have recently received an [[organ transplant]], may develop severe toxoplasmosis. This can cause damage to the brain ([[encephalitis]]) or the eyes ([[Toxoplasmic chorioretinitis|necrotizing retinochoroiditis]]).<ref name="Jones_2001">{{cite journal |vauthors=Jones JL, Kruszon-Moran D, Wilson M, McQuillan G, Navin T, McAuley JB | title = ''Toxoplasma gondii'' infection in the United States: seroprevalence and risk factors | journal = American Journal of Epidemiology | volume = 154 | issue = 4 | pages = 357–65 | year = 2001 | pmid = 11495859 | doi = 10.1093/aje/154.4.357 | doi-access = free }}</ref> Infants infected via [[Vertically transmitted infection|placental transmission]] may be born with either of these problems, or with nasal malformations, although these complications are rare in newborns. The toxoplasmic [[trophozoite]]s causing acute toxoplasmosis are referred to as [[tachyzoites]], and are typically found in various tissues and body fluids, but rarely in blood or cerebrospinal fluid.<ref>{{cite book |doi=10.1016/B978-0-443-06668-9.50102-2 |date=2006 |isbn=978-0-443-06668-9 |last1=Schwartzman |first1=Joseph D. |last2=Maguire |first2=James H. |title=Tropical Infectious Diseases |chapter=Systemic Coccidia (Toxoplasmosis) |publisher=Elsevier |quote=Tachyzoites are found in all organs in acute infection, most prominently in muscle, including heart, and in the liver, spleen, lymph nodes, and the CNS. }}</ref>

[[Swollen lymph node]]s are commonly found in the neck or under the chin, followed by the armpits and the groin. Swelling may occur at different times after the initial infection, persist, and recur for various times independently of antiparasitic treatment.<ref>{{cite journal | author = Paul M | title = Immunoglobulin G Avidity in Diagnosis of Toxoplasmic Lymphadenopathy and Ocular Toxoplasmosis | journal = Clin. Diagn. Lab. Immunol. | volume = 6 | issue = 4 | pages = 514–8 | date = 1 July 1999 | pmid = 10391853 | pmc = 95718 | doi = 10.1128/CDLI.6.4.514-518.1999 }}</ref> It is usually found at single sites in adults, but in children, multiple sites may be more common. Enlarged lymph nodes will resolve within 1–2 months in 60% of cases. However, a quarter of those affected take 2–4 months to return to normal, and 8% take 4–6 months. A substantial number (6%) do not return to normal until much later.<ref>{{cite web |url=http://ukneqasmicro.org.uk/parasitology/images/pdf/ToxoplasmaSerology/Immunocompetent/Lymphadenopathy.pdf |title=Lymphadenopathy |publisher=UK Neqas Micro |access-date=2016-04-12 |url-status=live |archive-url=https://web.archive.org/web/20160424213931/http://ukneqasmicro.org.uk/parasitology/images/pdf/ToxoplasmaSerology/Immunocompetent/Lymphadenopathy.pdf |archive-date=2016-04-24 }}</ref>

===Latent===
Due to the absence of obvious symptoms,<ref name=Dupont_2012 /><ref name=Dubey2008 /> hosts easily become infected with ''T.&nbsp;gondii'' and develop toxoplasmosis without knowing it. Although mild, flu-like symptoms occasionally occur during the first few weeks following exposure, infection with ''T.&nbsp;gondii'' produces no readily observable symptoms in healthy human adults.<ref name="Global threat" /><ref name=CDCdisease>{{cite web|title=CDC Parasites – Toxoplasmosis (Toxoplasma infection) – Disease|url=https://www.cdc.gov/parasites/toxoplasmosis/disease.html|access-date=12 March 2013|url-status=live|archive-url=https://web.archive.org/web/20130307193139/http://www.cdc.gov/parasites/toxoplasmosis/disease.html|archive-date=7 March 2013}}</ref> In most [[immunocompetent]] people, the infection enters a latent phase, during which only [[bradyzoite]]s ([[Toxoplasma gondii#Formation of tissue cysts|in tissue cysts]]) are present;<ref name="Dubey_2006">{{cite journal |vauthors=Dubey JP, Hodgin EC, Hamir AN | title = Acute fatal toxoplasmosis in squirrels (''Sciurus carolensis'') with bradyzoites in visceral tissues | journal = The Journal of Parasitology | volume = 92 | issue = 3 | pages = 658–9 | year = 2006 | pmid = 16884019 | doi = 10.1645/GE-749R.1 | s2cid = 20384171 }}</ref> these tissue cysts and even lesions can occur in the [[retina]]s, [[Pulmonary alveolus|alveolar]] lining of the lungs (where an acute infection may mimic a ''[[Pneumocystis jirovecii]]'' infection), heart, skeletal muscle, and the [[central nervous system]] (CNS), including the brain.<ref name="Nawaz Khan_2015">{{EMedicine|article|344706|CNS Toxoplasmosis Imaging}}</ref> Cysts form in the CNS ([[nervous tissue|brain tissue]]) upon infection with ''T.&nbsp;gondii'' and persist for the lifetime of the host.<ref name="TG CNS review" /> Most infants who are infected while in the womb have no symptoms at birth, but may develop symptoms later in life.<ref name="futurepundit.com">Randall Parker: [http://www.futurepundit.com/archives/001675.html Humans Get Personality Altering Infections From Cats] {{webarchive|url=https://web.archive.org/web/20051217220821/http://www.futurepundit.com/archives/001675.html |date=2005-12-17 }}. September 30, 2003</ref>

Reviews of [[Serology|serological]] studies have estimated that 30–50% of the global population has been exposed to and may be chronically infected with latent toxoplasmosis, although infection rates differ significantly from country to country.<ref name="Global threat"/><ref name="TG Neuronal review" /><ref name="Pappas_2009"/> This latent state of infection has recently been associated with numerous [[disease burden]]s,<ref name="Global threat" /> neural alterations,<ref name="TG CNS review">{{cite journal | vauthors = Blanchard N, Dunay IR, Schlüter D | title = Persistence of ''Toxoplasma gondii'' in the central nervous system: a fine-tuned balance between the parasite, the brain and the immune system | journal = Parasite Immunology | volume = 37 | issue = 3 | pages = 150–158 | year = 2015 | pmid = 25573476 | doi = 10.1111/pim.12173 | s2cid = 1711188 | quote = The seroprevalence of T. gondii in humans varies between 10 and 70% worldwide, depending on the region and increases significantly with age. Upon infection, the parasites persist as intraneuronal cysts in the central nervous system (CNS) for the lifetime of the host (1, Figure 1). Until recently, parasite persistence in healthy individuals was regarded as clinically asymptomatic. However, in the last decade, several reports have indicated that chronic cerebral toxoplasmosis may impact on the behaviour of its host (2).| doi-access = free }}</ref><ref name="TG Neuronal review">{{cite journal | vauthors = Parlog A, Schlüter D, Dunay IR | title = ''Toxoplasma gondii''-induced neuronal alterations | journal = Parasite Immunology | volume = 37 | issue = 3 | pages = 159–170 | date  = March 2015 | pmid = 25376390 | doi = 10.1111/pim.12157 | quote = The zoonotic pathogen ''Toxoplasma gondii'' infects over 30% of the human population. The intracellular parasite can persist lifelong in the CNS within neurons modifying their function and structure, thus leading to specific behavioural changes of the host.&nbsp;...  Furthermore, investigations of the human population have correlated ''Toxoplasma'' seropositivity with changes in neurological functions; however, the complex underlying mechanisms of the subtle behavioural alteration are still not fully understood. The parasites are able to induce direct modifications in the infected cells, for example by altering dopamine metabolism, by functionally silencing neurons as well as by hindering apoptosis.| hdl = 10033/346575 | s2cid = 17132378 }}</ref> and subtle sex-dependent behavioral changes in immunocompetent humans,<ref name="Cook2015 primary source">{{cite journal |last1=Cook |first1=Thomas B. |last2=Brenner |first2=Lisa A. |last3=Cloninger |first3=C. Robert |last4=Langenberg |first4=Patricia |last5=Igbide |first5=Ajirioghene |last6=Giegling |first6=Ina |last7=Hartmann |first7=Annette M. |last8=Konte |first8=Bettina |last9=Friedl |first9=Marion |last10=Brundin |first10=Lena |last11=Groer |first11=Maureen W. |last12=Can |first12=Adem |last13=Rujescu |first13=Dan |last14=Postolache |first14=Teodor T. |title='Latent' infection with Toxoplasma gondii: Association with trait aggression and impulsivity in healthy adults |journal=Journal of Psychiatric Research |date=January 2015 |volume=60 |pages=87–94 |doi=10.1016/j.jpsychires.2014.09.019 |pmid=25306262 }}</ref><ref name="TG behavioral effects review">{{cite journal | vauthors = Hurley RA, Taber KH | title = Latent ''Toxoplasmosis gondii'': emerging evidence for influences on neuropsychiatric disorders | journal = Journal of Neuropsychiatry and Clinical Neurosciences | volume = 24 | issue = 4 | pages = 376–83 | year = 2012 | pmid = 23224444 | doi = 10.1176/appi.neuropsych.12100234 | quote = Nine of eleven studies using the Cattell's 16-Personality Factor self-report questionnaire found significant and consistent results for both genders. Seropositive men overall had lower regard for rules and higher vigilance (suspicious, jealous, rigid/inflexible) than seronegative men. In contrast, seropositive women had greater regard for rules and higher warmth than seronegative women. Both seropositive genders were more anxious than matched healthy-comparison subjects.&nbsp;...  Behavioral observations and interviews were completed to ascertain whether the gender differences found in self-report measures were replicated by objective measures. Seropositive men scored significantly lower than seronegative men on Self-Control, Clothes Tidiness, and Relationships. The differences were less impressive for the seropositive women, with only trends toward higher scores on Self-Control and Clothes Tidiness as compared with seronegative women. The authors view the study results as objective confirmation that ''T. gondii'' presence can change a human host's behaviors.}}</ref> as well as an increased risk of motor vehicle collisions.<ref>{{cite journal |last1=Gohardehi |first1=S |last2=Sharif |first2=M |last3=Sarvi |first3=S |last4=Moosazadeh |first4=M |last5=Alizadeh-Navaei |first5=R |last6=Hosseini |first6=SA |last7=Amouei |first7=A |last8=Pagheh |first8=A |last9=Sadeghi |first9=M |last10=Daryani |first10=A |title=The potential risk of toxoplasmosis for traffic accidents: A systematic review and meta-analysis. |journal=Experimental Parasitology |date=August 2018 |volume=191 |pages=19–24 |doi=10.1016/j.exppara.2018.06.003 |pmid=29906469|s2cid=49234104 }}</ref>

===Skin===
While rare, skin lesions may occur in the acquired form of the disease, including [[roseola]] and [[erythema]] multiforme-like eruptions, [[prurigo]]-like nodules, [[urticaria]], and [[Maculopapular rash|maculopapular lesions]]. Newborns may have punctate macules, [[ecchymoses]], or "blueberry muffin" lesions.

Diagnosis of cutaneous toxoplasmosis is based on the tachyzoite form of ''T.&nbsp;gondii'' being found in the [[Epidermis (skin)|epidermis]].<ref>{{cite journal |last1=Zimmermann |first1=Stefan |last2=Hadaschik |first2=Eva |last3=Dalpke |first3=Alexander |last4=Hassel |first4=Jessica C. |last5=Ajzenberg |first5=Daniel |last6=Tenner-Racz |first6=Klara |last7=Lehners |first7=Nicola |last8=Kapaun |first8=Annette |last9=Schnitzler |first9=Paul |title=Varicella-Like Cutaneous Toxoplasmosis in a Patient with Aplastic Anemia |journal=Journal of Clinical Microbiology |date=April 2013 |volume=51 |issue=4 |pages=1341–1344 |doi=10.1128/JCM.02851-12 |pmid=23390283 |pmc=3666818 }}</ref> It is found in all levels of the epidermis, is about 6 by 2''&nbsp;''μm and bow-shaped, with the nucleus being one-third of its size. It can be identified by electron microscopy or by [[Giemsa stain]]ing tissue where the cytoplasm shows blue, the nucleus red.<ref>{{Fitzpatrick 6|235}}</ref>